style.css

/* OpenMathBoard Styles */
:root {
  --toolbar-height: 56px;
  --toolbar-bg: #ffffff;
  --toolbar-border: #e5e7eb;
  --btn-hover: #f3f4f6;
  --btn-active: #e5e7eb;
  --primary-color: #2563eb;
  --canvas-bg: #ffffff;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --radius-sm: 6px;
  --radius-md: 8px;
}

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

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--canvas-bg);
  -webkit-user-select: none;
  user-select: none;
  overscroll-behavior: none;
}

/* Toolbar */
.toolbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--toolbar-height);
  background: var(--toolbar-bg);
  border-bottom: 1px solid var(--toolbar-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px;
  z-index: 100;
  box-shadow: var(--shadow-sm);
  touch-action: manipulation;
}

/* Hamburger Menu */
.menu-wrapper {
  position: relative;
  display: none;
}

.menu-btn {
  display: flex;
}

.menu-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  left: auto;
  background: white;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  padding: 6px;
  display: none;
  visibility: hidden;
  opacity: 0;
  flex-direction: column;
  gap: 2px;
  min-width: 200px;
  z-index: 200;
}

.menu-dropdown.show {
  display: flex;
  visibility: visible;
  opacity: 1;
}

.menu-option {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px 12px;
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 14px;
  color: #374151;
  text-align: left;
}

.menu-option:hover {
  background: var(--btn-hover);
}

.menu-option svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.menu-divider {
  height: 1px;
  background: var(--toolbar-border);
  margin: 4px 0;
}

/* Mobile Tools Section (in topbar) */
.mobile-tools {
  display: none;
  align-items: center;
  gap: 2px;
  overflow: visible;
  touch-action: manipulation;
}

.mobile-tools .toolbar-btn,
.mobile-tools .color-picker,
.mobile-tools .stroke-picker,
.mobile-tools .smart-shape-picker {
  flex-shrink: 0;
}

/* Ensure iOS Safari treats taps as immediate clicks inside scrollable .mobile-tools */
.mobile-tools .toolbar-btn {
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

.mobile-tools .toolbar-divider {
  height: 24px;
  margin: 0 4px;
  flex-shrink: 0;
}

/* Mobile dropdowns use position:fixed to escape overflow container on iOS */
.color-dropdown-mobile,
.stroke-dropdown-mobile,
.smart-shape-dropdown-mobile {
  position: fixed !important;
  z-index: 300;
}

.toolbar-left,
.toolbar-center,
.toolbar-right {
  display: flex;
  align-items: center;
  gap: 4px;
}

.toolbar-logo {
  display: flex;
  align-items: center;
  padding: 8px;
  border-radius: var(--radius-sm);
  transition: background 0.2s;
}

.toolbar-logo:hover {
  background: var(--btn-hover);
}

.toolbar-logo img {
  width: 28px;
  height: 28px;
}

.toolbar-divider {
  width: 1px;
  height: 28px;
  background: var(--toolbar-border);
  margin: 0 8px;
}

.toolbar-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 0.2s;
  color: #374151;
}

.toolbar-btn:hover:not(:disabled) {
  background: var(--btn-hover);
}

.toolbar-btn:active:not(:disabled) {
  background: var(--btn-active);
}

.toolbar-btn.active {
  background: var(--primary-color);
  color: white;
}

.toolbar-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.toolbar-btn svg {
  width: 20px;
  height: 20px;
}

/* Color Picker */
.color-picker,
.stroke-picker,
.smart-shape-picker,
.lang-picker {
  position: relative;
}

.color-btn {
  padding: 6px;
}

.color-indicator {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid #d1d5db;
}

.color-dropdown,
.stroke-dropdown,
.smart-shape-dropdown,
.lang-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  background: white;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  padding: 8px;
  display: none;
  visibility: hidden;
  opacity: 0;
  z-index: 200;
}

.color-dropdown.show,
.stroke-dropdown.show,
.smart-shape-dropdown.show,
.lang-dropdown.show {
  display: flex;
  visibility: visible;
  opacity: 1;
  gap: 6px;
}

.color-option {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform 0.15s, border-color 0.15s;
}

.color-option:hover {
  transform: scale(1.1);
}

.color-option.active {
  border-color: #374151;
}

.stroke-dropdown {
  flex-direction: column;
  padding: 6px;
  gap: 4px;
}

/* Smart Shapes Dropdown */
.smart-shape-dropdown {
  flex-direction: column;
  gap: 10px;
  padding: 10px;
  min-width: 220px;
}

.smart-shape-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.smart-shape-toggle {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  color: #111827;
  cursor: pointer;
  user-select: none;
}

.smart-shape-toggle input {
  width: 18px;
  height: 18px;
}

.smart-shape-row-slider {
  gap: 8px;
}

.smart-shape-label {
  font-size: 12px;
  color: #374151;
  width: 72px;
}

#smartShapeSensitivity {
  flex: 1;
}

.smart-shape-value {
  font-size: 12px;
  color: #374151;
  width: 28px;
  text-align: right;
}

.smart-shape-presets {
  display: flex;
  gap: 6px;
}

.smart-shape-preset {
  flex: 1;
  height: 34px;
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 12px;
  color: #374151;
}

.smart-shape-preset:hover {
  background: var(--btn-hover);
}

.smart-shape-preset.active {
  background: var(--btn-active);
}

.stroke-option {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 32px;
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.stroke-option:hover {
  background: var(--btn-hover);
}

.stroke-option.active {
  background: var(--btn-active);
}

.stroke-preview {
  width: 60px;
  background: #374151;
  border-radius: 2px;
}

/* Language Picker */
.lang-dropdown {
  flex-direction: column;
  padding: 6px;
  gap: 4px;
  right: 0;
  left: auto;
  transform: none;
}

.lang-option {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 32px;
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 14px;
  color: #374151;
}

.lang-option:hover {
  background: var(--btn-hover);
}

.lang-option.active {
  background: var(--btn-active);
}

/* Canvas Container */
.canvas-container {
  position: fixed;
  top: var(--toolbar-height);
  left: 0;
  right: 0;
  bottom: 0;
  overflow: hidden;
  background: var(--canvas-bg);
  touch-action: none;
}

/* Hero / Welcome Section */
.hero-section {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
  background: var(--canvas-bg);
  transition: opacity 0.3s, visibility 0.3s;
  pointer-events: none;
}

.hero-section.hidden {
  opacity: 0;
  visibility: hidden;
}

.hero-content {
  text-align: center;
  max-width: 400px;
  padding: 24px;
  pointer-events: none;
}

.hero-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-icon img {
  width: 100%;
  height: 100%;
}

.hero-title {
  font-size: 24px;
  font-weight: 600;
  color: #111827;
  margin-bottom: 8px;
}

.hero-brand {
  color: #2563eb;
}

.hero-subtitle {
  font-size: 16px;
  color: #6b7280;
  margin-bottom: 24px;
}

.hero-features {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.hero-feature {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: #f9fafb;
  border-radius: var(--radius-md);
  color: #374151;
  font-size: 14px;
}

.hero-feature svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--primary-color);
}

.hero-divider {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.hero-divider::before,
.hero-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: #e5e7eb;
}

.hero-divider span {
  font-size: 14px;
  color: #9ca3af;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.hero-import-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.hero-import-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  background: white;
  border: 2px solid var(--toolbar-border);
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 500;
  color: #374151;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
  pointer-events: auto;
}

.hero-import-btn:hover {
  border-color: var(--primary-color);
  background: #f9fafb;
}

.hero-import-btn svg {
  width: 20px;
  height: 20px;
  color: var(--primary-color);
}

.hero-hint {
  font-size: 14px;
  color: #6b7280;
}

.hero-formats {
  font-size: 12px;
  color: #9ca3af;
}

@media (max-width: 480px) {
  .hero-content {
    padding: 16px;
  }

  .hero-icon {
    width: 64px;
    height: 64px;
  }

  .hero-title {
    font-size: 20px;
  }

  .hero-subtitle {
    font-size: 14px;
  }

  .hero-import-btn {
    padding: 12px 20px;
    font-size: 14px;
  }

  .hero-feature {
    padding: 10px 12px;
    font-size: 13px;
  }

  .hero-feature svg {
    width: 18px;
    height: 18px;
  }
}

.images-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
}

.images-layer .imported-image {
  position: absolute;
  pointer-events: auto;
  cursor: move;
  border: 2px solid transparent;
  transition: border-color 0.2s;
}

.images-layer .imported-image:hover,
.images-layer .imported-image.selected {
  border-color: var(--primary-color);
}

.images-layer .imported-image img {
  display: block;
  max-width: 100%;
  height: auto;
  pointer-events: none;
}

.images-layer .imported-image .resize-handle {
  position: absolute;
  width: 12px;
  height: 12px;
  background: var(--primary-color);
  border: 2px solid white;
  border-radius: 2px;
  cursor: se-resize;
  right: -6px;
  bottom: -6px;
  display: none;
}

.images-layer .imported-image.selected .resize-handle {
  display: block;
}

.images-layer .imported-image .delete-handle {
  position: absolute;
  width: 24px;
  height: 24px;
  background: #dc2626;
  border-radius: 50%;
  cursor: pointer;
  right: -8px;
  top: -8px;
  display: none;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 14px;
  font-weight: bold;
}

.images-layer .imported-image.selected .delete-handle {
  display: flex;
}

#drawingCanvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2;
  touch-action: none;
  pointer-events: none;
}

#liveCanvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 3;
  touch-action: none;
}

/* Drop Zone */
.drop-zone {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(37, 99, 235, 0.1);
  border: 3px dashed var(--primary-color);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 50;
}

.drop-zone.active {
  display: flex;
}

.drop-zone-content {
  text-align: center;
  color: var(--primary-color);
}

.drop-zone-content svg {
  width: 64px;
  height: 64px;
  margin-bottom: 16px;
}

.drop-zone-content p {
  font-size: 18px;
  font-weight: 500;
}

/* Toast Notifications */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: #1f2937;
  color: white;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  opacity: 0;
  transition: transform 0.3s, opacity 0.3s;
  z-index: 300;
}

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

.toast.success {
  background: #16a34a;
}

.toast.error {
  background: #dc2626;
}

/* Mobile Responsive */
@media (max-width: 768px) {
  :root {
    --toolbar-height: 48px;
  }

  .toolbar {
    padding: 0 8px;
  }

  .toolbar-btn {
    width: 36px;
    height: 36px;
  }

  .toolbar-btn svg {
    width: 18px;
    height: 18px;
  }

  .toolbar-divider {
    margin: 0 4px;
  }

  .toolbar-logo img {
    width: 24px;
    height: 24px;
  }

  .color-indicator {
    width: 18px;
    height: 18px;
  }
}

/* Narrow screens: show mobile tools in topbar + hamburger menu on right */
@media (max-width: 600px) {
  .desktop-only {
    display: none !important;
  }

  .menu-wrapper {
    display: block;
  }

  .mobile-tools {
    display: flex;
  }

  .toolbar {
    justify-content: space-between;
    gap: 4px;
  }

  .toolbar-left {
    flex: 1;
    min-width: 0;
    overflow: visible;
  }

  .toolbar-right {
    flex-shrink: 0;
  }
}

@media (max-width: 480px) {
  .mobile-tools {
    gap: 1px;
  }

  .mobile-tools .toolbar-btn {
    width: 32px;
    height: 32px;
  }

  .mobile-tools .toolbar-btn svg {
    width: 16px;
    height: 16px;
  }

  .mobile-tools .toolbar-divider {
    display: none;
  }

  .mobile-tools .color-indicator {
    width: 16px;
    height: 16px;
  }
}

/* High contrast for accessibility */
@media (prefers-contrast: high) {
  .toolbar-btn.active {
    outline: 2px solid black;
  }
}

/* Cursor styles for tools */
.canvas-container.tool-pen {
  cursor: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="10" height="10" viewBox="0 0 10 10"><circle cx="5" cy="5" r="3" fill="white"/><circle cx="5" cy="5" r="2" fill="black"/></svg>') 5 5, crosshair;
}

.canvas-container.tool-eraser {
  cursor: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 20 20"><g transform="rotate(45 10 10)"><rect x="6" y="4" width="8" height="12" rx="1" fill="white" stroke="black" stroke-width="1.5"/><line x1="6" y1="13" x2="14" y2="13" stroke="black" stroke-width="1"/></g></svg>') 10 10, crosshair;
}

.canvas-container.tool-select {
  cursor: crosshair;
}

.canvas-container.tool-select.has-selection {
  cursor: move;
}