/* ===================================================
   AI PRIMER — Global Styles
   =================================================== */

/* --- CSS Variables (Light Theme Default) --- */
:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f7f8fa;
  --bg-tertiary: #eef0f4;
  --bg-hover: #e8ebf0;
  --bg-active: #dce1e9;
  --bg-card: #ffffff;
  --text-primary: #1a1c24;
  --text-secondary: #5c6070;
  --text-tertiary: #8b909e;
  --border-primary: #d0d4dd;
  --border-secondary: #e4e7ed;
  --border-tertiary: #ebedf2;

  /* Brand Colors */
  --accent: #2e7d32;
  --accent-hover: #256428;
  --accent-soft: #e8f5e9;
  --accent-border: #a5d6a7;
  --accent2: #4caf50;
  --accent3: #81c784;

  /* Tag Colors */
  --tag-green-bg: #e8f5e9;
  --tag-green-text: #2e7d32;
  --tag-blue-bg: #e3f2fd;
  --tag-blue-text: #1565c0;
  --tag-amber-bg: #fff8e1;
  --tag-amber-text: #f57f17;
  --tag-red-bg: #ffebee;
  --tag-red-text: #c62828;
  --tag-purple-bg: #ede7f6;
  --tag-purple-text: #512da8;
  --tag-teal-bg: #e0f2f1;
  --tag-teal-text: #00695c;
  --tag-gray-bg: #eceff1;
  --tag-gray-text: #546e7a;

  /* Semantic */
  --highlight: #fff9c4;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,.08), 0 2px 4px rgba(0,0,0,.04);
  --shadow-lg: 0 10px 30px rgba(0,0,0,.10), 0 4px 8px rgba(0,0,0,.06);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;

  /* Header */
  --header-h: 52px;
  /* Sidebar */
  --sidebar-w: 240px;
  /* Content max */
  --content-max: 860px;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans KR', sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Consolas', monospace;
}

/* --- Dark Theme --- */
[data-theme="dark"] {
  --bg-primary: #0d0f14;
  --bg-secondary: #14161e;
  --bg-tertiary: #1a1d27;
  --bg-hover: #21253a;
  --bg-active: #2a2f44;
  --bg-card: #14161e;
  --text-primary: #e4e7ef;
  --text-secondary: #8b909e;
  --text-tertiary: #5c6070;
  --border-primary: #2a2f44;
  --border-secondary: #1e2231;
  --border-tertiary: #1a1d27;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,.4);
  --shadow-lg: 0 10px 30px rgba(0,0,0,.5);
  --tag-green-bg: #1b3d1f;
  --tag-green-text: #81c784;
  --tag-blue-bg: #1a2d47;
  --tag-blue-text: #64b5f6;
  --tag-amber-bg: #3d2f0a;
  --tag-amber-text: #ffd54f;
  --tag-red-bg: #3d1a1a;
  --tag-red-text: #ef9a9a;
  --tag-purple-bg: #2a1d47;
  --tag-purple-text: #ce93d8;
  --tag-teal-bg: #1a3d3a;
  --tag-teal-text: #80cbc4;
  --tag-gray-bg: #2a2f44;
  --tag-gray-text: #90a4ae;
  --highlight: #3d3520;
}

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 15px; }
body {
  font-family: var(--font-sans);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

/* --- App Layout --- */
.app { min-height: 100vh; display: flex; flex-direction: column; }

/* --- Header --- */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-tertiary);
  backdrop-filter: blur(12px);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  padding: 0 1.25rem;
}
.header-brand {
  display: flex;
  align-items: center;
  gap: .5rem;
}
.brand-icon { font-size: 1.4rem; }
.brand-title { font-size: 1rem; font-weight: 600; letter-spacing: -.01em; }
.brand-sub {
  font-size: .75rem;
  color: var(--text-tertiary);
  padding: 2px 8px;
  background: var(--bg-secondary);
  border-radius: 20px;
  border: 1px solid var(--border-secondary);
}
.header-actions { display: flex; gap: .5rem; }
.icon-btn {
  width: 34px; height: 34px;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--border-secondary);
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all .15s;
}
.icon-btn:hover { background: var(--bg-hover); color: var(--text-primary); }

/* --- App Body (sidebar + content) --- */
.app-body { display: flex; flex: 1; }

/* --- Sidebar --- */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--bg-primary);
  border-right: 1px solid var(--border-tertiary);
  position: sticky;
  top: var(--header-h);
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  padding: 1rem .75rem;
}
.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border-primary); border-radius: 4px; }
.sidebar-section { margin-bottom: 1.25rem; }
.sidebar-section-title {
  font-size: .7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-tertiary);
  padding: 0 .5rem;
  margin-bottom: .35rem;
}
.sidebar-link {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .4rem .5rem;
  border-radius: var(--radius-sm);
  font-size: .85rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all .12s;
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  text-decoration: none;
}
.sidebar-link:hover { background: var(--bg-hover); color: var(--text-primary); }
.sidebar-link.active { background: var(--accent-soft); color: var(--accent); font-weight: 500; }
.sidebar-link .link-icon { font-size: 1rem; flex-shrink: 0; }
.sidebar-link .link-label { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* --- Main Content --- */
.content {
  flex: 1;
  min-width: 0;
  padding: 2rem 2rem 4rem;
  max-width: calc(var(--content-max) + 4rem);
}

/* --- Section --- */
.section { display: none; animation: fadeUp .25s ease; }
.section.active { display: block; }
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- Hero --- */
.hero { margin-bottom: 2.5rem; }
.hero h1 { font-size: 1.9rem; font-weight: 600; line-height: 1.25; letter-spacing: -.02em; margin-bottom: .5rem; }
.hero p { font-size: 1rem; color: var(--text-secondary); line-height: 1.7; }
.hero-meta { margin-top: .75rem; display: flex; gap: .75rem; flex-wrap: wrap; }

/* --- Section Header --- */
.section-header { margin-bottom: 1.5rem; }
.section-header h2 { font-size: 1.4rem; font-weight: 600; letter-spacing: -.015em; margin-bottom: .4rem; }
.section-header p { font-size: .95rem; color: var(--text-secondary); line-height: 1.7; }

/* --- Card --- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-sm);
}
.card h3 { font-size: .95rem; font-weight: 600; margin-bottom: .6rem; }
.card p { font-size: .9rem; color: var(--text-secondary); line-height: 1.7; }
.card.full-p { font-size: .9rem; color: var(--text-secondary); line-height: 1.75; }
.card.nopad { padding: 0; overflow: hidden; }

/* --- Cards Grid --- */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: .75rem;
  margin-bottom: 1rem;
}
.cards-grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: .75rem;
  margin-bottom: 1rem;
}

/* --- Tag --- */
.tag {
  display: inline-block;
  font-size: .72rem;
  padding: 3px 10px;
  border-radius: 20px;
  margin: 2px;
  font-weight: 500;
  line-height: 1.5;
  white-space: nowrap;
}
.tag.green { background: var(--tag-green-bg); color: var(--tag-green-text); }
.tag.blue { background: var(--tag-blue-bg); color: var(--tag-blue-text); }
.tag.amber { background: var(--tag-amber-bg); color: var(--tag-amber-text); }
.tag.red { background: var(--tag-red-bg); color: var(--tag-red-text); }
.tag.purple { background: var(--tag-purple-bg); color: var(--tag-purple-text); }
.tag.teal { background: var(--tag-teal-bg); color: var(--tag-teal-text); }
.tag.gray { background: var(--tag-gray-bg); color: var(--tag-gray-text); }

/* --- Compare Grid --- */
.compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .75rem;
  margin-bottom: 1rem;
}
.compare-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: .75rem;
  margin-bottom: 1rem;
}
.compare-card {
  background: var(--bg-card);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-lg);
  padding: 1.1rem;
  box-shadow: var(--shadow-sm);
}
.compare-card.featured {
  border: 2px solid var(--accent-border);
  background: var(--accent-soft);
}
.compare-card h3 { font-size: .9rem; font-weight: 600; margin-bottom: .75rem; }
.compare-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: .5rem;
  padding: 5px 0;
  border-bottom: 1px solid var(--border-tertiary);
  font-size: .82rem;
}
.compare-row:last-child { border-bottom: none; }
.compare-row .label { color: var(--text-tertiary); flex-shrink: 0; }
.compare-row .value { color: var(--text-primary); font-weight: 500; text-align: right; }

/* --- Code Block --- */
.code-block {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-md);
  padding: .9rem 1.1rem;
  font-family: var(--font-mono);
  font-size: .82rem;
  color: var(--text-primary);
  line-height: 1.65;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
}
.code-block .comment { color: var(--text-tertiary); }
.code-block .keyword { color: #6c5ce7; font-weight: 500; }
.code-block .string { color: #e17055; }
.code-block .number { color: #00b894; }
[data-theme="dark"] .code-block .keyword { color: #a29bfe; }
[data-theme="dark"] .code-block .string { color: #fab1a0; }
[data-theme="dark"] .code-block .number { color: #55efc4; }

.code-inline {
  font-family: var(--font-mono);
  font-size: .82em;
  background: var(--bg-secondary);
  padding: 1px 6px;
  border-radius: 4px;
  border: 1px solid var(--border-secondary);
  color: var(--accent);
}

/* --- Timeline --- */
.timeline { position: relative; padding-left: 1.5rem; margin: .5rem 0; }
.timeline::before {
  content: "";
  position: absolute;
  left: .4rem;
  top: .25rem;
  bottom: .25rem;
  width: 1.5px;
  background: var(--border-primary);
}
.timeline-item { position: relative; margin-bottom: 1.25rem; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -1.25rem;
  top: .45rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-primary);
}
.timeline-item:last-child { margin-bottom: 0; }
.timeline-item h4 { font-size: .88rem; font-weight: 600; margin-bottom: .2rem; }
.timeline-item p { font-size: .83rem; color: var(--text-secondary); line-height: 1.6; }

/* --- Tabs --- */
.tabs { display: flex; gap: .35rem; flex-wrap: wrap; margin-bottom: 1rem; }
.tab-btn {
  padding: .45rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-secondary);
  background: none;
  color: var(--text-secondary);
  font-size: .85rem;
  cursor: pointer;
  transition: all .15s;
  font-family: var(--font-sans);
}
.tab-btn:hover { background: var(--bg-hover); color: var(--text-primary); }
.tab-btn.active {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: var(--accent-border);
  font-weight: 500;
}
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* --- Filter Buttons --- */
.filter-row { display: flex; gap: .5rem; flex-wrap: wrap; margin-bottom: 1rem; }
.filter-btn {
  padding: .4rem .9rem;
  border-radius: 20px;
  border: 1px solid var(--border-secondary);
  background: none;
  color: var(--text-secondary);
  font-size: .82rem;
  cursor: pointer;
  transition: all .15s;
  font-family: var(--font-sans);
}
.filter-btn:hover { background: var(--bg-hover); }
.filter-btn.active { background: var(--accent-soft); color: var(--accent); border-color: var(--accent-border); }

/* --- Provider Grid --- */
.provider-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: .6rem; margin-bottom: 1rem; }
.provider-card {
  background: var(--bg-card);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-lg);
  padding: .9rem;
  cursor: pointer;
  transition: all .15s;
  box-shadow: var(--shadow-sm);
}
.provider-card:hover { border-color: var(--border-primary); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.provider-card.selected { border: 2px solid var(--accent-border); background: var(--accent-soft); }
.provider-card h4 { font-size: .88rem; font-weight: 600; margin-bottom: .2rem; }
.provider-card p { font-size: .75rem; color: var(--text-tertiary); }
.provider-detail {
  background: var(--bg-card);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-lg);
  padding: 1.1rem;
  min-height: 80px;
  box-shadow: var(--shadow-sm);
}

/* --- Model Grid --- */
.model-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(195px, 1fr)); gap: .6rem; }
.model-card {
  background: var(--bg-card);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-lg);
  padding: .9rem;
  box-shadow: var(--shadow-sm);
  transition: all .15s;
}
.model-card:hover { border-color: var(--border-primary); box-shadow: var(--shadow-md); }
.model-card h4 { font-size: .88rem; font-weight: 600; margin: .3rem 0 .15rem; }
.model-card p { font-size: .78rem; color: var(--text-secondary); line-height: 1.5; }
.model-card.hidden { display: none; }

/* --- Progress Bar --- */
.progress-wrap { margin: .5rem 0; }
.progress-label { font-size: .82rem; color: var(--text-secondary); margin-bottom: .2rem; display: flex; justify-content: space-between; }
.progress-bar { height: 6px; border-radius: 3px; background: var(--bg-tertiary); overflow: hidden; }
.progress-fill { height: 100%; border-radius: 3px; background: var(--accent); transition: width .6s ease; }

/* --- Collapsible / Details --- */
.term-grid { display: flex; flex-direction: column; gap: .4rem; }
.term-card {
  background: var(--bg-card);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}
.term-card summary {
  font-size: .88rem;
  font-weight: 600;
  padding: .9rem 1.1rem;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}
.term-card summary::-webkit-details-marker { display: none; }
.term-card summary::after { content: "+"; color: var(--text-tertiary); font-size: 1.1rem; transition: transform .2s; font-weight: 300; }
.term-card[open] summary::after { content: "−"; transform: none; }
.term-card[open] summary { border-bottom: 1px solid var(--border-tertiary); }
.term-card p,
.term-card .term-body {
  font-size: .83rem;
  color: var(--text-secondary);
  padding: .8rem 1.1rem;
  line-height: 1.7;
}
.term-card .term-body ul { margin: .5rem 0 .5rem 1.2rem; }
.term-card .term-body li { margin-bottom: .25rem; }

/* --- Visualization Container --- */
.viz-container {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  margin-bottom: 1rem;
  overflow: hidden;
}
.viz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}
.viz-title { font-size: .9rem; font-weight: 600; }
.viz-subtitle { font-size: .78rem; color: var(--text-tertiary); margin-top: .15rem; }
.viz-controls { display: flex; gap: .5rem; flex-wrap: wrap; align-items: center; }

/* --- Perceptron SVG Styles --- */
.perceptron-svg { width: 100%; max-width: 600px; margin: 0 auto; display: block; }
.perceptron-svg text { font-family: var(--font-sans); fill: currentColor; }
.perceptron-svg .node-label { font-size: 11px; font-weight: 500; }
.perceptron-svg .weight-label { font-size: 10px; fill: var(--text-tertiary); }
.perceptron-svg .bias-label { font-size: 10px; fill: var(--text-tertiary); }
.perceptron-svg .connection { stroke: var(--border-primary); stroke-width: 1.5; transition: stroke .3s, stroke-width .3s; }
.perceptron-svg .connection.active { stroke: var(--accent); stroke-width: 2.5; }
.perceptron-svg .node { fill: var(--bg-card); stroke: var(--border-primary); stroke-width: 1.5; transition: fill .2s, stroke .2s; }
.perceptron-svg .node.input { fill: var(--tag-blue-bg); stroke: var(--tag-blue-text); }
.perceptron-svg .node.bias { fill: var(--tag-purple-bg); stroke: var(--tag-purple-text); }
.perceptron-svg .node.sum { fill: var(--tag-amber-bg); stroke: var(--tag-amber-text); }
.perceptron-svg .node.output { fill: var(--tag-green-bg); stroke: var(--tag-green-text); }
.perceptron-svg .node.active { fill: var(--accent-soft); stroke: var(--accent); }
.perceptron-svg .sum-circle { fill: var(--bg-secondary); stroke: var(--border-primary); stroke-width: 1.5; }
.perceptron-svg .step-indicator { font-size: 10px; fill: var(--text-tertiary); }

/* --- Network SVG --- */
.network-svg { width: 100%; max-width: 600px; margin: 0 auto; display: block; }
.network-svg text { font-family: var(--font-sans); fill: currentColor; }
.network-svg .layer-label { font-size: 10px; fill: var(--text-tertiary); font-weight: 500; text-transform: uppercase; letter-spacing: .05em; }
.network-svg .net-node { fill: var(--bg-card); stroke: var(--border-primary); stroke-width: 1.5; transition: fill .2s, stroke .2s; }
.network-svg .net-node.hl { fill: var(--accent-soft); stroke: var(--accent-border); }
.network-svg .net-conn { stroke: var(--border-secondary); stroke-width: .8; opacity: .6; }
.network-svg .net-conn.hl { stroke: var(--accent-border); opacity: 1; }

/* --- Attention Viz --- */
.attention-viz { overflow-x: auto; }
.attention-matrix { border-collapse: collapse; margin: .5rem 0; width: 100%; min-width: 280px; }
.attention-matrix th, .attention-matrix td {
  padding: 5px 8px;
  font-size: .75rem;
  text-align: center;
  border: 1px solid var(--border-tertiary);
  font-family: var(--font-mono);
}
.attention-matrix th { background: var(--bg-secondary); font-weight: 600; color: var(--text-secondary); }
.attention-matrix td { transition: background .3s; cursor: default; }
.attention-matrix td:hover { filter: brightness(.9); }
.word-row { display: flex; flex-wrap: wrap; gap: .4rem; margin-bottom: .5rem; align-items: center; }
.word-chip {
  padding: .3rem .6rem;
  border-radius: var(--radius-sm);
  font-size: .82rem;
  font-weight: 500;
  background: var(--bg-secondary);
  border: 1px solid var(--border-secondary);
  cursor: default;
  user-select: none;
  transition: all .15s;
}
.word-chip.q { background: var(--tag-blue-bg); border-color: var(--tag-blue-text); color: var(--tag-blue-text); }
.word-chip.k { background: var(--tag-purple-bg); border-color: var(--tag-purple-text); color: var(--tag-purple-text); }
.word-chip.v { background: var(--tag-amber-bg); border-color: var(--tag-amber-text); color: var(--tag-amber-text); }
.word-chip.highlight { background: var(--accent-soft); border-color: var(--accent-border); color: var(--accent); transform: scale(1.05); }
.word-chip-label { font-size: .7rem; color: var(--text-tertiary); }

/* --- ReAct Flow --- */
.react-flow { display: flex; flex-direction: column; gap: .5rem; }
.react-step {
  display: flex;
  gap: .75rem;
  align-items: flex-start;
  padding: .75rem;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  border: 1px solid var(--border-tertiary);
}
.react-step-icon { width: 28px; height: 28px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: .8rem; flex-shrink: 0; font-weight: 700; }
.react-step-icon.thought { background: var(--tag-purple-bg); color: var(--tag-purple-text); }
.react-step-icon.action { background: var(--tag-blue-bg); color: var(--tag-blue-text); }
.react-step-icon.obs { background: var(--tag-green-bg); color: var(--tag-green-text); }
.react-step-icon.answer { background: var(--accent-soft); color: var(--accent); }
.react-step-content { flex: 1; min-width: 0; }
.react-step-label { font-size: .7rem; font-weight: 600; text-transform: uppercase; letter-spacing: .05em; color: var(--text-tertiary); margin-bottom: .2rem; }
.react-step-text { font-size: .85rem; color: var(--text-primary); font-family: var(--font-mono); line-height: 1.5; word-break: break-word; }

/* --- Product Comparison Table --- */
.compare-table { width: 100%; border-collapse: collapse; margin-bottom: 1rem; }
.compare-table th, .compare-table td { padding: .6rem .8rem; font-size: .82rem; text-align: left; border-bottom: 1px solid var(--border-tertiary); }
.compare-table th { background: var(--bg-secondary); font-weight: 600; color: var(--text-secondary); }
.compare-table td:first-child { font-weight: 500; color: var(--text-primary); }
.compare-table tr:last-child td { border-bottom: none; }
.compare-table tr:hover td { background: var(--bg-hover); }
.compare-table .check { color: var(--accent); }
.compare-table .cross { color: var(--tag-red-text); }
.compare-table .partial { color: var(--tag-amber-text); }

/* --- Badge --- */
.badge { display: inline-block; font-size: .7rem; padding: 2px 8px; border-radius: 20px; font-weight: 500; }
.badge.green { background: var(--tag-green-bg); color: var(--tag-green-text); }
.badge.blue { background: var(--tag-blue-bg); color: var(--tag-blue-text); }
.badge.amber { background: var(--tag-amber-bg); color: var(--tag-amber-text); }
.badge.red { background: var(--tag-red-bg); color: var(--tag-red-text); }
.badge.purple { background: var(--tag-purple-bg); color: var(--tag-purple-text); }
.badge.teal { background: var(--tag-teal-bg); color: var(--tag-teal-text); }

/* --- Quiz Card --- */
.quiz-card {
  background: var(--bg-card);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-lg);
  padding: 1.1rem;
  margin-bottom: 1rem;
}
.quiz-question { font-size: .9rem; font-weight: 600; margin-bottom: .6rem; }
.quiz-options { display: flex; flex-direction: column; gap: .4rem; }
.quiz-option {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .55rem .8rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-secondary);
  background: var(--bg-secondary);
  cursor: pointer;
  font-size: .83rem;
  transition: all .15s;
  font-family: var(--font-sans);
}
.quiz-option:hover { border-color: var(--border-primary); background: var(--bg-hover); }
.quiz-option.correct { background: var(--tag-green-bg); border-color: var(--tag-green-text); color: var(--tag-green-text); }
.quiz-option.wrong { background: var(--tag-red-bg); border-color: var(--tag-red-text); color: var(--tag-red-text); }
.quiz-feedback { margin-top: .5rem; padding: .6rem .8rem; border-radius: var(--radius-sm); font-size: .82rem; display: none; }
.quiz-feedback.show { display: block; }
.quiz-feedback.correct-fb { background: var(--tag-green-bg); color: var(--tag-green-text); }
.quiz-feedback.wrong-fb { background: var(--tag-red-bg); color: var(--tag-red-text); }

/* --- Split Layout --- */
.split-2 { display: grid; grid-template-columns: 1fr 1fr; gap: .75rem; }
.split-2-1 { display: grid; grid-template-columns: 2fr 1fr; gap: .75rem; }

/* --- Icon Box --- */
.icon-box {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: var(--accent-soft);
  font-size: 1.1rem;
  flex-shrink: 0;
}

/* --- MCP Diagram --- */
.mcp-diagram { background: var(--bg-secondary); border: 1px solid var(--border-tertiary); border-radius: var(--radius-lg); padding: 1rem; }
.mcp-row { display: flex; align-items: center; gap: .75rem; margin-bottom: .5rem; flex-wrap: wrap; }
.mcp-box {
  padding: .5rem .85rem;
  border-radius: var(--radius-md);
  font-size: .8rem;
  font-weight: 500;
  background: var(--bg-card);
  border: 1px solid var(--border-secondary);
}
.mcp-box.client { background: var(--tag-blue-bg); border-color: var(--tag-blue-text); color: var(--tag-blue-text); }
.mcp-box.server { background: var(--tag-green-bg); border-color: var(--tag-green-text); color: var(--tag-green-text); }
.mcp-box.protocol { background: var(--tag-purple-bg); border-color: var(--tag-purple-text); color: var(--tag-purple-text); }
.mcp-arrow { color: var(--text-tertiary); font-size: 1.2rem; }
.mcp-label { font-size: .72rem; color: var(--text-tertiary); }

/* --- Prompt Template --- */
.prompt-template {
  background: var(--bg-secondary);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-md);
  padding: 1rem;
  margin-bottom: .75rem;
}
.prompt-template-header { font-size: .78rem; font-weight: 600; color: var(--text-secondary); margin-bottom: .5rem; text-transform: uppercase; letter-spacing: .05em; }
.prompt-template-body { font-family: var(--font-mono); font-size: .82rem; line-height: 1.65; color: var(--text-primary); white-space: pre-wrap; }
.prompt-template-body .pt-role { color: var(--tag-blue-text); }
.prompt-template-body .pt-user { color: var(--tag-green-text); }
.prompt-template-body .pt-system { color: var(--tag-purple-text); }

/* --- Highlight Box --- */
.highlight-box {
  background: var(--highlight);
  border: 1px solid #e6d98a;
  border-radius: var(--radius-md);
  padding: .9rem 1rem;
  margin-bottom: 1rem;
  font-size: .88rem;
  line-height: 1.65;
}
[data-theme="dark"] .highlight-box { background: #3d3520; border-color: #6b6020; }

/* --- Token Counter --- */
.token-demo { margin-top: .75rem; }
.token-demo-row { display: flex; align-items: center; gap: .5rem; margin-bottom: .4rem; font-size: .83rem; }
.token-demo-text { flex: 1; color: var(--text-secondary); }
.token-demo-count { font-family: var(--font-mono); font-size: .8rem; background: var(--bg-secondary); padding: 2px 8px; border-radius: 4px; border: 1px solid var(--border-secondary); }

/* --- Price Table --- */
.price-table { width: 100%; border-collapse: collapse; margin-bottom: .75rem; }
.price-table th, .price-table td { padding: .55rem .75rem; font-size: .82rem; text-align: left; border-bottom: 1px solid var(--border-tertiary); }
.price-table th { background: var(--bg-secondary); font-weight: 600; color: var(--text-secondary); }
.price-table td:first-child { font-weight: 500; }
.price-table tr:last-child td { border-bottom: none; }

/* --- Scrollable container --- */
.scroll-x { overflow-x: auto; }
.scroll-x::-webkit-scrollbar { height: 4px; }
.scroll-x::-webkit-scrollbar-thumb { background: var(--border-primary); border-radius: 4px; }

/* --- Footer CTA --- */
.cta-card {
  background: linear-gradient(135deg, var(--accent-soft) 0%, var(--bg-card) 100%);
  border: 2px solid var(--accent-border);
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  text-align: center;
  margin-top: 1rem;
}
.cta-card h3 { font-size: 1.1rem; font-weight: 600; margin-bottom: .4rem; }
.cta-card p { font-size: .88rem; color: var(--text-secondary); margin-bottom: 1rem; }
.cta-btn {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .6rem 1.4rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  font-size: .9rem;
  font-weight: 500;
  cursor: pointer;
  font-family: var(--font-sans);
  transition: background .15s;
}
.cta-btn:hover { background: var(--accent-hover); }

/* --- Scrollbar --- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-thumb { background: var(--border-primary); border-radius: 6px; }

/* --- Responsive --- */
@media (max-width: 768px) {
  :root { --sidebar-w: 0px; --header-h: 48px; }
  .sidebar {
    display: none;
    position: fixed;
    top: var(--header-h);
    left: 0;
    bottom: 0;
    width: 260px;
    z-index: 200;
    box-shadow: var(--shadow-lg);
  }
  .sidebar.open { display: block; }
  .sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    top: var(--header-h);
    background: rgba(0,0,0,.4);
    z-index: 199;
  }
  .sidebar-overlay.open { display: block; }
  .content { padding: 1.25rem 1rem 3rem; }
  .compare-grid { grid-template-columns: 1fr; }
  .compare-grid-3 { grid-template-columns: 1fr; }
  .split-2 { grid-template-columns: 1fr; }
  .split-2-1 { grid-template-columns: 1fr; }
  .hero h1 { font-size: 1.5rem; }
  .section-header h2 { font-size: 1.2rem; }
  .mcp-row { flex-direction: column; align-items: flex-start; }
}

/* --- Utility --- */
.mt-0 { margin-top: 0 !important; }
.mb-0 { margin-bottom: 0 !important; }
.mb-5 { margin-bottom: .5rem !important; }
.text-secondary { color: var(--text-secondary); }
.text-sm { font-size: .83rem; }
.text-xs { font-size: .75rem; }
.font-mono { font-family: var(--font-mono); }
.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.gap-5 { gap: .5rem; }
.gap-75 { gap: .75rem; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.hidden { display: none !important; }

/* --- Docker Visualization --- */
.docker-svg { width: 100%; max-width: 720px; margin: 0 auto; display: block; }
.docker-svg text { font-family: var(--font-sans); }
.docker-flow { display: flex; align-items: center; gap: .5rem; flex-wrap: wrap; margin: .75rem 0; }
.docker-flow-box {
  padding: .4rem .75rem;
  border-radius: var(--radius-sm);
  font-size: .8rem;
  font-weight: 500;
  background: var(--bg-secondary);
  border: 1px solid var(--border-secondary);
}
.docker-flow-arrow { color: var(--text-tertiary); font-size: 1.1rem; }

/* --- Git Visualization --- */
.git-svg { width: 100%; max-width: 680px; margin: 0 auto; display: block; }
.git-svg text { font-family: var(--font-sans); }

/* --- HTTP Flow --- */
.http-flow { display: flex; flex-direction: column; gap: .5rem; margin: .75rem 0; }
.http-step {
  display: flex;
  gap: .75rem;
  align-items: flex-start;
  padding: .75rem;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  border: 1px solid var(--border-tertiary);
  transition: border-color .2s;
}
.http-step:hover { border-color: var(--border-primary); }
.http-step-num {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .78rem;
  font-weight: 700;
  flex-shrink: 0;
  background: var(--accent);
  color: #fff;
}
.http-step-content { flex: 1; min-width: 0; }
.http-step-title { font-size: .88rem; font-weight: 600; margin-bottom: .15rem; }
.http-step-desc { font-size: .78rem; color: var(--text-secondary); line-height: 1.5; }

/* --- DB JOIN Visualization --- */
.db-svg { width: 100%; max-width: 640px; margin: 0 auto; display: block; }
.db-svg text { font-family: var(--font-sans); }

/* --- REST Endpoints --- */
.rest-endpoints { margin: .75rem 0; }
.rest-endpoint-row {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .55rem .75rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-tertiary);
  margin-bottom: .4rem;
  background: var(--bg-secondary);
  font-size: .82rem;
}
.rest-method {
  font-family: var(--font-mono);
  font-size: .75rem;
  font-weight: 700;
  padding: 2px 7px;
  border-radius: 4px;
  flex-shrink: 0;
}
.rest-method.get { background: var(--tag-green-bg); color: var(--tag-green-text); }
.rest-method.post { background: var(--tag-blue-bg); color: var(--tag-blue-text); }
.rest-method.put { background: var(--tag-amber-bg); color: var(--tag-amber-text); }
.rest-method.patch { background: var(--tag-purple-bg); color: var(--tag-purple-text); }
.rest-method.delete { background: var(--tag-red-bg); color: var(--tag-red-text); }
.rest-path { font-family: var(--font-mono); font-size: .8rem; flex: 1; }
.rest-desc { color: var(--text-secondary); font-size: .78rem; }

/* --- CLI Simulator --- */
.cli-terminal {
  background: #1a1a2e;
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin: .75rem 0;
  font-family: var(--font-mono);
  box-shadow: var(--shadow-md);
}
.cli-top-bar {
  background: #2d2d44;
  padding: .5rem .75rem;
  display: flex;
  align-items: center;
  gap: .4rem;
}
.cli-dot { width: 10px; height: 10px; border-radius: 50%; }
.cli-dot.red { background: #ff5f57; }
.cli-dot.yellow { background: #febc2e; }
.cli-dot.green { background: #28c840; }
.cli-title { font-size: .72rem; color: #888; margin-left: .5rem; }
.cli-body { padding: .75rem 1rem; min-height: 120px; }
.cli-prompt { color: #4ade80; font-size: .82rem; margin-bottom: .5rem; }
.cli-output { font-size: .8rem; color: #e2e8f0; line-height: 1.6; white-space: pre-wrap; word-break: break-word; }
.cli-commands { display: flex; flex-wrap: wrap; gap: .4rem; padding: .75rem 1rem; border-top: 1px solid #2d2d44; background: #12121f; }
.cli-cmd-chip {
  padding: .3rem .6rem;
  border-radius: var(--radius-sm);
  font-size: .75rem;
  background: #2d2d44;
  color: #e2e8f0;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all .15s;
  font-family: var(--font-mono);
}
.cli-cmd-chip:hover { background: #3d3d5c; border-color: #4ade80; color: #4ade80; }

/* --- SKILL Visualization --- */
.skill-svg { width: 100%; max-width: 640px; margin: 0 auto; display: block; }
.skill-svg text { font-family: var(--font-sans); }

/* --- OpenClaw Visualization --- */
.openclaw-svg { width: 100%; max-width: 640px; margin: 0 auto; display: block; }
.openclaw-svg text { font-family: var(--font-sans); }

/* --- OS startup tabs --- */
.os-tabs { display: flex; gap: .35rem; flex-wrap: wrap; margin-bottom: 1rem; }
.os-tab {
  padding: .4rem .9rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-secondary);
  background: none;
  color: var(--text-secondary);
  font-size: .82rem;
  cursor: pointer;
  transition: all .15s;
  font-family: var(--font-sans);
}
.os-tab:hover { background: var(--bg-hover); color: var(--text-primary); }
.os-tab.active { background: var(--accent-soft); color: var(--accent); border-color: var(--accent-border); font-weight: 500; }