/* Original lesson-specific/demo styles extracted from position/position-lecture.html; consolidate after visual QA. */

:root{
  --bg: var(--page);
  --card: var(--panel);
  --primary: var(--primary-ui);
  --primary-light: var(--primary-ui-pale);
  --primary-dark: var(--primary-ui-hover);
  --text: var(--ink);
  --sub: var(--ink-sub);
  --muted: var(--ink-muted);
  --border: var(--line);
  --code-bg: #1e1e2e;
  --radius: 12px;
  --green: #10b981;
  --amber: #f59e0b;
  --pink: #f72585;
  --purple: #7c3aed;
}
body {
  font-family: 'Segoe UI', 'Noto Sans KR', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

/* 사이드바 */
.sidebar {
  position: fixed;
  left: 0; top: 0; bottom: 0;
  width: 220px;
  background: var(--card);
  border-right: 1px solid var(--border);
  padding: 24px 0;
  overflow-y: auto;
  z-index: 100;
  transition: transform 0.3s ease;
}
.sidebar.collapsed { transform: translateX(-220px); }
.sidebar-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 20px 16px;
  border-bottom: 1px solid var(--border); margin-bottom: 12px;
}
.sidebar-title { font-size: 13px; font-weight: 700; color: var(--primary-dark); letter-spacing: 0.05em; }
.sidebar-toggle { display: none; background: none; border: none; cursor: pointer; font-size: 18px; color: var(--sub); padding: 2px; line-height: 1; }
.nav-home {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 20px 12px; font-size: 12px; font-weight: 600;
  color: var(--primary); text-decoration: none;
  border-bottom: 1px solid var(--border); margin-bottom: 8px; transition: all 0.15s;
}
.nav-home:hover { background: var(--primary-light); }
.nav-home-icon { font-size: 14px; }
.nav-item {
  display: block; padding: 8px 20px;
  font-size: 13px; color: var(--sub);
  text-decoration: none; transition: all 0.15s;
  border-left: 3px solid transparent;
}
.nav-item:hover { color: var(--primary); background: var(--primary-light); }
.nav-item.active { color: var(--primary); border-left-color: var(--primary); background: var(--primary-light); font-weight: 600; }
.nav-num { font-family: monospace; font-size: 11px; color: var(--muted); margin-right: 6px; }
.menu-btn {
  display: none; position: fixed; top: 12px; left: 12px; z-index: 200;
  background: var(--primary); color: #fff; border: none; border-radius: 8px;
  width: 40px; height: 40px; font-size: 18px; cursor: pointer;
  align-items: center; justify-content: center;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15); transition: all 0.15s;
}
.menu-btn:hover { opacity: 0.85; }
.sidebar-overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.3); z-index: 99; backdrop-filter: blur(2px); }
.sidebar-overlay.show { display: block; }

/* 메인 */
.main { margin-left: 220px; padding: 40px 40px 100px; max-width: 960px; transition: margin 0.3s; }

@media (max-width: 768px) {
  .sidebar { transform: translateX(-220px); }
  .sidebar.open { transform: translateX(0); }
  .menu-btn { display: flex; }
  .sidebar-toggle { display: block; }
  .main { margin-left: 0; padding: 60px 16px 80px; }
}

/* 히어로 */
.hero {
  text-align: center;
  padding: 60px 20px 48px;
  background: linear-gradient(135deg, #0ea5e9 0%, #7c3aed 100%);
  border-radius: var(--radius);
  color: #fff;
  margin-bottom: 48px;
}
.hero h1 { font-size: 36px; font-weight: 800; margin-bottom: 12px; letter-spacing: -1px; }
.hero p  { font-size: 16px; opacity: 0.85; }
.hero-badges { display: flex; gap: 8px; justify-content: center; margin-top: 20px; flex-wrap: wrap; }
.hero-badge {
  background: rgba(255,255,255,0.2);
  border: 1px solid rgba(255,255,255,0.3);
  color: #fff; font-size: 12px;
  padding: 4px 12px; border-radius: 20px; font-weight: 500;
}

/* 섹션 */
.section { margin-bottom: 64px; scroll-margin-top: 24px; }
.section-num { font-size: 12px; font-weight: 700; color: var(--primary); letter-spacing: 0.1em; margin-bottom: 6px; }
.section-title { font-size: 26px; font-weight: 800; color: var(--text); margin-bottom: 8px; letter-spacing: -0.5px; }
.section-desc { font-size: 14px; color: var(--sub); line-height: 1.7; }

/* 카드 */
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); overflow: hidden; margin-bottom: 20px;
}
.card-title {
  font-size: 13px; font-weight: 600; color: var(--sub);
  padding: 12px 16px; border-bottom: 1px solid var(--border);
  background: var(--bg); display: flex; align-items: center; gap: 8px;
}
.dot { width: 8px; height: 8px; border-radius: 50%; }
.dot-blue   { background: var(--primary); }
.dot-green  { background: var(--green); }
.dot-amber  { background: var(--amber); }
.dot-purple { background: var(--purple); }

/* 코드 */
.code-block {
  background: var(--code-bg); padding: 20px;
  font-family: 'Fira Code', 'Courier New', monospace;
  font-size: 13px; color: #cdd6f4; line-height: 2; overflow-x: auto;
}
.code-block .cm   { color: #6c7086; }
.code-block .sel  { color: #cba6f7; }
.code-block .prop { color: #89b4fa; }
.code-block .val  { color: #a6e3a1; }
.code-block .str  { color: #f38ba8; }

/* 프리뷰 */
.preview { padding: 20px; background: #f1f5f9; }
.preview-label { font-size: 11px; color: var(--muted); font-weight: 600; letter-spacing: 0.08em; margin-bottom: 12px; }

/* 컨트롤 */
.controls {
  padding: 16px 20px; border-top: 1px solid var(--border);
  background: var(--card); display: flex; flex-wrap: wrap; gap: 14px; align-items: center;
}
.ctrl-group { display: flex; align-items: center; gap: 10px; }
.ctrl-label { font-size: 12px; color: var(--sub); font-weight: 500; min-width: 80px; }
.ctrl-group select {
  font-size: 12px; padding: 5px 8px; border-radius: 6px;
  border: 1px solid var(--border); background: var(--card);
  color: var(--text); font-family: inherit;
}
.ctrl-group input[type=range] { width: 100px; accent-color: var(--primary); }
.ctrl-val { font-size: 12px; font-family: monospace; font-weight: 600; color: var(--primary); min-width: 36px; }
.tab-btns { display: flex; gap: 6px; flex-wrap: wrap; }
.tab-btn {
  font-size: 12px; padding: 5px 12px; border-radius: 20px;
  border: 1px solid var(--border); background: var(--card);
  color: var(--sub); cursor: pointer; transition: all 0.15s; font-weight: 500;
}
.tab-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); }

/* 팁 */
.tip {
  border-left: 3px solid var(--primary); background: var(--primary-light);
  padding: 12px 16px; border-radius: 0 8px 8px 0;
  font-size: 13px; color: var(--primary-dark); margin-top: 16px; line-height: 1.8;
}
.tip.green  { border-color: var(--green);  background: #d1fae5; color: #065f46; }
.tip.amber  { border-color: var(--amber);  background: #fef3c7; color: #92400e; }
.tip.purple { border-color: var(--purple); background: #ede9fe; color: #4c1d95; }
.tip.pink   { border-color: var(--pink);   background: #fff0f6; color: #9d0049; }

.divider { border: none; border-top: 1px solid var(--border); margin: 32px 0; }
.badge {
  display: inline-block; font-size: 11px; padding: 2px 8px;
  border-radius: 20px; font-weight: 600; margin-left: 6px;
}
.badge-blue   { background: var(--primary-light); color: var(--primary-dark); }
.badge-green  { background: #d1fae5; color: #065f46; }
.badge-amber  { background: #fef3c7; color: #92400e; }
.badge-purple { background: #ede9fe; color: #4c1d95; }

/* 포지션 시각화 공통 */
.pos-scene {
  background: #e2e8f0;
  border-radius: 8px;
  position: relative;
  overflow: hidden;
  min-height: 200px;
  padding: 20px;
}
.pos-box {
  width: 100px; height: 60px;
  border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 600;
  transition: all 0.4s;
}
.box-static   { background: #bfdbfe; border: 2px solid #60a5fa; color: #1e40af; }
.box-relative { background: #bbf7d0; border: 2px solid #34d399; color: #065f46; }
.box-absolute { background: #fde68a; border: 2px solid #fbbf24; color: #78350f; }
.box-fixed    { background: #fecaca; border: 2px solid #f87171; color: #7f1d1d; }
.box-sticky   { background: #ddd6fe; border: 2px solid #a78bfa; color: #4c1d95; }
.box-ghost    { background: transparent; border: 2px dashed #94a3b8; color: #94a3b8; font-size: 11px; }

/* 비교 그리드 */
.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 16px; }
.compare-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.compare-title { font-size: 12px; font-weight: 600; padding: 10px 14px; border-bottom: 1px solid var(--border); background: var(--bg); }

/* 스크롤 데모 */
.scroll-demo {
  height: 200px;
  overflow-y: scroll;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 8px;
  position: relative;
}
.scroll-content {
  padding: 16px;
  height: 600px;
}
.scroll-item {
  height: 60px;
  background: #e2e8f0;
  border-radius: 6px;
  margin-bottom: 10px;
  display: flex; align-items: center;
  padding: 0 14px;
  font-size: 12px; color: var(--sub);
}

/* z-index 시각화 */
.z-scene {
  position: relative;
  height: 160px;
  background: #f1f5f9;
  border-radius: 8px;
  overflow: hidden;
}
.z-box {
  position: absolute;
  width: 120px; height: 80px;
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 600;
  transition: all 0.3s;
}

/* Additional formerly inline demo styles */

.hover-card:hover .overlay-box { left: 0 !important; }