:root {
  --hku-green: #003D33;
  --hku-light: #e8f5f0;
  --accent: #00b894;
  --accent-dim: #00b89433;
  --think-bg: #1a1a2e;
  --think-text: #a8e6cf;
  --tool-bg: #16213e;
  --tool-text: #f8c291;
  --result-bg: #0f3460;
  --result-text: #e2e2e2;
  --positive: #00b894;
  --negative: #e17055;
  --card-shadow: 0 4px 24px rgba(0,0,0,.08);
  --radius: 12px;
  --mono: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
}

* { box-sizing: border-box; }

.demo-section {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.demo-section h2 {
  font-family: 'Google Sans', sans-serif;
  font-size: 2rem;
  color: var(--hku-green);
  text-align: center;
  margin-bottom: .4rem;
}
.demo-subtitle {
  text-align: center;
  color: #666;
  font-size: 1rem;
  margin-bottom: 2rem;
}

/* Case selector cards */
.case-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}
.case-card {
  position: relative;
  background: #fff;
  border: 2px solid #e0e0e0;
  border-radius: var(--radius);
  padding: 1rem;
  cursor: pointer;
  transition: all .25s ease;
  overflow: hidden;
}
.case-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--card-shadow); }
.case-card.active { border-color: var(--hku-green); background: var(--hku-light); }
.case-card .type-badge {
  display: inline-block;
  font-size: .7rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: .5px;
}
.type-SM { background: #dfe6e9; color: #2d3436; }
.type-CC { background: #ffeaa7; color: #6c5b00; }
.type-OC { background: #fab1a0; color: #6b2c18; }
.case-card h4 { margin: .5rem 0 .25rem; font-size: 1.1rem; color: var(--hku-green); }
.case-card .prompts-preview {
  margin-top: .5rem;
  font-size: .72rem;
  font-family: var(--mono);
}
.case-card .prompts-preview span { display: block; padding: 1px 0; }
.case-card .prompts-preview .pos { color: var(--positive); }
.case-card .prompts-preview .neg { color: var(--negative); }

/* Main viewer */
.demo-viewer {
  display: none;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  overflow: hidden;
}
.demo-viewer.visible { display: block; }

.viewer-header {
  background: var(--hku-green);
  color: #fff;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}
.viewer-header h3 { margin: 0; font-size: 1.1rem; flex: 1; }

/* Prompt toggle */
.prompt-toggle {
  display: flex;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,.3);
}
.prompt-toggle button {
  padding: .4rem 1rem;
  border: none;
  font-size: .8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all .2s;
  background: transparent;
  color: rgba(255,255,255,.6);
}
.prompt-toggle button.active-pos { background: var(--positive); color: #fff; }
.prompt-toggle button.active-neg { background: var(--negative); color: #fff; }

.viewer-body {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 520px;
}
.demo-viewer { margin-bottom: 2rem; }

/* Left panel: image */
.image-panel {
  background: #1a1a1a;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  position: relative;
}
.image-panel img {
  max-width: 100%;
  max-height: 420px;
  border-radius: 8px;
  object-fit: contain;
}
.image-label {
  position: absolute;
  bottom: .75rem;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0,0,0,.7);
  color: #fff;
  font-size: .7rem;
  padding: 3px 10px;
  border-radius: 20px;
  white-space: nowrap;
}

/* Right panel: agent trace */
.trace-panel {
  display: flex;
  flex-direction: column;
  max-height: 600px;
}

.trace-scroll {
  flex: 1;
  overflow-y: auto;
  padding: 1rem;
  scroll-behavior: smooth;
}

/* Step blocks */
.step-block {
  margin-bottom: 1rem;
  opacity: 0;
  transform: translateY(12px);
  transition: all .5s cubic-bezier(.22,1,.36,1);
}
.step-block.visible {
  opacity: 1;
  transform: translateY(0);
}

.step-query {
  background: linear-gradient(135deg, var(--hku-green), #005a4a);
  color: #fff;
  padding: .75rem 1rem;
  border-radius: var(--radius);
  font-size: .85rem;
}
.step-query .concept {
  font-weight: 700;
  font-size: 1rem;
  display: block;
  margin-top: .25rem;
}

.step-think {
  background: var(--think-bg);
  color: var(--think-text);
  padding: .75rem 1rem;
  border-radius: var(--radius);
  font-size: .8rem;
  line-height: 1.55;
  font-family: var(--mono);
  position: relative;
}
.step-think::before {
  content: 'THINK';
  position: absolute;
  top: .4rem;
  right: .5rem;
  font-size: .55rem;
  font-weight: 700;
  color: rgba(168,230,207,.4);
  letter-spacing: 1px;
}

.step-tool {
  background: var(--tool-bg);
  color: var(--tool-text);
  padding: .6rem 1rem;
  border-radius: var(--radius);
  font-size: .8rem;
  font-family: var(--mono);
  display: flex;
  align-items: center;
  gap: .5rem;
}
.step-tool .tool-icon { font-size: 1.1rem; }
.tool-name { font-weight: 700; }
.tool-params { color: rgba(248,194,145,.6); font-size: .72rem; }

.step-result {
  background: var(--result-bg);
  color: var(--result-text);
  padding: .6rem 1rem;
  border-radius: var(--radius);
  font-size: .78rem;
  line-height: 1.5;
  border-left: 3px solid #3498db;
}
.result-images {
  display: flex;
  gap: .5rem;
  margin-top: .5rem;
  flex-wrap: wrap;
}
.result-img {
  max-width: 180px;
  max-height: 140px;
  border-radius: 6px;
  cursor: pointer;
  transition: all .3s ease;
  border: 1px solid rgba(52,152,219,.3);
  object-fit: cover;
}
.result-img:hover { border-color: #3498db; transform: scale(1.03); }
.result-img.expanded {
  max-width: 100%;
  max-height: 400px;
  object-fit: contain;
}
.step-result .img-placeholder {
  display: inline-block;
  background: rgba(52,152,219,.2);
  border: 1px dashed #3498db;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: .7rem;
  margin-left: .3rem;
}

.step-outcome {
  text-align: center;
  padding: .85rem 1rem;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: .95rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
}
.outcome-icon { font-size: 1.3rem; }
.outcome-correct { background: #d4edda; color: #155724; border: 2px solid #28a745; }
.outcome-wrong { background: #f8d7da; color: #721c24; border: 2px solid #dc3545; }

/* Playback controls */
.playback-bar {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .75rem 1rem;
  border-top: 1px solid #eee;
  background: #fafafa;
}
.playback-bar button {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: none;
  background: var(--hku-green);
  color: #fff;
  font-size: 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all .2s;
}
.playback-bar button:hover { background: #005a4a; transform: scale(1.08); }
.playback-bar button:disabled { background: #ccc; cursor: default; transform: none; }
.playback-bar .progress-track {
  flex: 1;
  height: 4px;
  background: #e0e0e0;
  border-radius: 2px;
  overflow: hidden;
}
.playback-bar .progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
  transition: width .3s ease;
}
.playback-bar .step-counter {
  font-size: .75rem;
  color: #888;
  min-width: 60px;
  text-align: right;
  font-family: var(--mono);
}
.speed-btn {
  font-size: .7rem !important;
  width: auto !important;
  padding: 0 8px !important;
  border-radius: 4px !important;
  font-family: var(--mono);
}

/* Typing cursor animation */
@keyframes blink { 50% { opacity: 0; } }
.typing-cursor::after {
  content: '|';
  animation: blink 1s step-end infinite;
  color: var(--think-text);
  font-weight: 300;
}

/* Responsive */
@media (max-width: 768px) {
  .viewer-body { grid-template-columns: 1fr; }
  .image-panel { max-height: 280px; }
  .trace-panel { max-height: 400px; }
}