/* Lesson-specific styles from tailwind/tailwind-lecture.html */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #f8f9fc;
  --card: #ffffff;
  --primary: #38bdf8;
  --primary-light: #f0f9ff;
  --primary-dark: #0c4a6e;
  --text: #1e293b;
  --sub: #64748b;
  --muted: #94a3b8;
  --border: #e2e8f0;
  --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-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-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);
}
.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; }
.code-block .tag  { color: #89dceb; }
.code-block .attr { color: #cba6f7; }
.code-block .cls  { color: #f9e2af; }
.code-block .new  { color: #a6e3a1; font-weight: 700; }

/* 대조 그리드 */
.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 0; }
.compare .code-block { border-right: 1px solid #313244; }
.compare .code-block:last-child { border-right: none; }
.compare-label { font-size: 11px; font-weight: 700; letter-spacing: 0.08em; padding: 8px 16px; border-bottom: 1px solid var(--border); }
.label-css { background: #f1f5f9; color: var(--sub); border-right: 1px solid var(--border); }
.label-tw  { background: #f0f9ff; color: var(--primary-dark); }

/* 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; }
.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; }

/* 단위 표 */
.unit-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.unit-table th { background: #1e293b; color: #f1f5f9; padding: 10px 14px; text-align: left; font-size: 12px; }
.unit-table td { padding: 9px 14px; border-bottom: 1px solid var(--border); }
.unit-table tr:nth-child(even) td { background: #f8fafc; }
.unit-table code { font-family: 'Fira Code', monospace; background: var(--primary-light); color: var(--primary-dark); padding: 1px 6px; border-radius: 4px; font-size: 12px; }

/* 버전 비교 */
.ver-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.ver-card { border-radius: 10px; overflow: hidden; border: 1px solid var(--border); }
.ver-header { padding: 10px 16px; font-size: 13px; font-weight: 700; }
.ver-v3 .ver-header { background: #1e293b; color: #94a3b8; }
.ver-v4 .ver-header { background: #0c4a6e; color: #38bdf8; }
.ver-body { padding: 14px 16px; font-size: 13px; color: var(--sub); line-height: 1.9; }

/* 라이브 데모 박스 */
.demo-box { background: #fff; border: 2px dashed var(--border); border-radius: 8px; padding: 20px; margin-top: 12px; display: flex; align-items: center; justify-content: center; min-height: 80px; }