/* =========================================================
   CalculationCloud – MathCAD Prime–style stylesheet
   ========================================================= */

/* --- CSS Custom Properties --------------------------------- */
:root {
  --ribbon-bg: #f4f5f7;
  --ribbon-border: #dde0e5;
  --ribbon-tab-active: #ffffff;
  --ribbon-tab-hover: #e8eaed;
  --accent: #0969da;
  --accent-hover: #0550ae;
  --accent-light: #ddf4ff;
  --canvas-bg: #ffffff;
  --grid-color: rgba(173, 216, 230, 0.6);
  --grid-minor: rgba(173, 216, 230, 0.3);
  --region-border: #d0d7de;
  --region-hover-border: #0969da;
  --region-selected-border: #0969da;
  --region-shadow: 0 1px 3px rgba(0,0,0,0.07);
  --region-hover-shadow: 0 2px 8px rgba(9,105,218,0.12);
  --text-primary: #1f2328;
  --text-secondary: #57606a;
  --text-muted: #8c959f;
  --status-bg: #f6f8fa;
  --status-border: #d0d7de;
  --toolbar-height: 38px;
  --ribbon-height: 106px;
  --ribbon-label-h: 20px;
  --statusbar-height: 26px;
  --font-ui: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-math: 'Latin Modern Math', 'STIX Two Math', 'Computer Modern', 'Cambria Math', Georgia, serif;
  --grid-size: 20px;
  --a4-page-width: 1200px;
  --a4-page-height: 1700px; /* multiples of --grid-size so page breaks align */
  /* Page stack + header/footer zone separators */
  --sheet-divider-line: #2a2a2a;
}

/* --- Reset & Base --------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  height: 100%;
  font-family: var(--font-ui);
  font-size: 13px;
  color: var(--text-primary);
  background: #e8e8e8;
  overflow: hidden;
}

/* --- App Shell ----------------------------------------- */
#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* --- Quick Access Toolbar ------------------------------ */
#quick-access-toolbar {
  height: var(--toolbar-height);
  background: #1155a6;
  background: linear-gradient(180deg, #1762bd 0%, #0d52a0 100%);
  display: flex;
  align-items: center;
  padding: 0 10px;
  gap: 1px;
  flex-shrink: 0;
  user-select: none;
  box-shadow: 0 1px 0 rgba(0,0,0,0.18);
}

#quick-access-toolbar .app-title {
  display: inline-flex;
  align-items: center;
  color: white;
  font-size: 12.5px;
  font-weight: 700;
  margin-right: 10px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  opacity: 0.95;
  white-space: nowrap;
}

.qat-btn {
  background: transparent;
  border: 1px solid transparent;
  color: rgba(255,255,255,0.88);
  cursor: pointer;
  padding: 0;
  border-radius: 4px;
  line-height: 1;
  transition: background 0.1s, border-color 0.1s, color 0.1s;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 26px;
  flex-shrink: 0;
}

.qat-btn:hover {
  background: rgba(255,255,255,0.16);
  border-color: rgba(255,255,255,0.2);
  color: white;
}
.qat-btn:active { background: rgba(0,0,0,0.15); }

.qat-btn:disabled,
.qat-btn:disabled:hover,
.qat-btn:disabled:active {
  opacity: 0.35;
  cursor: not-allowed;
  background: transparent;
}

.qat-separator {
  width: 1px;
  height: 16px;
  background: rgba(255,255,255,0.22);
  margin: 0 5px;
  flex-shrink: 0;
}

#worksheet-name-input {
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  color: white;
  font-size: 12.5px;
  font-weight: 500;
  padding: 3px 8px;
  border-radius: 4px;
  margin-left: 8px;
  min-width: 180px;
  font-family: var(--font-ui);
  transition: border-color 0.15s, background 0.15s;
}

#worksheet-name-input::placeholder { color: rgba(255,255,255,0.5); }

#worksheet-name-input:hover {
  border-color: rgba(255,255,255,0.38);
  background: rgba(255,255,255,0.13);
}

#worksheet-name-input:focus {
  outline: none;
  background: rgba(255,255,255,0.18);
  border-color: rgba(255,255,255,0.65);
}

/* --- Ribbon -------------------------------------------- */
#ribbon {
  background: var(--ribbon-bg);
  border-bottom: 2px solid var(--accent);
  flex-shrink: 0;
  user-select: none;
  box-shadow: 0 1px 3px rgba(0,0,0,0.07);
}

#ribbon-tabs {
  display: flex;
  align-items: flex-end;
  padding: 0 8px;
  gap: 1px;
  border-bottom: 1px solid var(--ribbon-border);
  background: var(--ribbon-bg);
}

.ribbon-tab {
  background: transparent;
  border: 1px solid transparent;
  border-bottom: none;
  padding: 6px 13px;
  font-weight: 500;
  cursor: pointer;
  color: var(--text-secondary);
  border-radius: 4px 4px 0 0;
  margin-bottom: -1px;
  transition: background 0.1s, color 0.1s;
  letter-spacing: 0.2px;
  font-size: 12px;
  white-space: nowrap;
  font-family: var(--font-ui);
}

.ribbon-tab:hover {
  background: var(--ribbon-tab-hover);
  color: var(--text-primary);
}

.ribbon-tab.active {
  background: var(--ribbon-tab-active);
  border-color: var(--ribbon-border);
  border-bottom-color: var(--ribbon-tab-active);
  color: var(--accent);
  font-weight: 600;
}

/* Ribbon content area — height drives group layout */
#ribbon-content {
  height: var(--ribbon-height);
  padding: 0 6px;
  display: flex;
  align-items: stretch;
  gap: 0;
  overflow-x: auto;
  overflow-y: visible;
  scrollbar-width: none;
}
#ribbon-content::-webkit-scrollbar { display: none; }

/* Tab panels */
.ribbon-panel { display: none; }
.ribbon-panel.active {
  display: flex;
  align-items: stretch;
  width: 100%;
  gap: 0;
}

/* ── Ribbon Group ──────────────────────────────────────── */
/*
 * Each group is a flex column:
 *   ribbon-group-body  – fills available height, holds buttons
 *   ribbon-group-label – fixed-height label strip at the bottom
 */
.ribbon-group {
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--ribbon-border);
  padding: 0 8px;
  min-width: 48px;
  flex-shrink: 0;
}
.ribbon-group:last-child { border-right: none; }

/* The button area — fills all space above the label */
.ribbon-group-body {
  flex: 1;
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  gap: 3px;
  padding: 6px 0 4px;
  min-height: 0;
  position: relative;
}

/* Vertical layout variant (label–control pairs) */
.ribbon-group-body.col {
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: 4px;
}

/* Wrap variant (for lots of small buttons) */
.ribbon-group-body.wrap {
  flex-wrap: wrap;
  align-content: center;
  justify-content: flex-start;
}

/* The group label strip */
.ribbon-group-label {
  height: var(--ribbon-label-h);
  line-height: var(--ribbon-label-h);
  text-align: center;
  font-size: 10px;
  color: var(--text-muted);
  letter-spacing: 0.3px;
  border-top: 1px solid var(--ribbon-border);
  flex-shrink: 0;
  white-space: nowrap;
  font-family: var(--font-ui);
}

/* ── Large ribbon button (icon + label stacked) ────────── */
.ribbon-btn {
  background: transparent;
  border: 1px solid transparent;
  cursor: pointer;
  border-radius: 5px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 4px 6px;
  min-width: 44px;
  height: 58px;
  gap: 3px;
  transition: background 0.1s, border-color 0.1s;
  color: var(--text-primary);
  flex-shrink: 0;
  font-family: var(--font-ui);
}

.ribbon-btn:hover {
  background: var(--ribbon-tab-hover);
  border-color: var(--ribbon-border);
}

.ribbon-btn:active {
  background: var(--accent-light);
  border-color: rgba(9,105,218,0.35);
}

.ribbon-btn:disabled,
.ribbon-btn:disabled:hover,
.ribbon-btn:disabled:active {
  opacity: 0.35;
  cursor: not-allowed;
  background: transparent;
  border-color: transparent;
}

/* Primary action button */
.ribbon-btn-primary {
  background: #e8f3ff;
  border-color: rgba(9,105,218,0.28) !important;
  color: var(--accent);
}
.ribbon-btn-primary:hover {
  background: #d5e9ff !important;
  border-color: rgba(9,105,218,0.45) !important;
}

/* Toggle buttons in active/on state (Grid / Header / Footer). */
.ribbon-btn.ribbon-btn-toggle-on {
  background: #e8f3ff;
  border-color: rgba(9,105,218,0.28) !important;
  color: var(--accent);
}
.ribbon-btn.ribbon-btn-toggle-on:hover {
  background: #d5e9ff !important;
  border-color: rgba(9,105,218,0.45) !important;
}
.ribbon-btn.ribbon-btn-toggle-on .btn-label {
  color: var(--accent);
}

/* Small icon-only button (30×28) */
.ribbon-btn.small {
  min-width: 28px;
  width: 28px;
  height: 28px;
  padding: 3px;
  gap: 0;
}

/* Split button: main action + colour dropdown (highlight) */
.ribbon-split-btn {
  display: inline-flex;
  flex-direction: row;
  align-items: stretch;
  height: 28px;
  border: 1px solid var(--ribbon-border);
  border-radius: 3px;
  overflow: hidden;
  background: var(--ribbon-tab-active);
  flex-shrink: 0;
}
.ribbon-split-btn:hover {
  border-color: rgba(9, 105, 218, 0.35);
}
.ribbon-split-btn__main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 26px;
  padding: 2px 4px;
  border: none;
  background: transparent;
  cursor: pointer;
  color: var(--text-primary);
  border-right: 1px solid var(--ribbon-border);
}
.ribbon-split-btn__main:hover {
  background: var(--ribbon-tab-hover);
}
.ribbon-split-btn__arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  min-width: 18px;
  padding: 0;
  border: none;
  background: transparent;
  cursor: pointer;
  color: var(--text-secondary);
  line-height: 0;
}
.ribbon-split-btn__arrow:hover {
  background: var(--ribbon-tab-hover);
  color: var(--text-primary);
}
.ribbon-split-btn__arrow svg {
  display: block;
}

.ribbon-btn .btn-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  flex-shrink: 0;
}

.ribbon-btn.small .btn-icon { width: 100%; height: 100%; }
.ribbon-btn.small .btn-icon svg { width: 14px; height: 14px; }

.ribbon-btn .btn-label {
  font-size: 10px;
  text-align: center;
  white-space: nowrap;
  color: var(--text-secondary);
  font-weight: 500;
  line-height: 1;
}
.ribbon-btn-primary .btn-label { color: var(--accent); }

/* ── Symbol button (28×28 grid cell) ───────────────────── */
.sym-btn {
  width: 26px;
  height: 26px;
  background: transparent;
  border: 1px solid transparent;
  cursor: pointer;
  border-radius: 3px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-family: var(--font-math);
  color: var(--text-primary);
  flex-shrink: 0;
  transition: background 0.08s, border-color 0.08s;
  padding: 0;
  line-height: 1;
}
.sym-btn:hover {
  background: var(--ribbon-tab-hover);
  border-color: var(--ribbon-border);
}
.sym-btn:active {
  background: var(--accent-light);
  border-color: rgba(9,105,218,0.35);
}
.sym-btn.text { font-size: 11px; font-family: var(--font-ui); }

/* ── Math symbol grid ──────────────────────────────────── */
.math-sym-grid {
  display: grid;
  grid-template-columns: repeat(4, 26px);
  gap: 2px;
}

/* ── Ribbon form row (label + control) ─────────────────── */
.ribbon-form-row {
  display: flex;
  align-items: center;
  gap: 5px;
  width: 100%;
}
.ribbon-form-row label {
  font-size: 10.5px;
  color: var(--text-secondary);
  white-space: nowrap;
  min-width: 52px;
}

/* Decimals spinbox + trailing-zeros checkbox on one row */
.ribbon-form-row.mf-decimals-inline-row label[for="mf-trailing-zeros"] {
  min-width: 0;
}

/* Document tab: graph paper + grid — label above select, controls in a row */
.ribbon-group-canvas-paper {
  min-width: 232px;
  padding-left: 10px;
  padding-right: 10px;
}
.ribbon-group-canvas-paper .ribbon-group-body {
  align-items: center;
  justify-content: flex-start;
  gap: 10px;
  padding-left: 2px;
  padding-right: 2px;
}
.ribbon-paper-stack {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 4px;
  padding-top: 2px;
}
.ribbon-paper-stack label {
  font-size: 10.5px;
  color: var(--text-secondary);
  line-height: 1.2;
  white-space: nowrap;
}
#paper-theme-select.ribbon-paper-select {
  width: 158px;
  min-width: 158px;
  height: 24px;
}

/* ── Small row of icon buttons inside a col group ──────── */
.ribbon-btn-row {
  display: flex;
  flex-direction: row;
  gap: 2px;
  align-items: center;
}

/* Document tab — Fields: 2×2 grid fits ribbon height (~106px) */
.ribbon-group-fields {
  min-width: 104px;
}
#panel-document .ribbon-group-body--hf-fields {
  flex-direction: column;
  align-items: stretch;
  justify-content: center;
  gap: 0;
  width: 100%;
  padding: 2px 0;
}
#panel-document .ribbon-hf-field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3px 6px;
  width: 100%;
}
#panel-document .ribbon-btn--hf-field {
  width: 100%;
  min-width: 0;
  height: 34px;
  min-height: 34px;
  max-height: 34px;
  padding: 0 4px;
  flex-direction: column;
  justify-content: center;
  gap: 0;
  flex-shrink: 0;
}
#panel-document .ribbon-btn--hf-field .btn-label {
  font-size: 10px;
  font-weight: 600;
  line-height: 1.15;
}

/* Header/footer inserted dynamic fields (page #, date, …) — match surrounding text */
.hf-var {
  display: inline-block;
  vertical-align: baseline;
  padding: 0;
  margin: 0;
  border-radius: 0;
  background: transparent;
  color: inherit;
  font-size: inherit;
  font-weight: inherit;
  font-family: inherit;
  white-space: nowrap;
  user-select: none;
}
#page-header-canvas .hf-var,
#page-footer-canvas .hf-var,
.page-header-mirror .hf-var,
.page-footer-mirror .hf-var {
  font-family: var(--font-ui);
}

/* ── Symbol Dropdown ───────────────────────────────────── */
.sym-dropdown {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.sym-dropdown-panel {
  display: none;
  position: fixed;
  background: #fff;
  border: 1px solid var(--ribbon-border);
  box-shadow: 0 6px 24px rgba(0,0,0,0.13);
  border-radius: 5px;
  z-index: 600;
  width: 228px;
  overflow: hidden;
}
.sym-dropdown.open .sym-dropdown-panel { display: block; }

.sym-panel-cats {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 3px;
  padding: 6px 7px 5px;
  border-bottom: 1px solid var(--ribbon-border);
  background: var(--ribbon-bg);
  min-height: 30px;
  box-sizing: border-box;
}

.sym-cat-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 22px;
  box-sizing: border-box;
  padding: 2px 8px;
  font-size: 11px;
  font-family: var(--font-ui);
  border: 1px solid var(--ribbon-border);
  border-radius: 3px;
  background: white;
  cursor: pointer;
  color: var(--text-secondary);
  transition: background 0.1s, color 0.1s, border-color 0.1s;
  white-space: nowrap;
  line-height: 1.2;
}
.sym-cat-btn:hover { background: var(--ribbon-tab-hover); color: var(--text-primary); }
.sym-cat-btn.active {
  background: var(--accent-light);
  color: var(--accent);
  border-color: rgba(9,105,218,0.35);
  font-weight: 600;
}

.sym-panel-grid {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: 2px;
  padding: 6px;
  max-height: 130px;
  overflow-y: auto;
}
.sym-panel-grid .sym-btn {
  width: 100%;
  aspect-ratio: 1;
  font-size: 15px;
}

/* Separator between button sets in a col group */
.ribbon-divider {
  width: 100%;
  height: 1px;
  background: var(--ribbon-border);
  flex-shrink: 0;
  margin: 1px 0;
}

/* Ribbon separators (keep for backwards compat) */
.ribbon-separator {
  width: 1px;
  height: 50px;
  background: var(--ribbon-border);
  margin: 0 3px;
  align-self: center;
  flex-shrink: 0;
}

/* ── Ribbon selects & spinboxes ────────────────────────── */
.ribbon-select {
  height: 22px;
  font-size: 11px;
  font-family: var(--font-ui);
  border: 1px solid var(--ribbon-border);
  border-radius: 3px;
  background: white;
  padding: 0 4px;
  color: var(--text-primary);
  outline: none;
}
.ribbon-select:focus { border-color: var(--accent); }

.ribbon-spinbox {
  width: 54px;
  height: 22px;
  font-size: 11px;
  font-family: var(--font-ui);
  border: 1px solid var(--ribbon-border);
  border-radius: 3px;
  padding: 0 4px;
  background: white;
  color: var(--text-primary);
  outline: none;
}
.ribbon-spinbox:focus { border-color: var(--accent); }

/* Text Styles ribbon group */
.ribbon-group-styles {
  min-width: 284px;
  flex-shrink: 0;
}
.ribbon-group-styles .ribbon-group-body {
  justify-content: flex-start;
  align-items: center;
  padding: 6px 8px 4px;
}
.ribbon-styles-group {
  width: 100%;
}
.ribbon-styles-grid {
  display: grid;
  grid-template-columns: repeat(3, 76px) 28px;
  grid-template-rows: repeat(2, 28px);
  gap: 4px;
  flex-shrink: 0;
}
.ribbon-styles-grid-spacer {
  display: block;
}
.ribbon-style-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 28px;
  margin: 0;
  padding: 0 6px;
  border: 1px solid var(--ribbon-border);
  border-radius: 4px;
  background: #fff;
  cursor: pointer;
  font-family: var(--font-ui);
  font-size: 11px;
  font-weight: 500;
  line-height: 1;
  color: var(--text-primary);
  white-space: nowrap;
  transition: background 0.1s, border-color 0.1s, color 0.1s;
}
.ribbon-style-btn:hover {
  background: var(--ribbon-tab-hover);
  border-color: rgba(9, 105, 218, 0.2);
}
.ribbon-style-btn.is-active {
  background: #e8f3ff;
  border-color: rgba(9, 105, 218, 0.28);
}
.ribbon-style-edit-btn {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  min-width: 28px;
  padding: 3px;
  border: 1px solid var(--ribbon-border);
  border-radius: 4px;
  background: #fff;
  cursor: pointer;
  color: var(--text-secondary);
  transition: background 0.1s, border-color 0.1s, color 0.1s;
}
.ribbon-style-edit-btn svg {
  display: block;
}
.ribbon-style-edit-btn:hover {
  background: var(--ribbon-tab-hover);
  border-color: rgba(9, 105, 218, 0.28);
  color: var(--accent);
}

/* --- Workspace (sidebar + canvas) ---------------------- */
#workspace {
  --calccloud-sidebar-width: 240px;
  --calccloud-ai-sidebar-width: 310px;
  display: flex;
  flex: 1;
  overflow: hidden;
  position: relative;
  overflow-anchor: none;
}

/* Draggable splitters (Sheets/Snippets vs canvas; canvas vs AI) */
.workspace-resize-handle {
  flex-shrink: 0;
  width: 5px;
  margin: 0 -2px;
  z-index: 25;
  cursor: col-resize;
  background: transparent;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  align-self: stretch;
  position: relative;
}
.workspace-resize-handle::after {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 1px;
  transform: translateX(-50%);
  background: var(--ribbon-border);
  opacity: 0.65;
  pointer-events: none;
}
.workspace-resize-handle:hover::after,
.workspace-resize-handle:focus-visible::after {
  background: var(--accent);
  opacity: 0.85;
}
body.workspace-resizing {
  cursor: col-resize !important;
  user-select: none !important;
}
body.workspace-resizing #sidebar,
body.workspace-resizing #ai-sidebar {
  transition: none !important;
}

#sidebar-resize-handle {
  display: none;
}
#sidebar.sidebar-open + #sidebar-resize-handle {
  display: block;
}

#ai-sidebar-resize-handle {
  display: none;
}
#workspace:has(#ai-sidebar.ai-sidebar-open) #ai-sidebar-resize-handle {
  display: block;
}

/* --- Main area (right of sidebar) ---------------------- */
#main-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
  overflow-anchor: none;
}

/* --- Worksheet paper (grid + margins; wraps header, body, footer) -------- */
#worksheet-paper {
  --paper-rule: rgba(0, 120, 212, 0.2);
  --paper-frame: rgba(0, 120, 212, 0.15);
  --paper-inset: rgba(173, 216, 230, 0.4);
  display: block;
  position: relative;
  min-width: var(--a4-page-width);
  background-color: var(--canvas-bg);
  background-image:
    linear-gradient(var(--grid-minor) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-minor) 1px, transparent 1px),
    linear-gradient(var(--grid-color) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
  background-size:
    var(--grid-size) var(--grid-size),
    var(--grid-size) var(--grid-size),
    calc(var(--grid-size) * 5) calc(var(--grid-size) * 5),
    calc(var(--grid-size) * 5) calc(var(--grid-size) * 5);
  box-shadow: 0 1px 4px rgba(0,0,0,0.18), inset 0 0 0 1px var(--paper-inset);
  margin: 20px auto;
  max-width: var(--a4-page-width);
  width: var(--a4-page-width);
  overflow-anchor: none;
}

/* Graph paper themes (Document → Paper theme) */
#worksheet-paper.paper-theme-engineering-blue {
  --canvas-bg: #ffffff;
  --grid-minor: rgba(173, 216, 230, 0.3);
  --grid-color: rgba(173, 216, 230, 0.6);
  --paper-rule: rgba(0, 120, 212, 0.2);
  --paper-frame: rgba(0, 120, 212, 0.15);
  --paper-inset: rgba(173, 216, 230, 0.4);
}

#worksheet-paper.paper-theme-engineering-green {
  --canvas-bg: #ffffff;
  --grid-minor: rgba(46, 160, 67, 0.22);
  --grid-color: rgba(46, 160, 67, 0.42);
  --paper-rule: rgba(20, 120, 60, 0.22);
  --paper-frame: rgba(20, 100, 50, 0.14);
  --paper-inset: rgba(46, 160, 67, 0.35);
}

#worksheet-paper.paper-theme-quadrille-ivory {
  --canvas-bg: #f7f5ef;
  --grid-minor: rgba(140, 135, 120, 0.22);
  --grid-color: rgba(140, 135, 120, 0.4);
  --paper-rule: rgba(120, 110, 95, 0.22);
  --paper-frame: rgba(120, 110, 95, 0.14);
  --paper-inset: rgba(130, 120, 105, 0.28);
}

/* --- Page Header / Footer ------------------------------ */
#page-header-bar,
#page-footer-bar {
  position: absolute;
  left: 0;
  right: 0;
  z-index: 200;
  background: transparent;
  padding: 0;
  min-height: 44px;
  box-sizing: border-box;
}
#page-header-bar {
  top: 0;
  border-bottom: 1px solid transparent;
}
/* Repeated strips on pages 2+ — outer box matches real bar size; inset highlight spans full width */
.page-header-mirror {
  border-bottom: 1px solid transparent;
  box-sizing: border-box;
  width: 100%;
}
.page-footer-mirror {
  border-top: 1px solid transparent;
  box-sizing: border-box;
  width: 100%;
}
#page-footer-bar {
  top: calc(var(--a4-page-height) - var(--footer-zone-height, 72px));
  bottom: auto;
  border-top: 1px solid transparent;
}
#worksheet-paper.hf-layout-ready #page-header-bar,
#worksheet-paper.hf-layout-ready .page-header-mirror {
  border-bottom-color: var(--sheet-divider-line);
}
#worksheet-paper.hf-layout-ready #page-footer-bar,
#worksheet-paper.hf-layout-ready .page-footer-mirror {
  border-top-color: var(--sheet-divider-line);
}
#page-header-canvas,
#page-footer-canvas {
  font-family: var(--font-ui);
  font-size: 12px;
  color: #555;
}
.sheet-zone-canvas {
  position: relative;
  width: 100%;
  box-sizing: border-box;
  min-height: 72px;
  z-index: 1;
}
#page-hf-mirror-layer {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  pointer-events: none;
  z-index: 15;
  overflow: visible;
}
/*
 * Repeated header mirrors live in #page-hf-mirror-layer; keep them above the dim while editing headers.
 * Footer repeats are appended as direct children of #canvas — see syncPageHeaderFooterMirrors —
 * so with footer edit mode below we can tuck this layer beneath the overlay and dim inactive headers.
 */
#worksheet-paper.editing-zone-page_header #page-hf-mirror-layer {
  z-index: 130;
}
#worksheet-paper.editing-zone-page_footer #page-hf-mirror-layer {
  z-index: 120;
}
#sheet-body-dim {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  background: rgba(72, 78, 92, 0.28);
  z-index: 125;
  pointer-events: auto;
}
#sheet-body-dim.active {
  display: block;
}
/* Footer edit: tint inactive header/chrome (below #sheet-body-dim) while keeping clickable footers above */
#worksheet-paper.editing-zone-page_footer #sheet-body-dim.active {
  z-index: 140;
}
#worksheet-paper.editing-zone-page_footer #page-header-bar {
  z-index: 110;
}
/* Footer clones on canvas — above overlay (140); primary footer bar stays z-index 200 */
#worksheet-paper.editing-zone-page_footer #canvas > .page-footer-mirror {
  z-index: 190 !important;
}
#worksheet-paper.editing-zone-page_header #page-header-bar,
#worksheet-paper.editing-zone-page_header .page-header-mirror,
#worksheet-paper.editing-zone-page_footer #page-footer-bar,
#worksheet-paper.editing-zone-page_footer .page-footer-mirror {
  box-shadow: inset 0 0 0 2px rgba(0, 120, 212, 0.55);
  border-radius: 2px;
  cursor: default;
}
/* I-beam over header/footer text — zone uses cursor:default above (inherits into editables). */
#worksheet-paper.editing-zone-page_header #page-header-bar .text-region-content,
#worksheet-paper.editing-zone-page_header .page-header-mirror .text-region-content,
#worksheet-paper.editing-zone-page_footer #page-footer-bar .text-region-content,
#worksheet-paper.editing-zone-page_footer .page-footer-mirror .text-region-content {
  cursor: text !important;
  caret-color: #0078d4;
}
body.dragging-regions #page-hf-mirror-layer,
body.dragging-regions #page-hf-mirror-layer * {
  cursor: grabbing !important;
}

/* ribbon-select, ribbon-spinbox, style-btn now defined in the ribbon block above */

/* --- Sidebar ------------------------------------------- */
#sidebar {
  display: flex;
  flex-direction: column;
  background: #f5f6f8;
  border-right: 1px solid var(--ribbon-border);
  overflow: hidden;
  transition: width 0.2s ease, min-width 0.2s ease;
  flex-shrink: 0;
}
#sidebar.sidebar-open {
  width: var(--calccloud-sidebar-width);
  min-width: var(--calccloud-sidebar-width);
}
#sidebar:not(.sidebar-open) {
  width: 0;
  min-width: 0;
}

.sidebar-adsense-rail {
  flex-shrink: 0;
  padding: 8px 6px 10px;
  border-top: 1px solid var(--ribbon-border);
  background: #eef0f3;
  text-align: center;
  overflow-x: hidden;
  min-height: 50px;
}
.sidebar-adsense-rail .adsbygoogle {
  margin: 0 auto;
}

#sidebar-header {
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--ribbon-border);
  flex-shrink: 0;
  background: #eeeff1;
}
.sidebar-tabs {
  display: flex;
  flex: 1;
  overflow: hidden;
}
.sidebar-tab {
  flex: 1;
  padding: 7px 4px;
  font-size: 12px;
  font-weight: 500;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  color: var(--text-secondary);
  white-space: nowrap;
  transition: color 0.15s, border-color 0.15s;
}
.sidebar-tab:hover { color: var(--text-primary); }
.sidebar-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

#sidebar-collapse-btn {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  margin: 2px;
  padding: 0;
  background: none;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
}
#sidebar-collapse-btn svg { width: 14px; height: 14px; }
#sidebar-collapse-btn:hover { background: var(--ribbon-tab-hover); color: var(--text-primary); }

#sidebar-expand-btn {
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  z-index: 20;
  width: 18px;
  height: 48px;
  padding: 0;
  background: #eeeff1;
  border: 1px solid var(--ribbon-border);
  border-left: none;
  border-radius: 0 4px 4px 0;
  cursor: pointer;
  color: var(--text-secondary);
  display: none;
  align-items: center;
  justify-content: center;
}
#sidebar-expand-btn svg { width: 12px; height: 12px; }
#sidebar-expand-btn:hover { background: var(--ribbon-tab-hover); color: var(--text-primary); }
#sidebar:not(.sidebar-open) ~ #sidebar-expand-btn { display: flex; }

.sidebar-panel {
  display: none;
  flex-direction: column;
  flex: 1;
  overflow: hidden;
  padding: 8px;
  gap: 6px;
}
.sidebar-panel.active { display: flex; }

.sidebar-search-row {
  display: flex;
  align-items: center;
  gap: 5px;
  background: white;
  border: 1px solid var(--ribbon-border);
  border-radius: 5px;
  padding: 3px 7px;
  flex-shrink: 0;
}
.sidebar-search-row svg { width: 13px; height: 13px; flex-shrink: 0; color: #999; }
.sidebar-search-row input {
  flex: 1;
  border: none;
  outline: none;
  font-size: 12px;
  background: none;
  color: var(--text-primary);
}

.sidebar-action-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  width: 100%;
  padding: 5px 8px;
  font-size: 12px;
  background: white;
  border: 1px solid var(--ribbon-border);
  border-radius: 5px;
  cursor: pointer;
  color: var(--text-primary);
  flex-shrink: 0;
  transition: background 0.12s;
}
.sidebar-action-btn svg { width: 13px; height: 13px; flex-shrink: 0; }
.sidebar-action-btn:hover { background: var(--ribbon-tab-hover); }
.sidebar-action-btn:disabled { opacity: 0.45; cursor: default; }

.sidebar-list {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.sidebar-list.sidebar-list-compact {
  flex: none;
  max-height: 168px;
}

.sidebar-templates-block {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid var(--ribbon-border);
  padding-top: 6px;
  margin-top: 4px;
}
.sidebar-templates-block.hidden {
  display: none !important;
}
.sidebar-templates-block.sidebar-templates-collapsed .sidebar-templates-body {
  display: none !important;
}
.sidebar-templates-body {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-top: 8px;
}
.sidebar-templates-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: 8px;
  margin: 0;
  padding: 6px 4px;
  border: none;
  border-radius: 5px;
  background: transparent;
  cursor: pointer;
  color: var(--text-secondary);
  transition: background 0.12s, color 0.12s;
  text-align: left;
  font: inherit;
}
.sidebar-templates-toggle:hover {
  background: rgba(0, 0, 0, 0.05);
  color: var(--text-primary);
}
.sidebar-templates-toggle-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.sidebar-templates-toggle-chevron {
  flex-shrink: 0;
  color: currentColor;
  opacity: 0.75;
  transition: transform 0.18s ease;
}
.sidebar-templates-block.sidebar-templates-collapsed .sidebar-templates-toggle-chevron {
  transform: rotate(180deg);
}
.sidebar-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 8px;
  border-radius: 5px;
  cursor: pointer;
  font-size: 12px;
  color: var(--text-primary);
  transition: background 0.12s;
  user-select: none;
}
.sidebar-item:hover { background: rgba(0,0,0,0.06); }
.sidebar-item.active-sheet { background: rgba(9,105,218,0.1); color: var(--accent); font-weight: 600; }
.sidebar-item svg { width: 13px; height: 13px; flex-shrink: 0; color: #888; }
.sidebar-sheet-icon-wrap {
  position: relative;
  flex-shrink: 0;
  width: 13px;
  height: 13px;
}
.sidebar-sheet-icon-wrap > svg {
  width: 13px;
  height: 13px;
  display: block;
  color: #888;
}
/* Mini share-network glyph — same artwork as QAT #btn-share (worksheet.html), scaled for sidebar sheet icons */
.sidebar-sheet-shared-icon {
  position: absolute;
  right: -6px;
  bottom: -5px;
  width: 11px;
  height: 11px;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
}
.sidebar-sheet-shared-icon svg {
  width: 9px;
  height: 9px;
  display: block;
  flex-shrink: 0;
  color: #2563eb;
}
.sidebar-item-name {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.sidebar-item-meta {
  font-size: 10px;
  font-weight: 400;
  color: var(--text-secondary);
  white-space: nowrap;
}
.sidebar-item-del {
  opacity: 0;
  background: none;
  border: none;
  cursor: pointer;
  color: #c0392b;
  padding: 2px;
  border-radius: 3px;
  line-height: 1;
  flex-shrink: 0;
}
.sidebar-item:hover .sidebar-item-del { opacity: 0.7; }
.sidebar-item-del:hover { opacity: 1 !important; background: rgba(192,57,43,0.1); }
.sidebar-item-del svg { width: 11px; height: 11px; }
.sidebar-item-rename {
  opacity: 0;
  background: none;
  border: none;
  cursor: pointer;
  color: #555;
  padding: 2px;
  border-radius: 3px;
  line-height: 1;
  flex-shrink: 0;
}
.sidebar-item:hover .sidebar-item-rename { opacity: 0.6; }
.sidebar-item-rename:hover { opacity: 1 !important; background: rgba(9,105,218,0.1); color: var(--accent); }
.sidebar-item-rename svg { width: 11px; height: 11px; }
.sidebar-item-pref {
  opacity: 0;
  background: none;
  border: none;
  cursor: pointer;
  color: #888;
  padding: 2px;
  border-radius: 3px;
  line-height: 1;
  flex-shrink: 0;
}
.sidebar-item:hover .sidebar-item-pref { opacity: 0.55; }
.sidebar-item-pref:hover { opacity: 1 !important; background: rgba(9,105,218,0.08); color: var(--accent); }
.sidebar-item-pref.is-preferred {
  opacity: 1;
  color: #c9a227;
}
.sidebar-item-pref.is-preferred:hover { background: rgba(201,162,39,0.12); }
.sidebar-item-pref svg { width: 11px; height: 11px; vertical-align: middle; }
.sidebar-item-name-input {
  flex: 1;
  min-width: 0;
  font: inherit;
  font-size: 12px;
  color: inherit;
  background: var(--surface);
  border: 1px solid var(--accent);
  border-radius: 3px;
  padding: 1px 4px;
  outline: none;
  box-shadow: 0 0 0 2px rgba(9,105,218,0.15);
}

/* Action button row (New Sheet / New Folder) */
.sidebar-action-row {
  display: flex;
  gap: 5px;
  flex-shrink: 0;
}
.sidebar-action-row .sidebar-action-btn { width: auto; flex: 1; }
.sidebar-action-btn--icon {
  flex: 0 0 auto;
  width: 30px;
  justify-content: center;
  padding: 5px;
}

/* Sidebar folders */
.sidebar-folder { display: flex; flex-direction: column; }
.sidebar-folder-header {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 6px 8px;
  border-radius: 5px;
  cursor: pointer;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-primary);
  transition: background 0.12s;
  user-select: none;
}
.sidebar-folder-header:hover { background: rgba(0,0,0,0.06); }
.sidebar-folder-chevron {
  width: 12px; height: 12px; flex-shrink: 0;
  color: var(--text-secondary);
  transition: transform 0.15s ease;
}
.sidebar-folder.collapsed .sidebar-folder-chevron { transform: rotate(-90deg); }
.sidebar-folder-icon { width: 14px; height: 14px; flex-shrink: 0; color: #c9a227; }
.sidebar-folder-name {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.sidebar-folder-children {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding-left: 14px;
  margin-left: 5px;
  border-left: 1px solid var(--ribbon-border);
}
.sidebar-folder.collapsed .sidebar-folder-children { display: none; }
.sidebar-folder-empty {
  font-size: 11px;
  color: var(--text-secondary);
  padding: 4px 8px;
  font-style: italic;
}
.sidebar-folder-header .sidebar-item-rename,
.sidebar-folder-header .sidebar-item-del { opacity: 0; }
.sidebar-folder-header:hover .sidebar-item-rename { opacity: 0.6; }
.sidebar-folder-header:hover .sidebar-item-del { opacity: 0.7; }

/* Drag-into-folder affordances */
.sidebar-folder.drag-over > .sidebar-folder-header,
.sidebar-folder-children.drag-over {
  background: rgba(9,105,218,0.12);
  outline: 1px dashed var(--accent);
  border-radius: 5px;
}
.sidebar-root-dropzone {
  flex-shrink: 0;
  margin-top: auto;
  padding: 7px 8px;
  font-size: 11px;
  color: var(--text-secondary);
  text-align: center;
  border: 1px dashed transparent;
  border-radius: 5px;
  transition: background 0.12s, border-color 0.12s;
}
.sidebar-root-dropzone.drag-active { border-color: var(--ribbon-border); }
.sidebar-root-dropzone.drag-over {
  background: rgba(9,105,218,0.1);
  border-color: var(--accent);
  color: var(--accent);
}

.sidebar-list.root-drag-over {
  background: rgba(9,105,218,0.04);
  outline: 1px dashed rgba(9,105,218,0.25);
  outline-offset: -2px;
  border-radius: 5px;
}

/* Drag ghost for snippets */
.snippet-drag-ghost {
  position: fixed;
  pointer-events: none;
  background: var(--accent);
  color: white;
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 4px;
  z-index: 9999;
  opacity: 0.85;
}

/* Drop indicator on canvas */
#canvas-container.snippet-drag-over { outline: 2px dashed var(--accent); }

/* Bounding-box ghost shown while dragging a snippet over the canvas */
.snippet-drop-preview {
  position: absolute;
  pointer-events: none;
  border: 1px dashed #999;
  border-radius: 2px;
  background: rgba(150, 150, 150, 0.06);
  z-index: 10;
}

/* --- Canvas Area --------------------------------------- */
#canvas-container {
  flex: 1;
  overflow: auto;
  position: relative;
  background: #c8c8c8;
  /* Avoid browser scroll anchoring when regions grow (math auto-width, results, etc.). */
  overflow-anchor: none;
}

#canvas {
  position: relative;
  z-index: 1;
  flex: 1 0 auto;
  width: 100%;
  min-height: var(--a4-page-height); /* overridden by JS pageCount * PAGE_HEIGHT */
  background: transparent;
  overflow-anchor: none;
}
/* Avoid browser focus ring on #canvas (tabindex set while insertion cursor is active);
   selection is already shown on regions. */
#canvas:focus,
#canvas:focus-visible {
  outline: none;
}

/* Vector print grid that does not depend on background printing. */
#print-grid-raster-layer {
  display: none;
}

/* --- Page breaks -------------------------------------- */
.page-break {
  position: absolute;
  left: 0; right: 0;
  height: 0;
  background: none;
  border-top: 1px solid var(--sheet-divider-line);
  border-bottom: none;
  pointer-events: none;
  z-index: 1;
  transform: none;
}

/* --- Regions ------------------------------------------ */
.region {
  position: absolute;
  cursor: default;
  border: 1px solid transparent;
  border-radius: 2px;
  min-width: 80px;
  min-height: 32px;
  z-index: 10;
  transition: border-color 0.1s, box-shadow 0.1s;
}

.region:hover {
  border-color: var(--region-hover-border);
  box-shadow: var(--region-hover-shadow);
  z-index: 20;
}

.region.selected {
  border-color: var(--region-selected-border);
  box-shadow: 0 0 0 2px rgba(0,120,212,0.2), var(--region-hover-shadow);
  z-index: 30;
  cursor: grab;
}
/* Keep text cursor inside the editable field for single-region editing */
.region.selected .mq-editable-field {
  cursor: text;
}
.region.selected .text-region-content {
  cursor: text;
}
/* Result-side unit chip/editor sit outside .mq-editable-field; keep I-beam vs region grab. */
.region.selected .math-result-units,
.region.selected .math-result-units .unit-chip,
.region.selected .math-result-units .unit-edit-input {
  cursor: text;
}
.region.multi-selected .math-result-units,
.region.multi-selected .math-result-units .unit-chip,
.region.multi-selected .math-result-units .unit-edit-input {
  cursor: text;
}
/* Multi-select: entire region is draggable, including over the input */
.region.multi-selected .mq-editable-field {
  cursor: grab;
}

.region.dragging {
  opacity: 0.85;
  z-index: 100;
  border-color: var(--accent);
  box-shadow: 0 4px 16px rgba(0,120,212,0.25);
  cursor: grabbing !important;
  user-select: none;
}
.region.dragging * {
  cursor: grabbing !important;
  user-select: none !important;
}

body.dragging-regions,
body.dragging-regions * {
  user-select: none !important;
  -webkit-user-select: none !important;
}

/* Draggable border strips — wide hit targets + hand cursor on the pickup ring */
.region-drag-edge {
  position: absolute;
  z-index: 6;
  background: transparent;
  pointer-events: auto;
  cursor: grab;
  box-sizing: border-box;
  user-select: none;
  -webkit-user-select: none;
  touch-action: none;
}
.region-drag-edge--top {
  top: 0;
  left: 0;
  right: 0;
  height: 14px;
  margin-top: -4px;
  padding-top: 4px;
}
.region-drag-edge--bottom {
  bottom: 0;
  left: 0;
  right: 20px;
  height: 14px;
  margin-bottom: -4px;
  padding-bottom: 4px;
}
.region-drag-edge--left {
  top: 14px;
  bottom: 14px;
  left: 0;
  width: 14px;
  margin-left: -4px;
  padding-left: 4px;
}
.region-drag-edge--right {
  top: 14px;
  bottom: 20px;
  right: 0;
  width: 14px;
  margin-right: -4px;
  padding-right: 4px;
}
.region.dragging .region-drag-edge {
  cursor: grabbing;
}

/* Resize handles */
.resize-handle {
  position: absolute;
  bottom: -4px;
  right: -4px;
  width: 10px;
  height: 10px;
  background: var(--accent);
  border-radius: 2px;
  cursor: se-resize;
  opacity: 0;
  transition: opacity 0.15s;
  z-index: 8;
}

.region.selected .resize-handle,
.region:hover .resize-handle { opacity: 1; }

/* --- Image Region -------------------------------------- */
.image-region {
  padding: 4px;
  box-sizing: border-box;
  background: var(--sheet-bg, #fff);
}

.image-region-inner {
  width: 100%;
  height: 100%;
  min-height: 0;
  box-sizing: border-box;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  border-radius: 2px;
}

.image-region-inner--empty {
  min-height: 120px;
  background: repeating-linear-gradient(
    -45deg,
    rgba(0, 0, 0, 0.04),
    rgba(0, 0, 0, 0.04) 8px,
    transparent 8px,
    transparent 16px
  );
}

.image-region-img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
  pointer-events: none;
  user-select: none;
}

/* --- Math Region --------------------------------------- */
.math-region {
  background: transparent;
  display: flex;
  /* Keep math text baseline anchored; centering causes visible drift from gridlines. */
  align-items: flex-start;
  padding: 1px 6px;
  min-height: 0;
  overflow: visible;
}

/* Math regions auto-size vertically — only horizontal resize allowed */
.math-region .resize-handle {
  cursor: ew-resize;
  bottom: -4px;
}

/* Out-of-flow so _fitSizeToContent / region height ignore the message */
.math-region-error-below {
  position: absolute;
  left: 0;
  top: 100%;
  margin-top: 2px;
  padding: 0 6px 2px;
  font-size: 12px;
  font-style: italic;
  color: #c0392b;
  line-height: 1.35;
  white-space: nowrap;
  width: max-content;
  max-width: none;
  user-select: text;
  z-index: 4;
}
.math-region-error-below[hidden] {
  display: none !important;
}

.math-mq-error-mark {
  position: absolute;
  pointer-events: none;
  box-sizing: border-box;
  border: 2px solid #c0392b;
  border-radius: 3px;
  background: rgba(192, 57, 43, 0.1);
  z-index: 6;
}

.mf-fmt-btn.active {
  background: rgba(9, 105, 218, 0.12);
  border-color: var(--accent);
  color: var(--accent);
}

.math-region-inner {
  --mr-font-size: 20px;
  --mr-font-family: var(--font-math);
  --mr-font-weight: 400;
  --mr-font-style: normal;
  --mr-text-decoration: none;
  --mr-color: var(--text-primary);
  --mr-bg: transparent;
  display: flex;
  /* Align expression + result on text baseline so `M := ... = result` shares one gridline. */
  align-items: baseline;
  flex-wrap: nowrap;
  gap: 0;
  width: 100%;
  min-height: 0;
  flex: 1;
  /* min-width: 0 lets flex squeeze the MQ line narrower than the glyphs → MathQuill scrolls the
     field horizontally and hides the LHS (e.g. l:=…) while typing MPa-sized units. */
  min-width: min-content;
  color: var(--mr-color);
  background-color: var(--mr-bg);
}

/* Matrix results (preview or full KaTeX): row is taller than the assignment line (`s:=`);
   baseline/flex-start pins that line to the top of the tinted box — centre so it sits midway. */
.math-region-inner.math-region-inner--matrix-preview,
.math-region-inner.math-region-inner--matrix-result {
  align-items: center;
}

.math-input-wrapper {
  flex: 1 1 auto;
  /* Match inner: never shrink narrower than rendered math baseline content. */
  min-width: max(60px, min-content);
  display: flex;
  align-items: baseline;
}

/* MathQuill mounts on this node — anchor for error-char overlay boxes. */
[data-mq-container] {
  position: relative;
}

/* Matrix cell grid: same typeface as .mq-operator-name (min, max, sin, …) */
.math-input-wrapper [data-matrix-surface] {
  flex: 1;
  min-width: 40px;
}
.math-matrix-bmatrix {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 0;
  background: linear-gradient(180deg, rgba(9, 105, 218, 0.06) 0%, rgba(9, 105, 218, 0.02) 100%);
  border: 1px solid rgba(9, 105, 218, 0.22);
  border-radius: 3px;
  padding: 4px 2px 4px 0;
  box-sizing: border-box;
  font-size: var(--mr-font-size, 20px);
  font-family: Symbola, "Times New Roman", Times, serif;
  color: var(--mr-color, var(--text-primary));
  font-style: normal;
  font-weight: 400;
}
.math-matrix-bracket {
  font-size: 1.35em;
  font-weight: 600;
  line-height: 1;
  color: var(--text-primary, #1a1a1a);
  padding: 0 1px 2px 1px;
  user-select: none;
  font-family: Symbola, "Times New Roman", Times, serif;
  font-style: normal;
  font-weight: 400;
}
.math-matrix-bracket-left { margin-right: 1px; }
.math-matrix-bracket-right { margin-left: 1px; }
.math-matrix-table {
  border-collapse: collapse;
  border: none;
  background: rgba(255, 255, 255, 0.4);
  margin: 0 2px;
}
.math-matrix-td {
  border: 1px solid rgba(9, 105, 218, 0.28);
  padding: 0;
  min-width: 2.1em;
  text-align: center;
  vertical-align: middle;
}
.math-matrix-cell {
  display: block;
  width: 100%;
  min-width: 2em;
  max-width: 6em;
  box-sizing: border-box;
  border: none;
  background: rgba(255, 255, 255, 0.85);
  font: inherit;
  font-family: Symbola, "Times New Roman", Times, serif !important;
  font-size: 0.95em;
  font-style: normal;
  font-weight: 400;
  text-align: right;
  padding: 2px 5px 3px 5px;
  outline: none;
  line-height: 1.3;
  color: inherit;
}
.math-matrix-cell:focus {
  background: #fff;
  box-shadow: inset 0 0 0 1px var(--accent, #0b57d0);
}

/* MathQuill puts `mq-editable-field` on the same node as `.math-input-wrapper` (same element passed
 * to MQ.MathField). Only neutral chrome belongs here: font-size/line-height/min-width on this node
 * were never meant to apply (old `.math-input-wrapper .mq-editable-field` targeted a missing child)
 * and they change flex baseline + region height vs historic layout. Selection still uses
 * `.math-input-wrapper.mq-editable-field .mq-selection`. */
.math-input-wrapper.mq-editable-field {
  border: none !important;
  background: transparent !important;
  padding: 0 !important;
  cursor: text;
  overflow-anchor: none;
}
/* Do not set `font-family: inherit` on `.mq-math-mode *`: the wrapper uses `--font-math`, and forcing
 * inherit on all descendants overwrote MathQuill's Symbola/serif glyphs (it matched only after fixing
 * `.math-input-wrapper.mq-math-mode` to the same element as the field). Operator names stay explicit. */
.math-input-wrapper.mq-math-mode .mq-operator-name,
.math-input-wrapper.mq-math-mode .mq-operator-name * {
  font-family: Symbola, "Times New Roman", Times, serif !important;
  font-style: normal !important;
  font-weight: 400 !important;
}

.math-input-wrapper.mq-editable-field.mq-focused {
  box-shadow: none !important;
  outline: none !important;
}

/* Selection inside math — match MathQuill / system selection (lighter than branded rgba on white). */
.math-input-wrapper.mq-editable-field .mq-selection,
.math-input-wrapper.mq-editable-field .mq-selection *,
.math-input-wrapper.mq-editable-field .mq-selection .mq-non-leaf,
.math-input-wrapper.mq-editable-field .mq-selection .mq-scaled {
  background: #b4d5fe !important;
  color: var(--mr-color, var(--text-primary)) !important;
  border-color: transparent !important;
}

/* Selection + unit: darker text (#005a9e) like `.unit-chip:hover` / native chip selection. */
.math-input-wrapper.mq-editable-field .mq-selection var.mq-unit-letter,
.math-input-wrapper.mq-editable-field .mq-selection .unit-token {
  color: #005a9e !important;
  background: #b4d5fe !important;
}
.math-input-wrapper.mq-editable-field .mq-selection .unit-token * {
  color: #005a9e !important;
  background: #b4d5fe !important;
}

/* Cursor styling */
.mq-cursor { border-color: var(--accent) !important; }

/* MathQuill math text size */
.mq-math-mode { font-size: var(--mr-font-size, 20px) !important; }
.mq-math-mode .mq-root-block { padding: 2px 0 !important; }

/* Result display area — immediately after the expression (no separator) */
.math-result {
  display: none;
  /* Center keeps the numeric value vertically stable when the unit swaps chip → <input>,
     which participates in baseline alignment differently and used to jog the KaTeX/text value. */
  align-items: center;
  gap: 5px;
  white-space: nowrap;
  flex-shrink: 0;
  margin-left: 6px;
}

.math-region-inner.has-result .math-result { display: flex; }

/* Matrix + trailing unit chip: keep clear space between closing bracket and unit (matches scalar). */
.math-region-inner--matrix-result .math-result {
  align-items: center;
  gap: 5px;
}
.math-region-inner--matrix-result .math-result > :first-child {
  margin-right: 0;
}
.math-region-inner--matrix-result .math-result-units .unit-chip {
  padding-left: 0;
}

.math-result-value {
  flex-shrink: 0;
  font-size: var(--mr-font-size, 20px);
  font-family: var(--mr-font-family, var(--font-math));
  color: var(--mr-color, var(--text-primary));
  font-weight: var(--mr-font-weight, 400);
  font-style: var(--mr-font-style, normal);
  text-decoration: var(--mr-text-decoration, none);
  letter-spacing: 0.2px;
  text-rendering: geometricPrecision;
}

.math-result-units {
  flex-shrink: 0;
  font-size: 14px;
  font-family: var(--font-ui);
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.3px;
  cursor: text;
}

/* Large matrix results: preview first rows/cols + ⋯; drag grips to reveal more */
.math-result-matrix-shell {
  display: inline-flex;
  flex-direction: column;
  align-items: stretch;
  vertical-align: top;
  max-width: 100%;
  /* Skinny column matrices: modest minimum grab width */
  min-width: 5rem;
}

.math-result-matrix-body {
  display: inline-flex;
  flex-direction: row;
  align-items: stretch;
  max-width: 100%;
  min-width: 0;
}

.math-result-matrix-viewport {
  display: inline-block;
  max-width: 100%;
  min-width: 0;
  align-self: center;
}

.math-result-matrix-resize-bar {
  flex-shrink: 0;
  box-sizing: border-box;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  background: color-mix(in srgb, var(--ribbon-border) 55%, transparent);
  border: 1px solid color-mix(in srgb, var(--ribbon-border) 65%, transparent);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.math-result-matrix-resize-bar--rows {
  align-self: stretch;
  width: 100%;
  min-width: 0;
  min-height: 20px;
  margin-top: 4px;
  padding: 5px 8px;
  cursor: ns-resize;
}

.math-result-matrix-resize-bar--rows::after {
  content: '';
  flex-shrink: 0;
  width: 36px;
  height: 3px;
  border-radius: 2px;
  background: repeating-linear-gradient(
    90deg,
    color-mix(in srgb, var(--text-primary) 55%, transparent) 0 3px,
    transparent 3px 6px
  );
  opacity: 0.88;
  pointer-events: none;
}

.math-result-matrix-resize-bar--cols {
  align-self: stretch;
  width: 20px;
  min-width: 20px;
  min-height: 2.5rem;
  margin-left: 4px;
  padding: 8px 5px;
  cursor: ew-resize;
}

.math-result-matrix-resize-bar--cols::after {
  content: '';
  flex-shrink: 0;
  width: 3px;
  height: 36px;
  border-radius: 2px;
  background: repeating-linear-gradient(
    180deg,
    color-mix(in srgb, var(--text-primary) 55%, transparent) 0 3px,
    transparent 3px 6px
  );
  opacity: 0.88;
  pointer-events: none;
}

.math-result-matrix-resize-bar:hover,
.math-result-matrix-resize-bar:focus-visible {
  background: color-mix(in srgb, var(--accent) 10%, var(--ribbon-border) 38%);
  border-color: color-mix(in srgb, var(--accent) 30%, var(--ribbon-border) 50%);
}

.math-result-matrix-resize-bar--rows:hover::after,
.math-result-matrix-resize-bar--rows:focus-visible::after {
  background: repeating-linear-gradient(
    90deg,
    var(--accent) 0 3px,
    transparent 3px 6px
  );
  opacity: 1;
}

.math-result-matrix-resize-bar--cols:hover::after,
.math-result-matrix-resize-bar--cols:focus-visible::after {
  background: repeating-linear-gradient(
    180deg,
    var(--accent) 0 3px,
    transparent 3px 6px
  );
  opacity: 1;
}

.math-result-matrix-resize-bar--hidden {
  display: none !important;
}

.csv-matrix-import-size {
  margin: 4px 0 0;
}

.math-region-inner--csv-matrix-import .math-input-wrapper {
  flex: 0 1 auto;
  min-width: 0;
  pointer-events: none;
  cursor: default;
}

body.matrix-result-rows-dragging {
  cursor: ns-resize !important;
  user-select: none !important;
}

body.matrix-result-cols-dragging {
  cursor: ew-resize !important;
  user-select: none !important;
}

/* Katex rendered math */
.katex-display { margin: 0 !important; }
.katex { font-size: 1em !important; line-height: 1.5 !important; }

/* Result-side KaTeX (matrices, sci notation): use same math font as expression + value */
.math-region-inner .math-result-value .katex {
  font-family: var(--mr-font-family, var(--font-math)) !important;
}

/* Keep fractions at full font size — lock the container and both halves */
.math-input-wrapper .mq-fraction {
  font-size: var(--mr-font-size, 20px) !important;
  /* vertical-align set dynamically via JS to keep text baseline stable as fraction grows */
}
.math-input-wrapper .mq-fraction .mq-numerator,
.math-input-wrapper .mq-fraction .mq-denominator {
  font-size: var(--mr-font-size, 20px) !important;
}

/* Math fallback input */
.math-fallback-input {
  border: none;
  background: transparent;
  font-size: var(--mr-font-size, 16px);
  width: 100%;
  outline: none;
  font-family: var(--mr-font-family, var(--font-math));
  color: var(--text-primary);
  padding: 0;
}

/* --- Text Region --------------------------------------- */
.text-region {
  background: transparent;
  display: flex;
  /* flex-start: baseline and first line stay at a stable place when minHeight changes
     (center would re-center a shorter/taller box and look like a line jump) */
  align-items: flex-start;
  padding: 1px 6px;
  min-height: 0;
}

.text-region-content {
  outline: none;
  flex: 1;
  min-width: 0;
  font-family: Arial, sans-serif;
  font-size: 18px;
  line-height: 1.2;
  color: var(--text-primary);
  white-space: nowrap;
  word-break: normal;
  cursor: text;
  text-align: left;
}

/* Text regions auto-size vertically — only horizontal resize allowed */
.text-region .resize-handle {
  cursor: ew-resize;
}

/* Kill block margins inside the contenteditable; preserve padding on style blocks (quote, caption). */
.text-region-content *:not(h1):not(h2):not(h3):not(h4):not(blockquote):not(p.caption) {
  margin: 0;
  padding: 0;
}
.text-region-content h1,
.text-region-content h2,
.text-region-content h3,
.text-region-content blockquote,
.text-region-content p.caption {
  display: block;
  width: auto;
  max-width: 100%;
  margin-left: 0;
  padding-left: 0;
  border-left: none;
  text-align: left;
  box-sizing: border-box;
}
.text-region-content blockquote {
  font-size: 14px;
  font-style: italic;
  color: #555;
  line-height: 1.35;
  margin: 0 0 4px;
}
/* Separator-only regions: no side padding so the rule uses the full region width */
.text-region:has(> .text-region-content > hr.worksheet-separator-line:only-child) {
  padding-left: 0;
  padding-right: 0;
  align-items: center;
}

.text-region-content hr.worksheet-separator-line {
  display: block;
  width: 100%;
  border: none;
  border-top: 2px solid #9c9c9c;
  margin: 6px 0;
  height: 0;
}
.text-region-content br { display: block; }

/* Placeholder when empty (also covers the implicit <br> Chrome inserts) */
.text-region-content:empty::before,
.text-region-content:has(> br:only-child)::before {
  content: attr(data-placeholder);
  color: var(--text-muted);
  pointer-events: none;
  display: block;
  white-space: nowrap;
}

/* Lone <br> after delete-all is display:block in this sheet; a block placeholder would
   stack as a second line. Inline keeps one line until JS collapses to :empty. */
.text-region-content:has(> br:only-child)::before {
  display: inline;
}

.text-region-content h1 { font-size: 20px; font-weight: 700; margin: 0 0 6px; line-height: 1.25; }
.text-region-content h2 { font-size: 16px; font-weight: 600; margin: 0 0 5px; line-height: 1.25; }
.text-region-content h3 { font-size: 14px; font-weight: 600; margin: 0 0 6px; line-height: 1.3; }
.text-region-content h4 { font-size: 13px; font-weight: 600; margin: 10px 0 4px; line-height: 1.3; color: inherit; }
.text-region-content h3:first-child,
.text-region-content h4:first-child { margin-top: 0; }
.text-region-content h3 + h4 { margin-top: 8px; }
.text-region-content h3 + p,
.text-region-content h4 + p { margin-top: 0; }
.text-region-content p.caption { font-size: 11px; color: #888; font-style: italic; text-align: left; margin: 2px 0; }

/* Per-worksheet style injection must not indent quote/caption or draw a quote bar. */
#worksheet-paper .text-region-content blockquote,
#worksheet-paper .text-region-content p.caption {
  margin-left: 0 !important;
  padding-left: 0 !important;
  border-left: none !important;
  width: auto !important;
  max-width: 100%;
  text-align: left;
}

/* --- Plot Region -------------------------------------- */
.plot-region {
  background: #fff;
  border: 1px solid var(--region-border);
  border-radius: 4px;
  overflow: hidden;
  min-width: 360px;
  min-height: 320px;
  display: flex;
  flex-direction: column;
}

.plot-inner {
  flex: 1 1 0;
  display: flex;
  flex-direction: column;
  min-height: 0;
  min-width: 0;
  overflow: hidden;
}

/* --- 3D Plot Region (Plotly surface) -------------------- */
.plot3d-region {
  background: #fff;
  border: 1px solid var(--region-border);
  border-radius: 4px;
  overflow: hidden;
  min-width: 360px;
  /* Below ~200px the toolbar + plot fight for space; JS enforces min height on drag. */
  min-height: 200px;
  display: flex;
  flex-direction: column;
}
.plot3d-inner {
  flex: 1 1 0;
  display: flex;
  flex-direction: column;
  min-height: 0;
  min-width: 0;
  overflow: hidden;
}
.plot3d-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 5px 8px;
  border-bottom: 1px solid var(--region-border);
  background: #f7f9fb;
  flex: 0 0 auto;
}
.plot3d-tools {
  display: flex;
  align-items: center;
  gap: 6px;
  flex: 0 0 auto;
}
.plot3d-title {
  font-size: 12px;
  font-weight: 600;
  color: #334155;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.plot3d-cfg-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  padding: 0;
  border: 1px solid var(--region-border);
  border-radius: 4px;
  background: #fff;
  color: #475569;
  cursor: pointer;
}
.plot3d-cfg-btn:hover { background: #eef2f6; color: #0078d4; }
.plot3d-config-panel {
  padding: 8px;
  border-bottom: 1px solid var(--region-border);
  background: #fcfcfd;
  flex: 0 0 auto;
  overflow: auto;
}
.plot3d-config-panel.hidden { display: none; }
.plot3d-row,
.plot3d-config-panel label {
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-size: 11px;
  color: #64748b;
}
.plot3d-row--expr { margin-bottom: 4px; }
.plot3d-row--expr > span { font-weight: 600; color: #334155; }
.plot3d-hint {
  font-size: 10.5px;
  color: #94a3b8;
  margin-bottom: 8px;
}
.plot3d-hint code {
  background: #eef2f6;
  padding: 1px 4px;
  border-radius: 3px;
  font-size: 10.5px;
  color: #475569;
}
.plot3d-check {
  flex-direction: row !important;
  align-items: center;
  gap: 5px !important;
}
.plot3d-check input { width: auto !important; }
.plot3d-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px 8px;
}
.plot3d-grid--meta {
  grid-template-columns: 2fr 1fr;
  margin-top: 8px;
}
.plot3d-col2 { grid-column: span 1; }
.plot3d-config-panel input,
.plot3d-config-panel select {
  width: 100%;
  box-sizing: border-box;
  padding: 4px 6px;
  font-size: 12px;
  border: 1px solid var(--region-border);
  border-radius: 4px;
  background: #fff;
  color: #1e293b;
}
.plot3d-config-panel input:focus,
.plot3d-config-panel select:focus {
  outline: none;
  border-color: #0078d4;
}
.plot3d-canvas-area {
  position: relative;
  flex: 1 1 0;
  min-height: 0;
  width: 100%;
}
.plot3d-canvas-area.hidden { display: none; }
.plot3d-var-select {
  width: 100%;
  box-sizing: border-box;
  padding: 4px 6px;
  font-size: 12px;
  border: 1px solid var(--region-border);
  border-radius: 4px;
  background: #fff;
  color: #1e293b;
}
.plot3d-var-select:focus { outline: none; border-color: #0078d4; }
.plot3d-canvas { width: 100%; height: 100%; overflow: hidden; }
/* Pin mode on: crosshair to show the surface is pickable (click to drop a
   pin). Pin mode off (default): grab cursor so it reads as orbit/pan and
   clicks don't accidentally pin while rotating. */
.plot3d-region.plot3d-pinning .plot3d-canvas .gl-container,
.plot3d-region.plot3d-pinning .plot3d-canvas .gl-container canvas,
.plot3d-region.plot3d-pinning .plot3d-canvas .svg-container,
.plot3d-region.plot3d-pinning .plot3d-canvas .user-select-none { cursor: crosshair !important; }
.plot3d-region:not(.plot3d-pinning) .plot3d-canvas .gl-container,
.plot3d-region:not(.plot3d-pinning) .plot3d-canvas .gl-container canvas,
.plot3d-region:not(.plot3d-pinning) .plot3d-canvas .svg-container,
.plot3d-region:not(.plot3d-pinning) .plot3d-canvas .user-select-none { cursor: grab !important; }
/* Toolbar pin toggle */
.plot3d-pin-btn.active { background: #e0ecfb; color: #0078d4; }
.plot3d-msg {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 12px;
  font-size: 12px;
  color: #64748b;
  background: rgba(255, 255, 255, 0.92);
}
.plot3d-msg[hidden] { display: none; }

/* --- Diagram Region (engineering sketch) ---------------- */
.diagram-region {
  background: #fff;
  border: 1px solid var(--region-border);
  border-radius: 4px;
  overflow: hidden;
  min-width: 260px;
  min-height: 200px;
  display: flex;
  flex-direction: column;
}

.diagram-inner {
  flex: 1 1 0;
  display: flex;
  flex-direction: column;
  min-height: 0;
  min-width: 0;
  overflow: hidden;
}

.diagram-toolbar {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 6px 8px 8px;
  background: linear-gradient(180deg, #fafbfc 0%, #f2f4f7 100%);
  border-bottom: 1px solid #e5e7eb;
}

.diagram-region .diagram-toolbar-panel.hidden {
  display: none !important;
}

.diagram-tool-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px;
}

.diagram-tool-meta {
  padding-top: 2px;
}

.diagram-meta {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  color: #4b5563;
}

.diagram-meta-cap {
  opacity: 0.9;
  white-space: nowrap;
}

.diagram-tool-btn {
  appearance: none;
  border: 1px solid #d1d5db;
  border-radius: 5px;
  background: #fff;
  color: #374151;
  font-size: 11px;
  padding: 4px 8px;
  cursor: pointer;
  line-height: 1.25;
}

.diagram-tool-btn:hover {
  background: #f9fafb;
  border-color: #9ca3af;
}

.diagram-tool-btn.active {
  background: #e0f2fe;
  border-color: #0284c7;
  color: #0c4a6e;
  font-weight: 600;
}

.diagram-tool-muted {
  color: #64748b;
}

.diagram-svg-host {
  flex: 1 1 0;
  min-height: 120px;
  position: relative;
  background-color: #fdfefe;
  background-image:
    linear-gradient(rgba(226, 232, 240, 0.45) 1px, transparent 1px),
    linear-gradient(90deg, rgba(226, 232, 240, 0.45) 1px, transparent 1px);
  background-size: 20px 20px;
}

.diagram-toolbar-toggle-btn {
  position: absolute;
  top: 5px;
  right: 5px;
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 8px 3px 6px;
  border: 1px solid #cbd5e1;
  border-radius: 5px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.06);
  font-size: 11px;
  font-weight: 600;
  color: #334155;
  cursor: pointer;
  line-height: 1.2;
}

.diagram-toolbar-toggle-btn:hover {
  background: #fff;
  border-color: #94a3b8;
  color: #0f172a;
}

.diagram-toolbar-toggle-btn .diagram-toolbar-toggle-icon {
  flex-shrink: 0;
  opacity: 0.85;
}

.diagram-region--toolbar-hidden .diagram-toolbar-toggle-btn {
  background: rgba(224, 242, 254, 0.95);
  border-color: #7dd3fc;
}

.diagram-region .diagram-svg {
  display: block;
  width: 100%;
  height: 100%;
  cursor: crosshair;
  touch-action: none;
  user-select: none;
}

.diagram-region[data-tool="select"] .diagram-svg {
  cursor: default;
}

.diagram-region .diagram-text-prop.hidden {
  display: none !important;
}

.diagram-region input[type="number"][data-diagram-stroke-w] {
  width: 44px;
}

/* --- Table Region (parametric sweep) ------------------ */
.table-region {
  background: #fff;
  border: 1px solid var(--region-border);
  border-radius: 4px;
  overflow: hidden;
  min-width: 320px;
  min-height: 200px;
  display: flex;
  flex-direction: column;
}

/* Table config layout (setting panel) */
.plot-config-panel.table-config-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 10px 12px;
}

.table-config-section {
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 6px;
  padding: 10px 12px;
}

.table-config-section-title {
  font-size: 11px;
  font-weight: 700;
  color: #374151;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.table-config-section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 6px;
}

.table-config-section-head .table-config-section-title {
  margin-bottom: 0;
}

.table-config-hint {
  font-size: 10px;
  color: #6b7280;
  line-height: 1.4;
  margin: 0 0 10px;
}

.table-config-hint strong {
  color: #4b5563;
  font-weight: 600;
}

.table-hint-mono {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 10px;
  color: #374151;
}

.table-sweep-input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 14px;
  align-items: end;
  margin-bottom: 12px;
}

.table-sweep-input-grid .pf-label-wide,
.table-output-col-main .pf-label-wide {
  min-width: 0;
}

.table-output-col-row .table-remove-col-btn {
  align-self: center;
}

.table-sweep-range-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.pf-label-heading-col {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 11px;
  color: #4b5563;
  min-width: 0;
}

.pf-label-heading-col .pf-input {
  width: 100%;
  min-width: 0;
}

.pf-label-num {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.pf-label-num .pf-label-text {
  font-size: 10px;
  font-weight: 600;
  color: #6b7280;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.pf-label-num .pf-input {
  width: 100%;
}

.table-output-col-row {
  display: flex;
  flex-direction: row;
  align-items: stretch;
  gap: 8px;
  padding: 8px;
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  border-radius: 5px;
}

.table-output-col-main {
  flex: 1;
  min-width: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 12px;
  align-items: end;
}

.table-output-cols-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.table-add-col-btn-inline {
  margin-top: 0;
  flex-shrink: 0;
  white-space: nowrap;
}

.table-toolbar-label {
  font-size: 11px;
  font-weight: 600;
  color: #4b5563;
  padding-left: 2px;
}

.table-remove-col-btn {
  flex-shrink: 0;
  width: 26px;
  height: 26px;
  border: 1px solid #d1d5db;
  border-radius: 3px;
  background: #fff;
  cursor: pointer;
  color: #6b7280;
  font-size: 12px;
  line-height: 1;
  padding: 0;
}

.table-remove-col-btn:hover {
  background: #fee2e2;
  border-color: #fca5a5;
  color: #b91c1c;
}

.table-add-col-btn {
  margin-top: 4px;
  padding: 4px 10px;
  font-size: 11px;
  border: 1px dashed #93c5fd;
  border-radius: 3px;
  background: #eff6ff;
  color: #1d4ed8;
  cursor: pointer;
}

.table-add-col-btn:hover { background: #dbeafe; }

.table-data-area {
  flex: 1 1 0;
  min-height: 0;
  overflow: hidden;
  background: #fff;
}

.table-scroll-wrap {
  height: 100%;
  overflow: auto;
}

.sweep-data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 11px;
  font-family: var(--font-ui);
}

.sweep-data-table th,
.sweep-data-table td {
  border: 1px solid #e5e7eb;
  padding: 4px 8px;
  text-align: center;
  white-space: nowrap;
}

.sweep-data-table th {
  background: #f3f4f6;
  font-weight: 600;
  color: #374151;
  position: sticky;
  top: 0;
  z-index: 1;
}

.sweep-data-table tbody tr:nth-child(even) { background: #fafafa; }

.table-empty-hint,
.table-loading,
.table-error {
  padding: 12px;
  font-size: 11px;
  color: #6b7280;
}

.table-error { color: #b91c1c; }

/* Summary table region */
.summary-region {
  background: #fff;
  border: 1px solid var(--region-border);
  border-radius: 4px;
  overflow: hidden;
  min-width: 240px;
  min-height: 80px;
  display: flex;
  flex-direction: column;
}

.summary-toolbar-compact {
  padding: 2px 6px;
  min-height: 0;
  border-bottom: none;
  background: transparent;
  position: absolute;
  top: 2px;
  right: 2px;
  z-index: 2;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s ease;
}

.summary-region:hover .summary-toolbar-compact,
.summary-region.selected .summary-toolbar-compact {
  opacity: 1;
  pointer-events: auto;
}

.summary-region .summary-inner {
  position: relative;
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.summary-region .summary-data-area {
  flex: 1 1 auto;
  padding: 0;
  min-height: 0;
}

.summary-data-table {
  font-family: var(--font-ui);
}

.summary-data-table td,
.summary-data-table th {
  text-align: left;
  padding: 6px 10px;
  vertical-align: middle;
}

.summary-data-table th {
  font-size: 12px;
  font-weight: 600;
}

.summary-data-table .summary-text-cell {
  font-family: var(--font-ui);
  color: var(--text-primary);
  font-size: 13px;
  line-height: 1.35;
}

.summary-data-table .summary-result-cell {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.summary-data-table .summary-result-formatted {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 5px;
  white-space: nowrap;
  background-color: var(--mr-bg, transparent);
  color: var(--mr-color, var(--text-primary));
  padding: 1px 6px;
  border-radius: 2px;
}

.summary-data-table .summary-result-math {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 5px;
  white-space: nowrap;
}

.summary-data-table .summary-result-value {
  flex-shrink: 0;
  font-size: var(--mr-font-size, 20px);
  font-family: var(--mr-font-family, var(--font-math));
  font-weight: var(--mr-font-weight, 400);
  font-style: var(--mr-font-style, normal);
  text-decoration: var(--mr-text-decoration, none);
  color: var(--mr-color, var(--text-primary));
  letter-spacing: 0.2px;
}

.summary-data-table .summary-result-units,
.summary-data-table .summary-result-unit-text {
  flex-shrink: 0;
  font-size: 14px;
  font-family: var(--font-ui);
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.3px;
}

.summary-data-table .summary-result-formatted.summary-result--cond-format .summary-result-value {
  color: var(--mr-color) !important;
  font-weight: var(--mr-font-weight, 400) !important;
  font-style: var(--mr-font-style, normal) !important;
  text-decoration: var(--mr-text-decoration, none) !important;
}

.summary-data-table .summary-result-formatted.summary-result--cond-format .summary-result-units,
.summary-data-table .summary-result-formatted.summary-result--cond-format .summary-result-unit-text {
  color: var(--mr-color) !important;
  font-weight: var(--mr-font-weight, 600) !important;
}

.summary-data-table .math-result-value .katex {
  font-size: 1em;
}

.summary-config-grid-wrap {
  overflow-x: auto;
}

.summary-config-grid .summary-config-cell-input {
  width: 100%;
  min-width: 80px;
  font-size: 11px;
}

.summary-config-grid .summary-var-select {
  width: 100%;
  min-width: 100px;
  font-size: 11px;
}

.summary-region.summary-region--settings {
  min-width: 680px;
  min-height: 420px;
}

.summary-region.summary-region--settings .summary-config-panel {
  overflow: visible;
  flex: 1 1 auto;
}

.summary-config-panel {
  overflow-y: auto;
  flex: 1 1 auto;
  min-height: 0;
}

.summary-config-panel .summary-col-row {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 8px;
  padding: 6px 0;
  border-bottom: 1px solid #f3f4f6;
}

.summary-config-panel .summary-col-row:last-child { border-bottom: none; }

.summary-result-link {
  color: #1d4ed8;
  text-decoration: none;
  cursor: pointer;
}

.summary-result-link:hover {
  color: #1e3a8a;
  text-decoration: underline;
}

.summary-result-empty,
.summary-result-unlinked {
  color: #9ca3af;
}

.summary-row-actions-col {
  width: 28px;
  padding: 2px !important;
  text-align: center;
}

.summary-remove-row-btn {
  border: none;
  background: transparent;
  color: #9ca3af;
  cursor: pointer;
  font-size: 12px;
  padding: 2px 4px;
  line-height: 1;
}

.summary-remove-row-btn:hover { color: #b91c1c; }

@media print {
  .summary-toolbar,
  .summary-config-panel,
  .summary-row-actions-col { display: none !important; }

  .summary-result-link {
    color: inherit;
    text-decoration: underline;
  }
}

/* Toolbar */
.plot-toolbar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 8px;
  background: #f8f9fa;
  border-bottom: 1px solid #e5e7eb;
  flex-shrink: 0;
  min-width: 0;
}

.plot-type-tabs {
  display: flex;
  align-items: center;
  gap: 2px;
  flex: 1;
  min-width: 0;
  overflow-x: auto;
  scrollbar-width: none;
}
.plot-type-tabs::-webkit-scrollbar { display: none; }

.plot-type-btn {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 3px 7px;
  border: 1px solid transparent;
  border-radius: 3px;
  background: none;
  cursor: pointer;
  font-size: 11px;
  color: #6b7280;
  white-space: nowrap;
  transition: background 0.12s, color 0.12s, border-color 0.12s;
}
.plot-type-btn:hover {
  background: #e9ecef;
  color: #374151;
}
.plot-type-btn.active {
  background: #dbeafe;
  border-color: #93c5fd;
  color: #1d4ed8;
}
.plot-type-btn span { pointer-events: none; }

.plot-toolbar-right {
  display: flex;
  align-items: center;
  gap: 5px;
  flex-shrink: 0;
}

.plot-config-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border: 1px solid #d1d5db;
  border-radius: 3px;
  background: #fff;
  cursor: pointer;
  color: #6b7280;
  transition: background 0.12s, border-color 0.12s, color 0.12s;
}
.plot-config-btn:hover { background: #f3f4f6; color: #374151; }
.plot-config-btn.active { background: #dbeafe; border-color: #93c5fd; color: #1d4ed8; }


/* Config panel — fills space below toolbar when open; series list scrolls inside */
.plot-config-panel {
  background: #f9fafb;
  border-bottom: 1px solid #e5e7eb;
  padding: 10px 12px;
  flex: 1 1 0;
  min-height: 0;
  min-width: 0;
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
  overflow-y: auto;
}
.plot-config-panel.hidden { display: none; }

.plot-meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 10px;
}
.plot-meta-input {
  flex: 1 1 160px;
  min-width: 0;
  max-width: 100%;
  padding: 3px 6px;
  border: 1px solid #d1d5db;
  border-radius: 3px;
  font-size: 11px;
  font-family: var(--font-ui);
  background: #fff;
  color: #374151;
  outline: none;
}
.plot-meta-input:focus { border-color: #0078d4; box-shadow: 0 0 0 2px #dbeafe; }

/* Series list */
.plot-series-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 6px;
}

.plot-series-item {
  border: 1px solid #e5e7eb;
  border-radius: 3px;
  background: #fff;
  padding: 8px 10px;
  min-width: 0;
  max-width: 100%;
}

.plot-series-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
  min-width: 0;
}

.plot-series-bar-spacer {
  flex: 1;
  min-width: 8px;
}

.plot-color-swatch {
  width: 22px;
  height: 22px;
  border: 1px solid #9ca3af;
  border-radius: 3px;
  cursor: pointer;
  padding: 0;
  flex-shrink: 0;
  background: var(--swatch-color, #4e79a7);
  outline: none;
  transition: box-shadow .1s;
}
.plot-color-swatch:hover {
  box-shadow: 0 0 0 2px rgba(37,99,235,.35);
}

/* ── Color Picker Popup ──────────────────────────────── */
.color-picker-popup {
  position: fixed;
  z-index: 9999;
  background: #fff;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  box-shadow: 0 4px 16px rgba(0,0,0,.18);
  padding: 8px;
  width: 176px;
  font-family: var(--font-ui);
  display: none;
}
.color-picker-popup.open { display: block; }

.cpp-swatches {
  display: grid;
  grid-template-columns: repeat(8, 18px);
  gap: 3px;
  margin-bottom: 8px;
}
.cpp-swatch {
  width: 18px;
  height: 18px;
  border-radius: 3px;
  border: 1px solid rgba(0,0,0,.12);
  cursor: pointer;
  transition: transform .1s, box-shadow .1s;
}
.cpp-swatch:hover {
  transform: scale(1.2);
  box-shadow: 0 1px 4px rgba(0,0,0,.3);
  z-index: 1;
  position: relative;
}
.cpp-swatch.selected {
  outline: 2px solid #2563eb;
  outline-offset: 1px;
}
.cpp-divider {
  border: none;
  border-top: 1px solid #e5e7eb;
  margin: 6px 0;
}
.cpp-custom-row {
  display: flex;
  align-items: center;
  gap: 6px;
}
.cpp-custom-row label {
  font-size: 11px;
  color: #6b7280;
  white-space: nowrap;
}
.cpp-custom-input {
  width: 28px;
  height: 22px;
  border: 1px solid #d1d5db;
  border-radius: 3px;
  cursor: pointer;
  padding: 1px;
  flex-shrink: 0;
}
.cpp-hex-input {
  flex: 1;
  min-width: 0;
  padding: 2px 5px;
  border: 1px solid #d1d5db;
  border-radius: 3px;
  font-size: 11px;
  font-family: monospace;
  outline: none;
}
.cpp-hex-input:focus { border-color: #2563eb; }

.plot-series-name {
  flex: 1 1 140px;
  min-width: 0;
  max-width: 100%;
  padding: 2px 6px;
  border: 1px solid #d1d5db;
  border-radius: 3px;
  font-size: 11px;
  font-family: var(--font-ui);
  background: #fff;
  outline: none;
}
.plot-series-name:focus { border-color: #0078d4; }

.plot-series-mode {
  display: flex;
  border: 1px solid #d1d5db;
  border-radius: 3px;
  overflow: hidden;
  flex-shrink: 1;
  min-width: 0;
  max-width: 100%;
}
.plot-mode-btn {
  padding: 2px 7px;
  background: #fff;
  border: none;
  font-size: 10.5px;
  font-family: var(--font-ui);
  cursor: pointer;
  color: #6b7280;
  transition: background 0.1s, color 0.1s;
}
.plot-mode-btn + .plot-mode-btn { border-left: 1px solid #d1d5db; }
.plot-mode-btn.active { background: #0078d4; color: #fff; }

.plot-series-remove {
  width: 22px;
  height: 22px;
  border: none;
  background: none;
  cursor: pointer;
  color: #9ca3af;
  font-size: 13px;
  padding: 0;
  flex-shrink: 0;
  border-radius: 3px;
  transition: background 0.1s, color 0.1s;
}
.plot-series-remove:hover { background: #fee2e2; color: #dc2626; }
.plot-series-remove.hidden { display: none; }

/* Series field rows */
.plot-series-fields {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
  align-items: flex-end;
  min-width: 0;
  max-width: 100%;
}

/* Manual Data mode: avoid two full-width bars — share one row, tighter controls */
.plot-series-fields[data-mode-panel="data"] {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 6px 10px;
  align-items: end;
}
.plot-series-fields[data-mode-panel="data"] .pf-label-wide {
  flex: unset;
}
.plot-series-fields[data-mode-panel="data"] .pf-input.pf-wide {
  flex: none;
}
.plot-series-fields[data-mode-panel="data"] .pf-input {
  padding: 1px 4px;
  font-size: 10px;
  line-height: 1.3;
}

.pf-label {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 10.5px;
  color: #6b7280;
  white-space: nowrap;
  min-width: 0;
  max-width: 100%;
}

/* Full-width variable dropdowns: stack label above control so nothing overflows */
.plot-series-fields .pf-label-wide {
  flex: 1 1 100%;
  min-width: 0;
  max-width: 100%;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  align-self: stretch;
  white-space: normal;
  gap: 3px;
}

.plot-series-fields .pf-label-wide .pf-input.pf-var-select,
.plot-series-fields .pf-label-wide select.pf-input {
  width: 100%;
  max-width: 100%;
  min-width: 0;
}

.pf-label-wide {
  flex: 1;
  min-width: 0;
}

.pf-input {
  padding: 2px 5px;
  border: 1px solid #d1d5db;
  border-radius: 3px;
  font-size: 11px;
  font-family: var(--font-ui);
  background: #fff;
  outline: none;
  color: #374151;
  max-width: 100%;
}
.pf-input:focus { border-color: #0078d4; }

.pf-formula {
  width: 110px;
  max-width: 100%;
  min-width: 0;
}
.pf-xvar    { width: 28px; text-align: center; flex-shrink: 0; }
.pf-num     { width: 58px; max-width: 100%; min-width: 0; }
.pf-pts     { width: 48px; max-width: 100%; min-width: 0; }
.pf-wide    { flex: 1 1 200px; min-width: 0; width: 100%; max-width: 100%; }
.pf-var-select { flex: 1; min-width: 0; max-width: 100%; }

/* Sweep: variable picker + unit picker share one row */
.pf-sweep-var-row {
  display: flex;
  flex-wrap: nowrap;
  gap: 8px;
  align-items: flex-end;
  flex: 1 1 100%;
  min-width: 0;
}
.plot-series-fields .pf-sweep-var-row .pf-label-wide.pf-sweep-var-col {
  flex: 1 1 auto;
  min-width: 0;
}
.pf-sweep-unit-col {
  flex: 0 0 90px;
  min-width: 70px;
  display: flex;
  flex-direction: column;
  gap: 3px;
  align-self: stretch;
}
.pf-sweep-unit-col .pf-unit-select {
  width: 100%;
  max-width: 100%;
  min-width: 0;
}
.pf-var-hint {
  font-size: 10px;
  color: #6b7280;
  font-style: italic;
  flex: 1 1 100%;
  min-width: 0;
  max-width: 100%;
  padding-left: 2px;
  white-space: normal;
}

.plot-add-series-btn {
  margin-top: 2px;
  padding: 3px 10px;
  border: 1px dashed #9ca3af;
  border-radius: 3px;
  background: none;
  font-size: 11px;
  color: #6b7280;
  cursor: pointer;
  transition: border-color 0.1s, color 0.1s;
}
.plot-add-series-btn:hover { border-color: #0078d4; color: #0078d4; }

/* Canvas area */
.plot-canvas-area.hidden { display: none; }
.plot-canvas-area {
  position: relative;
  /* Wide right inset: callouts use translate(-50%, …) on the anchor, so the rightmost point leaves
     half the bubble past the data — extra space avoids clipping under .plot-region { overflow: hidden } */
  padding: 8px 52px 8px 8px;
  height: 220px;
  flex-shrink: 0;
}

/* Parametric tables reuse .plot-canvas-area but have no callout overflow; drop plot-only right inset. */
.table-data-area.plot-canvas-area {
  padding: 8px;
}
.plot-canvas-wrap {
  position: relative;
  width: 100%;
  height: 100%;
}

.plot-sweep-loading {
  position: absolute;
  inset: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.88);
  pointer-events: none;
}
.plot-canvas-area canvas {
  display: block;
  width: 100% !important;
  height: 100% !important;
  cursor: crosshair;
}
/* Near-edge drag zone: JS sets .plot-edge-hover on the region */
.region.plot-edge-hover { cursor: grab !important; }
.region.plot-edge-hover .plot-canvas-area canvas { cursor: grab !important; }

/* Leader line SVG overlay */
.plot-leader-svg {
  position: absolute;
  left: 0; top: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  overflow: visible;
  z-index: 9;
}

/* Multiple saved callouts (persisted in region content) */
.plot-saved-callouts {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 11;
}
.plot-saved-callouts .plot-callout {
  pointer-events: auto;
  opacity: 1 !important;
  cursor: pointer;
}

/* Custom chart tooltip — speech bubble with downward-pointing tail */
.plot-tooltip {
  position: absolute;
  pointer-events: none;
  z-index: 12;
  opacity: 0;
  transition: opacity 0.15s;
  /* shift up by full height + tail height (8px) so tail tip sits on the data point */
  transform: translate(-50%, calc(-100% - 8px));
}
.plot-tooltip::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 0;
  border-left: 7px solid transparent;
  border-right: 7px solid transparent;
  border-top: 8px solid rgba(17,24,39,0.92);
}
.plot-tooltip.plot-callout {
  pointer-events: auto;
}
/* Pinned / hover callouts — tail colour matches 3D Plotly annotation border */
.plot-tooltip.plot-tooltip--pinned::after {
  border-top-color: #94a3b8;
}
.plot-tooltip-inner {
  background: rgba(17,24,39,0.92);
  color: #f9fafb;
  border-radius: 6px;
  padding: 7px 10px;
  font-size: 12px;
  line-height: 1.5;
  white-space: nowrap;
  box-shadow: 0 4px 12px rgba(0,0,0,0.25);
  border: 1px solid rgba(255,255,255,0.12);
}
/* Light box + slate border — same as 3D scene annotations */
.plot-tooltip-inner.plot-tooltip-inner--pinned {
  background: rgba(255, 255, 255, 0.92);
  color: #1e293b;
  border-radius: 4px;
  padding: 4px 8px;
  font-size: 11px;
  line-height: 1.45;
  white-space: nowrap;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
  border: 1px solid #94a3b8;
}
.plot-tooltip-x {
  font-weight: 600;
  margin-bottom: 3px;
  color: #d1d5db;
  font-size: 11px;
}
.plot-tooltip-row {
  display: flex;
  align-items: center;
  gap: 6px;
}
.plot-tooltip-swatch {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}


/* --- Status Bar --------------------------------------- */
#status-bar {
  height: var(--statusbar-height);
  background: var(--status-bg);
  border-top: 1px solid var(--status-border);
  display: flex;
  align-items: center;
  padding: 0 12px;
  gap: 20px;
  flex-shrink: 0;
  font-size: 11px;
  color: var(--text-muted);
  user-select: none;
}

#status-bar .status-item { display: flex; align-items: center; gap: 4px; }
#status-bar .status-item.right { margin-left: auto; }

#status-message {
  color: var(--text-secondary);
  font-weight: 500;
}

/* --- Dialogs / Modals -------------------------------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.45);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal {
  background: white;
  border-radius: 6px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.2);
  min-width: 360px;
  max-width: 560px;
  padding: 24px;
}

.modal-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.modal-body { margin-bottom: 20px; }

.modal-footer {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
}

.btn-primary {
  background: var(--accent);
  color: white;
  border: none;
  padding: 7px 16px;
  border-radius: 3px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  transition: background 0.1s;
}

.btn-primary:hover { background: var(--accent-hover); }

.btn-secondary {
  background: white;
  color: var(--text-primary);
  border: 1px solid var(--ribbon-border);
  padding: 7px 16px;
  border-radius: 3px;
  cursor: pointer;
  font-size: 13px;
  transition: background 0.1s;
}

.btn-secondary:hover { background: var(--ribbon-tab-hover); }

.form-control {
  width: 100%;
  padding: 6px 10px;
  border: 1px solid var(--ribbon-border);
  border-radius: 3px;
  font-size: 13px;
  font-family: var(--font-ui);
  outline: none;
  transition: border-color 0.15s;
}

.form-control:focus { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(0,120,212,0.15); }

.form-label {
  display: block;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

/* --- Worksheet Picker -------------------------------- */
#worksheet-picker {
  position: fixed;
  top: 36px;
  left: 0;
  width: 280px;
  background: white;
  border: 1px solid var(--ribbon-border);
  border-top: none;
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
  z-index: 500;
  display: none;
}

#worksheet-picker.open { display: block; }

.worksheet-picker-header {
  padding: 10px 14px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--ribbon-bg);
  border-bottom: 1px solid var(--ribbon-border);
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.worksheet-list-item {
  display: flex;
  align-items: center;
  padding: 8px 14px;
  cursor: pointer;
  gap: 8px;
  border-bottom: 1px solid #f0f0f0;
  transition: background 0.1s;
}

.worksheet-list-item:hover { background: var(--accent-light); }

.worksheet-list-item.active {
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
}

.worksheet-list-item .ws-icon { font-size: 16px; color: var(--accent); }
.worksheet-list-item .ws-name { font-size: 13px; }

/* --- Tooltip ----------------------------------------- */
#ui-tooltip {
  position: fixed;
  background: #1f2328;
  color: #f0f6fc;
  font-size: 11.5px;
  font-weight: 500;
  padding: 4px 9px;
  border-radius: 5px;
  white-space: nowrap;
  z-index: 99999;
  pointer-events: none;
  box-shadow: 0 2px 8px rgba(0,0,0,0.22);
  opacity: 0;
  transition: opacity 0.12s;
  font-family: var(--font-ui);
}

#ui-tooltip.visible { opacity: 1; }

/* --- Loading / Spinner -------------------------------- */
.spinner {
  display: inline-block;
  width: 14px;
  height: 14px;
  border: 2px solid var(--ribbon-border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* --- Context Menu ------------------------------------- */
.context-menu {
  position: fixed;
  background: white;
  border: 1px solid var(--ribbon-border);
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
  border-radius: 4px;
  padding: 4px 0;
  min-width: 160px;
  z-index: 800;
  font-size: 13px;
}

.context-menu-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  cursor: pointer;
  color: var(--text-primary);
  transition: background 0.1s;
}

.context-menu-item:hover { background: var(--accent-light); color: var(--accent); }
.context-menu-item.danger { color: #c0392b; }
.context-menu-item.danger:hover { background: #fde8e8; }
.context-menu-separator { border-top: 1px solid #f0f0f0; margin: 4px 0; }

/* --- Scrollbars --------------------------------------- */
#canvas-container::-webkit-scrollbar { width: 10px; height: 10px; }
#canvas-container::-webkit-scrollbar-track { background: #e0e0e0; }
#canvas-container::-webkit-scrollbar-thumb { background: #aaa; border-radius: 5px; }
#canvas-container::-webkit-scrollbar-thumb:hover { background: #888; }

/* --- Selection box ------------------------------------ */
#selection-box {
  position: absolute;
  border: 1px solid var(--accent);
  background: rgba(0,120,212,0.05);
  pointer-events: none;
  z-index: 50;
  display: none;
}
#worksheet-paper.editing-zone-page_footer #selection-box {
  z-index: 195;
}

/* --- Cursor area for inserting regions ---------------- */
.cursor-crosshair { cursor: crosshair !important; }

/*
 * Insert mode: show crosshair + blue preview dot in header/footer.
 * Must beat #worksheet-paper.editing-zone-* { cursor:default } and .region/.region.selected.
 */
#canvas-container.cursor-crosshair #worksheet-paper #page-header-bar,
#canvas-container.cursor-crosshair #worksheet-paper #page-footer-bar,
#canvas-container.cursor-crosshair #worksheet-paper .page-header-mirror,
#canvas-container.cursor-crosshair #worksheet-paper .page-footer-mirror {
  cursor: crosshair !important;
}
#canvas-container.cursor-crosshair #worksheet-paper #page-header-bar .region,
#canvas-container.cursor-crosshair #worksheet-paper #page-footer-bar .region,
#canvas-container.cursor-crosshair #worksheet-paper .page-header-mirror .region,
#canvas-container.cursor-crosshair #worksheet-paper .page-footer-mirror .region {
  cursor: crosshair !important;
}
#canvas-container.cursor-crosshair #worksheet-paper #page-header-canvas,
#canvas-container.cursor-crosshair #worksheet-paper #page-footer-canvas {
  cursor: crosshair !important;
}
#canvas-container.cursor-crosshair #worksheet-paper .page-header-mirror .sheet-zone-canvas,
#canvas-container.cursor-crosshair #worksheet-paper .page-footer-mirror .sheet-zone-canvas {
  cursor: crosshair !important;
}
#canvas-container.cursor-crosshair #worksheet-paper #page-header-canvas .text-region-content,
#canvas-container.cursor-crosshair #worksheet-paper #page-footer-canvas .text-region-content,
#canvas-container.cursor-crosshair #worksheet-paper .page-header-mirror .text-region-content,
#canvas-container.cursor-crosshair #worksheet-paper .page-footer-mirror .text-region-content {
  cursor: text !important;
}

/* --- Notification toast ------------------------------- */
#toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: #333;
  color: white;
  padding: 8px 18px;
  border-radius: 4px;
  font-size: 13px;
  opacity: 0;
  transition: opacity 0.25s, transform 0.25s;
  z-index: 2000;
  pointer-events: none;
}

#toast.visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* Live blue colouring of unit letters during typing — no latex() round-trip,
 * applied per-<var> by applyUnitLetterStyling() in math_input.js. The full
 * \class{unit-token}{...} chip styling below replaces this on blur/eval.
 * Use em (not px): nested args (e.g. inside if(…)) skip latex() recolor, so this path
 * must also render units subordinate in size, matching the unit-token class. */
.mq-math-mode var.mq-unit-letter {
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-size: 0.7em !important;
  /* 500: IBM Plex is only loaded at 400/500/600/700 — 550 snaps to 600 with no visible change. */
  font-weight: 500 !important;
  font-style: normal !important;
  letter-spacing: 0.3px;
  cursor: text;
}

/* --- Unit tokens inside MathQuill expressions (plain blue text) --- */
.mq-math-mode .unit-token {
  background: none !important;
  border: none !important;
  border-radius: 0;
  padding: 0 1px;
  margin-left: 4px;
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-size: 0.7em !important;
  font-weight: 500 !important;
  font-style: normal !important;
  letter-spacing: 0.3px;
  cursor: text;
}
/* Override MathQuill's per-character <var> and <span> elements inside the token. */
.mq-math-mode .unit-token *,
.mq-math-mode .unit-token var,
.mq-math-mode .unit-token span {
  background: none !important;
  border: none !important;
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-size: inherit !important;
  font-weight: 500 !important;
  font-style: normal !important;
  cursor: text;
}
/* Pin MathQuill superscript inside unit tokens to match the output chip <sup> */
.mq-math-mode .unit-token .mq-supsub {
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-weight: 500 !important;
  font-style: normal !important;
  cursor: text;
}
.mq-math-mode .unit-token .mq-sup {
  font-size: 0.8em !important;
  vertical-align: top !important;
  cursor: text;
}
.mq-math-mode .unit-token .mq-supsub .mq-sub {
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-weight: 500 !important;
  font-style: normal !important;
  cursor: text;
}
/* Live typing: ^ after mq-unit-letter (before latex \\class round-trip) */
.mq-math-mode .mq-supsub.mq-unit-sup {
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-weight: 500 !important;
  font-style: normal !important;
  cursor: text;
}
.mq-math-mode .mq-supsub.mq-unit-sup .mq-sup {
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-size: 0.8em !important;
  font-weight: 500 !important;
  font-style: normal !important;
  vertical-align: top !important;
  cursor: text;
}
.mq-math-mode .mq-supsub.mq-unit-sup .mq-sub {
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-weight: 500 !important;
  font-style: normal !important;
  cursor: text;
}
.mq-math-mode .mq-supsub.mq-unit-sup var,
.mq-math-mode .mq-supsub.mq-unit-sup span {
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-weight: 500 !important;
  font-style: normal !important;
  cursor: text;
}
/* Slash (or ÷) between unit letters must not stay at full math height */
.mq-math-mode .mq-binary-operator.mq-unit-ratio-slash,
.mq-math-mode span.mq-unit-ratio-slash {
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-size: 0.7em !important;
  font-weight: 500 !important;
  font-style: normal !important;
  padding: 0 0.08em !important;
  vertical-align: baseline !important;
  cursor: text;
}
.mq-math-mode .unit-token .mq-binary-operator {
  color: #0078d4 !important;
  font-family: var(--font-ui) !important;
  font-size: inherit !important;
  font-weight: 500 !important;
  font-style: normal !important;
  padding: 0 0.08em !important;
  vertical-align: baseline !important;
}

/* Built-in numerical constants π, e, g, inf, … (\class{math-constant-token}{…}) — navy.
   Scoped `.math-input-wrapper.mq-math-mode .math-constant-token` beats generic math styling inside the field.
   KaTeX matrix/scalar previews use the same \\class wrapper when trust mode renders results. */
.math-input-wrapper.mq-math-mode .math-constant-token,
.math-region .katex .math-constant-token {
  background: none !important;
  border: none !important;
  padding: 0 1px;
  color: #000080 !important;
  font-style: italic !important;
}
.math-input-wrapper.mq-math-mode .math-constant-token *,
.math-input-wrapper.mq-math-mode .math-constant-token var,
.math-input-wrapper.mq-math-mode .math-constant-token span,
.math-region .katex .math-constant-token *,
.math-region .katex .math-constant-token .mord,
.math-region .katex .math-constant-token span {
  background: none !important;
  border: none !important;
  color: #000080 !important;
  font-size: inherit !important;
  font-style: italic !important;
}
/* If live unit-letter tagging ever touches a constant atom, force navy over unit blue. */
.math-input-wrapper.mq-math-mode .math-constant-token var.mq-unit-letter {
  color: #000080 !important;
  font-family: inherit !important;
  font-size: inherit !important;
  font-weight: inherit !important;
  font-style: italic !important;
}

/* Live baseline edit: `applyBuiltinConstantStyling` — same navy when mq.latex() \\class is deferred. */
.math-input-wrapper.mq-math-mode .mq-math-constant-live,
.math-input-wrapper.mq-math-mode .mq-math-constant-live * {
  background: none !important;
  border: none !important;
  color: #000080 !important;
  font-size: inherit !important;
  font-style: italic !important;
}

/* --- Unit indicator (plain blue text, no badge) ------ */
.unit-chip {
  display: inline-block;
  background: none;
  color: #0078d4;
  border: none;
  padding: 0 2px;
  font-size: 14px;
  font-weight: 500;
  font-family: var(--font-ui);
  letter-spacing: 0.3px;
  cursor: text;
  vertical-align: middle;
}
.unit-chip:not(.unit-chip-pinned):hover {
  color: #005a9e;
  /* Underline via shadow — text-decoration shifts line metrics on some browsers. */
  box-shadow: 0 1px 0 0 currentColor;
}
.unit-chip-pinned:hover {
  color: #005a9e;
  border-bottom-color: #005a9e;
}
.unit-chip:hover sup {
  color: currentColor;
}
/* Native drag-select in result-side units (chip + contenteditable editor + nested sup):
   match `.mq-selection` styling for engineering units in the MathQuill input (#b4d5fe fill). */
.math-result-units ::-moz-selection,
.math-result-units *::-moz-selection {
  color: #005a9e;
  background: #b4d5fe;
}
.math-result-units ::selection,
.math-result-units *::selection {
  color: #005a9e;
  background: #b4d5fe;
}
/* Match MathQuill's .mq-sup sizing so mm² looks the same as in the input field */
.unit-chip sup {
  font-size: 0.8em;
  vertical-align: top;
  line-height: 1;
  font-weight: 600;
  color: #0078d4;
}
.unit-chip-pinned {
  border-bottom: 1px dashed #0078d4;
}
.unit-edit-input {
  display: inline-block;
  box-sizing: border-box;
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
  color: #003a7a;
  /* Box-shadow underline avoids border box/baseline shifts vs .unit-chip (layout + flex baseline). */
  border: none;
  border-radius: 0;
  padding: 0 2px;
  margin: 0;
  font-size: 14px;
  font-weight: 500;
  font-family: var(--font-ui);
  letter-spacing: 0.3px;
  line-height: normal;
  width: auto;
  min-width: 0;
  outline: none;
  vertical-align: middle;
  box-shadow: 0 1px 0 0 #0078d4;
  white-space: nowrap;
  cursor: text;
}
.unit-edit-input:focus {
  box-shadow: 0 1px 0 0 #005a9e;
}
/* Rich unit editor (contenteditable): same superscript metrics as the chip. */
.unit-edit-input sup {
  font-size: 0.8em;
  vertical-align: top;
  line-height: 1;
  font-weight: 600;
  color: #003a7a;
}

/* --- Canvas insertion cursor ------------------------- */
#rubber-band,
.rubber-band-zone {
  position: absolute;
  border: 1.5px solid #0078d4;
  background: rgba(0, 120, 212, 0.08);
  pointer-events: none;
  z-index: 150;
}

#insertion-cursor {
  position: absolute;
  pointer-events: none;
  z-index: 200;
  width: 0;
  height: 0;
}
.insertion-cursor-dot {
  position: absolute;
  left: 0;
  top: 0;
  width: 0;
  height: 0;
}
.insertion-cursor-dot::before,
.insertion-cursor-dot::after {
  content: '';
  position: absolute;
  background: #0078d4;
}
.insertion-cursor-dot::before {
  width: 2px;
  height: 10px;
  left: -1px;
  top: -5px;
}
.insertion-cursor-dot::after {
  width: 10px;
  height: 2px;
  left: -5px;
  top: -1px;
}

/* --- Placeholder region hint ------------------------- */
.insert-hint {
  position: absolute;
  pointer-events: none;
  border: 2px dashed var(--accent);
  border-radius: 3px;
  background: rgba(0,120,212,0.04);
  display: none;
  z-index: 5;
}

/* --- Page outline (A4-like) -------------------------- */
.page-border {
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
}

/* sym-dropdown replaces old ribbon-dropdown */

/* ── Units Dropdown (wider panel, text-based grid) ──── */
.units-dropdown-panel {
  width: 280px;
}
.units-panel-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 3px;
  padding: 7px;
  max-height: 140px;
  overflow-y: auto;
}
.units-panel-grid .sym-btn {
  aspect-ratio: unset;
  font-size: 11.5px;
  font-family: var(--font-ui);
  font-weight: 500;
  letter-spacing: 0;
  height: 22px;
}

/* --- Responsive adjustments -------------------------- */
@media (max-width: 900px) {
  .ribbon-group { padding: 0 5px; }
  .ribbon-btn { min-width: 38px; padding: 4px 4px; }
  .ribbon-tab { padding: 5px 8px; }
}

/* ── Operators Dropdown (mixed symbols + text) ──────── */
.ops-panel-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 3px;
  padding: 7px;
  max-height: 150px;
  overflow-y: auto;
}
.ops-panel-grid .sym-btn {
  aspect-ratio: unset;
  min-width: 28px;
  width: auto;
  padding: 0 5px;
  font-size: 13px;
  font-family: var(--font-ui);
  height: 26px;
  line-height: 1;
  box-sizing: border-box;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* Functions ▾ grid — uniform UI metrics on every chip (More tab mixes letters + digits) */
#func-panel-grid.ops-panel-grid .sym-btn {
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 500;
  font-style: normal;
  font-variant-numeric: tabular-nums lining-nums;
  white-space: nowrap;
}

/* Matrix result display: allow multi-line for matrix values */
.math-result-value .katex {
  font-size: 12px;
}

/* --- Print styles ------------------------------------- */
@page {
  size: A4 portrait;
  margin: 0;
}

@media print {
  :root {
    /*
     Uniform scale so one logical page (--a4-page-height) fits A4 vertically.
     Width-only scale (210mm / 1200px) was ~0.661417 and made 1700px-tall pages
     spill past 297mm, producing an extra blank sheet in preview.
    */
    --print-page-scale: min(210mm / var(--a4-page-width), 297mm / var(--a4-page-height));
  }
  html, body, #app {
    height: auto !important;
    overflow: visible !important;
    background: white;
    margin: 0;
    padding: 0;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }
  #quick-access-toolbar,
  #ribbon,
  #status-bar,
  #sidebar,
  #sidebar-expand-btn,
  #sidebar-resize-handle,
  #ai-sidebar-resize-handle { display: none !important; }
  #workspace {
    display: block;
    overflow: visible !important;
    height: auto !important;
  }
  #main-area {
    display: block;
    overflow: visible !important;
    height: auto !important;
    width: 100%;
    padding: 0;
    margin: 0;
  }
  #canvas-container {
    overflow: visible !important;
    background: transparent;
    padding: 0;
    margin: 0;
    width: 100%;
    height: auto !important;
    flex: none;
  }
  #worksheet-paper {
    box-shadow: none;
    margin: 0;
    zoom: var(--print-page-scale) !important;
    position: relative;
    z-index: 1;
    width: var(--a4-page-width) !important;
    max-width: none !important;
    min-width: 0 !important;
    background-color: transparent !important;
    background-image: none !important;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
    /* Grid drawn by fixed SVG overlay injected via JS beforeprint. */
  }
  #canvas {
    width: 100% !important;
    background: transparent !important;
  }
  #print-grid-raster-layer {
    display: block !important;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    object-fit: fill;
    image-rendering: -webkit-optimize-contrast;
  }
  #worksheet-paper:not(.print-grid-enabled) #print-grid-raster-layer {
    display: none !important;
  }
  .region { border-color: transparent; }
  .region-drag-edge { display: none !important; }
  .math-result-matrix-resize-bar { display: none !important; }
  /* Print engines can over-darken MathQuill strokes; force lighter math rendering. */
  .math-region,
  .math-region *,
  .math-result,
  .math-result * {
    color: #000 !important;
  }
  /* Keep engineering unit markers blue in print preview/output. */
  .math-result-units,
  .math-result-units *,
  .mq-math-mode var.mq-unit-letter,
  .mq-math-mode .unit-token,
  .mq-math-mode .unit-token *,
  .mq-math-mode .mq-supsub.mq-unit-sup,
  .mq-math-mode .mq-supsub.mq-unit-sup *,
  .mq-math-mode .mq-binary-operator.mq-unit-ratio-slash,
  .mq-math-mode span.mq-unit-ratio-slash,
  .unit-chip,
  .unit-chip sup,
  .unit-chip-pinned {
    color: #0078d4 !important;
    border-color: #0078d4 !important;
  }
  .math-input-wrapper.mq-math-mode .math-constant-token,
  .math-input-wrapper.mq-math-mode .math-constant-token *,
  .math-input-wrapper.mq-math-mode .mq-math-constant-live,
  .math-input-wrapper.mq-math-mode .mq-math-constant-live *,
  .math-region .katex .math-constant-token,
  .math-region .katex .math-constant-token * {
    color: #000080 !important;
  }
  .math-input-wrapper.mq-math-mode,
  .math-input-wrapper.mq-math-mode * {
    font-weight: 400 !important;
    text-shadow: none !important;
  }
  .math-input-wrapper .mq-fraction .mq-denominator {
    border-top: 0.5px solid #000 !important;
  }
  .math-input-wrapper .mq-sqrt-stem {
    border-top-width: 0.5px !important;
    border-top-color: #000 !important;
  }
  .math-input-wrapper .mq-fraction .mq-numerator,
  .math-input-wrapper .mq-fraction .mq-denominator,
  .math-input-wrapper .mq-sqrt-stem,
  .math-input-wrapper .mq-sqrt-prefix,
  .math-input-wrapper .mq-paren {
    border-color: #000 !important;
  }
  .math-region .katex .frac-line,
  .math-region .katex .sqrt > .sqrt-line {
    border-bottom-color: #000 !important;
    border-bottom-width: 0.5px !important;
  }
  .text-region-content hr.worksheet-separator-line {
    border-top: 0.5px solid #9c9c9c !important;
  }
  /* Native <select> arrows can render oversized in print preview; pin to a fixed glyph. */
  select.select-region-control {
    -webkit-appearance: none !important;
    appearance: none !important;
    padding-right: 22px !important;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 10 6'%3E%3Cpath d='M1 1l4 4 4-4' fill='none' stroke='%23666' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") !important;
    background-repeat: no-repeat !important;
    background-position: right 8px center !important;
    background-size: 10px 6px !important;
  }
  .page-break { display: none !important; }
  #selection-box,
  #ui-tooltip,
  #insertion-cursor,
  #rubber-band,
  #toast,
  .region-toolbar,
  .context-menu,
  .insertion-cursor,
  .insert-hint { display: none !important; }
  #worksheet-paper::before { display: none !important; }
}

/* =========================================================
   USER MENU (top-right of toolbar)
   ========================================================= */
#user-menu-container {
  margin-left: auto;
  position: relative;
  flex-shrink: 0;
}

.user-avatar-btn {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: rgba(255,255,255,0.22);
  border: 1.5px solid rgba(255,255,255,0.4);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background .15s;
  letter-spacing: 0;
}
.user-avatar-btn:hover { background: rgba(255,255,255,0.32); }

.qat-signin-btn {
  background: rgba(255,255,255,0.18);
  border: 1px solid rgba(255,255,255,0.35);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  padding: 4px 13px;
  border-radius: 4px;
  cursor: pointer;
  font-family: var(--font-ui);
  transition: background .15s;
}
.qat-signin-btn:hover { background: rgba(255,255,255,0.28); }

.user-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: #fff;
  border: 1px solid #dde1e7;
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0,0,0,.14);
  min-width: 200px;
  z-index: 2000;
  overflow: hidden;
}
.user-dropdown.hidden { display: none; }

.user-dropdown-header {
  padding: 12px 14px 10px;
  border-bottom: 1px solid #eee;
}
.user-dropdown-name { font-size: 13px; font-weight: 600; color: #1a1a2e; }
.user-dropdown-email { font-size: 11px; color: #888; margin-top: 2px; }

.user-dropdown-divider { border: none; border-top: 1px solid #eee; margin: 4px 0; }

.user-dropdown-item {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  font-size: 13px;
  color: #333;
  text-decoration: none;
  background: transparent;
  border: none;
  width: 100%;
  text-align: left;
  cursor: pointer;
  font-family: var(--font-ui);
  transition: background .1s;
}
.user-dropdown-item:hover { background: #f4f5f7; }

/* =========================================================
   AUTH MODAL
   ========================================================= */
.auth-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.5);
  z-index: 9000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}
.auth-modal-overlay.hidden { display: none; }

/* Conditional formatting typography: unify MathQuill, result value, KaTeX, units vs --mr-* */
.math-region-inner.math-region-inner--cond-format-unify .math-input-wrapper.mq-editable-field.mq-math-mode {
  color: var(--mr-color, var(--text-primary)) !important;
  font-weight: var(--mr-font-weight, 400) !important;
  font-style: var(--mr-font-style, normal) !important;
  text-decoration: var(--mr-text-decoration, none) !important;
}
.math-region-inner.math-region-inner--cond-format-unify .math-input-wrapper.mq-math-mode .mq-operator-name,
.math-region-inner.math-region-inner--cond-format-unify .math-input-wrapper.mq-math-mode .mq-operator-name * {
  font-weight: var(--mr-font-weight, 400) !important;
  font-style: var(--mr-font-style, normal) !important;
}
.math-region-inner.math-region-inner--cond-format-unify .mq-math-mode .unit-token,
.math-region-inner.math-region-inner--cond-format-unify .mq-math-mode .unit-token *,
.math-region-inner.math-region-inner--cond-format-unify var.mq-unit-letter {
  color: var(--mr-color) !important;
  font-weight: var(--mr-font-weight, 500) !important;
  font-style: var(--mr-font-style, normal) !important;
}
.math-region-inner.math-region-inner--cond-format-unify .mq-math-mode .mq-binary-operator.mq-unit-ratio-slash,
.math-region-inner.math-region-inner--cond-format-unify .mq-math-mode span.mq-unit-ratio-slash {
  color: var(--mr-color) !important;
}
.math-region-inner.math-region-inner--cond-format-unify .math-input-wrapper.mq-math-mode .math-constant-token,
.math-region-inner.math-region-inner--cond-format-unify .math-input-wrapper.mq-math-mode .math-constant-token *,
.math-region-inner.math-region-inner--cond-format-unify .math-region .katex .math-constant-token,
.math-region-inner.math-region-inner--cond-format-unify .math-region .katex .math-constant-token * {
  color: var(--mr-color) !important;
  font-style: var(--mr-font-style, italic) !important;
  font-weight: var(--mr-font-weight, 400) !important;
}
.math-region-inner.math-region-inner--cond-format-unify .math-result-value {
  color: var(--mr-color) !important;
}
.math-region-inner.math-region-inner--cond-format-unify .math-result-value .katex,
.math-region-inner.math-region-inner--cond-format-unify .math-result-value .katex * {
  color: var(--mr-color) !important;
}
.math-region-inner.math-region-inner--cond-format-unify .math-result-units,
.math-region-inner.math-region-inner--cond-format-unify .math-result-units .unit-chip {
  color: var(--mr-color) !important;
  font-weight: var(--mr-font-weight, 600) !important;
}

/* ── Text styles modal (per worksheet) ─────────── */
.auth-modal-box.text-styles-modal-box {
  max-width: 520px;
  width: calc(100vw - 32px);
}
.text-styles-modal-title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
  color: #1a1a2e;
  font-family: var(--font-ui);
}
.text-styles-modal-help {
  margin: 0 0 14px !important;
  line-height: 1.45;
  font-size: 13px;
}
.text-styles-modal-body {
  display: grid;
  grid-template-columns: 132px 1fr;
  gap: 14px;
  margin-bottom: 16px;
}
.text-styles-modal-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.text-styles-nav-btn {
  text-align: left;
  padding: 8px 10px;
  font-size: 12px;
  font-family: var(--font-ui);
  border: 1px solid #dde2ea;
  border-radius: 6px;
  background: #fff;
  cursor: pointer;
  color: var(--text-primary);
  transition: background 0.1s, border-color 0.1s;
}
.text-styles-nav-btn:hover {
  background: var(--ribbon-tab-hover);
}
.text-styles-nav-btn.is-selected {
  background: #e8f3ff;
  border-color: rgba(9, 105, 218, 0.28);
  color: var(--accent);
  font-weight: 600;
}
.text-styles-preview {
  min-height: 48px;
  padding: 10px 12px;
  margin-bottom: 12px;
  border: 1px solid #dde2ea;
  border-radius: 6px;
  background: #fafbfc;
  line-height: 1.3;
}
.text-styles-form {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.text-styles-form-row {
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 8px;
  align-items: center;
}
.text-styles-form-row > label:first-child {
  font-size: 12px;
  font-family: var(--font-ui);
  color: var(--text-secondary);
}
.text-styles-form-row .ribbon-select {
  width: 100%;
  height: 28px;
  font-size: 12px;
}
.text-styles-toggles {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 16px;
  grid-column: 1 / -1;
  padding-left: 72px;
}
.text-styles-toggles label {
  font-size: 12px;
  font-family: var(--font-ui);
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
}
.text-styles-color-row {
  display: flex;
  gap: 6px;
  align-items: center;
}
.text-styles-color-row .ribbon-select {
  flex: 1;
}
.text-styles-reset-btn {
  margin-top: 4px;
  padding: 0;
  border: none;
  background: none;
  color: var(--accent);
  font-size: 12px;
  font-family: var(--font-ui);
  cursor: pointer;
  text-align: left;
  grid-column: 1 / -1;
}
.text-styles-reset-btn:hover { text-decoration: underline; }
.text-styles-modal-actions {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
}
.text-styles-modal-actions .auth-submit-btn { min-width: 96px; }

/* ── Math region: conditional format modal ─────── */
.auth-modal-box.math-cond-format-box {
  max-width: 540px;
}
.math-cond-format-heading {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: #1a1a2e;
  font-family: var(--font-ui);
}
.math-cond-format-help {
  margin: 0 0 14px !important;
  line-height: 1.45;
  font-size: 13px;
  max-width: 100%;
}
.math-cond-rules-list {
  max-height: min(52vh, 420px);
  overflow-y: auto;
  margin-bottom: 10px;
  padding-right: 4px;
}
.math-cond-rule-row {
  border: 1px solid #dde2ea;
  border-radius: 8px;
  padding: 10px 10px 12px;
  margin-bottom: 10px;
  background: #fafbfc;
}
.math-cond-rule-main {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px 12px;
  align-items: start;
}
.math-cond-rule-compare {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  align-items: flex-end;
}
.math-cond-rule-compare label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin: 0;
  font-family: var(--font-ui);
}
.math-cond-rule-label {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: #5a6270;
}
.math-cond-rule-select {
  min-width: 170px;
  padding: 6px 8px;
  border: 1px solid #cdd4df;
  border-radius: 4px;
  font-family: var(--font-ui);
  font-size: 13px;
  box-sizing: border-box;
}
.math-cond-num {
  width: 7rem;
  padding: 6px 8px;
  border: 1px solid #cdd4df;
  border-radius: 4px;
  font-family: var(--font-ui);
  box-sizing: border-box;
}
.math-cond-rule-style {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  grid-column: 1 / -1;
  align-items: flex-end;
}
.math-cond-rule-bg-tint-opt {
  flex: 0 0 auto;
  display: flex !important;
  flex-direction: column !important;
  gap: 4px;
  margin: 0 !important;
  font-family: var(--font-ui);
  font-size: 13px;
  color: #1f2937;
  cursor: pointer;
  user-select: none;
}
.math-cond-rule-bg-tint-row {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 8px;
  height: 22px;
  white-space: nowrap;
}
.math-cond-rule-bg-tint-opt input[type="checkbox"] {
  width: auto;
  margin: 0;
  cursor: pointer;
}
.math-cond-rule-style label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin: 0;
  flex: 0 0 auto;
  min-width: 0;
  font-family: var(--font-ui);
}
.math-cond-color-swatch {
  width: 72px;
  height: 22px;
  border: 1px solid #d8dde6;
  border-radius: 3px;
  cursor: pointer;
  padding: 0;
  background: var(--swatch-color, #1f2937);
  outline: none;
  transition: box-shadow 0.1s, opacity 0.1s;
  box-sizing: border-box;
  flex-shrink: 0;
}
.math-cond-color-swatch:hover:not(:disabled) {
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.35);
}
.math-cond-color-swatch:disabled {
  cursor: not-allowed;
}
.math-cond-rule-toggles {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
  font-family: var(--font-ui);
  font-size: 13px;
  color: #1f2937;
}
.math-cond-rule-toggles label {
  margin: 0;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  user-select: none;
}
.math-cond-rule-toggles input {
  width: auto;
  margin: 0;
  cursor: pointer;
}
.math-cond-rule-move {
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-self: start;
}
.math-cond-mini-btn {
  min-width: 36px;
  padding: 4px 6px;
  border: 1px solid #cdd4df;
  border-radius: 4px;
  background: #fff;
  font-size: 14px;
  line-height: 1.15;
  cursor: pointer;
  color: #333;
  font-family: var(--font-ui);
}
.math-cond-mini-btn:hover {
  background: #eef1f6;
}
.math-cond-mini-btn.math-cond-mini-btn--danger {
  border-color: #eab4b4;
  color: #991b1b;
}
@media (max-width: 560px) {
  .math-cond-rule-main {
    grid-template-columns: 1fr;
  }
  .math-cond-rule-move {
    flex-direction: row;
    justify-content: flex-start;
    flex-wrap: wrap;
  }
}
.math-cond-rule-add-row {
  margin-bottom: 12px;
}
.math-cond-rule-add-row .auth-submit-btn {
  width: 100%;
}
.math-cond-format-check {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  font-family: var(--font-ui);
  font-size: 14px;
  color: #1a1a2e;
  cursor: pointer;
  user-select: none;
}
.math-cond-format-check input {
  width: auto;
  margin: 0;
  cursor: pointer;
}
.math-cond-format-actions {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}
.math-cond-format-actions .auth-submit-btn {
  flex: 1;
}
.math-cond-format-actions .auth-submit-btn:last-child {
  flex: 2;
}

/* ── First-visit spotlight tour ───────────────────────────────── */
.first-visit-tour {
  position: fixed;
  inset: 0;
  z-index: 9050;
  pointer-events: auto;
}

.first-visit-tour.hidden { display: none; }

.first-visit-tour-svg {
  display: block;
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: auto;
}

.first-visit-tour-frame {
  position: fixed;
  box-sizing: border-box;
  border: 3px solid #2b6cce;
  border-radius: 8px;
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.95),
    0 12px 40px rgba(43, 108, 206, 0.25);
  pointer-events: none;
  z-index: 9042;
  transition: left 0.15s ease, top 0.15s ease, width 0.15s ease, height 0.15s ease;
}

.first-visit-tour-popover {
  position: fixed;
  z-index: 9052;
  min-width: 280px;
  max-width: min(380px, calc(100vw - 24px));
  background: #fff;
  border-radius: 12px;
  box-shadow:
    0 4px 24px rgba(0, 0, 0, 0.12),
    0 24px 64px rgba(0, 0, 0, 0.16);
  padding: 22px 22px 16px;
  font-family: var(--font-ui);
  pointer-events: auto;
}

.first-visit-tour-popover-close {
  position: absolute;
  top: 10px;
  right: 12px;
  background: transparent;
  border: none;
  font-size: 22px;
  color: #999;
  cursor: pointer;
  line-height: 1;
  padding: 2px 6px;
  border-radius: 4px;
}
.first-visit-tour-popover-close:hover {
  background: #f0f0f0;
  color: #333;
}

.first-visit-tour-popover-title {
  margin: 0 28px 8px 0;
  font-size: 17px;
  font-weight: 700;
  color: #1a1a2e;
  line-height: 1.25;
}

.first-visit-tour-popover-body {
  font-size: 14px;
  color: #3d4556;
  line-height: 1.55;
  margin: 0 0 16px;
}
.first-visit-tour-popover-body strong {
  color: #1a1a2e;
}
.first-visit-tour-kbd {
  font-family: ui-monospace, "IBM Plex Mono", monospace;
  font-size: 12px;
  background: #eef1f5;
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid #dde2ea;
}

.first-visit-tour-popover-footer {
  border-top: 1px solid #eceef2;
  padding-top: 14px;
  margin: 0 -4px;
  padding-left: 4px;
  padding-right: 4px;
}

.first-visit-tour-step-label {
  display: block;
  font-size: 12px;
  color: #8892a4;
  margin-bottom: 10px;
}

.first-visit-tour-actions {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
}
.first-visit-tour-actions .auth-submit-btn {
  flex: 0 1 auto;
  min-width: 88px;
  padding-left: 16px;
  padding-right: 16px;
}

.auth-modal-box {
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 20px 60px rgba(0,0,0,.25);
  width: 100%;
  max-width: 400px;
  position: relative;
  padding: 28px 28px 24px;
  animation: authFadeIn .18s ease;
}
@keyframes authFadeIn {
  from { opacity: 0; transform: translateY(-10px) scale(0.97); }
  to   { opacity: 1; transform: none; }
}

.auth-modal-close {
  position: absolute;
  top: 12px; right: 14px;
  background: transparent; border: none;
  font-size: 22px; color: #999; cursor: pointer; line-height: 1;
  padding: 2px 6px; border-radius: 4px;
  transition: background .1s, color .1s;
}
.auth-modal-close:hover { background: #f0f0f0; color: #333; }

.share-modal-share-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
  font-family: var(--font-ui);
  font-size: 13px;
  color: #1a1a2e;
}
.share-modal-share-row-label {
  font-weight: 600;
}
.share-modal-switch {
  position: relative;
  width: 44px;
  height: 26px;
  border-radius: 13px;
  border: none;
  padding: 0;
  cursor: pointer;
  flex-shrink: 0;
  background: #c5ccd8;
  transition: background 0.15s ease;
}
.share-modal-switch.share-modal-switch--on {
  background: #2d6a9f;
}
.share-modal-switch:disabled {
  opacity: 0.55;
  cursor: wait;
}
.share-modal-switch-thumb {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  transition: transform 0.15s ease;
}
.share-modal-switch.share-modal-switch--on .share-modal-switch-thumb {
  transform: translateX(18px);
}
.share-modal-switch:focus-visible {
  outline: 2px solid #1a4b8c;
  outline-offset: 2px;
}

.auth-tabs {
  display: flex;
  gap: 0;
  border-bottom: 2px solid #eee;
  margin-bottom: 20px;
}
.auth-tab {
  background: transparent;
  border: none;
  font-size: 14px;
  font-weight: 600;
  color: #888;
  padding: 6px 16px 10px;
  cursor: pointer;
  font-family: var(--font-ui);
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: color .15s, border-color .15s;
}
.auth-tab.active { color: #1a4b8c; border-bottom-color: #1a4b8c; }

/* Hide Sign In / Create Account tabs while the forgot-password panel is shown */
.auth-tabs.auth-modal-forgot-mode {
  display: none;
}

.auth-inline-link-btn {
  background: none;
  border: none;
  padding: 0;
  margin: 0;
  font: inherit;
  font-size: 12px;
  color: #1a4b8c;
  cursor: pointer;
  text-decoration: none;
}
.auth-inline-link-btn:hover { text-decoration: underline; }

.auth-back-link {
  background: none;
  border: none;
  padding: 0;
  margin: 0 0 14px;
  font: inherit;
  font-size: 12px;
  color: #1a4b8c;
  cursor: pointer;
  text-align: left;
}
.auth-back-link:hover { text-decoration: underline; }

.auth-panel { display: none; }
.auth-panel.active { display: block; }

.auth-subtitle {
  font-size: 13px; color: #666; margin: 0 0 16px;
}

.auth-google-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 10px 14px;
  border: 1.5px solid #dadce0;
  border-radius: 6px;
  background: #fff;
  font-size: 14px;
  font-weight: 500;
  color: #3c4043;
  text-decoration: none;
  cursor: pointer;
  font-family: var(--font-ui);
  transition: background .12s, box-shadow .12s;
  box-sizing: border-box;
}
.auth-google-btn:hover { background: #f8f9fa; box-shadow: 0 1px 4px rgba(0,0,0,.1); }

.auth-divider {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 16px 0;
  color: #aaa;
  font-size: 12px;
}
.auth-divider::before, .auth-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: #e5e7eb;
}

.auth-form .auth-field { margin-bottom: 13px; }
.auth-form .auth-field label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: #555;
  margin-bottom: 4px;
}
.auth-form .auth-field input {
  width: 100%;
  box-sizing: border-box;
  padding: 9px 11px;
  border: 1.5px solid #d1d5db;
  border-radius: 5px;
  font-size: 14px;
  font-family: var(--font-ui);
  color: #1a1a2e;
  transition: border-color .15s;
}
.auth-form .auth-field select {
  width: 100%;
  box-sizing: border-box;
  padding: 9px 34px 9px 11px;
  border: 1.5px solid #d1d5db;
  border-radius: 5px;
  font-size: 14px;
  font-family: var(--font-ui);
  color: #1a1a2e;
  background-color: #fff;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-image:
    linear-gradient(45deg, transparent 50%, #6b7280 50%),
    linear-gradient(135deg, #6b7280 50%, transparent 50%);
  background-position:
    calc(100% - 16px) calc(50% - 1px),
    calc(100% - 11px) calc(50% - 1px);
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  transition: border-color .15s, box-shadow .15s;
}
.auth-form .auth-field input:focus {
  outline: none;
  border-color: #1a4b8c;
  box-shadow: 0 0 0 3px rgba(26,75,140,.12);
}
.auth-form .auth-field select:focus {
  outline: none;
  border-color: #1a4b8c;
  box-shadow: 0 0 0 3px rgba(26,75,140,.12);
}

.auth-error {
  font-size: 12.5px;
  color: #c62828;
  min-height: 18px;
  margin-bottom: 10px;
}

.auth-error a.auth-resend-confirmation {
  color: #1a4b8c;
  font-weight: 600;
  text-decoration: underline;
  margin-left: 4px;
}

.auth-error a.auth-resend-confirmation:hover {
  color: #15397a;
}

.auth-error.is-resend-ok {
  color: #2e7d32;
}

.auth-submit-btn {
  width: 100%;
  padding: 10px;
  background: #1a4b8c;
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font-ui);
  transition: background .15s;
}
.auth-submit-btn:hover { background: #15397a; }
.auth-submit-btn:disabled { background: #9bb4d8; cursor: default; }
.auth-submit-btn.secondary { background: #f3f4f6; color: #444; }
.auth-submit-btn.secondary:hover { background: #e5e7eb; }

.auth-confirm-notice {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 13px;
  color: #2e7d32;
  background: #f1f8e9;
  border: 1px solid #c5e1a5;
  border-radius: 5px;
  padding: 10px 12px;
  margin-top: 14px;
}
.auth-confirm-notice.hidden { display: none; }

/* =========================================================
   SELECT (dropdown) REGION
   ========================================================= */
.region.select-region {
  min-height: 32px;
  z-index: 2;
  border-radius: 6px;
  background: #fafbfc;
  box-shadow: 0 0 0 1px rgba(0,0,0,.08) inset;
}
.select-region-inner {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 8px 4px 10px;
  font-family: var(--font-ui);
  font-size: 14px;
}
.select-region-label {
  color: #333;
  white-space: nowrap;
  font-weight: 500;
  flex: 0 0 auto;
}
select.select-region-control {
  flex: 1 1 auto;
  min-width: 120px;
  padding: 4px 8px;
  font: inherit;
  border: 1px solid #c8ccd0;
  border-radius: 4px;
  background: #fff;
  color: #222;
  cursor: pointer;
}
select.select-region-control:focus {
  outline: 2px solid #1a4b8c;
  outline-offset: 0;
}
.select-config-box {
  max-width: 640px;
  /* Cap height so the footer stays reachable; centering overlay can clip tall boxes. */
  max-height: calc(100vh - 32px);
  overflow-y: auto;
  overflow-x: hidden;
  box-sizing: border-box;
  min-height: 0;
  align-self: center;
  -webkit-overflow-scrolling: touch;
}
.select-config-title {
  font-size: 18px; margin: 0 0 8px;
  font-weight: 600; color: #1a1a1a;
  font-family: var(--font-ui);
}
.select-config-hint {
  font-size: 13px; color: #555; margin: 0 0 16px; line-height: 1.45;
}
.select-config-subtitle {
  font-size: 14px; font-weight: 600; color: #333; margin: 12px 0 8px;
  font-family: var(--font-ui);
}
.select-config-section { margin-bottom: 8px; }
.select-config-inline-btn { margin-top: 8px; }
.select-config-entries-scroll {
  overflow-x: auto;
  max-width: 100%;
  border: 1px solid #e2e4e7;
  border-radius: 6px;
  background: #fafbfc;
}
.select-config-entries-table { min-width: 100%; }
.select-config-th-list-entry, .select-config-td-list-entry { min-width: 120px; }
.select-config-narrow { width: 32px; text-align: center; }
.select-config-var-table { margin-bottom: 0; }
.select-config-row {
  display: flex; align-items: center; gap: 10px; margin-bottom: 14px;
}
.select-config-row label { flex: 0 0 48px; font-size: 13px; color: #444; }
.select-config-input {
  flex: 1; padding: 6px 10px; border: 1px solid #c8ccd0; border-radius: 4px; font: inherit;
}
.select-config-options { max-height: 52vh; overflow: auto; margin-bottom: 12px; }
/* Single vertical scroll on .select-config-box — avoids stacked scroll areas and clipped footer */
.select-config-box .select-config-options {
  max-height: none;
  overflow: visible;
}
.select-config-option {
  border: 1px solid #e2e4e7; border-radius: 6px; padding: 12px; margin-bottom: 10px;
  background: #f9fafb;
}
.select-config-option-header > label { display: block; font-size: 12px; color: #666; margin-bottom: 4px; }
.select-config-option-header-row {
  display: flex; gap: 8px; margin-bottom: 8px; align-items: center;
}
.select-config-option-label { flex: 1; padding: 6px 8px; border: 1px solid #c8ccd0; border-radius: 4px; }
.select-config-rm-opt {
  flex: 0 0 auto; font-size: 12px; padding: 4px 8px; cursor: pointer;
  border: 1px solid #d32f2f; color: #c62828; border-radius: 4px; background: #fff;
}
.select-config-rm-opt:hover { background: #ffebee; }
.select-config-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.select-config-table th { text-align: left; font-weight: 600; color: #555; padding: 4px; border-bottom: 1px solid #ddd; }
.select-config-table td { padding: 4px; vertical-align: middle; }
.select-config-table input {
  width: 100%; box-sizing: border-box; padding: 4px 6px; border: 1px solid #c8ccd0; border-radius: 3px; font: inherit;
}
.select-config-rm-row {
  border: none; background: #eee; color: #666; width: 28px; height: 28px; border-radius: 4px; cursor: pointer; font-size: 16px; line-height: 1;
}
.select-config-rm-row:hover { background: #e0e0e0; }
.select-config-add-row { margin-top: 6px; font-size: 12px; cursor: pointer; border: 1px dashed #9e9e9e; background: #fff; padding: 4px 8px; border-radius: 4px; }
.select-config-add-row:hover { background: #f5f5f5; }
.select-config-footer {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px; margin-top: 8px;
  padding-top: 12px; border-top: 1px solid #eee;
}
.select-config-footer-actions { display: flex; gap: 8px; }
.select-config-box .ribbon-btn {
  height: 32px;
  min-height: 32px;
  min-width: 0;
  padding: 0 12px;
  flex-direction: row;
  gap: 0;
}
.select-config-box .ribbon-btn.primary { background: #1a4b8c; color: #fff; border: none; }
.select-config-box .ribbon-btn.primary:hover { background: #15397a; }
#select-config-save {
  min-width: 120px;
  padding-left: 20px;
  padding-right: 20px;
}

/* =====================================================
   AI SIDEBAR (right panel)
   ===================================================== */
#ai-sidebar {
  width: var(--calccloud-ai-sidebar-width);
  min-width: var(--calccloud-ai-sidebar-width);
  display: flex;
  flex-direction: column;
  background: var(--ribbon-bg);
  border-left: 1px solid var(--ribbon-border);
  overflow: hidden;
  transition: width 0.22s ease, min-width 0.22s ease;
  flex-shrink: 0;
}
#ai-sidebar:not(.ai-sidebar-open) {
  width: 0;
  min-width: 0;
}

/* Header bar */
#ai-sidebar-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 10px 0 4px;
  height: 36px;
  flex-shrink: 0;
  background: linear-gradient(180deg, #1762bd 0%, #0d52a0 100%);
  border-bottom: 1px solid rgba(0,0,0,0.18);
  box-shadow: 0 1px 0 rgba(0,0,0,0.12);
}
.ai-sidebar-title {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 13px;
  font-weight: 600;
  color: #fff;
  letter-spacing: 0.02em;
  flex: 1;
}
.ai-sidebar-title svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  color: rgba(255,255,255,0.72);
}
#ai-sidebar-collapse-btn {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  padding: 0;
  background: rgba(255,255,255,0.1);
  border: none;
  border-radius: 5px;
  cursor: pointer;
  color: rgba(255,255,255,0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
}
#ai-sidebar-collapse-btn svg { width: 14px; height: 14px; }
#ai-sidebar-collapse-btn:hover { background: rgba(255,255,255,0.22); color: #fff; }

/* Expand tab (right edge, shown when sidebar is closed) */
#ai-sidebar-expand-btn {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  z-index: 20;
  width: 18px;
  height: 52px;
  padding: 0;
  background: linear-gradient(180deg, #1762bd, #0d52a0);
  border: 1px solid rgba(17,85,166,0.85);
  border-right: none;
  border-radius: 5px 0 0 5px;
  cursor: pointer;
  color: rgba(255,255,255,0.9);
  display: none;
  align-items: center;
  justify-content: center;
  box-shadow: -2px 0 6px rgba(13,82,160,0.35);
  transition: background 0.15s;
}
#ai-sidebar-expand-btn svg { width: 11px; height: 11px; }
#ai-sidebar-expand-btn:hover {
  background: linear-gradient(180deg, #1e6fd4, #1155a6);
}
#ai-sidebar:not(.ai-sidebar-open) ~ #ai-sidebar-expand-btn { display: flex; }

/* Scrollable body */
#ai-sidebar-body {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

/* Panel sections */
.ai-panel {
  padding: 12px 13px;
  border-bottom: 1px solid var(--ribbon-border);
  flex-shrink: 0;
}

/* AI Create / Overview tabs */
#ai-tabs-panel {
  padding-top: 10px;
}
.ai-tabs-bar {
  display: flex;
  gap: 0;
  margin: 0 0 12px;
  padding: 0;
  border-radius: 6px;
  background: #e8eaf0;
  border: 1px solid var(--ribbon-border);
  overflow: hidden;
}
.ai-tab-btn {
  flex: 1;
  margin: 0;
  padding: 7px 8px;
  font-size: 11px;
  font-weight: 700;
  text-transform: none;
  letter-spacing: 0.02em;
  color: var(--text-secondary);
  background: transparent;
  border: none;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}
.ai-tab-btn:hover {
  background: rgba(255,255,255,0.55);
  color: var(--text-primary);
}
.ai-tab-btn[aria-selected="true"] {
  background: #fff;
  color: var(--accent-hover);
  box-shadow: 0 1px 3px rgba(0,0,0,0.08);
}
.ai-tab-pane { display: none; }
.ai-tab-pane.ai-tab-pane-active { display: block; }

.ai-review-hint {
  margin: 0 0 10px;
  font-size: 11px;
  line-height: 1.45;
  color: var(--text-secondary);
}

.ai-disclaimer {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  margin: 14px 0 4px;
  padding: 10px 12px;
  font-size: 10.5px;
  line-height: 1.5;
  color: #7a5300;
  background: #fff8e1;
  border: 1px solid #f0d385;
  border-radius: 6px;
}
.ai-disclaimer svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
  margin-top: 1px;
  color: #b87a00;
}

#ai-overview-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 100%;
  padding: 8px 12px;
  font-size: 12px;
  font-weight: 600;
  background: linear-gradient(180deg, #2e7d32 0%, #1b5e20 100%);
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: opacity 0.15s, box-shadow 0.15s;
  box-shadow: 0 2px 6px rgba(27,94,32,0.35);
}
#ai-overview-btn svg { width: 15px; height: 15px; flex-shrink: 0; }
#ai-overview-btn:hover:not(:disabled) {
  opacity: 0.97;
  box-shadow: 0 3px 10px rgba(27,94,32,0.4);
}
#ai-overview-btn:disabled {
  opacity: 0.42;
  cursor: default;
  box-shadow: none;
}

.ai-overview-output {
  margin-top: 12px;
  min-height: 72px;
  max-height: 280px;
  overflow-y: auto;
  padding: 8px 10px;
  font-size: 11.5px;
  line-height: 1.5;
  color: var(--text-primary);
  background: #fafbff;
  border: 1px solid var(--ribbon-border);
  border-radius: 5px;
}
.ai-overview-output.ai-overview-empty {
  color: var(--text-secondary);
  font-style: italic;
}
.ai-overview-section-title {
  margin: 12px 0 5px;
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
}
.ai-overview-section-title:first-child { margin-top: 0; }
.ai-overview-text {
  white-space: pre-wrap;
}
.ai-overview-list {
  margin: 0;
  padding-left: 18px;
}
.ai-overview-list li { margin: 4px 0; }
.ai-overview-list.ai-overview-errors li { color: #991b1b; }
.ai-overview-list.ai-overview-warn li { color: #92400e; }
.ai-overview-list.ai-overview-notes li { color: #166534; }
.ai-panel-label {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 10.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-secondary);
  margin-bottom: 9px;
}
.ai-panel-label svg { width: 12px; height: 12px; flex-shrink: 0; }

/* Monthly token quota bar */
.ai-quota-bar {
  position: relative;
  width: 100%;
  height: 8px;
  background: #eef0f4;
  border-radius: 999px;
  overflow: hidden;
  border: 1px solid #dde1e8;
}
.ai-quota-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #2563eb 0%, #1762bd 100%);
  border-radius: 999px;
  transition: width 0.3s ease, background 0.2s ease;
}
.ai-quota-bar-fill.ai-quota-warn { background: linear-gradient(90deg, #f59e0b 0%, #d97706 100%); }
.ai-quota-bar-fill.ai-quota-empty { background: linear-gradient(90deg, #ef4444 0%, #b91c1c 100%); }

.ai-quota-meta {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
  margin-top: 6px;
  font-size: 11px;
  color: var(--text-secondary);
}
.ai-quota-meta #ai-quota-remaining { font-weight: 600; color: var(--text-primary); }
.ai-quota-total { color: var(--text-secondary); font-variant-numeric: tabular-nums; }

.ai-quota-anon { text-align: center; }
.ai-quota-anon-msg {
  margin: 0 0 8px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-secondary);
}
.ai-quota-signup-btn {
  width: 100%;
  padding: 7px 12px;
  font-size: 12px;
  font-weight: 600;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  transition: background 0.15s;
}
.ai-quota-signup-btn:hover { background: var(--accent-hover); }

/* Top-up balance + buy button */
.ai-quota-purchased {
  margin-top: 4px;
  font-size: 11px;
  color: #0a7c46;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}
.ai-buy-tokens-btn {
  margin-top: 8px;
  width: 100%;
  padding: 6px 12px;
  font-size: 12px;
  font-weight: 600;
  background: white;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 5px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}
.ai-buy-tokens-btn:hover { background: var(--accent); color: white; }
.ai-buy-tokens-btn.is-empty {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}
.ai-buy-tokens-btn.is-empty:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.ai-buy-tokens-btn:disabled { opacity: 0.6; cursor: default; }

/* Buy tokens modal — pack summary card */
.ai-buy-tokens-pack {
  margin: 14px 0 6px;
  padding: 14px 16px;
  border: 1px solid var(--ribbon-border);
  border-radius: 8px;
  background: #f8fafc;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}
.ai-buy-tokens-pack-tokens {
  font-size: 18px;
  font-weight: 700;
  color: #1a1a2e;
  font-variant-numeric: tabular-nums;
}
.ai-buy-tokens-pack-price {
  font-size: 22px;
  font-weight: 700;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

/* Prompt textarea */
#ai-prompt-input {
  width: 100%;
  box-sizing: border-box;
  padding: 8px 10px;
  font-size: 12px;
  font-family: inherit;
  line-height: 1.55;
  border: 1px solid var(--ribbon-border);
  border-radius: 5px;
  background: white;
  color: var(--text-primary);
  outline: none;
  resize: vertical;
  min-height: 90px;
  transition: border-color 0.15s;
}
#ai-prompt-input:focus { border-color: var(--accent); }

.ai-prompt-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin: 4px 0 8px;
}
.ai-prompt-toolbar .ai-prompt-hint {
  margin: 0;
  flex-shrink: 0;
}
.ai-prompt-toolbar-actions {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

#ai-attach-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 9px;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  background: #f3f4f6;
  border: 1px solid var(--ribbon-border);
  border-radius: 5px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
#ai-attach-btn svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}
#ai-attach-btn:hover:not(:disabled) {
  background: #e8eaef;
  color: var(--text-primary);
  border-color: #c5cad3;
}
#ai-attach-btn:disabled {
  opacity: 0.45;
  cursor: default;
}

.ai-attachment-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  max-width: 100%;
  padding: 4px 6px 4px 8px;
  margin: 0 0 8px;
  font-size: 11px;
  font-weight: 500;
  color: #0d52a0;
  background: #e8f0fe;
  border: 1px solid #b9d0f0;
  border-radius: 5px;
}
.ai-attachment-chip[hidden] { display: none; }
.ai-attachment-chip-icon {
  width: 13px;
  height: 13px;
  flex-shrink: 0;
}
.ai-attachment-chip-name {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-width: 0;
}
.ai-attachment-chip-size {
  color: #4a73a8;
  font-weight: 400;
  flex-shrink: 0;
}
.ai-attachment-chip-remove {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  padding: 0;
  background: transparent;
  border: none;
  border-radius: 3px;
  color: #0d52a0;
  cursor: pointer;
  flex-shrink: 0;
  transition: background 0.12s;
}
.ai-attachment-chip-remove:hover {
  background: rgba(13, 82, 160, 0.12);
}
.ai-attachment-chip-remove svg {
  width: 10px;
  height: 10px;
}

.ai-edit-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  margin: 0 0 8px;
  padding: 5px 8px;
  font-size: 11px;
  font-weight: 500;
  color: var(--text-secondary);
  background: #f7f8fa;
  border: 1px solid var(--ribbon-border);
  border-radius: 5px;
  cursor: pointer;
  user-select: none;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.ai-edit-toggle:hover:not(.is-disabled) {
  background: #eef0f4;
  border-color: #c5cad3;
  color: var(--text-primary);
}
.ai-edit-toggle input[type="checkbox"] {
  margin: 0;
  flex-shrink: 0;
  cursor: pointer;
}
.ai-edit-toggle.is-disabled {
  opacity: 0.55;
  cursor: not-allowed;
}
.ai-edit-toggle.is-disabled input { cursor: not-allowed; }
.ai-edit-toggle.is-active {
  background: #e8f0fe;
  border-color: #b9d0f0;
  color: #0d52a0;
}
.ai-edit-toggle-text { flex-shrink: 0; }
.ai-edit-toggle-hint {
  color: var(--text-secondary);
  font-weight: 400;
  font-size: 10px;
  margin-left: auto;
}
.ai-edit-toggle.is-active .ai-edit-toggle-hint { color: #4a73a8; }

#ai-dictate-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 9px;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  background: #f3f4f6;
  border: 1px solid var(--ribbon-border);
  border-radius: 5px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
#ai-dictate-btn svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}
#ai-dictate-btn:hover:not(:disabled) {
  background: #e8eaef;
  color: var(--text-primary);
  border-color: #c5cad3;
}
#ai-dictate-btn:disabled {
  opacity: 0.45;
  cursor: default;
}
#ai-dictate-btn.ai-dictating {
  background: #e8f0fe;
  border-color: #7aa7e8;
  color: #0d52a0;
}
#ai-dictate-btn.ai-dictating svg {
  animation: ai-mic-pulse 1.2s ease-in-out infinite;
}
@keyframes ai-mic-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.45; }
}

.ai-prompt-hint {
  font-size: 10px;
  color: var(--text-secondary);
  text-align: right;
}

/* Generate button */
#ai-generate-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  width: 100%;
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 600;
  background: linear-gradient(180deg, #1762bd 0%, #0d52a0 100%);
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: opacity 0.15s, box-shadow 0.15s, background 0.15s;
  box-shadow: 0 2px 6px rgba(13,82,160,0.35);
  letter-spacing: 0.01em;
}
#ai-generate-btn svg { width: 15px; height: 15px; flex-shrink: 0; }
#ai-generate-btn:hover:not(:disabled) {
  opacity: 0.98;
  background: linear-gradient(180deg, #1e6fd4 0%, #1155a6 100%);
  box-shadow: 0 3px 10px rgba(13,82,160,0.45);
}
#ai-generate-btn:disabled {
  opacity: 0.42;
  cursor: default;
  box-shadow: none;
}

/* Status / message panel */
#ai-status-panel { gap: 0; }
#ai-status-msg {
  font-size: 12px;
  line-height: 1.55;
  padding: 8px 10px;
  border-radius: 5px;
  white-space: pre-line; /* preserve \n line breaks in multi-line error summaries */
  word-break: break-word;
}
#ai-status-msg.ai-info    { background: var(--accent-light); color: var(--accent-hover); }
#ai-status-msg.ai-success { background: #f0fdf4; color: #15803d; }
#ai-status-msg.ai-error   { background: #fef2f2; color: #b91c1c; }

/* Spinner used inside buttons */
.ai-spin-icon {
  display: inline-block;
  width: 13px;
  height: 13px;
  border: 2px solid rgba(255,255,255,0.35);
  border-top-color: rgba(255,255,255,0.9);
  border-radius: 50%;
  animation: ai-spin 0.65s linear infinite;
  flex-shrink: 0;
}
@keyframes ai-spin { to { transform: rotate(360deg); } }

/* Print: hide AI sidebar */
@media print {
  #ai-sidebar,
  #ai-sidebar-expand-btn,
  #first-visit-tour { display: none !important; }
}