/* curvat.css - Modern Styling & Design Token System for curvat.io */

:root {
  --paper: #FBFAF7;
  --card: #FFFFFF;
  --ink: #1C1E2B;
  --muted: #5C6178;
  --line: rgba(28, 30, 43, 0.12);
  --line-strong: rgba(28, 30, 43, 0.22);
  --indigo: #3B4CCA;
  --indigo-light: rgba(59, 76, 202, 0.08);
  --coral: #C2410C;
  --coral-light: rgba(194, 65, 12, 0.08);
  --teal: #0F766E;
  --teal-light: rgba(15, 118, 110, 0.08);
  --purple: #7C3AED;
  --purple-light: rgba(124, 58, 237, 0.08);
  --amber: #D97706;
  --amber-light: rgba(217, 119, 6, 0.08);
  --burgundy: #702638;
  --burgundy-light: rgba(112, 38, 56, 0.08);
  --darkgrey: #334155;
  --darkgrey-light: rgba(51, 65, 85, 0.08);
  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Fraunces', Georgia, serif;
  --font-mono: 'Space Mono', monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

/* Fullscreen JSXGraph Canvas */
#jxgbox {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  width: 100% !important;
  height: 100% !important;
  overflow: hidden;
  touch-action: none;
  z-index: 1;
}

/* Top Navigation Bar */
.top-nav {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 52px;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  background: rgba(251, 250, 247, 0.88);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-brand-mark {
  width: 26px;
  height: 26px;
  flex-shrink: 0;
  display: block;
  color: var(--ink);
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.nav-logo:hover .nav-brand-mark {
  transform: scale(1.08) rotate(-1deg);
}

.nav-title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 18px;
  color: var(--ink);
  letter-spacing: -0.02em;
}

.nav-title span {
  color: var(--coral);
}

.nav-tagline {
  font-family: var(--font-sans);
  font-size: 11.5px;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: -0.01em;
  padding-left: 10px;
  border-left: 1px solid var(--line);
  display: inline-flex;
  align-items: center;
  line-height: 1.2;
}

@media (max-width: 900px) {
  .nav-tagline {
    display: none;
  }
}

.nav-badge {
  font-family: var(--font-serif);
  font-size: 13px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--burgundy-light);
  color: var(--ink);
  letter-spacing: -0.02em;
  border: 1px solid rgba(112, 38, 56, 0.18);
  display: inline-flex;
  align-items: center;
  line-height: 1;
}

.nav-badge span {
  color: var(--burgundy);
  font-weight: 700;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-actions .btn {
  height: 32px;
  padding: 0 11px;
  font-size: 12px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  white-space: nowrap;
  box-sizing: border-box;
}

/* Common Button Styles */
.btn {
  appearance: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-family: var(--font-sans);
  font-size: 12.5px;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--ink);
  cursor: pointer;
  transition: all 0.15s ease;
  user-select: none;
}

.btn:hover {
  border-color: var(--indigo);
  color: var(--indigo);
  background: #FFF;
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--indigo);
  color: #FFF;
  border-color: var(--indigo);
}

.btn-primary:hover {
  background: #2E3CA6;
  border-color: #2E3CA6;
  color: #FFF;
}

.btn-sm {
  padding: 4px 8px;
  font-size: 11px;
}

.btn-icon {
  width: 32px;
  height: 32px;
  padding: 0;
  border-radius: var(--radius-sm);
}

/* Expression Deck Panel */
.deck-panel {
  position: absolute;
  top: 64px;
  left: 16px;
  width: 390px;
  max-width: calc(100vw - 32px);
  max-height: calc(100vh - 84px);
  z-index: 15;
  display: flex;
  flex-direction: column;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  box-shadow: 0 10px 30px rgba(28, 30, 43, 0.08);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.2s ease, bottom 0.25s cubic-bezier(0.16, 1, 0.3, 1), max-height 0.25s ease;
}

.deck-panel.keyboard-active {
  max-height: calc(100vh - var(--keyboard-height, 300px) - 80px);
}

.deck-panel.is-collapsed {
  transform: translateX(-410px);
}

.deck-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  background: rgba(251, 250, 247, 0.6);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.deck-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: 6px;
}

.deck-header-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.deck-header-actions .btn {
  height: 28px;
  padding: 0 9px;
  font-size: 11.5px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  gap: 5px;
  box-sizing: border-box;
}

#clear-all-btn {
  color: var(--muted);
  border-color: transparent;
  background: transparent;
  transition: all 0.15s ease;
}

#clear-all-btn:hover {
  color: var(--coral);
  border-color: var(--coral-light);
  background: var(--coral-light);
}

.deck-body {
  overflow-y: auto;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex: 1;
}

/* Edge Collapse Tab on Deck Panel (When Deck is Open) */
.deck-edge-tab {
  appearance: none;
  position: absolute;
  top: 10px;
  right: -20px;
  width: 20px;
  height: 38px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  border-left: none;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  font-size: 11px;
  cursor: pointer;
  box-shadow: 2px 2px 8px rgba(0, 0, 0, 0.06);
  transition: all 0.15s ease;
  z-index: 2;
}

.deck-edge-tab:hover {
  background: #ffffff;
  color: var(--indigo);
  border-color: var(--indigo);
}

.deck-panel.is-collapsed .deck-edge-tab {
  display: none;
}

/* Docked Expressions Tab (Visible when Deck is Collapsed) */
#dock-reveal-btn.dock-reveal-tab {
  appearance: none;
  position: absolute;
  top: 64px;
  left: 16px;
  z-index: 15;
  display: none;
  align-items: center;
  gap: 7px;
  padding: 5px 10px 5px 8px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.08);
  cursor: pointer;
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 12.5px;
  font-weight: 600;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  text-decoration: none;
  user-select: none;
}

#dock-reveal-btn.dock-reveal-tab.is-visible {
  display: inline-flex;
}

#dock-reveal-btn.dock-reveal-tab:hover {
  background: #ffffff;
  border-color: var(--indigo);
  box-shadow: 0 6px 22px rgba(59, 76, 202, 0.12);
  transform: translateY(-1px);
}

.dock-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  color: var(--muted);
  font-size: 11px;
  transition: transform 0.15s ease, color 0.15s ease;
}

#dock-reveal-btn.dock-reveal-tab:hover .dock-arrow {
  color: var(--indigo);
  transform: translateX(2px);
}

.dock-icon {
  color: var(--indigo);
  font-size: 12.5px;
}

.dock-title {
  color: var(--ink);
  font-size: 12px;
  letter-spacing: -0.01em;
}

.dock-count-badge {
  background: var(--indigo-light);
  color: var(--indigo);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  padding: 1px 7px;
  border-radius: 999px;
  border: 1px solid rgba(59, 76, 202, 0.2);
  line-height: 1.3;
}

/* Expression Card */
.entry-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.entry-card:focus-within,
.entry-card.is-editing {
  border-color: var(--indigo);
  box-shadow: 0 0 0 2px var(--indigo-light);
}

.card-top-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Left controls column: Color toggle with Dashed button underneath */
.card-left-controls {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex-shrink: 0;
  width: 26px;
}

.color-dot {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid #FFF;
  box-shadow: 0 0 0 1px var(--line);
  cursor: pointer;
  flex-shrink: 0;
  transition: transform 0.12s ease, box-shadow 0.12s ease;
  position: relative;
  overflow: hidden;
}

.color-dot:hover {
  transform: scale(1.15);
}

/* Transparent / Hidden Graph State for Color Dot */
.color-dot.is-transparent {
  background-color: #f1f5f9 !important;
  background-image: 
    linear-gradient(45deg, #cbd5e1 25%, transparent 25%), 
    linear-gradient(-45deg, #cbd5e1 25%, transparent 25%), 
    linear-gradient(45deg, transparent 75%, #cbd5e1 75%), 
    linear-gradient(-45deg, transparent 75%, #cbd5e1 75%) !important;
  background-size: 8px 8px !important;
  background-position: 0 0, 0 4px, 4px -4px, -4px 0 !important;
  border-color: #cbd5e1 !important;
  box-shadow: 0 0 0 1.5px rgba(220, 38, 38, 0.45) !important;
}

.color-dot.is-transparent::after {
  content: '';
  position: absolute;
  top: 50%;
  left: -2px;
  right: -2px;
  height: 2px;
  background: #dc2626;
  transform: rotate(-45deg);
  border-radius: 1px;
  box-shadow: 0 0 2px rgba(255, 255, 255, 0.9);
}

.input-wrap {
  flex: 1;
  position: relative;
  display: flex;
  flex-direction: column;
}

math-field.math-field {
  width: 100%;
  font-size: var(--mathfield-font-size, 15px);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: #FAF9F6;
  color: var(--ink);
  outline: none;
  transition: border-color 0.15s, background-color 0.15s, box-shadow 0.15s;
  min-height: 38px;
  display: block;
  overflow: hidden;
  scrollbar-width: none;
  -ms-overflow-style: none;

  /* MathLive Theme & Highlight Overrides:
     Ensures fractions and parenthetical containers use a soft, readable light-indigo tint
     instead of MathLive's default dark charcoal grey box when dark mode is enabled on the OS */
  --contains-highlight-background-color: rgba(59, 76, 202, 0.08);
  --contains-highlight-color: var(--ink);
  --selection-background-color: rgba(59, 76, 202, 0.20);
  --selection-color: var(--ink);
  --caret-color: var(--indigo);
  --primary-color: var(--indigo);
  --placeholder-color: rgba(28, 30, 43, 0.45);
  --placeholder-opacity: 0.7;
  --text-highlight-background-color: rgba(59, 76, 202, 0.12);
}

math-field.math-field::-webkit-scrollbar {
  display: none;
  width: 0;
  height: 0;
}

math-field.math-field:focus,
math-field.math-field:focus-within {
  border-color: var(--indigo);
  background: #FFF;
  box-shadow: 0 0 0 2px var(--indigo-light);
}

math-field.math-field::part(virtual-keyboard-toggle) {
  color: var(--muted);
}

math-field.math-field::part(menu-toggle) {
  display: none;
}

.math-error-banner {
  font-size: 11px;
  color: var(--coral);
  margin-top: 3px;
  display: none;
}

.math-error-banner.is-visible {
  display: block;
}

.math-preview {
  display: none;
}

.card-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.btn-stacked {
  width: 26px;
  height: 26px;
  padding: 0;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  background: var(--card);
  cursor: pointer;
  transition: all 0.15s ease;
  user-select: none;
}

.btn-stacked.remove-btn {
  color: var(--coral);
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
}

.btn-stacked.remove-btn:hover {
  background: #FEE2E2;
  border-color: var(--coral);
  color: #B91C1C;
}

.btn-stacked.dash-btn {
  width: 24px;
  height: 16px;
  font-size: 8px;
  font-weight: 700;
  color: var(--muted);
  letter-spacing: -0.5px;
  line-height: 1;
  border-radius: 4px;
}

.btn-stacked.dash-btn:hover {
  border-color: var(--indigo);
  color: var(--indigo);
  background: #FFF;
}

.btn-stacked.dash-btn.is-active {
  background: var(--indigo-light);
  border-color: var(--indigo);
  color: var(--indigo);
}

/* Quick Math Chips Ribbon */
.math-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  padding-top: 2px;
}

.chip {
  appearance: none;
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--line);
  background: #FAF9F6;
  color: var(--muted);
  cursor: pointer;
}

.chip:hover {
  background: var(--card);
  color: var(--indigo);
  border-color: var(--indigo);
}

/* Calculus Drawer */
.calc-drawer-btn {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  font-size: 11.5px;
  font-weight: 600;
  padding: 6px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: rgba(59, 76, 202, 0.04);
  color: var(--indigo);
  cursor: pointer;
  margin-top: 2px;
}

.calc-drawer-btn:hover {
  background: rgba(59, 76, 202, 0.08);
}

.calc-drawer-content {
  display: none;
  flex-direction: column;
  gap: 8px;
  padding: 8px;
  background: #FAF9F6;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  margin-top: 4px;
}

.calc-drawer-content.is-open {
  display: flex;
}

.calc-tool-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
  font-size: 11.5px;
}

.calc-btn-group {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

.badge-tool {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  padding: 3px 7px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--muted);
  cursor: pointer;
  white-space: nowrap;
}

.badge-tool:hover {
  border-color: var(--indigo);
  color: var(--indigo);
}

.badge-tool.is-active {
  background: var(--indigo);
  color: #FFF;
  border-color: var(--indigo);
}

.badge-tool.tangent-btn.is-active {
  background: #334155;
  border-color: #334155;
  color: #FFF;
}

.readout-pill {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 700;
  padding: 2px 7px;
  border-radius: 999px;
  background: var(--teal-light);
  color: var(--teal);
  display: inline-flex;
  align-items: center;
  white-space: nowrap;
}

.readout-pill.darkgrey {
  background: #F1F5F9;
  color: #334155;
  border: 1px solid #CBD5E1;
}

.tangent-implicit-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.readout-pill.coral {
  background: var(--coral-light);
  color: var(--coral);
}

.readout-pill.purple {
  background: var(--purple-light);
  color: var(--purple);
}

.calc-subrow {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 11.5px;
  color: var(--muted);
  padding: 4px 0;
}

.calc-subrow input[type="number"] {
  width: 54px;
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 3px 5px;
  border-radius: 4px;
  border: 1px solid var(--line);
  background: #FFF;
}

.calc-subrow input[type="range"] {
  flex: 1;
  accent-color: var(--indigo);
}

.calc-subrow select {
  font-size: 11px;
  padding: 3px 6px;
  border-radius: 4px;
  border: 1px solid var(--line);
  background: #FFF;
}

/* Points on Curve (Gliders) in Calculus Drawer */
.curve-points-container {
  display: flex;
  flex-direction: column;
  gap: 5px;
  margin-top: 2px;
}

.curve-point-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
  background: #FFF;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 4px 7px;
  font-size: 11px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.02);
}

.curve-point-left {
  display: flex;
  align-items: center;
  gap: 6px;
}

.curve-point-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  flex-shrink: 0;
  box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.1);
}

.curve-point-tag {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 11.5px;
  color: var(--ink);
  min-width: 12px;
}

.curve-point-coord-label {
  color: var(--muted);
  font-size: 10.5px;
  font-family: var(--font-mono);
}

.curve-point-x-input {
  width: 52px;
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 5px;
  border-radius: 4px;
  border: 1px solid var(--line);
  background: #FAF9F6;
  color: var(--ink);
  transition: border-color 0.15s ease;
}

.curve-point-x-input:focus {
  outline: none;
  border-color: var(--indigo);
  background: #FFF;
}

.curve-point-right {
  display: flex;
  align-items: center;
  gap: 6px;
}

.curve-point-readout {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 999px;
  background: #F1F5F9;
  color: #334155;
  border: 1px solid #E2E8F0;
  white-space: nowrap;
}

.btn-remove-curve-point {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: none;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 10.5px;
  padding: 0;
  transition: all 0.15s ease;
}

.btn-remove-curve-point:hover {
  background: #FEE2E2;
  color: #DC2626;
}

/* Floating Zoom & Nav Controls (Canvas Controls) */
.canvas-controls {
  position: absolute;
  bottom: 20px;
  right: 20px;
  z-index: 10;
  display: flex;
  flex-direction: row;
  align-items: stretch;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.08);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.controls-collapse-tab {
  appearance: none;
  border: none;
  background: transparent;
  border-right: 1px solid var(--line);
  width: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--muted);
  font-size: 11px;
  padding: 0;
  transition: background-color 0.15s, color 0.15s;
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.controls-collapse-tab:hover {
  background: rgba(59, 76, 202, 0.06);
  color: var(--indigo);
}

.controls-body {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 5px;
}

.controls-row {
  display: flex;
  gap: 4px;
  align-items: center;
}

.canvas-controls.is-collapsed {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.canvas-controls.is-collapsed .controls-body {
  display: none;
}

.canvas-controls.is-collapsed .controls-collapse-tab {
  border-right: none;
  width: 24px;
  height: 48px;
  border-radius: var(--radius-md);
}

/* Modals */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(28, 30, 43, 0.35);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 100;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

.modal-backdrop.is-open {
  display: flex;
}

.modal-dialog {
  background: var(--card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
  width: 100%;
  max-width: 540px;
  max-height: 85vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--line);
}

.modal-title {
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.modal-body {
  padding: 20px;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--muted);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.modal-body strong {
  color: var(--ink);
}

.modal-footer {
  padding: 12px 20px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: flex-end;
  background: #FAF9F6;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

/* Preset Cards inside Modal */
.preset-grid {
  display: grid;
  gap: 8px;
}

.preset-card {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: #FAF9F6;
  cursor: pointer;
  transition: all 0.15s ease;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.preset-card:hover {
  border-color: var(--indigo);
  background: #FFF;
  box-shadow: 0 2px 8px rgba(59, 76, 202, 0.08);
}

.preset-card-title {
  font-weight: 600;
  font-size: 13px;
  color: var(--ink);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.preset-card-cat {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--indigo);
  background: var(--indigo-light);
  padding: 2px 6px;
  border-radius: 999px;
}

.preset-card-desc {
  font-size: 12px;
  color: var(--muted);
}

/* Syntax Help Table */
.help-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
  margin-top: 6px;
}

.help-table th, .help-table td {
  padding: 6px 8px;
  text-align: left;
  border-bottom: 1px solid var(--line);
}

.help-table th {
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
  color: var(--muted);
}

.help-table code {
  font-family: var(--font-mono);
  background: #FAF9F6;
  padding: 2px 4px;
  border-radius: 4px;
  color: var(--indigo);
}

/* Embed Mode overrides */
body.is-embedded .top-nav {
  display: none;
}

body.is-embedded .deck-panel {
  top: 12px;
}

body.is-embedded #dock-reveal-btn {
  top: 12px;
}

/* Projector Mode Menu & Popover */
.projector-wrap {
  position: relative;
  display: inline-flex;
}

#projector-btn.is-active {
  border-color: var(--indigo);
  background: var(--indigo-light);
  color: var(--indigo);
}

.thickness-pill {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 700;
  padding: 1px 5px;
  border-radius: 999px;
  background: rgba(28, 30, 43, 0.06);
  color: var(--muted);
  margin-left: 2px;
}

#projector-btn.is-active .thickness-pill {
  background: rgba(59, 76, 202, 0.15);
  color: var(--indigo);
}

.projector-popover {
  position: absolute;
  right: calc(100% + 10px);
  bottom: 0;
  width: 220px;
  box-sizing: border-box;
  padding: 12px 14px;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 10px 30px rgba(28, 30, 43, 0.14), 0 2px 6px rgba(28, 30, 43, 0.05);
  z-index: 50;
  display: none;
  flex-direction: column;
  gap: 10px;
  animation: popoverFadeIn 0.15s ease-out;
}

.projector-popover.is-open {
  display: flex;
}

@keyframes popoverFadeIn {
  from { opacity: 0; transform: translateX(6px); }
  to { opacity: 1; transform: translateX(0); }
}

.popover-header {
  font-size: 11px;
  font-weight: 700;
  color: var(--ink);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--line);
}

.popover-slider-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.popover-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--muted);
  min-width: 32px;
}

#projector-slider {
  flex: 1;
  height: 4px;
  appearance: none;
  background: rgba(28, 30, 43, 0.12);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}

#projector-slider::-webkit-slider-thumb {
  appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--indigo);
  cursor: pointer;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  transition: transform 0.1s ease;
}

#projector-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.popover-val {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  color: var(--ink);
  min-width: 36px;
  text-align: right;
}

.popover-presets {
  display: flex;
  gap: 4px;
}

.thick-chip {
  flex: 1;
  font-family: var(--font-sans);
  font-size: 10.5px;
  font-weight: 600;
  padding: 4px 6px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: #FAF9F6;
  color: var(--muted);
  cursor: pointer;
  transition: all 0.15s ease;
  text-align: center;
}

.thick-chip:hover {
  background: #FFF;
  border-color: var(--indigo);
  color: var(--indigo);
}

.thick-chip.active {
  background: var(--indigo);
  border-color: var(--indigo);
  color: #FFF;
}

/* X-Axis Radian Scale Menu & Popover */
.scale-wrap {
  position: relative;
  display: inline-flex;
}

#scale-mode-btn.is-active {
  border-color: var(--indigo);
  background: var(--indigo-light);
}

.rad-btn-text {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--muted);
  transition: color 0.15s ease;
}

#scale-mode-btn:hover .rad-btn-text {
  color: var(--indigo);
}

#scale-mode-btn.is-active .rad-btn-text {
  color: var(--indigo);
  font-weight: 800;
}

.scale-popover {
  position: absolute;
  right: calc(100% + 10px);
  bottom: 0;
  width: 210px;
  box-sizing: border-box;
  padding: 12px 14px;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 10px 30px rgba(28, 30, 43, 0.14), 0 2px 6px rgba(28, 30, 43, 0.05);
  z-index: 50;
  display: none;
  flex-direction: column;
  gap: 10px;
  animation: popoverFadeIn 0.15s ease-out;
}

.scale-popover.is-open {
  display: flex;
}

.scale-presets {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.scale-chip.full-width {
  grid-column: span 2;
}

.scale-chip {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  padding: 6px 4px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: #FAF9F6;
  color: var(--muted);
  cursor: pointer;
  transition: all 0.15s ease;
  text-align: center;
}

.scale-chip:hover {
  background: #FFF;
  border-color: var(--indigo);
  color: var(--indigo);
}

.scale-chip.active {
  background: var(--indigo);
  border-color: var(--indigo);
  color: #FFF;
}

/* Grid Paper Controls */
.grid-wrap {
  position: relative;
  width: 100%;
}

#grid-mode-btn.is-active {
  border-color: var(--indigo);
  background: var(--indigo-light);
  color: var(--indigo);
}

.grid-popover {
  position: absolute;
  bottom: 0;
  right: calc(100% + 12px);
  width: 200px;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.12);
  padding: 12px;
  display: none;
  flex-direction: column;
  gap: 10px;
  z-index: 100;
}

.grid-popover.is-open {
  display: flex;
}

.grid-presets {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.grid-chip {
  font-family: var(--font-sans);
  font-size: 11.5px;
  font-weight: 500;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: #FAF9F6;
  color: var(--ink);
  cursor: pointer;
  transition: all 0.15s ease;
  display: flex;
  align-items: center;
  gap: 8px;
  text-align: left;
}

.grid-chip:hover {
  background: #FFF;
  border-color: var(--indigo);
  color: var(--indigo);
}

.grid-chip.active {
  background: var(--indigo);
  border-color: var(--indigo);
  color: #FFF;
  font-weight: 600;
}

/* Polar & Parametric Subrows in Expression Card */
.polar-subrow,
.parametric-subrow {
  margin-top: 8px;
  padding: 8px 10px;
  background: rgba(248, 250, 252, 0.85);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 11px;
}

.polar-domain-wrap {
  display: flex;
  align-items: center;
  gap: 6px;
}

.polar-subrow-label {
  font-weight: 600;
  color: var(--muted);
  display: inline-flex;
  align-items: center;
}

.polar-domain-chips {
  display: inline-flex;
  gap: 4px;
}

.polar-chip,
.param-chip {
  appearance: none;
  background: #FFF;
  border: 1px solid var(--line);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.polar-chip:hover,
.param-chip:hover {
  border-color: var(--indigo);
  color: var(--indigo);
}

.polar-chip.active,
.param-chip.active {
  background: var(--indigo);
  border-color: var(--indigo);
  color: #FFF;
}

.polar-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.polar-actions .btn {
  padding: 3px 8px;
  font-size: 11px;
}

.polar-trace-btn.is-active,
.param-trace-btn.is-active {
  background: #059669;
  border-color: #059669;
  color: #FFF;
}

/* Mobile & Tablet Responsiveness */
@media (max-width: 768px) {
  .top-nav {
    padding: 0 10px;
    height: 48px;
  }

  .nav-brand {
    gap: 6px;
  }

  .nav-badge {
    display: none;
  }

  .nav-title {
    font-size: 16px;
  }

  .nav-actions {
    gap: 4px;
  }

  #share-btn span,
  #presets-btn span,
  #about-btn span {
    display: none;
  }

  .deck-panel {
    top: auto;
    bottom: 0;
    left: 0;
    right: 0;
    width: 100%;
    max-width: 100%;
    max-height: 55vh;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    transform: translateY(0);
    transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), bottom 0.25s cubic-bezier(0.16, 1, 0.3, 1), max-height 0.25s ease;
  }

  .deck-panel.is-collapsed {
    transform: translateY(105%);
  }

  .deck-panel.keyboard-active {
    bottom: var(--keyboard-height, 280px);
    max-height: calc(100dvh - var(--keyboard-height, 280px) - 52px);
    box-shadow: 0 -8px 28px rgba(0, 0, 0, 0.22);
  }

  .deck-edge-tab {
    position: absolute;
    right: 12px;
    top: 10px;
    width: 28px;
    height: 28px;
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
  }

  .deck-edge-tab i::before {
    content: "\f078"; /* fa-chevron-down */
  }

  .deck-header {
    padding-right: 48px;
  }

  #dock-reveal-btn.dock-reveal-tab {
    top: auto;
    bottom: 16px;
    left: 16px;
  }

  .canvas-controls {
    bottom: auto;
    top: 56px;
    right: 12px;
  }
}

/* Interactive Unit Circle HUD */
.unit-circle-hud {
  position: absolute;
  top: 64px;
  right: 20px;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  padding: 12px 16px;
  z-index: 20;
  min-width: 240px;
  pointer-events: auto;
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--ink);
  transition: all 0.2s ease;
}

.unit-circle-hud-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--line);
  font-size: 11.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--ink-secondary);
}

.unit-circle-hud-close {
  appearance: none;
  background: transparent;
  border: 1px solid rgba(220, 38, 38, 0.3);
  color: #DC2626;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 600;
  padding: 2px 7px;
  cursor: pointer;
  transition: all 0.15s ease;
  line-height: 1.2;
}

.unit-circle-hud-close:hover {
  background: #FEE2E2;
  border-color: #DC2626;
  color: #B91C1C;
}

.unit-circle-hud-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 5px;
  gap: 12px;
}

.unit-circle-hud-row:last-child {
  margin-bottom: 0;
}

.unit-circle-hud-val {
  font-family: var(--font-mono);
  font-weight: 600;
  text-align: right;
}

.unit-circle-hud-cos {
  color: #2563EB;
}

.unit-circle-hud-sin {
  color: #D97706;
}

.unit-circle-hud-tan {
  color: #059669;
}

@media (max-width: 768px) {
  .unit-circle-hud {
    top: 56px;
    right: 10px;
    min-width: 200px;
    padding: 8px 12px;
    font-size: 11.5px;
  }
}

/* curvat.io Virtual Keyboard Dock Button (Inside MathLive Toolbar) */
.curvatio-vk-dock-btn {
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  gap: 6px !important;
  height: 26px !important;
  padding: 0 12px !important;
  margin-left: auto !important;
  margin-right: 12px !important;
  border-radius: 6px !important;
  background: rgba(255, 255, 255, 0.16) !important;
  color: #f8fafc !important;
  border: 1px solid rgba(255, 255, 255, 0.28) !important;
  font-family: var(--font-sans, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif) !important;
  font-size: 11.5px !important;
  font-weight: 600 !important;
  letter-spacing: 0.02em !important;
  cursor: pointer !important;
  pointer-events: auto !important;
  user-select: none !important;
  -webkit-tap-highlight-color: transparent !important;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.25) !important;
  transition: all 0.15s ease !important;
  flex-shrink: 0 !important;
}

.curvatio-vk-dock-btn svg {
  display: inline-block !important;
  vertical-align: middle !important;
  color: #f8fafc !important;
  stroke: #f8fafc !important;
  transition: transform 0.15s ease !important;
}

.curvatio-vk-dock-btn:hover {
  background: rgba(255, 255, 255, 0.28) !important;
  border-color: rgba(255, 255, 255, 0.5) !important;
  color: #ffffff !important;
}

.curvatio-vk-dock-btn:hover svg {
  transform: translateY(1.5px) !important;
}

.curvatio-vk-dock-btn:active {
  background: rgba(255, 255, 255, 0.42) !important;
  transform: scale(0.96) !important;
}

/* Light keyboard theme support */
[theme="light"] .curvatio-vk-dock-btn,
.ML__keyboard:not([theme="dark"]) .curvatio-vk-dock-btn {
  background: rgba(0, 0, 0, 0.07) !important;
  border-color: rgba(0, 0, 0, 0.16) !important;
  color: var(--ink, #1e293b) !important;
}

[theme="light"] .curvatio-vk-dock-btn svg,
.ML__keyboard:not([theme="dark"]) .curvatio-vk-dock-btn svg {
  color: var(--ink, #1e293b) !important;
  stroke: var(--ink, #1e293b) !important;
}

[theme="light"] .curvatio-vk-dock-btn:hover,
.ML__keyboard:not([theme="dark"]) .curvatio-vk-dock-btn:hover {
  background: rgba(0, 0, 0, 0.12) !important;
  border-color: rgba(0, 0, 0, 0.25) !important;
}

/* Floating fallback dock button */
.curvatio-vk-dock-btn.is-floating {
  position: absolute !important;
  top: 6px !important;
  right: 12px !important;
  z-index: 1000 !important;
}

/* Small mobile screens */
@media (max-width: 480px) {
  .curvatio-vk-dock-btn {
    padding: 0 8px !important;
    margin-right: 6px !important;
    gap: 4px !important;
  }
}



/* Share controls keep the complete link selectable at every viewport size. */
[hidden] { display: none !important; }
.share-dialog { max-width: 540px; }
.share-dialog label { font-size: 12px; font-weight: 600; color: var(--ink); }
.share-field { box-sizing: border-box; display: block; width: 100%; min-width: 0; padding: 10px 12px; border: 1px solid var(--line-strong); border-radius: 8px; background: var(--paper); color: var(--ink); font: 13px var(--font-mono); }
textarea.share-field { resize: vertical; overflow-wrap: anywhere; margin: 8px 0 12px; }
.share-actions, .share-file-actions { display: flex; flex-wrap: wrap; gap: 8px; }
.share-actions .btn { min-height: 44px; flex: 1; justify-content: center; }
.share-status { min-height: 1.5em; color: var(--indigo); overflow-wrap: anywhere; }
.share-embed { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding: 14px 0; }
.share-embed summary { cursor: pointer; font-weight: 600; color: var(--ink); }
.share-embed p { margin: 12px 0; }
.share-footnote { font-size: 12px; }
.share-dialog :focus-visible { outline: 3px solid var(--indigo); outline-offset: 3px; }
.graph-notice { position: fixed; top: 65px; left: 50%; transform: translateX(-50%); max-width: min(560px, calc(100% - 32px)); padding: 12px 16px; border: 1px solid var(--line-strong); border-radius: 10px; box-shadow: 0 4px 20px #0002; background: var(--card); color: var(--ink); z-index: 50; display: flex; gap: 12px; font-size: 13px; overflow-wrap: anywhere; }
.graph-notice.is-error { border-color: var(--coral); }
.graph-notice button { border: 0; background: transparent; color: inherit; cursor: pointer; font-size: 22px; align-self: start; }
@media (max-width: 480px) {
  .share-dialog .modal-body { padding: 16px; }
  .share-file-actions .btn { min-height: 44px; flex: 1; }
}

/* Narrow embeds use the same bottom drawer geometry as phone layouts. */
@media (max-width: 768px) {
  body.is-embedded .deck-panel,
  body.is-embedded #dock-reveal-btn { top: auto; }
}