/* ==========================================================================
   ASCII Diagram Viewer — Styles
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Custom Properties — Theme Variables
   -------------------------------------------------------------------------- */

:root {
  /* UI Chrome */
  --ui-bg: #ffffff;
  --ui-bg-secondary: #f8f9fa;
  --ui-text: #1a1a2e;
  --ui-text-muted: #6b7280;
  --ui-border: #e2e4e8;
  --ui-accent: #3b82f6;
  --ui-accent-hover: #2563eb;
  --ui-hover: #f1f3f5;
  --ui-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  --ui-radius: 6px;
  --ui-font: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --mono-font: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', 'Consolas', 'Monaco', monospace;

  /* Diagram defaults (Light theme) */
  --diagram-bg: #ffffff;
  --diagram-stroke: #334155;
  --diagram-fill: #e8edf3;
  --diagram-text: #1e293b;
  --diagram-arrow: #334155;
  --diagram-stroke-width: 1.8;
  --diagram-corner-radius: 5;
  --diagram-font-size: 14;

  /* Editor */
  --editor-bg: #fafbfc;
  --editor-text: #24292e;
  --editor-line-bg: #f0f1f3;
  --editor-line-text: #9ca3af;
  --grid-color: rgba(0, 0, 0, 0.06);

  /* Sizing */
  --toolbar-height: 48px;
  --status-height: 28px;
  --char-width: 8.4px;
  --line-height: 18px;

  color-scheme: light dark;
}

/* --------------------------------------------------------------------------
   UI Dark Mode
   -------------------------------------------------------------------------- */

[data-ui-mode="dark"] {
  --ui-bg: #1e1e2e;
  --ui-bg-secondary: #181825;
  --ui-text: #cdd6f4;
  --ui-text-muted: #6c7086;
  --ui-border: #313244;
  --ui-accent: #89b4fa;
  --ui-accent-hover: #74c7ec;
  --ui-hover: #313244;
  --ui-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);

  --editor-bg: #1e1e2e;
  --editor-text: #cdd6f4;
  --editor-line-bg: #181825;
  --editor-line-text: #585b70;
  --grid-color: rgba(255, 255, 255, 0.06);
}

/* --------------------------------------------------------------------------
   Diagram Themes
   -------------------------------------------------------------------------- */

[data-diagram-theme="light"] {
  --diagram-bg: #ffffff;
  --diagram-stroke: #334155;
  --diagram-fill: #e8edf3;
  --diagram-text: #1e293b;
  --diagram-arrow: #334155;
}

[data-diagram-theme="dark"] {
  --diagram-bg: #1e1e2e;
  --diagram-stroke: #cdd6f4;
  --diagram-fill: #313244;
  --diagram-text: #cdd6f4;
  --diagram-arrow: #89b4fa;
}

[data-diagram-theme="high-contrast"] {
  --diagram-bg: #000000;
  --diagram-stroke: #ffffff;
  --diagram-fill: #1a1a1a;
  --diagram-text: #ffff00;
  --diagram-arrow: #00ff00;
}

[data-diagram-theme="blueprint"] {
  --diagram-bg: #0a1929;
  --diagram-stroke: #5090d3;
  --diagram-fill: #0d2847;
  --diagram-text: #a8d4f0;
  --diagram-arrow: #5090d3;
}

[data-diagram-theme="solarized"] {
  --diagram-bg: #fdf6e3;
  --diagram-stroke: #657b83;
  --diagram-fill: #eee8d5;
  --diagram-text: #586e75;
  --diagram-arrow: #268bd2;
}

[data-diagram-theme="monochrome"] {
  --diagram-bg: #f5f5f5;
  --diagram-stroke: #000000;
  --diagram-fill: #ffffff;
  --diagram-text: #000000;
  --diagram-arrow: #000000;
}

/* --------------------------------------------------------------------------
   Reset & Base
   -------------------------------------------------------------------------- */

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

html, body {
  height: 100%;
  overflow: hidden;
  font-family: var(--ui-font);
  font-size: 14px;
  color: var(--ui-text);
  background: var(--ui-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --------------------------------------------------------------------------
   Screen Reader Only
   -------------------------------------------------------------------------- */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --------------------------------------------------------------------------
   App Layout
   -------------------------------------------------------------------------- */

.app {
  display: grid;
  grid-template-rows: var(--toolbar-height) 1fr var(--status-height);
  height: 100vh;
  height: 100dvh;
}

/* --------------------------------------------------------------------------
   Toolbar
   -------------------------------------------------------------------------- */

.toolbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  background: var(--ui-bg);
  border-bottom: 1px solid var(--ui-border);
  z-index: 10;
}

.toolbar-left {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.logo {
  font-size: 20px;
  line-height: 1;
}

.app-title {
  font-size: 15px;
  font-weight: 600;
  white-space: nowrap;
  letter-spacing: -0.01em;
}

.toolbar-center {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  justify-content: center;
}

.toolbar-right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.separator {
  width: 1px;
  height: 20px;
  background: var(--ui-border);
}

.zoom-controls,
.theme-controls,
.export-controls,
.sample-controls,
.text-size-controls {
  display: flex;
  align-items: center;
  gap: 4px;
}

.text-size-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--ui-text-muted);
  cursor: default;
  user-select: none;
}

.text-size-display {
  min-width: 22px;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  color: var(--ui-text-muted);
  text-align: center;
}

.range-input {
  width: 64px;
  height: 4px;
  accent-color: var(--ui-accent);
  cursor: pointer;
}

.zoom-display {
  min-width: 48px;
  text-align: center;
  font-size: 12px;
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  color: var(--ui-text-muted);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--ui-border);
  background: var(--ui-bg);
  color: var(--ui-text);
  border-radius: var(--ui-radius);
  cursor: pointer;
  font-family: inherit;
  font-size: 13px;
  transition: background 0.15s, border-color 0.15s;
}

.btn:hover {
  background: var(--ui-hover);
  border-color: var(--ui-accent);
}

.btn:active {
  transform: scale(0.97);
}

.btn-icon {
  width: 30px;
  height: 30px;
  font-size: 16px;
  padding: 0;
}

.btn-small {
  height: 30px;
  padding: 0 10px;
  font-size: 12px;
  font-weight: 500;
}

/* Select */
.select {
  height: 30px;
  padding: 0 28px 0 10px;
  border: 1px solid var(--ui-border);
  border-radius: var(--ui-radius);
  background: var(--ui-bg);
  color: var(--ui-text);
  font-family: inherit;
  font-size: 12px;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%236b7280'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
}

.select:hover {
  border-color: var(--ui-accent);
}

/* --------------------------------------------------------------------------
   Panels (Split Layout)
   -------------------------------------------------------------------------- */

.panels {
  display: grid;
  grid-template-columns: 1fr 6px 1.5fr;
  overflow: hidden;
}

.mobile-tabs {
  display: none;
}

/* Editor Panel */
.editor-panel {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--editor-bg);
  border-right: 1px solid var(--ui-border);
}

.editor-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px;
  border-bottom: 1px solid var(--ui-border);
  font-size: 12px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  color: var(--ui-text-muted);
  user-select: none;
}

.checkbox-label input[type="checkbox"] {
  accent-color: var(--ui-accent);
}

.editor-wrapper {
  display: flex;
  flex: 1;
  overflow: hidden;
  position: relative;
}

.line-numbers {
  width: 40px;
  padding: 8px 8px 8px 4px;
  background: var(--editor-line-bg);
  color: var(--editor-line-text);
  font-family: var(--mono-font);
  font-size: 13px;
  line-height: var(--line-height);
  text-align: right;
  overflow: hidden;
  user-select: none;
  flex-shrink: 0;
  border-right: 1px solid var(--ui-border);
}

.editor-textarea {
  flex: 1;
  padding: 8px 12px;
  border: none;
  outline: none;
  resize: none;
  background: var(--editor-bg);
  color: var(--editor-text);
  font-family: var(--mono-font);
  font-size: 13px;
  line-height: var(--line-height);
  tab-size: 4;
  white-space: pre;
  overflow: auto;
}

.editor-textarea::placeholder {
  color: var(--ui-text-muted);
}

.editor-textarea.grid-visible {
  background-image:
    repeating-linear-gradient(
      90deg,
      var(--grid-color) 0,
      var(--grid-color) 1px,
      transparent 1px,
      transparent var(--char-width)
    ),
    repeating-linear-gradient(
      0deg,
      var(--grid-color) 0,
      var(--grid-color) 1px,
      transparent 1px,
      transparent var(--line-height)
    );
  background-position: 12px 8px;
}

/* Resize Handle */
.resize-handle {
  background: var(--ui-border);
  cursor: col-resize;
  position: relative;
  transition: background 0.15s;
  z-index: 5;
}

.resize-handle:hover,
.resize-handle.dragging {
  background: var(--ui-accent);
}

/* Preview Panel */
.preview-panel {
  display: flex;
  overflow: hidden;
  background: var(--diagram-bg);
  position: relative;
}

.preview-container {
  flex: 1;
  overflow: hidden;
  position: relative;
  cursor: grab;
}

.preview-container.panning {
  cursor: grabbing;
}

.preview-content {
  transform-origin: 0 0;
  position: absolute;
  top: 0;
  left: 0;
  will-change: transform;
}

.preview-content svg {
  display: block;
}

/* Preview placeholder */
.preview-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ui-text-muted);
  font-size: 15px;
  pointer-events: none;
}

/* --------------------------------------------------------------------------
   Status Bar
   -------------------------------------------------------------------------- */

.status-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 16px;
  background: var(--ui-bg-secondary);
  border-top: 1px solid var(--ui-border);
  font-size: 11px;
  color: var(--ui-text-muted);
  font-variant-numeric: tabular-nums;
}

.status-sep {
  opacity: 0.4;
}

.status-spacer {
  flex: 1;
}

.status-hint {
  opacity: 0.6;
}

/* --------------------------------------------------------------------------
   Drop Overlay
   -------------------------------------------------------------------------- */

.drop-overlay {
  position: fixed;
  inset: 0;
  background: rgba(59, 130, 246, 0.12);
  backdrop-filter: blur(4px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 100;
  pointer-events: none;
}

.drop-overlay.visible {
  display: flex;
}

.drop-message {
  padding: 24px 40px;
  background: var(--ui-bg);
  border: 2px dashed var(--ui-accent);
  border-radius: 12px;
  font-size: 16px;
  font-weight: 500;
  color: var(--ui-accent);
  box-shadow: var(--ui-shadow);
}

/* --------------------------------------------------------------------------
   View Transitions
   -------------------------------------------------------------------------- */

::view-transition-old(root),
::view-transition-new(root) {
  animation-duration: 0.25s;
}

/* --------------------------------------------------------------------------
   Responsive — Mobile
   -------------------------------------------------------------------------- */

@media (max-width: 768px) {
  .toolbar {
    padding: 0 8px;
    gap: 6px;
  }

  .app-title {
    display: none;
  }

  .toolbar-center {
    gap: 6px;
  }

  .separator {
    display: none;
  }

  .panels {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }

  .mobile-tabs {
    display: flex;
    border-bottom: 1px solid var(--ui-border);
    background: var(--ui-bg-secondary);
  }

  .tab {
    flex: 1;
    padding: 8px;
    border: none;
    background: none;
    color: var(--ui-text-muted);
    font-family: inherit;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    border-bottom: 2px solid transparent;
  }

  .tab.active {
    color: var(--ui-accent);
    border-bottom-color: var(--ui-accent);
  }

  .resize-handle {
    display: none;
  }

  .editor-panel,
  .preview-panel {
    display: none;
  }

  .editor-panel.active,
  .preview-panel.active {
    display: flex;
  }
}

/* --------------------------------------------------------------------------
   Print
   -------------------------------------------------------------------------- */

@media print {
  .toolbar,
  .editor-panel,
  .resize-handle,
  .status-bar,
  .mobile-tabs,
  .drop-overlay {
    display: none !important;
  }

  .panels {
    display: block;
  }

  .preview-panel {
    width: 100%;
    height: auto;
    overflow: visible;
    background: #ffffff !important;
  }

  .preview-content {
    position: static;
    transform: none !important;
  }
}

/* --------------------------------------------------------------------------
   Interactive Features — Spotlight / Flow / Build / Presentation
   -------------------------------------------------------------------------- */

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

.btn.active {
  background: var(--ui-accent);
  color: #fff;
  border-color: var(--ui-accent);
}

/* Spotlight dimming & highlighting */
.diagram-dimmed {
  opacity: 0.1;
  transition: opacity 0.3s ease;
}

.diagram-highlighted {
  opacity: 1;
  transition: opacity 0.3s ease;
}

.diagram-visited {
  opacity: 0.55;
  transition: opacity 0.3s ease;
}

.diagram-box-glow {
  filter: drop-shadow(0 0 8px var(--diagram-stroke));
}

/* Data flow dots */
.flow-dot {
  fill: var(--diagram-arrow);
  opacity: 0.85;
}

.flow-dot-trail {
  fill: var(--diagram-arrow);
  opacity: 0.3;
}

/* --------------------------------------------------------------------------
   Presentation Mode
   -------------------------------------------------------------------------- */

.presentation-active .editor-panel,
.presentation-active .resize-handle {
  display: none !important;
}

.presentation-active .panels {
  grid-template-columns: 1fr !important;
}

.present-controls {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 20px;
  background: var(--ui-bg);
  border: 1px solid var(--ui-border);
  border-radius: 10px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
  z-index: 20;
  font-size: 13px;
  user-select: none;
}

.present-step-display {
  min-width: 60px;
  text-align: center;
  font-variant-numeric: tabular-nums;
  color: var(--ui-text-muted);
  font-weight: 500;
}