/* ============================================================
   css/layouts/preview.css
   Zolto v8.1.0 — Preview Pane Layout & Rendered Content Styles
   ============================================================
   Purpose:
   - Preview pane chrome (toolbar, scroll container)
   - Rendered document layout and block spacing
   - Diagram, chart, vector, math figure wrappers
   - Spatial layout wrappers (grid, flex, canvas, presentation)
   - Lazy / streaming placeholder states
   - Scroll sync indicator
   - All values via CSS custom properties from variables.css
   ============================================================ */


/* ─────────────────────────────────────────────────────────────
   1. Preview Pane Shell
   ───────────────────────────────────────────────────────────── */

.zolto-preview-pane {
  display:        flex;
  flex-direction: column;
  flex:           1;
  min-width:      var(--preview-min-width);
  overflow:       hidden;
  background:     var(--preview-bg);
  position:       relative;
}


/* ─────────────────────────────────────────────────────────────
   2. Preview Toolbar
   ───────────────────────────────────────────────────────────── */

.zolto-preview-toolbar {
  display:      flex;
  align-items:  center;
  height:       var(--preview-toolbar-height);
  min-height:   var(--preview-toolbar-height);
  flex-shrink:  0;
  padding:      0 var(--space-4);
  background:   var(--toolbar-bg);
  border-bottom: 1px solid var(--toolbar-border);
  gap:          var(--space-2);
}

.zolto-preview-label {
  font-size:      var(--text-xs);
  font-weight:    var(--weight-semibold);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color:          var(--text-faint);
  user-select:    none;
}


/* ─────────────────────────────────────────────────────────────
   3. Preview Scroll Container
   ───────────────────────────────────────────────────────────── */

.zolto-preview {
  flex:       1;
  overflow-y: auto;
  overflow-x: hidden;
  padding:    var(--preview-padding-y) var(--preview-padding-x);
  background: var(--preview-bg);
  position:   relative;

  /* Smooth scrolling for anchor links */
  scroll-behavior: smooth;

  /* Indent nested scroll areas nicely */
  scroll-padding-top: var(--space-6);
}

/* Constrain prose width */
.zolto-preview > * {
  max-width: var(--preview-max-width);
  margin-inline: auto;
}

/* Full-width override for layouts that span the pane */
.zolto-preview > .zolto-grid,
.zolto-preview > .zolto-flex,
.zolto-preview > .zolto-canvas,
.zolto-preview > .zolto-whiteboard,
.zolto-preview > .zolto-presentation,
.zolto-preview > .zolto-split,
.zolto-preview > .zolto-table-wrapper,
.zolto-preview > .zolto-diagram,
.zolto-preview > .zolto-chart,
.zolto-preview > .zolto-vector {
  max-width: none;
}


/* ─────────────────────────────────────────────────────────────
   4. Block spacing — gap between all top-level rendered nodes
   ───────────────────────────────────────────────────────────── */

.zolto-preview > * + * {
  margin-top: var(--prose-block-gap);
}

/* Tighter gap after headings */
.zolto-preview > .zolto-heading + * {
  margin-top: var(--prose-heading-gap);
}

/* No top margin on the very first block */
.zolto-preview > *:first-child {
  margin-top: 0;
}


/* ─────────────────────────────────────────────────────────────
   5. Math Block Figure
   ───────────────────────────────────────────────────────────── */

.zolto-math-block {
  background:    var(--math-block-bg);
  border:        1px solid var(--math-block-border);
  border-radius: var(--radius-md);
  padding:       var(--math-block-padding);
  text-align:    center;
  overflow-x:    auto;
}

.zolto-math-equation {
  display:         flex;
  align-items:     center;
  justify-content: center;
  overflow-x:      auto;
}

/* KaTeX overrides — ensure colours match theme */
.zolto-math-block .katex,
.zolto-math-inline .katex {
  color: var(--text-main);
}

/* Math plot figure */
.zolto-math-plot {
  background:    var(--math-plot-bg);
  border:        1px solid var(--math-block-border);
  border-radius: var(--radius-md);
  overflow:      hidden;
}

.zolto-plot-svg {
  display: block;
  width:   100%;
  height:  auto;
}


/* ─────────────────────────────────────────────────────────────
   6. Diagram Figure
   ───────────────────────────────────────────────────────────── */

.zolto-diagram {
  border:        1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow:      hidden;
  background:    var(--diagram-bg);
}

.zolto-diagram-canvas {
  overflow:   auto;
  max-height: 600px;
  cursor:     grab;
}

.zolto-diagram-canvas:active {
  cursor: grabbing;
}

.zolto-diagram-canvas svg {
  display: block;
  width:   100%;
  height:  auto;
  min-width: 300px;
}

/* Interactive overlay hints */
.zolto-diagram[data-interactive="true"] .zolto-diagram-canvas::after {
  content:        'Scroll to zoom · Drag to pan';
  position:       absolute;
  bottom:         var(--space-2);
  right:          var(--space-3);
  font-size:      var(--text-xs);
  color:          var(--text-faint);
  pointer-events: none;
  opacity:        0;
  transition:     opacity var(--duration-normal) var(--ease-out);
}

.zolto-diagram[data-interactive="true"]:hover .zolto-diagram-canvas::after {
  opacity: 1;
}


/* ─────────────────────────────────────────────────────────────
   7. Chart Figure
   ───────────────────────────────────────────────────────────── */

.zolto-chart {
  border:        1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background:    var(--diagram-bg);
  padding:       var(--space-5);
  overflow:      hidden;
}

.zolto-chart-svg {
  display: block;
  width:   100%;
  height:  auto;
}

.zolto-chart-legend {
  display:         flex;
  flex-wrap:       wrap;
  gap:             var(--space-3);
  justify-content: center;
  margin-top:      var(--space-4);
}

.zolto-chart-legend-item {
  display:     flex;
  align-items: center;
  gap:         var(--space-1-5);
  font-size:   var(--text-xs);
  color:       var(--text-mute);
}

.zolto-chart-legend-swatch {
  width:         10px;
  height:        10px;
  border-radius: var(--radius-sm);
  flex-shrink:   0;
}


/* ─────────────────────────────────────────────────────────────
   8. Vector Scene
   ───────────────────────────────────────────────────────────── */

.zolto-vector {
  border:        1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background:    var(--diagram-bg);
  overflow:      hidden;
  position:      relative;
}

.zolto-vector-svg {
  display:   block;
  width:     100%;
  height:    auto;
  max-width: 100%;
}


/* ─────────────────────────────────────────────────────────────
   9. Embed (images, video, iframes)
   ───────────────────────────────────────────────────────────── */

.zolto-embed {
  margin-bottom: var(--prose-block-gap);
}

.zolto-embed-image {
  text-align: center;
}

.zolto-embed-img {
  max-width:     100%;
  height:        auto;
  border-radius: var(--embed-radius);
  border:        1px solid var(--embed-border);
  display:       inline-block;
}

.zolto-embed-ratio {
  position:       relative;
  width:          100%;
  padding-bottom: var(--ratio, 56.25%);
  border-radius:  var(--embed-radius);
  overflow:       hidden;
  background:     var(--bg-surface);
  border:         1px solid var(--embed-border);
}

.zolto-embed-iframe {
  position: absolute;
  inset:    0;
  width:    100%;
  height:   100%;
}

.zolto-embed-youtube .zolto-embed-ratio,
.zolto-embed-vimeo   .zolto-embed-ratio {
  --ratio: 56.25%; /* 16:9 */
}


/* ─────────────────────────────────────────────────────────────
   10. Spatial Layouts
   ───────────────────────────────────────────────────────────── */

/* Grid */
.zolto-grid {
  display:               grid;
  grid-template-columns: repeat(var(--grid-cols, 1), minmax(0, 1fr));
  gap:                   var(--grid-gap, var(--space-5));
  grid-auto-flow:        row;
}

/* Auto-fill variant */
.zolto-grid[data-auto="true"] {
  grid-template-columns: repeat(
    auto-fill,
    minmax(var(--grid-min-col-width, 200px), 1fr)
  );
}

/* Flex */
.zolto-flex {
  display:         flex;
  flex-direction:  var(--flex-direction, row);
  flex-wrap:       var(--flex-wrap, wrap);
  gap:             var(--flex-gap, var(--space-4));
  align-items:     var(--flex-align, flex-start);
  justify-content: var(--flex-justify, flex-start);
}

/* Canvas (absolute positioned children) */
.zolto-canvas {
  position:      relative;
  width:         var(--canvas-width, 100%);
  height:        var(--canvas-height, 480px);
  overflow:      hidden;
  background:    var(--bg-surface);
  border:        1px solid var(--border-subtle);
  border-radius: var(--radius-md);
}

.zolto-canvas[data-grid="true"] {
  background-image:
    linear-gradient(var(--diagram-grid-color) 1px, transparent 1px),
    linear-gradient(90deg, var(--diagram-grid-color) 1px, transparent 1px);
  background-size: 24px 24px;
}

/* Whiteboard */
.zolto-whiteboard {
  position:      relative;
  overflow:      hidden;
  background:    var(--bg-canvas);
  border:        1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  height:        var(--whiteboard-height, 600px);
  cursor:        grab;
}

.zolto-whiteboard:active {
  cursor: grabbing;
}

.zolto-whiteboard-viewport {
  position: absolute;
  inset:    0;
  overflow: hidden;
}

.zolto-whiteboard-content {
  position:   absolute;
  top:        0;
  left:       0;
  transform:  translate(var(--wb-x, 0px), var(--wb-y, 0px)) scale(var(--wb-zoom, 1));
  transform-origin: 0 0;
  will-change: transform;
}

/* Split */
.zolto-split {
  display:   flex;
  overflow:  hidden;
  border:    1px solid var(--border-subtle);
  border-radius: var(--radius-md);
}

.zolto-split-horizontal {
  flex-direction: row;
}

.zolto-split-vertical {
  flex-direction: column;
}

.zolto-split-pane {
  overflow: auto;
  min-width: 0;
  min-height: 0;
}

.zolto-split-pane-a {
  flex: 0 0 var(--split-ratio, 50%);
  max-width: var(--split-ratio, 50%);
}

.zolto-split-pane-b {
  flex: 1;
}

.zolto-split .zolto-split-handle {
  flex-shrink: 0;
  background:  var(--split-handle-bg);
}

.zolto-split-horizontal .zolto-split-handle {
  width:  var(--split-handle-width);
  cursor: col-resize;
}

.zolto-split-vertical .zolto-split-handle {
  height: var(--split-handle-width);
  cursor: row-resize;
}

/* Panel */
.zolto-panel {
  border:        1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow:      hidden;
  background:    var(--bg-surface);
}

.zolto-panel-header {
  display:         flex;
  align-items:     center;
  justify-content: space-between;
  padding:         var(--space-3) var(--space-4);
  background:      var(--bg-surface);
  border-bottom:   1px solid var(--border-subtle);
  cursor:          pointer;
  user-select:     none;
}

.zolto-panel-title {
  font-size:   var(--text-sm);
  font-weight: var(--weight-semibold);
  color:       var(--text-main);
}

.zolto-panel-toggle {
  color:       var(--text-faint);
  font-size:   var(--text-md);
  line-height: 1;
  width:       24px;
  height:      24px;
  display:     flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  transition:  background var(--duration-fast) var(--ease-out),
               color      var(--duration-fast) var(--ease-out);
}

.zolto-panel-toggle:hover {
  background: var(--bg-surface-2);
  color:      var(--text-mute);
}

.zolto-panel-body {
  padding:    var(--space-4);
  transition: height var(--duration-normal) var(--ease-out);
}

.zolto-panel[data-collapsed="true"] .zolto-panel-body {
  display: none;
}

.zolto-panel[data-collapsed="true"] .zolto-panel-header {
  border-bottom: none;
}


/* ─────────────────────────────────────────────────────────────
   11. Presentation & Slides
   ───────────────────────────────────────────────────────────── */

.zolto-presentation {
  border:        1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow:      hidden;
  background:    var(--slide-bg);
  position:      relative;
}

.zolto-slide-deck {
  position: relative;
}

.zolto-slide {
  display:       flex;
  flex-direction: column;
  justify-content: center;
  padding:       var(--space-12) var(--space-16);
  min-height:    480px;
  background:    var(--slide-bg);
  position:      relative;
}

.zolto-slide-hidden {
  display: none;
}

/* Slide layouts */
.zolto-slide-title {
  align-items: center;
  text-align:  center;
}

.zolto-slide-two-col,
.zolto-slide-three-col {
  flex-direction: row;
  align-items:    stretch;
  gap:            var(--space-8);
}

.zolto-slide-two-col   > * { flex: 1; min-width: 0; }
.zolto-slide-three-col > * { flex: 1; min-width: 0; }

.zolto-slide-media {
  padding: var(--space-6);
}

.zolto-slide-section {
  align-items: center;
  text-align:  center;
  background:  var(--accent-primary-subtle);
}

/* Slide navigation */
.zolto-slide-nav {
  display:         flex;
  align-items:     center;
  justify-content: center;
  gap:             var(--space-4);
  padding:         var(--space-2) var(--space-4);
  background:      var(--slide-nav-bg);
  border-top:      1px solid var(--slide-border);
}

.zolto-slide-prev,
.zolto-slide-next {
  width:           32px;
  height:          32px;
  border-radius:   var(--radius-sm);
  color:           var(--slide-nav-text);
  font-size:       1.2em;
  display:         flex;
  align-items:     center;
  justify-content: center;
  transition:      background var(--duration-fast) var(--ease-out),
                   color      var(--duration-fast) var(--ease-out);
}

.zolto-slide-prev:hover,
.zolto-slide-next:hover {
  background: var(--bg-surface-2);
  color:      var(--text-main);
}

.zolto-slide-counter {
  font-size:   var(--text-xs);
  font-family: var(--font-mono);
  color:       var(--slide-counter-text);
  min-width:   5ch;
  text-align:  center;
  font-variant-numeric: tabular-nums;
}


/* ─────────────────────────────────────────────────────────────
   12. Column Layout
   ───────────────────────────────────────────────────────────── */

.zolto-columns {
  display: flex;
  gap:     var(--space-6);
}

.zolto-column {
  flex:      1;
  min-width: 0;
}

/* 2-column → stack on narrow */
@media (max-width: 640px) {
  .zolto-columns {
    flex-direction: column;
  }
}


/* ─────────────────────────────────────────────────────────────
   13. Lazy & Streaming Render Placeholders
   ───────────────────────────────────────────────────────────── */

.zolto-lazy-placeholder {
  background:    var(--bg-surface);
  border:        1px dashed var(--border-subtle);
  border-radius: var(--radius-md);
  display:       flex;
  align-items:   center;
  justify-content: center;
  min-height:    120px;
  color:         var(--text-faint);
  font-size:     var(--text-sm);
  animation:     zolto-placeholder-pulse 1.8s ease-in-out infinite;
}

@keyframes zolto-placeholder-pulse {
  0%, 100% { opacity: 0.6; }
  50%       { opacity: 1;   }
}

.zolto-streaming-shell {
  position: relative;
}

.zolto-streaming-spinner {
  position:    absolute;
  top:         var(--space-3);
  right:       var(--space-3);
  width:       16px;
  height:      16px;
  border:      2px solid var(--border-subtle);
  border-top-color: var(--accent-primary);
  border-radius: 50%;
  animation:   zolto-spin 600ms linear infinite;
}

/* Skeleton loading blocks */
.zolto-skeleton {
  background:    linear-gradient(
    90deg,
    var(--bg-surface)    0%,
    var(--bg-surface-2)  50%,
    var(--bg-surface)    100%
  );
  background-size: 200% 100%;
  border-radius: var(--radius-sm);
  animation:     zolto-skeleton-shimmer 1.5s ease-in-out infinite;
}

@keyframes zolto-skeleton-shimmer {
  from { background-position: 200% 0; }
  to   { background-position: -200% 0; }
}


/* ─────────────────────────────────────────────────────────────
   14. Scroll Sync Indicator
   ───────────────────────────────────────────────────────────── */

/* Thin bar at top of preview indicating scroll sync is active */
.zolto-preview-pane[data-scroll-sync="true"]::before {
  content:    '';
  position:   absolute;
  top:        var(--preview-toolbar-height);
  left:       0;
  right:      0;
  height:     2px;
  background: linear-gradient(
    90deg,
    var(--accent-primary) var(--scroll-progress, 0%),
    transparent          var(--scroll-progress, 0%)
  );
  z-index:    var(--z-raised);
  pointer-events: none;
  transition: none;
}


/* ─────────────────────────────────────────────────────────────
   15. Responsive
   ───────────────────────────────────────────────────────────── */

@media (max-width: 1024px) {
  .zolto-preview {
    padding: var(--space-6) var(--space-6);
  }
}

@media (max-width: 768px) {
  .zolto-preview {
    padding: var(--space-5) var(--space-4);
  }

  .zolto-slide {
    padding:    var(--space-8) var(--space-6);
    min-height: 320px;
  }

  .zolto-slide-two-col,
  .zolto-slide-three-col {
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  .zolto-preview {
    padding: var(--space-4) var(--space-3);
  }

  /* Grid collapses to 1 column on phone */
  .zolto-grid {
    grid-template-columns: 1fr !important;
  }

  .zolto-slide {
    padding:    var(--space-6) var(--space-4);
    min-height: 260px;
  }
}

/* ─────────────────────────────────────────────────────────────
   16. Print — preview becomes the document
   ───────────────────────────────────────────────────────────── */

@media print {
  .zolto-preview-pane {
    flex:     1;
    overflow: visible;
  }

  .zolto-preview-toolbar {
    display: none;
  }

  .zolto-preview {
    padding:    0;
    max-width:  none;
    overflow:   visible;
  }

  /* Avoid page breaks inside figures */
  .zolto-math-block,
  .zolto-diagram,
  .zolto-chart,
  .zolto-vector,
  .zolto-card {
    page-break-inside: avoid;
    break-inside:      avoid;
  }

  /* Presentations print each slide on its own page */
  .zolto-slide {
    page-break-after: always;
    break-after:      always;
  }
}