/* ====== TOKENS ====== */
:root {
  --bg:       #08080d;
  --bg-alt:   #0e0e16;
  --bg-card:  #131320;
  --bg-hover: #1a1a2e;
  --bg-elev:  #1e1e30;

  --text:     #e2e2ea;
  --text2:    #9898ac;
  --text3:    #5e5e74;

  --purple:   #a78bfa;
  --blue:     #6366f1;
  --cyan:     #22d3ee;
  --green:    #34d399;
  --orange:   #fb923c;
  --red:      #f87171;
  --pink:     #f472b6;

  --grad:     linear-gradient(135deg, #a78bfa 0%, #6366f1 50%, #3b82f6 100%);
  --border:   #222238;
  --radius:   10px;
  --font:     'Inter', -apple-system, sans-serif;
  --mono:     'JetBrains Mono', monospace;
}

*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body { font-family: var(--font); background: var(--bg); color: var(--text); line-height: 1.75; -webkit-font-smoothing: antialiased; }

a { color: var(--purple); text-decoration: none; }
strong { color: var(--text); font-weight: 600; }
em { color: var(--cyan); font-style: normal; }
code { font-family: var(--mono); font-size: 0.82em; background: var(--bg-card); padding: 2px 7px; border-radius: 4px; color: var(--cyan); }
pre { font-family: var(--mono); font-size: 0.82em; line-height: 1.6; padding: 12px 16px; background: rgba(0,0,0,.4); border-radius: 6px; overflow-x: auto; color: var(--text2); }

.container { max-width: 1140px; margin: 0 auto; padding: 0 24px; }

/* ====== NAV ====== */
.nav { position: fixed; top: 0; left: 0; right: 0; z-index: 1000; background: rgba(8,8,13,.88); backdrop-filter: blur(16px); border-bottom: 1px solid var(--border); }
.nav-inner { max-width: 1140px; margin: 0 auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; height: 56px; }
.nav-logo { font-size: 1.1rem; font-weight: 800; color: var(--text); }
.nav-logo .accent { background: var(--grad); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.nav-toggle { display: none; flex-direction: column; gap: 4px; background: none; border: none; cursor: pointer; padding: 4px; }
.nav-toggle span { display: block; width: 20px; height: 2px; background: var(--text); }
.nav-links { display: flex; list-style: none; gap: 4px; }
.nav-links a { color: var(--text2); font-size: .78rem; font-weight: 500; padding: 5px 10px; border-radius: 6px; transition: all .2s; }
.nav-links a:hover, .nav-links a.active { color: var(--text); background: rgba(99,102,241,.1); }

@media (max-width: 900px) {
  .nav-toggle { display: flex; }
  .nav-links { position: fixed; top: 56px; left: 0; right: 0; background: rgba(8,8,13,.97); flex-direction: column; padding: 12px 20px; border-bottom: 1px solid var(--border); transform: translateY(-110%); opacity: 0; pointer-events: none; transition: all .3s; }
  .nav-links.open { transform: translateY(0); opacity: 1; pointer-events: all; }
  .nav-links a { padding: 8px 12px; font-size: .9rem; }
}

/* ====== HERO ====== */
.hero { position: relative; min-height: 100vh; display: flex; align-items: center; justify-content: center; overflow: hidden; padding: 120px 0 80px; }
.hero-bg-grid {
  position: absolute; inset: 0;
  background-image: linear-gradient(rgba(99,102,241,.05) 1px, transparent 1px), linear-gradient(90deg, rgba(99,102,241,.05) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 40%, black 30%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 40%, black 30%, transparent 70%);
}
.hero::before { content: ''; position: absolute; top: -200px; left: 50%; transform: translateX(-50%); width: 800px; height: 800px; background: radial-gradient(circle, rgba(99,102,241,.12) 0%, transparent 60%); pointer-events: none; }
.hero-content { position: relative; text-align: center; }
.hero-badge { display: inline-block; font-family: var(--mono); font-size: .72rem; color: var(--purple); background: rgba(167,139,250,.1); border: 1px solid rgba(167,139,250,.15); padding: 5px 16px; border-radius: 50px; margin-bottom: 24px; letter-spacing: .5px; }
.hero-title { font-size: clamp(2.5rem, 6vw, 4.5rem); font-weight: 900; line-height: 1.1; letter-spacing: -2px; margin-bottom: 20px; }
.gradient-text { background: var(--grad); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-subtitle { font-size: 1.1rem; color: var(--text2); max-width: 600px; margin: 0 auto 40px; line-height: 1.8; }
.hero-stats { display: flex; justify-content: center; gap: 48px; margin-bottom: 40px; flex-wrap: wrap; }
.stat { text-align: center; }
.stat-number { display: block; font-size: 2rem; font-weight: 800; background: var(--grad); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.stat-label { font-size: .78rem; color: var(--text3); margin-top: 4px; }
.hero-cta-row { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-cta { display: inline-flex; align-items: center; gap: 8px; padding: 12px 28px; background: var(--grad); color: white; font-weight: 600; border-radius: 50px; transition: all .3s; box-shadow: 0 4px 20px rgba(99,102,241,.3); font-size: .9rem; }
.hero-cta:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(99,102,241,.4); color: white; }
.hero-cta-outline { background: rgba(99,102,241,.12); border: 1px solid rgba(99,102,241,.25); box-shadow: none; }
.hero-cta-outline:hover { background: rgba(99,102,241,.2); box-shadow: none; }

/* ====== SECTIONS ====== */
.section { padding: 80px 0; }
.section.alt { background: var(--bg-alt); }
.section-header { display: flex; gap: 20px; align-items: flex-start; margin-bottom: 40px; }
.section-num { font-family: var(--mono); font-size: 2.5rem; font-weight: 800; color: rgba(99,102,241,.15); line-height: 1; flex-shrink: 0; }
.section-header h2 { font-size: 1.8rem; font-weight: 800; letter-spacing: -.5px; margin-bottom: 6px; }
.section-desc { font-size: .95rem; color: var(--text2); max-width: 600px; }
.sub-title { font-size: 1.2rem; font-weight: 700; margin: 40px 0 16px; }

/* ====== ARCH DIAGRAM ====== */
.arch-box { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border); background: var(--bg-card); margin-bottom: 32px; }
.arch-svg { width: 100%; min-width: 700px; display: block; font-family: var(--font); }

/* ====== DECISION CARDS ====== */
.decision-grid { display: grid; gap: 16px; }
.decision-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.decision-q { font-size: 1.05rem; font-weight: 700; margin-bottom: 12px; color: var(--purple); }
.decision-options { display: flex; flex-direction: column; gap: 8px; }
.opt { padding: 10px 14px; background: rgba(0,0,0,.2); border-radius: 6px; border-left: 3px solid var(--border); }
.opt strong { font-size: .9rem; display: block; margin-bottom: 2px; }
.opt span { font-size: .8rem; color: var(--text2); }
.opt.recommended { border-left-color: var(--green); background: rgba(52,211,153,.05); }

/* ====== TABLES ====== */
.table-wrap { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border); margin-bottom: 24px; }
.data-table { width: 100%; border-collapse: collapse; font-size: .82rem; }
.data-table th { background: var(--bg-card); padding: 12px 14px; text-align: left; font-weight: 600; color: var(--text2); font-size: .75rem; text-transform: uppercase; letter-spacing: .5px; border-bottom: 1px solid var(--border); white-space: nowrap; }
.data-table td { padding: 10px 14px; border-bottom: 1px solid rgba(255,255,255,.03); color: var(--text2); }
.data-table tr:hover td { background: rgba(99,102,241,.03); }
.highlight-row td { background: rgba(52,211,153,.04); }
.highlight-row td:first-child code { color: var(--green); }
.score { font-family: var(--mono); font-size: .75rem; }
.score.high { color: var(--green); }
.score.mid { color: var(--orange); }
.score.easy { color: var(--green); }
.score.medium { color: var(--orange); }
.score.hard { color: var(--red); }

/* ====== INSIGHT BOX ====== */
.insight-box { display: flex; gap: 16px; align-items: flex-start; background: rgba(99,102,241,.06); border: 1px solid rgba(99,102,241,.12); border-radius: var(--radius); padding: 20px; margin-bottom: 24px; }
.insight-icon { font-size: 1.5rem; flex-shrink: 0; }
.insight-text { font-size: .88rem; color: var(--text2); }
.insight-text strong { color: var(--text); }

/* ====== CALLOUT ====== */
.callout { background: rgba(251,146,60,.06); border: 1px solid rgba(251,146,60,.15); border-radius: var(--radius); padding: 16px 20px; margin-bottom: 24px; font-size: .88rem; color: var(--text2); }
.callout strong { color: var(--orange); }

/* ====== TECHNIQUE DEEP ====== */
.technique-deep { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; margin-bottom: 20px; }
.deep-header { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 10px; margin-bottom: 12px; }
.deep-header h4 { font-size: 1.15rem; font-weight: 700; display: flex; align-items: center; gap: 10px; }
.badge { font-family: var(--mono); font-size: .65rem; color: var(--cyan); background: rgba(34,211,238,.1); padding: 2px 8px; border-radius: 4px; font-weight: 500; }
.impact { font-size: .78rem; color: var(--green); font-weight: 600; background: rgba(52,211,153,.08); padding: 4px 10px; border-radius: 50px; }
.technique-deep > p { font-size: .88rem; color: var(--text2); margin-bottom: 16px; }

/* Code block */
.code-block { margin-bottom: 8px; }
.code-label { font-size: .7rem; font-weight: 600; color: var(--text3); margin-bottom: 4px; text-transform: uppercase; letter-spacing: .5px; }

/* Metric row */
.metric-row { display: flex; gap: 16px; margin-top: 16px; flex-wrap: wrap; }
.metric-item { flex: 1; min-width: 140px; text-align: center; padding: 12px; background: rgba(0,0,0,.3); border-radius: 8px; }
.metric-value { display: block; font-size: 1.5rem; font-weight: 800; color: var(--green); }
.metric-label { font-size: .72rem; color: var(--text3); }

/* Tradeoff box */
.tradeoff-box { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 16px; }
.trade-pro, .trade-con { padding: 12px; border-radius: 8px; font-size: .82rem; color: var(--text2); }
.trade-pro { background: rgba(52,211,153,.06); border: 1px solid rgba(52,211,153,.15); }
.trade-pro strong { color: var(--green); }
.trade-con { background: rgba(248,113,113,.06); border: 1px solid rgba(248,113,113,.15); }
.trade-con strong { color: var(--red); }

/* ====== TIPS ROW ====== */
.tips-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; margin-bottom: 20px; }
.tip { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.tip-title { font-size: .9rem; font-weight: 700; margin-bottom: 6px; }
.tip p { font-size: .82rem; color: var(--text2); }

/* ====== PATTERN GRID ====== */
.pattern-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 14px; margin-bottom: 28px; }
.pattern-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; transition: border-color .2s; }
.pattern-card:hover { border-color: rgba(99,102,241,.3); }
.pattern-card h4 { font-size: 1rem; font-weight: 700; margin-bottom: 8px; }
.pattern-card p { font-size: .85rem; color: var(--text2); margin-bottom: 10px; }
.when-use { font-size: .78rem; color: var(--cyan); background: rgba(34,211,238,.06); padding: 6px 10px; border-radius: 4px; margin-bottom: 8px; }
.tradeoff { font-size: .72rem; color: var(--text3); }

/* ====== FORMULA ====== */
.deep-section { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; margin-bottom: 20px; }
.formula-box { margin-bottom: 14px; }
.formula-label { font-size: .72rem; font-weight: 600; color: var(--text3); margin-bottom: 4px; text-transform: uppercase; letter-spacing: .5px; }
.formula { display: block; font-size: .85rem; padding: 10px 14px; background: rgba(0,0,0,.4); border-radius: 6px; color: var(--purple); }
.alpha-guide { margin-top: 16px; }
.alpha-guide h4 { font-size: .9rem; font-weight: 700; margin-bottom: 8px; }
.alpha-row { display: flex; gap: 12px; align-items: center; padding: 6px 0; font-size: .82rem; color: var(--text2); }
.alpha-val { font-family: var(--mono); font-weight: 600; color: var(--purple); background: rgba(167,139,250,.1); padding: 2px 10px; border-radius: 4px; min-width: 70px; text-align: center; }

/* ====== TOKEN GRID ====== */
.token-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 10px; margin-top: 12px; }
.token-item { display: flex; align-items: center; gap: 10px; padding: 10px 12px; background: rgba(0,0,0,.3); border-radius: 6px; }
.token-item code { font-size: .78rem; color: var(--orange); background: rgba(251,146,60,.1); }
.token-item span { font-size: .78rem; color: var(--text2); }

/* ====== CRAG PATHS ====== */
.crag-paths { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
.crag-path { padding: 10px 14px; border-radius: 6px; font-size: .82rem; color: var(--text2); }
.crag-path strong { display: inline; margin-right: 4px; }
.crag-path.correct { background: rgba(52,211,153,.06); border-left: 3px solid var(--green); }
.crag-path.correct strong { color: var(--green); }
.crag-path.incorrect { background: rgba(248,113,113,.06); border-left: 3px solid var(--red); }
.crag-path.incorrect strong { color: var(--red); }
.crag-path.ambiguous { background: rgba(251,146,60,.06); border-left: 3px solid var(--orange); }
.crag-path.ambiguous strong { color: var(--orange); }

/* ====== ROUTING TABLE ====== */
.routing-table { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
.route { display: flex; align-items: center; gap: 12px; padding: 10px 14px; background: rgba(0,0,0,.2); border-radius: 6px; font-size: .82rem; color: var(--text2); }
.route-level { font-family: var(--mono); font-size: .72rem; font-weight: 700; padding: 3px 10px; border-radius: 4px; white-space: nowrap; }
.route-level.easy { background: rgba(52,211,153,.15); color: var(--green); }
.route-level.medium { background: rgba(251,146,60,.15); color: var(--orange); }
.route-level.hard { background: rgba(248,113,113,.15); color: var(--red); }

/* ====== EVAL MATRIX ====== */
.eval-matrix { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 32px; }
.eval-quadrant { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.quad-header { font-size: .85rem; font-weight: 700; padding: 6px 12px; border-radius: 6px; margin-bottom: 16px; }
.retrieval-header { background: rgba(99,102,241,.1); color: var(--blue); }
.generation-header { background: rgba(52,211,153,.1); color: var(--green); }
.eval-metric { margin-bottom: 12px; }
.eval-metric strong { font-size: .88rem; display: block; margin-bottom: 2px; }
.eval-metric p { font-size: .78rem; color: var(--text2); }

/* ====== TOOL STACK ====== */
.tool-stack { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; }
.tool-item { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.tool-item h4 { font-size: 1rem; font-weight: 700; margin-bottom: 4px; }
.tool-tag { font-family: var(--mono); font-size: .65rem; color: var(--green); background: rgba(52,211,153,.1); padding: 2px 8px; border-radius: 50px; }
.tool-item p { font-size: .82rem; color: var(--text2); margin-top: 8px; }

/* ====== GUIDE GRID ====== */
.guide-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; margin-bottom: 20px; }
.guide-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.guide-card h4 { font-size: .95rem; font-weight: 700; margin-bottom: 6px; }
.guide-rec { font-family: var(--mono); font-size: .78rem; color: var(--cyan); background: rgba(34,211,238,.06); padding: 4px 10px; border-radius: 4px; margin-bottom: 8px; display: inline-block; }
.guide-card p { font-size: .82rem; color: var(--text2); }

/* ====== LATENCY BUDGET ====== */
.latency-budget { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; margin-bottom: 28px; }
.budget-row { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.5fr; padding: 10px 16px; font-size: .82rem; color: var(--text2); border-bottom: 1px solid rgba(255,255,255,.03); }
.budget-row.header-row { background: var(--bg-elev); font-weight: 600; color: var(--text); font-size: .75rem; text-transform: uppercase; letter-spacing: .5px; }
.budget-row.total-row { background: rgba(99,102,241,.06); border-top: 1px solid var(--border); }

/* ====== CHECKLIST ====== */
.checklist { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.check-group { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.check-group h4 { font-size: .95rem; font-weight: 700; margin-bottom: 12px; }
.check-item { font-size: .8rem; color: var(--text2); padding: 4px 0; border-bottom: 1px solid rgba(255,255,255,.03); }

/* ====== FOOTER ====== */
.footer { padding: 48px 0; text-align: center; border-top: 1px solid var(--border); }
.footer-text { font-weight: 700; font-size: .9rem; margin-bottom: 4px; }
.footer-sub { font-size: .78rem; color: var(--text3); margin-bottom: 16px; }
.footer-link { font-size: .82rem; color: var(--purple); }

/* ====== REVEAL ====== */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .5s, transform .5s; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ====== RESPONSIVE ====== */
@media (max-width: 768px) {
  .section { padding: 48px 0; }
  .section-header { flex-direction: column; gap: 8px; }
  .section-num { font-size: 1.8rem; }
  .eval-matrix { grid-template-columns: 1fr; }
  .tradeoff-box { grid-template-columns: 1fr; }
  .budget-row { grid-template-columns: 1fr 1fr; gap: 4px; font-size: .75rem; }
  .pattern-grid { grid-template-columns: 1fr; }
}

/* ====== LANG SWITCH ====== */
.lang-switch { font-family:var(--mono); font-size:.72rem; font-weight:700; color:var(--text3); background:var(--bg-card); border:1px solid var(--border); padding:4px 12px; border-radius:6px; margin-left:12px; transition:all .2s; flex-shrink:0; }
.lang-switch:hover { color:var(--text); border-color:var(--purple); background:rgba(99,102,241,.1); }

/* ====== LANG TOGGLE ====== */
.lang-toggle { display:flex; gap:2px; background:var(--bg-card); border:1px solid var(--border); border-radius:8px; padding:2px; margin-left:12px; flex-shrink:0; }
.lang-btn { font-family:var(--mono); font-size:.7rem; font-weight:600; padding:4px 10px; border:none; border-radius:6px; background:none; color:var(--text3); cursor:pointer; transition:all .2s; }
.lang-btn.active { background:var(--blue); color:white; }
.lang-btn:hover:not(.active) { color:var(--text); background:rgba(255,255,255,.05); }

::selection { background: rgba(99,102,241,.3); }
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }