/* ================================================================
   DataVisu compare slider (video ↔ trajectory map)
   Self-contained, dark-themed; embedded as a "stage" inside the
   light-themed dataset pages. Everything scoped under .dv-stage.
   ================================================================ */

.dv-stage {
  --dv-bg-deep: #04070d;
  --dv-bg-mid: #0a1320;
  --dv-line: rgba(140, 200, 255, 0.12);
  --dv-line-strong: rgba(140, 200, 255, 0.28);
  --dv-text-strong: #f3f8ff;
  --dv-text: #cfd9ec;
  --dv-text-dim: #8aa0c2;
  --dv-accent: #4ea0ff;
  --dv-accent-bright: #7dc6ff;
  --dv-accent-glow: rgba(78, 160, 255, 0.45);
  --dv-cyan: #5fe6e0;
  --dv-pane-radius: 14px;

  max-width: 1040px;
  margin: 0 auto;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

.dv-compare {
  position: relative;
  aspect-ratio: 16 / 9;
  background: #02050a;
  border: 1px solid var(--dv-line);
  border-radius: var(--dv-pane-radius);
  overflow: hidden;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.18);
  user-select: none;
  -webkit-user-select: none;
  color: var(--dv-text);
  font-size: 13px;
}

.dv-layer {
  position: absolute;
  inset: 0;
  overflow: hidden;
}
.dv-layer-video {
  clip-path: inset(0 calc(100% - var(--dv-split-pos, 50%)) 0 0);
}
.dv-layer-map {
  clip-path: inset(0 0 0 var(--dv-split-pos, 50%));
}

/* Swap mode: video on right, trajectory map on left.  Mirrors the clip-paths,
   loading curtains, and tag positions so the divider still parts the same two
   panes visually — only the side each one lives on is flipped. */
.dv-stage.dv-swap .dv-layer-video {
  clip-path: inset(0 0 0 var(--dv-split-pos, 50%));
}
.dv-stage.dv-swap .dv-layer-map {
  clip-path: inset(0 calc(100% - var(--dv-split-pos, 50%)) 0 0);
}
.dv-stage.dv-swap .dv-video-loading { left: 50%; right: 0; }
.dv-stage.dv-swap .dv-map-loading   { left: 0;   right: 50%; }
.dv-stage.dv-swap .dv-tag-left  { left: auto; right: 18px; }
.dv-stage.dv-swap .dv-tag-right { right: auto; left: 18px; }

.dv-layer-video video {
  width: 100%;
  height: 100%;
  object-fit: contain;
  background: black;
  display: block;
}
.dv-layer-map canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.dv-tag {
  position: absolute;
  top: 14px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 6px 14px;
  background: rgba(4, 10, 22, 0.72);
  border: 1px solid var(--dv-line);
  border-radius: 999px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  font-size: 12.5px;
  color: var(--dv-text);
  letter-spacing: 0.02em;
  pointer-events: none;
  white-space: nowrap;
}
.dv-tag-left { left: 18px; }
.dv-tag-right { right: 18px; }
.dv-pane-meta {
  color: var(--dv-text-dim);
  font-feature-settings: "tnum";
  font-size: 11.5px;
}
.dv-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  box-shadow: 0 0 12px currentColor;
}
.dv-dot-blue { background: var(--dv-accent-bright); color: var(--dv-accent-bright); }
.dv-dot-cyan { background: var(--dv-cyan); color: var(--dv-cyan); }

.dv-divider {
  position: absolute;
  top: 0;
  bottom: 0;
  left: var(--dv-split-pos, 50%);
  width: 2px;
  background: linear-gradient(180deg,
    rgba(255, 255, 255, 0.0) 0%,
    rgba(255, 255, 255, 0.55) 12%,
    rgba(255, 255, 255, 0.85) 50%,
    rgba(255, 255, 255, 0.55) 88%,
    rgba(255, 255, 255, 0.0) 100%);
  transform: translateX(-1px);
  box-shadow: 0 0 18px rgba(125, 198, 255, 0.55);
  z-index: 4;
  pointer-events: none;
}
.dv-handle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(8, 18, 36, 0.85);
  border: 2px solid var(--dv-accent-bright);
  box-shadow: 0 0 22px var(--dv-accent-glow), inset 0 0 12px rgba(125, 198, 255, 0.18);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 9px;
  cursor: ew-resize;
  pointer-events: auto;
  transition: transform 0.15s ease, box-shadow 0.2s ease;
  touch-action: none;
}
.dv-handle:hover,
.dv-handle:focus-visible {
  transform: translate(-50%, -50%) scale(1.08);
  box-shadow: 0 0 28px var(--dv-accent-glow), inset 0 0 14px rgba(125, 198, 255, 0.28);
  outline: none;
}
.dv-handle .dv-arrow {
  color: var(--dv-accent-bright);
  font-size: 18px;
  line-height: 1;
  font-weight: 700;
  pointer-events: none;
}
.dv-compare.dragging .dv-handle { cursor: ew-resize; }

.dv-legend {
  position: absolute;
  right: 18px;
  bottom: 16px;
  z-index: 5;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  align-items: center;
  padding: 8px 14px;
  background: rgba(4, 10, 22, 0.72);
  border: 1px solid var(--dv-line);
  border-radius: 10px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: var(--dv-text);
  font-size: 12px;
  letter-spacing: 0.02em;
  pointer-events: none;
}
.dv-legend .dv-legend-title {
  color: var(--dv-text-dim);
  font-size: 11.5px;
  margin-right: 4px;
  letter-spacing: 0.06em;
}
.dv-legend .dv-legend-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--dv-text);
}
.dv-legend .dv-legend-swatch {
  width: 14px;
  height: 4px;
  border-radius: 2px;
  box-shadow: 0 0 8px currentColor;
}

.dv-video-loading, .dv-map-loading {
  position: absolute;
  top: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--dv-text-dim);
  font-size: 14px;
  background: rgba(2, 5, 10, 0.65);
  transition: opacity 0.4s ease;
  z-index: 3;
}
.dv-video-loading { left: 0; right: 50%; }
.dv-map-loading { left: 50%; right: 0; }
.dv-video-loading.hide, .dv-map-loading.hide {
  opacity: 0;
  pointer-events: none;
}

/* ===== Controls =========================================== */
.dv-controls {
  margin-top: 14px;
  padding: 14px 18px;
  background: var(--dv-bg-mid);
  border: 1px solid var(--dv-line);
  border-radius: var(--dv-pane-radius);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  color: var(--dv-text);
  font-size: 13px;
}
.dv-btn {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--dv-line-strong);
  background: rgba(78, 160, 255, 0.12);
  color: var(--dv-text-strong);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s ease;
}
.dv-btn:hover {
  background: rgba(78, 160, 255, 0.22);
  border-color: var(--dv-accent);
}
.dv-seek {
  flex: 1 1 240px;
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 200px;
}
.dv-seek-bar {
  flex: 1;
  appearance: none;
  -webkit-appearance: none;
  height: 4px;
  background: rgba(140, 200, 255, 0.18);
  border-radius: 2px;
}
.dv-seek-bar::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--dv-accent-bright);
  box-shadow: 0 0 8px var(--dv-accent-glow);
  cursor: pointer;
}
.dv-seek-bar::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--dv-accent-bright);
  border: none;
}
.dv-seek-time {
  font-feature-settings: "tnum";
  font-size: 12.5px;
  color: var(--dv-text-dim);
  min-width: 100px;
  text-align: right;
}
.dv-speed-group {
  display: inline-flex;
  border: 1px solid var(--dv-line);
  border-radius: 8px;
  overflow: hidden;
}
.dv-speed-btn {
  background: transparent;
  color: var(--dv-text-dim);
  border: none;
  padding: 7px 12px;
  cursor: pointer;
  font-size: 12.5px;
  transition: all 0.18s ease;
  font-family: inherit;
}
.dv-speed-btn:hover { color: var(--dv-text-strong); }
.dv-speed-btn.active {
  background: rgba(78, 160, 255, 0.2);
  color: var(--dv-text-strong);
}
.dv-layer-toggles {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}
.dv-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--dv-text-dim);
  font-size: 12.5px;
  cursor: pointer;
  user-select: none;
}
.dv-toggle input { accent-color: var(--dv-accent); }
.dv-toggle:hover { color: var(--dv-text); }

.dv-caption {
  text-align: center;
  font-size: 13px;
  color: var(--muted, #6b6b66);
  margin-top: 14px;
  font-style: italic;
}

@media (max-width: 640px) {
  .dv-controls { padding: 12px 14px; gap: 12px; }
  .dv-seek-time { min-width: 80px; font-size: 11.5px; }
  .dv-speed-btn { padding: 6px 9px; font-size: 11.5px; }
  .dv-toggle { font-size: 11.5px; }
  .dv-tag { font-size: 11px; padding: 5px 11px; }
  .dv-legend { right: 10px; bottom: 10px; padding: 6px 10px; font-size: 11px; }
}