@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;700;900&family=JetBrains+Mono:wght@400;600&display=swap');

:root {
  --bg: #0b0b0d;
  --surface: #111114;
  --surface2: #18181d;
  --border: #222228;
  --accent: #00f2ff;
  --accent2: #6e00ff;
  --accent3: #00ffaa;
  --danger: #ff4466;
  --text: #e8e8f0;
  --muted: #888888;
  --font-display: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { background: var(--bg); color: var(--text); font-family: var(--font-body); font-size: 1rem; line-height: 1.75; min-height: 100vh; }

.topbar { position: sticky; top: 0; z-index: 100; background: rgba(11,11,13,0.94); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border); padding: 0 2rem; height: 60px; display: flex; align-items: center; justify-content: space-between; }
.topbar-brand { font-family: var(--font-mono); font-size: 1.05rem; font-weight: 700; color: var(--accent); text-decoration: none; letter-spacing: -0.02em; }
.topbar-nav { display: flex; gap: 1.5rem; align-items: center; }
.topbar-nav a { color: var(--muted); text-decoration: none; font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.08em; text-transform: uppercase; transition: color 0.2s; }
.topbar-nav a:hover, .topbar-nav a.active { color: var(--accent); }

.breadcrumb { display: flex; gap: 0.5rem; align-items: center; padding: 1rem 2rem; font-family: var(--font-mono); font-size: 0.74rem; color: var(--muted); flex-wrap: wrap; }
.breadcrumb a { color: var(--muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb .sep { color: var(--border); }

.page-wrap { max-width: 960px; margin: 0 auto; padding: 0 2rem 6rem; }

.page-hero { padding: 2.5rem 0 2rem; animation: fadeUp 0.5s ease both; }
.category-pill { display: inline-block; padding: 0.25rem 0.9rem; border-radius: 999px; font-family: var(--font-mono); font-size: 0.7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 1rem; }
.pill-creational { background: rgba(0,242,255,0.1); color: var(--accent); border: 1px solid rgba(0,242,255,0.3); }
.pill-structural  { background: rgba(110,0,255,0.15); color: #b380ff; border: 1px solid rgba(110,0,255,0.4); }
.pill-behavioral  { background: rgba(0,255,170,0.1); color: var(--accent3); border: 1px solid rgba(0,255,170,0.3); }

.page-title { font-family: var(--font-display); font-size: clamp(2.2rem,5vw,3.5rem); font-weight: 900; line-height: 1.1; color: #fff; margin-bottom: 0.75rem; letter-spacing: -1px; }
.page-tagline { font-size: 1.05rem; color: var(--muted); margin-bottom: 1.5rem; max-width: 640px; font-family: var(--font-mono); }
.difficulty-row { display: flex; gap: 1rem; align-items: center; flex-wrap: wrap; }
.diff-badge { font-family: var(--font-mono); font-size: 0.72rem; padding: 0.2rem 0.7rem; border-radius: 4px; border: 1px solid var(--border); color: var(--muted); }
.diff-beginner { border-color: var(--accent3); color: var(--accent3); }
.diff-intermediate { border-color: var(--accent); color: var(--accent); }
.diff-advanced { border-color: var(--danger); color: var(--danger); }

.divider { border: none; border-top: 1px solid var(--border); margin: 2.5rem 0; }
.section { margin-bottom: 3rem; animation: fadeUp 0.5s ease both; animation-delay: 0.1s; }
.section-label { font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.15em; text-transform: uppercase; color: var(--accent); margin-bottom: 0.6rem; }
.section-title { font-family: var(--font-display); font-size: 1.6rem; font-weight: 800; color: #fff; margin-bottom: 1rem; letter-spacing: -0.5px; }
.section p { color: var(--text); margin-bottom: 0.75rem; }

.callout { border-left: 3px solid var(--accent); background: rgba(0,242,255,0.04); border-radius: 0 8px 8px 0; padding: 1.2rem 1.5rem; margin: 1.5rem 0; color: var(--muted); }
.callout strong { color: var(--text); }

.participants { display: flex; flex-direction: column; gap: 0.75rem; margin: 1rem 0; }
.participant { display: flex; gap: 1rem; align-items: flex-start; background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 1rem 1.2rem; }
.participant-name { font-family: var(--font-mono); font-size: 0.82rem; font-weight: 600; color: var(--accent); min-width: 160px; padding-top: 2px; }
.participant-desc { font-size: 0.92rem; color: var(--text); }

.flow-diagram { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 2rem 1.5rem; margin: 1.5rem 0; overflow-x: auto; text-align: center; }
.flow-diagram svg { display: inline-block; max-width: 100%; height: auto; }

.code-wrap { background: #070709; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; margin: 1.5rem 0; }
.code-header { display: flex; justify-content: space-between; align-items: center; padding: 0.65rem 1.2rem; background: var(--surface); border-bottom: 1px solid var(--border); font-family: var(--font-mono); font-size: 0.74rem; color: var(--muted); }
.code-lang { color: var(--accent); font-weight: 600; }
.copy-btn { background: none; border: 1px solid var(--border); color: var(--muted); font-family: var(--font-mono); font-size: 0.7rem; padding: 0.2rem 0.6rem; border-radius: 4px; cursor: pointer; transition: all 0.2s; }
.copy-btn:hover { border-color: var(--accent); color: var(--accent); }
pre { padding: 1.5rem; overflow-x: auto; font-family: var(--font-mono); font-size: 0.82rem; line-height: 1.7; color: #abb2bf; }
.kw { color: #c678dd; } .cm { color: #5c6370; font-style: italic; } .st { color: #98c379; } .cl { color: #e5c07b; } .fn { color: #61afef; } .nm { color: #d19a66; }

.use-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin: 1rem 0; }
@media(max-width:600px){ .use-grid { grid-template-columns: 1fr; } }
.use-card { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 1.2rem; }
.use-card h4 { font-family: var(--font-mono); font-size: 0.75rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; margin-bottom: 0.8rem; }
.use-card.yes h4 { color: var(--accent3); } .use-card.no h4 { color: var(--danger); }
.use-card ul { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
.use-card ul li { font-size: 0.88rem; padding-left: 1.2rem; position: relative; color: var(--text); }
.use-card.yes ul li::before { content: '✓'; position: absolute; left: 0; color: var(--accent3); }
.use-card.no  ul li::before { content: '✕'; position: absolute; left: 0; color: var(--danger); }

.pros-cons { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin: 1rem 0; }
@media(max-width:600px){ .pros-cons { grid-template-columns: 1fr; } }
.pc-card { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 1.2rem; }
.pc-card h4 { font-family: var(--font-mono); font-size: 0.75rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; margin-bottom: 0.8rem; }
.pc-card.pros h4 { color: var(--accent3); } .pc-card.cons h4 { color: var(--danger); }
.pc-card ul { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
.pc-card ul li { font-size: 0.88rem; padding-left: 1.2rem; position: relative; color: var(--text); }
.pc-card.pros ul li::before { content: '+'; position: absolute; left: 0; color: var(--accent3); font-weight: 700; }
.pc-card.cons ul li::before { content: '−'; position: absolute; left: 0; color: var(--danger); font-weight: 700; }

.rw-list { list-style: none; display: flex; flex-direction: column; gap: 0.6rem; margin: 1rem 0; }
.rw-list li { display: flex; gap: 0.75rem; align-items: flex-start; font-size: 0.92rem; }
.rw-list li::before { content: '◆'; color: var(--accent); font-size: 0.6rem; margin-top: 0.35rem; flex-shrink: 0; }
.rw-list code { font-family: var(--font-mono); font-size: 0.8rem; background: rgba(0,242,255,0.06); border: 1px solid rgba(0,242,255,0.15); padding: 0.05rem 0.4rem; border-radius: 4px; color: var(--accent); }

.related-grid { display: flex; flex-direction: column; gap: 0.75rem; margin: 1rem 0; }
.related-card { display: flex; gap: 1rem; align-items: flex-start; background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 1rem 1.2rem; text-decoration: none; transition: border-color 0.2s, background 0.2s; cursor: pointer; }
.related-card:hover { border-color: var(--accent); background: var(--surface2); }
.related-name { font-family: var(--font-display); font-size: 1rem; font-weight: 700; color: #fff; margin-bottom: 0.25rem; }
.related-tag { display: inline-block; font-family: var(--font-mono); font-size: 0.65rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; padding: 0.15rem 0.5rem; border-radius: 999px; margin-bottom: 0.4rem; }
.tag-together   { background: rgba(0,255,170,0.1); color: var(--accent3); border: 1px solid rgba(0,255,170,0.3); }
.tag-competes   { background: rgba(255,68,102,0.1); color: var(--danger); border: 1px solid rgba(255,68,102,0.3); }
.tag-extends    { background: rgba(0,242,255,0.1); color: var(--accent); border: 1px solid rgba(0,242,255,0.3); }
.tag-confused   { background: rgba(110,0,255,0.12); color: #b380ff; border: 1px solid rgba(110,0,255,0.35); }
.tag-simplifies { background: rgba(0,242,255,0.08); color: var(--accent); border: 1px solid rgba(0,242,255,0.25); }
.related-desc { font-size: 0.88rem; color: var(--muted); }

.recap-box { background: linear-gradient(135deg, rgba(0,242,255,0.04) 0%, rgba(110,0,255,0.06) 100%); border: 1px solid rgba(0,242,255,0.25); border-radius: 12px; padding: 2rem; }
.recap-box h3 { font-family: var(--font-display); font-size: 1.3rem; font-weight: 800; color: var(--accent); margin-bottom: 1rem; }
.recap-box ol { padding-left: 1.4rem; display: flex; flex-direction: column; gap: 0.5rem; }
.recap-box ol li { font-size: 0.95rem; color: var(--text); }

.page-nav { display: flex; justify-content: space-between; align-items: center; padding: 2rem 0; border-top: 1px solid var(--border); margin-top: 3rem; flex-wrap: wrap; gap: 1rem; }
.page-nav a { display: flex; flex-direction: column; font-family: var(--font-mono); text-decoration: none; border: 1px solid var(--border); border-radius: 8px; padding: 0.8rem 1.2rem; transition: border-color 0.2s; max-width: 220px; }
.page-nav a:hover { border-color: var(--accent); }
.page-nav .nav-dir { font-size: 0.65rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 0.2rem; }
.page-nav .nav-title { font-size: 0.88rem; color: var(--text); }
.page-nav a.right { text-align: right; }

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

@keyframes fadeUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }

@media(max-width:640px){ .topbar { padding: 0 1rem; } .page-wrap { padding: 0 1rem 4rem; } .topbar-nav { display: none; } }