:root {
  --bg: #060912;
  --bg2: #0b1120;
  --panel: rgba(255, 255, 255, 0.035);
  --panel2: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.09);
  --border2: rgba(255, 255, 255, 0.16);
  --text: #e8edf7;
  --muted: #8e99b3;
  --dim: #5d6880;
  --accent: #7c5cff;
  --accent2: #22d3ee;
  --ok: #22c55e;
  --warn: #f59e0b;
  --bad: #ef4444;
  --c: #7c5cff;
  --c2: #22d3ee;
  --radius: 18px;
  --shadow: 0 20px 60px -20px rgba(0, 0, 0, 0.6);
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Inter", "Segoe UI", system-ui, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", ui-monospace, Menlo, Consolas, monospace;
  --k-client: #60a5fa; --k-edge: #2dd4bf; --k-service: #a78bfa; --k-cache: #fb923c;
  --k-db: #4ade80; --k-queue: #f472b6; --k-external: #94a3b8;
  color-scheme: dark;
}
:root[data-theme="light"] {
  --bg: #f6f7fb; --bg2: #ffffff;
  --panel: rgba(15, 23, 42, 0.035); --panel2: rgba(15, 23, 42, 0.06);
  --border: rgba(15, 23, 42, 0.09); --border2: rgba(15, 23, 42, 0.18);
  --text: #0f172a; --muted: #55627a; --dim: #8a94a8;
  --shadow: 0 20px 50px -24px rgba(15, 23, 42, 0.25);
  --k-client: #2563eb; --k-edge: #0d9488; --k-service: #7c3aed; --k-cache: #ea580c;
  --k-db: #16a34a; --k-queue: #db2777; --k-external: #64748b;
  color-scheme: light;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; font-family: var(--font); background: var(--bg); color: var(--text);
  -webkit-font-smoothing: antialiased; line-height: 1.6; overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; }
code, .mono { font-family: var(--mono); font-size: 0.88em; }
code { background: var(--panel2); padding: 0.1em 0.4em; border-radius: 6px; border: 1px solid var(--border); }
.muted { color: var(--muted); }
.small { font-size: 0.85rem; }
::selection { background: color-mix(in srgb, var(--c) 40%, transparent); }

/* ── Ambient background ───────────────────────────── */
.bg { position: fixed; inset: 0; z-index: -1; overflow: hidden; pointer-events: none; }
.bg::before {
  content: ""; position: absolute; inset: 0;
  background-image: linear-gradient(var(--border) 1px, transparent 1px), linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 56px 56px; mask-image: radial-gradient(ellipse at 50% 0%, #000 20%, transparent 70%);
  opacity: 0.55;
}
.orb { position: absolute; border-radius: 50%; filter: blur(90px); opacity: 0.35; animation: float 22s ease-in-out infinite; }
.orb.o1 { width: 520px; height: 520px; background: var(--c); top: -160px; left: -120px; transition: background 0.8s; }
.orb.o2 { width: 460px; height: 460px; background: var(--c2); top: 20%; right: -160px; animation-delay: -7s; transition: background 0.8s; }
.orb.o3 { width: 380px; height: 380px; background: #7c5cff; bottom: -160px; left: 30%; animation-delay: -14s; opacity: 0.18; }
:root[data-theme="light"] .orb { opacity: 0.18; }
@keyframes float { 0%,100% { transform: translate(0,0) scale(1); } 33% { transform: translate(60px,40px) scale(1.08); } 66% { transform: translate(-40px,30px) scale(0.95); } }

/* ── Top bar ───────────────────────────── */
.topbar {
  position: sticky; top: 0; z-index: 50; display: flex; align-items: center; gap: 24px;
  padding: 14px 32px; backdrop-filter: blur(18px) saturate(1.4); -webkit-backdrop-filter: blur(18px) saturate(1.4);
  background: color-mix(in srgb, var(--bg) 70%, transparent); border-bottom: 1px solid var(--border);
}
.logo { display: flex; align-items: center; gap: 10px; font-weight: 750; letter-spacing: -0.02em; font-size: 1.1rem; }
.logo-mark {
  width: 30px; height: 30px; border-radius: 9px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--accent), var(--accent2)); box-shadow: 0 6px 20px -6px var(--accent);
}
.logo-mark svg { width: 18px; height: 18px; }
.nav { display: flex; gap: 4px; margin-left: 12px; }
.nav a { padding: 7px 14px; border-radius: 10px; color: var(--muted); font-weight: 550; font-size: 0.93rem; transition: 0.2s; }
.nav a:hover { color: var(--text); background: var(--panel2); }
.nav a.active { color: var(--text); background: var(--panel2); box-shadow: inset 0 0 0 1px var(--border); }
.spacer { flex: 1; }
.xp { display: flex; align-items: center; gap: 10px; font-size: 0.85rem; color: var(--muted); }
.xp-bar { width: 110px; height: 7px; border-radius: 99px; background: var(--panel2); overflow: hidden; }
.xp-bar i { display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent2)); border-radius: 99px; transition: width 0.8s cubic-bezier(.2,.8,.2,1); }
.xp b { color: var(--text); font-variant-numeric: tabular-nums; }
.icon-btn { width: 36px; height: 36px; border-radius: 10px; border: 1px solid var(--border); background: var(--panel); display: grid; place-items: center; transition: 0.2s; }
.icon-btn:hover { background: var(--panel2); border-color: var(--border2); }

main { max-width: 1240px; margin: 0 auto; padding: 0 32px 120px; }
.view { animation: viewIn 0.5s cubic-bezier(.2,.8,.2,1); }
@keyframes viewIn { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }

/* ── Reveal on scroll ───────────────────────────── */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.7s cubic-bezier(.2,.8,.2,1), transform 0.7s cubic-bezier(.2,.8,.2,1); }
.reveal.in { opacity: 1; transform: none; }
.stagger > * { opacity: 0; transform: translateY(18px); transition: 0.6s cubic-bezier(.2,.8,.2,1); }
.stagger.in > * { opacity: 1; transform: none; }
.stagger.in > *:nth-child(2) { transition-delay: .06s } .stagger.in > *:nth-child(3) { transition-delay: .12s }
.stagger.in > *:nth-child(4) { transition-delay: .18s } .stagger.in > *:nth-child(5) { transition-delay: .24s }
.stagger.in > *:nth-child(6) { transition-delay: .30s } .stagger.in > *:nth-child(7) { transition-delay: .36s }
.stagger.in > *:nth-child(8) { transition-delay: .42s } .stagger.in > *:nth-child(n+9) { transition-delay: .48s }

/* ── Typography ───────────────────────────── */
h1, h2, h3, h4 { letter-spacing: -0.025em; line-height: 1.15; margin: 0; }
.eyebrow { text-transform: uppercase; letter-spacing: 0.14em; font-size: 0.72rem; font-weight: 700; color: var(--c); }
.grad { background: linear-gradient(120deg, var(--text) 10%, var(--c) 55%, var(--c2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.section { margin-top: 96px; }
.section-head { margin-bottom: 28px; max-width: 720px; }
.section-head h2 { font-size: clamp(1.7rem, 3vw, 2.3rem); margin-top: 8px; }
.section-head p { color: var(--muted); margin: 10px 0 0; font-size: 1.05rem; }

/* ── Buttons & chips ───────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 11px 20px; border-radius: 12px; font-weight: 650; font-size: 0.95rem;
  border: 1px solid var(--border2); background: var(--panel); transition: 0.2s; white-space: nowrap;
}
.btn:hover { background: var(--panel2); transform: translateY(-1px); }
.btn.primary { background: linear-gradient(135deg, var(--c), color-mix(in srgb, var(--c2) 70%, var(--c))); border-color: transparent; color: #fff; box-shadow: 0 10px 30px -10px var(--c); }
.btn.primary:hover { box-shadow: 0 14px 36px -10px var(--c); }
.btn.sm { padding: 7px 13px; font-size: 0.85rem; border-radius: 10px; }
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }
.chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 4px 11px; border-radius: 99px; font-size: 0.78rem; font-weight: 600;
  background: var(--panel2); border: 1px solid var(--border); color: var(--muted); transition: 0.2s; cursor: pointer;
}
.chip:hover { color: var(--text); border-color: color-mix(in srgb, var(--c) 60%, transparent); background: color-mix(in srgb, var(--c) 12%, transparent); }
.chip.on { color: var(--text); background: color-mix(in srgb, var(--c) 20%, transparent); border-color: color-mix(in srgb, var(--c) 60%, transparent); }
.tag { display: inline-block; font-size: 0.68rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; padding: 2px 8px; border-radius: 6px; background: var(--panel2); color: var(--muted); }
.seg { display: inline-flex; padding: 4px; border-radius: 12px; background: var(--panel2); border: 1px solid var(--border); gap: 2px; }
.seg button { padding: 6px 14px; border-radius: 9px; border: 0; background: transparent; color: var(--muted); font-weight: 600; font-size: 0.86rem; transition: 0.2s; }
.seg button.on { background: var(--c); color: #fff; box-shadow: 0 4px 14px -4px var(--c); }

.card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; position: relative; }
.glass { backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); }

/* ── Home hero ───────────────────────────── */
.hero { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; padding: 80px 0 30px; }
.hero h1 { font-size: clamp(2.4rem, 5vw, 4.1rem); font-weight: 800; letter-spacing: -0.04em; }
.hero p.lead { font-size: 1.18rem; color: var(--muted); margin: 22px 0 32px; max-width: 560px; }
.hero .ctas { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-badge { display: inline-flex; gap: 8px; align-items: center; padding: 6px 14px 6px 6px; border-radius: 99px; border: 1px solid var(--border); background: var(--panel); font-size: 0.83rem; color: var(--muted); margin-bottom: 22px; }
.hero-badge span { background: linear-gradient(135deg, var(--accent), var(--accent2)); color: #fff; padding: 2px 10px; border-radius: 99px; font-weight: 700; font-size: 0.75rem; }
.hero-visual { border-radius: 24px; border: 1px solid var(--border); background: var(--panel); padding: 10px; box-shadow: var(--shadow); position: relative; }
.typing::after { content: "▍"; animation: blink 1s steps(1) infinite; color: var(--c); margin-left: 2px; }
@keyframes blink { 50% { opacity: 0; } }

.how { display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; }
.how .card { padding: 20px; }
.how .n { width: 30px; height: 30px; border-radius: 9px; display: grid; place-items: center; font-weight: 800; font-size: 0.85rem; background: color-mix(in srgb, var(--c) 18%, transparent); color: var(--c); margin-bottom: 12px; }
.how h4 { font-size: 1rem; margin-bottom: 6px; }
.how p { margin: 0; font-size: 0.86rem; color: var(--muted); }

.cases { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 18px; }
.case-card {
  --c: #7c5cff; display: flex; flex-direction: column; padding: 22px; border-radius: 20px; border: 1px solid var(--border);
  background: var(--panel); position: relative; overflow: hidden; transition: transform 0.25s, border-color 0.25s, box-shadow 0.25s;
  transform-style: preserve-3d; min-height: 270px;
}
.case-card::before {
  content: ""; position: absolute; inset: 0; opacity: 0; transition: opacity 0.3s;
  background: radial-gradient(400px circle at var(--mx, 50%) var(--my, 0%), color-mix(in srgb, var(--c) 22%, transparent), transparent 60%);
}
.case-card:hover { border-color: color-mix(in srgb, var(--c) 55%, transparent); box-shadow: 0 24px 60px -28px var(--c); }
.case-card:hover::before { opacity: 1; }
.case-card > * { position: relative; }
.case-card .app-icon { width: 52px; height: 52px; border-radius: 15px; display: grid; place-items: center; font-size: 1.6rem; background: linear-gradient(135deg, var(--c), var(--c2)); box-shadow: 0 10px 26px -10px var(--c); margin-bottom: 16px; }
.case-card .app { font-size: 0.8rem; font-weight: 700; color: var(--c); text-transform: uppercase; letter-spacing: 0.1em; }
.case-card h3 { font-size: 1.25rem; margin: 4px 0 8px; }
.case-card p { font-size: 0.9rem; color: var(--muted); margin: 0 0 16px; flex: 1; }
.case-card .meta { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; font-size: 0.78rem; color: var(--muted); }
.case-card .done-badge { position: absolute; top: 18px; right: 18px; background: var(--ok); color: #fff; width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center; font-size: 0.8rem; font-weight: 800; box-shadow: 0 6px 16px -4px var(--ok); }
.case-card .num { position: absolute; top: 14px; right: 20px; font-size: 3.4rem; font-weight: 800; color: var(--text); opacity: 0.05; }

.concept-cloud { display: flex; flex-wrap: wrap; gap: 10px; }
.concept-cloud .chip { font-size: 0.88rem; padding: 7px 14px; }

/* ── Case page ───────────────────────────── */
.case-hero { padding: 64px 0 20px; position: relative; }
.back { display: inline-flex; gap: 6px; align-items: center; color: var(--muted); font-size: 0.9rem; margin-bottom: 30px; transition: 0.2s; }
.back:hover { color: var(--text); transform: translateX(-3px); }
.case-hero .app-row { display: flex; align-items: center; gap: 16px; margin-bottom: 20px; }
.case-hero .app-icon { width: 64px; height: 64px; border-radius: 18px; display: grid; place-items: center; font-size: 2rem; background: linear-gradient(135deg, var(--c), var(--c2)); box-shadow: 0 14px 40px -12px var(--c); animation: bob 5s ease-in-out infinite; }
@keyframes bob { 50% { transform: translateY(-6px) rotate(-3deg); } }
.case-hero h1 { font-size: clamp(2.2rem, 4.6vw, 3.6rem); font-weight: 800; letter-spacing: -0.035em; max-width: 900px; }
.case-hero .tagline { font-size: 1.2rem; color: var(--muted); max-width: 780px; margin: 18px 0 26px; }
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 36px; }
.stat { padding: 22px; border-radius: 18px; background: var(--panel); border: 1px solid var(--border); position: relative; overflow: hidden; }
.stat::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 3px; background: linear-gradient(90deg, var(--c), var(--c2)); transform: scaleX(0); transform-origin: left; transition: transform 1.2s cubic-bezier(.2,.8,.2,1) .2s; }
.stat.in::after { transform: scaleX(1); }
.stat .v { font-size: 2.3rem; font-weight: 800; letter-spacing: -0.03em; font-variant-numeric: tabular-nums; }
.stat .l { color: var(--muted); font-size: 0.88rem; margin-top: 4px; }
.stat .tag { position: absolute; top: 14px; right: 14px; }

.case-layout { display: grid; grid-template-columns: 200px 1fr; gap: 48px; margin-top: 40px; }
.toc { position: sticky; top: 92px; align-self: start; display: flex; flex-direction: column; gap: 2px; padding-top: 96px; }
.toc a { padding: 7px 12px; border-radius: 9px; font-size: 0.87rem; color: var(--dim); border-left: 2px solid transparent; transition: 0.2s; }
.toc a:hover { color: var(--text); }
.toc a.active { color: var(--text); border-left-color: var(--c); background: color-mix(in srgb, var(--c) 10%, transparent); }
.toc .progress { margin: 18px 12px 0; height: 4px; background: var(--panel2); border-radius: 9px; overflow: hidden; }
.toc .progress i { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--c), var(--c2)); transition: width 0.2s; }
.case-body { min-width: 0; }

.story { font-size: 1.22rem; line-height: 1.75; max-width: 780px; }
.story b { color: var(--text); background: linear-gradient(transparent 62%, color-mix(in srgb, var(--c) 35%, transparent) 0); }

.req-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.req-grid ul { list-style: none; padding: 0; margin: 14px 0 0; display: flex; flex-direction: column; gap: 10px; }
.req-grid li { display: flex; gap: 10px; align-items: flex-start; font-size: 0.95rem; }
.req-grid li::before { content: ""; flex: none; width: 18px; height: 18px; margin-top: 3px; border-radius: 6px; background: color-mix(in srgb, var(--c) 22%, transparent) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='white'%3E%3Cpath d='M8 13.2 4.8 10l-1.1 1.1L8 15.4l8.6-8.6-1.1-1.1z'/%3E%3C/svg%3E") center/13px no-repeat; }
.req-grid .nf li::before { background-color: color-mix(in srgb, var(--c2) 22%, transparent); }

.est { width: 100%; border-collapse: collapse; font-size: 0.95rem; }
.est td { padding: 14px 16px; border-bottom: 1px solid var(--border); }
.est tr:last-child td { border-bottom: 0; }
.est td:nth-child(2) { color: var(--muted); font-family: var(--mono); font-size: 0.85rem; }
.est td:last-child { text-align: right; font-weight: 750; font-variant-numeric: tabular-nums; color: var(--c); white-space: nowrap; }
.insight { margin-top: 16px; padding: 16px 18px; border-radius: 14px; background: color-mix(in srgb, var(--c) 9%, transparent); border: 1px solid color-mix(in srgb, var(--c) 30%, transparent); display: flex; gap: 12px; font-size: 0.95rem; }

.naive { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.naive .card.bad { border-color: color-mix(in srgb, var(--bad) 35%, transparent); background: color-mix(in srgb, var(--bad) 6%, transparent); }
.naive h3 { font-size: 1.15rem; margin: 10px 0; }
.naive .code { font-family: var(--mono); font-size: 0.85rem; padding: 14px; border-radius: 12px; background: rgba(0,0,0,.25); border: 1px solid var(--border); color: var(--muted); white-space: pre-wrap; }
:root[data-theme="light"] .naive .code { background: rgba(15,23,42,.04); }
.breaks { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 12px; }
.breaks li { display: flex; gap: 12px; padding: 14px; border-radius: 12px; background: var(--panel); border: 1px solid var(--border); font-size: 0.93rem; }
.breaks li .x { flex: none; width: 24px; height: 24px; border-radius: 8px; display: grid; place-items: center; background: color-mix(in srgb, var(--bad) 20%, transparent); color: var(--bad); font-weight: 800; font-size: 0.8rem; }
.reveal.in .breaks li { animation: shake 0.5s ease both; }
.reveal.in .breaks li:nth-child(2) { animation-delay: 0.15s } .reveal.in .breaks li:nth-child(3) { animation-delay: 0.3s }
@keyframes shake { 0% { transform: translateX(0); opacity: 0 } 30% { transform: translateX(-6px); opacity: 1 } 60% { transform: translateX(4px) } 100% { transform: none } }

.timeline { position: relative; padding-left: 56px; }
.timeline::before { content: ""; position: absolute; left: 21px; top: 10px; bottom: 10px; width: 2px; background: var(--border); }
.timeline .fill { position: absolute; left: 21px; top: 10px; width: 2px; background: linear-gradient(var(--c), var(--c2)); height: 0; transition: height 0.15s linear; }
.step { position: relative; margin-bottom: 22px; }
.step .dot { position: absolute; left: -56px; top: 18px; width: 44px; height: 44px; border-radius: 14px; background: var(--bg2); border: 2px solid var(--border2); display: grid; place-items: center; font-weight: 800; color: var(--muted); transition: 0.4s; z-index: 1; }
.step.in .dot { border-color: var(--c); color: #fff; background: linear-gradient(135deg, var(--c), var(--c2)); box-shadow: 0 0 0 6px color-mix(in srgb, var(--c) 18%, transparent); }
.step .card { padding: 24px 26px; }
.step h3 { font-size: 1.25rem; margin-bottom: 10px; display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.step p { margin: 0; color: color-mix(in srgb, var(--text) 82%, var(--muted)); }
.analogy { margin-top: 16px; padding: 14px 16px; border-radius: 12px; background: color-mix(in srgb, var(--warn) 9%, transparent); border: 1px dashed color-mix(in srgb, var(--warn) 45%, transparent); font-size: 0.92rem; display: flex; gap: 10px; }
.analogy b { color: var(--warn); }

/* ── Diagram ───────────────────────────── */
.diagram-wrap { border-radius: 22px; border: 1px solid var(--border); background: var(--bg2); overflow: hidden; box-shadow: var(--shadow); }
.diagram-bar { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; padding: 14px 16px; border-bottom: 1px solid var(--border); background: var(--panel); }
.diagram-bar .label { font-size: 0.8rem; color: var(--muted); font-weight: 600; margin-right: 4px; }
.diagram svg { display: block; width: 100%; height: auto; }
.dg-edge { stroke: var(--border2); stroke-width: 1.6; fill: none; stroke-dasharray: 5 6; animation: dash 1.6s linear infinite; }
@keyframes dash { to { stroke-dashoffset: -22; } }
.dg-edge.hot { stroke: var(--c); stroke-width: 2.6; stroke-dasharray: none; filter: drop-shadow(0 0 6px var(--c)); }
.dg-node { cursor: pointer; transition: transform 0.25s; }
.dg-node rect.box { fill: var(--bg2); stroke: var(--border2); stroke-width: 1.4; transition: 0.3s; }
.dg-node:hover rect.box { stroke: var(--kc); }
.dg-node .bar { fill: var(--kc); }
.dg-node text { fill: var(--text); font-family: var(--font); }
.dg-node .lbl { font-weight: 700; font-size: 14px; }
.dg-node .sub { font-size: 11px; fill: var(--muted); }
.dg-node .ico { font-size: 20px; }
.dg-node.active rect.box { stroke: var(--kc); stroke-width: 2.5; fill: color-mix(in srgb, var(--kc) 14%, var(--bg2)); filter: drop-shadow(0 0 14px color-mix(in srgb, var(--kc) 60%, transparent)); }
.dg-node.sel rect.box { stroke: var(--kc); stroke-width: 2.5; }
.dg-packet { fill: var(--c); filter: drop-shadow(0 0 8px var(--c)); }
.dg-ripple { fill: none; stroke: var(--c); stroke-width: 2; }
.diagram-foot { display: grid; grid-template-columns: 1.3fr 1fr; border-top: 1px solid var(--border); }
.caption { padding: 16px 18px; min-height: 76px; display: flex; gap: 14px; align-items: center; font-size: 0.95rem; }
.caption .stepn { flex: none; font-family: var(--mono); font-size: 0.78rem; padding: 4px 9px; border-radius: 8px; background: color-mix(in srgb, var(--c) 18%, transparent); color: var(--c); font-weight: 700; }
.node-info { padding: 16px 18px; border-left: 1px solid var(--border); font-size: 0.9rem; color: var(--muted); }
.node-info b { color: var(--text); display: block; margin-bottom: 2px; }
.legend { display: flex; gap: 14px; flex-wrap: wrap; padding: 10px 16px; border-top: 1px solid var(--border); font-size: 0.75rem; color: var(--muted); }
.legend span { display: inline-flex; align-items: center; gap: 6px; }
.legend i { width: 10px; height: 10px; border-radius: 3px; display: inline-block; }

/* ── Labs (shared) ───────────────────────────── */
.lab { border-radius: 22px; border: 1px solid color-mix(in srgb, var(--c) 35%, var(--border)); background: var(--bg2); overflow: hidden; box-shadow: 0 30px 80px -40px var(--c); }
.lab-head { padding: 16px 20px; display: flex; align-items: center; gap: 12px; border-bottom: 1px solid var(--border); background: linear-gradient(90deg, color-mix(in srgb, var(--c) 14%, transparent), transparent); }
.lab-head .pulse { width: 9px; height: 9px; border-radius: 50%; background: var(--ok); box-shadow: 0 0 0 0 var(--ok); animation: pulse 1.8s infinite; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--ok) 70%, transparent); } 70% { box-shadow: 0 0 0 10px transparent; } 100% { box-shadow: 0 0 0 0 transparent; } }
.lab-head h3 { font-size: 1.05rem; }
.lab-hint { padding: 14px 20px; font-size: 0.92rem; color: var(--muted); border-bottom: 1px solid var(--border); }
.lab-body { padding: 20px; }
.row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.pane { border: 1px solid var(--border); border-radius: 16px; padding: 18px; background: var(--panel); min-width: 0; }
.pane h4 { font-size: 0.82rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--muted); margin-bottom: 12px; }
input[type="text"], input[type="number"] {
  width: 100%; padding: 11px 14px; border-radius: 11px; border: 1px solid var(--border2); background: var(--bg); color: var(--text); font: inherit; font-size: 0.92rem; outline: none; transition: 0.2s;
}
input[type="text"]:focus, input[type="number"]:focus { border-color: var(--c); box-shadow: 0 0 0 4px color-mix(in srgb, var(--c) 20%, transparent); }
input[type="range"] { -webkit-appearance: none; appearance: none; width: 100%; height: 6px; border-radius: 9px; background: var(--panel2); outline: none; }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 18px; height: 18px; border-radius: 50%; background: var(--c); box-shadow: 0 0 0 4px color-mix(in srgb, var(--c) 25%, transparent); cursor: pointer; }
input[type="range"]::-moz-range-thumb { width: 18px; height: 18px; border-radius: 50%; background: var(--c); border: 0; cursor: pointer; }
.field { display: flex; flex-direction: column; gap: 8px; }
.field label { font-size: 0.82rem; color: var(--muted); font-weight: 600; display: flex; justify-content: space-between; }
.field label b { color: var(--text); font-variant-numeric: tabular-nums; }
.metric { padding: 14px; border-radius: 14px; background: var(--panel); border: 1px solid var(--border); }
.metric .k { font-size: 0.74rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.08em; font-weight: 700; }
.metric .v { font-size: 1.45rem; font-weight: 800; font-variant-numeric: tabular-nums; margin-top: 2px; letter-spacing: -0.02em; transition: color 0.3s; }
.metric.good .v { color: var(--ok); } .metric.warn .v { color: var(--warn); } .metric.bad .v { color: var(--bad); }
.verdict { margin-top: 14px; padding: 13px 16px; border-radius: 12px; font-size: 0.92rem; border: 1px solid var(--border); background: var(--panel); transition: 0.3s; }
.verdict.good { border-color: color-mix(in srgb, var(--ok) 40%, transparent); background: color-mix(in srgb, var(--ok) 8%, transparent); }
.verdict.warn { border-color: color-mix(in srgb, var(--warn) 40%, transparent); background: color-mix(in srgb, var(--warn) 8%, transparent); }
.verdict.bad { border-color: color-mix(in srgb, var(--bad) 40%, transparent); background: color-mix(in srgb, var(--bad) 8%, transparent); }
canvas { display: block; width: 100%; }
.log { font-family: var(--mono); font-size: 0.78rem; max-height: 190px; overflow-y: auto; display: flex; flex-direction: column; gap: 3px; padding: 12px; border-radius: 12px; background: rgba(0,0,0,.25); border: 1px solid var(--border); }
:root[data-theme="light"] .log { background: rgba(15,23,42,.04); }
.log div { animation: logIn 0.3s ease; color: var(--muted); }
.log .ok { color: var(--ok); } .log .bad { color: var(--bad); } .log .warn { color: var(--warn); } .log .hl { color: var(--c); }
@keyframes logIn { from { opacity: 0; transform: translateX(-6px); } }
.toggle { display: inline-flex; align-items: center; gap: 10px; cursor: pointer; font-size: 0.88rem; font-weight: 600; user-select: none; }
.toggle input { display: none; }
.toggle .sw { width: 38px; height: 22px; border-radius: 99px; background: var(--panel2); border: 1px solid var(--border2); position: relative; transition: 0.25s; }
.toggle .sw::after { content: ""; position: absolute; top: 2px; left: 2px; width: 16px; height: 16px; border-radius: 50%; background: var(--muted); transition: 0.25s cubic-bezier(.2,.8,.2,1); }
.toggle input:checked + .sw { background: var(--c); border-color: var(--c); }
.toggle input:checked + .sw::after { left: 18px; background: #fff; }

/* Shortener lab */
.b62 { display: flex; flex-direction: column; gap: 6px; font-family: var(--mono); font-size: 0.82rem; margin-top: 14px; min-height: 40px; }
.b62 .r { display: flex; justify-content: space-between; gap: 10px; padding: 7px 10px; border-radius: 9px; background: var(--panel); animation: logIn 0.35s ease both; }
.b62 .r em { font-style: normal; color: var(--c); font-weight: 700; }
.short-out { margin-top: 16px; padding: 16px; border-radius: 14px; text-align: center; font-family: var(--mono); font-size: 1.4rem; background: color-mix(in srgb, var(--c) 10%, transparent); border: 1px dashed color-mix(in srgb, var(--c) 50%, transparent); }
.short-out span { color: var(--c); font-weight: 800; display: inline-block; }
.short-out span.pop { animation: pop 0.4s cubic-bezier(.2,1.6,.4,1) both; }
@keyframes pop { from { transform: scale(0) rotate(-20deg); opacity: 0; } }
.clicks { display: flex; flex-wrap: wrap; gap: 4px; margin-top: 12px; min-height: 30px; }
.clicks i { width: 14px; height: 14px; border-radius: 4px; animation: pop 0.25s ease both; }
.clicks i.hit { background: var(--ok); } .clicks i.miss { background: var(--bad); }
.cache-slots { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 10px; }
.cache-slots div { font-family: var(--mono); font-size: 0.75rem; padding: 5px 8px; border-radius: 8px; background: color-mix(in srgb, var(--k-cache) 15%, transparent); border: 1px solid color-mix(in srgb, var(--k-cache) 40%, transparent); transition: 0.3s; }
.cache-slots div.flash { animation: pop 0.3s ease; }
.cache-slots div.empty { background: transparent; border-style: dashed; border-color: var(--border2); color: var(--dim); }

/* Chat lab */
.chat-stage { display: grid; grid-template-columns: 1fr 1.1fr 1fr; gap: 16px; position: relative; }
.phone { border-radius: 30px; border: 1px solid var(--border2); background: var(--bg); padding: 12px; height: 420px; display: flex; flex-direction: column; box-shadow: inset 0 0 0 6px var(--panel); }
.phone .ph-head { display: flex; align-items: center; gap: 10px; padding: 8px 10px 12px; border-bottom: 1px solid var(--border); font-weight: 700; font-size: 0.92rem; }
.phone .ph-head .av { width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center; background: linear-gradient(135deg, var(--c), var(--c2)); font-size: 0.85rem; }
.phone .ph-head small { display: block; font-weight: 500; color: var(--muted); font-size: 0.72rem; }
.phone .ph-head small.on { color: var(--ok); }
.msgs { flex: 1; overflow-y: auto; display: flex; flex-direction: column; gap: 6px; padding: 10px 4px; }
.bubble { max-width: 85%; padding: 7px 11px 5px; border-radius: 14px; font-size: 0.86rem; animation: pop 0.3s ease both; }
.bubble.me { align-self: flex-end; background: color-mix(in srgb, var(--c) 30%, var(--bg2)); border-bottom-right-radius: 4px; }
.bubble.them { align-self: flex-start; background: var(--panel2); border-bottom-left-radius: 4px; }
.bubble .meta { display: flex; justify-content: flex-end; gap: 4px; font-size: 0.7rem; color: var(--muted); margin-top: 2px; }
.ticks { font-weight: 800; letter-spacing: -3px; transition: color 0.3s; }
.ticks.read { color: #53bdeb; }
.ph-input { display: flex; gap: 6px; padding-top: 8px; border-top: 1px solid var(--border); }
.ph-input input { padding: 9px 12px; border-radius: 99px; font-size: 0.85rem; }
.ph-input button { flex: none; width: 38px; height: 38px; border-radius: 50%; border: 0; background: var(--c); color: #fff; font-size: 1rem; }
.server-col { display: flex; flex-direction: column; gap: 12px; justify-content: center; }
.srv { border: 1px solid var(--border2); border-radius: 16px; padding: 14px; background: var(--panel); text-align: center; position: relative; transition: 0.3s; }
.srv.flash { border-color: var(--c); box-shadow: 0 0 24px -6px var(--c); }
.srv .t { font-weight: 700; font-size: 0.9rem; }
.srv .s { font-size: 0.75rem; color: var(--muted); }
.inbox-items { display: flex; flex-direction: column; gap: 4px; margin-top: 8px; min-height: 24px; }
.inbox-items div { font-family: var(--mono); font-size: 0.72rem; padding: 4px 8px; border-radius: 7px; background: color-mix(in srgb, var(--k-queue) 18%, transparent); animation: pop 0.3s ease both; }
.packet { position: absolute; z-index: 5; pointer-events: none; padding: 3px 8px; border-radius: 99px; font-size: 0.7rem; font-family: var(--mono); font-weight: 700; background: var(--c); color: #fff; box-shadow: 0 0 18px var(--c); white-space: nowrap; }
.packet.ack { background: var(--ok); box-shadow: 0 0 14px var(--ok); }
.packet.lost { background: var(--bad); box-shadow: 0 0 14px var(--bad); }

/* ABR lab */
.player { position: relative; border-radius: 16px; overflow: hidden; aspect-ratio: 16/8; background: #000; }
.player canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.player .q { position: absolute; top: 12px; left: 12px; padding: 4px 10px; border-radius: 8px; background: rgba(0,0,0,.6); color: #fff; font-weight: 800; font-size: 0.8rem; backdrop-filter: blur(6px); transition: 0.3s; }
.player .q.up { animation: pop .4s ease; background: var(--ok); } .player .q.down { animation: pop .4s ease; background: var(--warn); }
.player .spinner { position: absolute; inset: 0; display: none; place-items: center; background: rgba(0,0,0,.45); }
.player .spinner.on { display: grid; }
.player .spinner i { width: 44px; height: 44px; border-radius: 50%; border: 4px solid rgba(255,255,255,.2); border-top-color: #fff; animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.buffer { height: 8px; border-radius: 9px; background: var(--panel2); overflow: hidden; margin-top: 10px; }
.buffer i { display: block; height: 100%; background: linear-gradient(90deg, var(--c), var(--c2)); transition: width .25s linear; }
.ladder { display: flex; flex-direction: column-reverse; gap: 5px; }
.ladder div { display: flex; justify-content: space-between; padding: 7px 12px; border-radius: 9px; font-size: 0.82rem; background: var(--panel); border: 1px solid var(--border); transition: 0.3s; font-variant-numeric: tabular-nums; }
.ladder div.cur { background: color-mix(in srgb, var(--c) 25%, transparent); border-color: var(--c); font-weight: 750; transform: scale(1.03); }
.ladder div.over { opacity: 0.4; }

/* Onsale lab */
.seatmap { display: grid; gap: 3px; padding: 14px; border-radius: 14px; background: var(--panel); border: 1px solid var(--border); }
.seatmap .stage { grid-column: 1 / -1; text-align: center; font-size: 0.7rem; font-weight: 800; letter-spacing: .2em; color: var(--muted); padding: 6px; margin-bottom: 8px; border-radius: 8px; background: var(--panel2); }
.seat { aspect-ratio: 1; border-radius: 4px 4px 2px 2px; background: var(--panel2); transition: background .25s, transform .25s; }
.seat.held { background: var(--warn); animation: heldPulse 1s ease-in-out infinite; }
.seat.sold { background: var(--c); }
.seat.dbl { background: var(--bad); animation: pop .3s ease; box-shadow: 0 0 10px var(--bad); }
.seat.rel { animation: released .7s ease; }
@keyframes heldPulse { 50% { opacity: .55; } }
@keyframes released { 0% { background: #fff; transform: scale(1.4); } }
.gauge { position: relative; width: 100%; max-width: 220px; margin: 0 auto; }
.gauge svg { width: 100%; display: block; }
.gauge .gv { position: absolute; left: 0; right: 0; bottom: 6px; text-align: center; font-size: 1.6rem; font-weight: 800; font-variant-numeric: tabular-nums; }
.queue-viz { height: 46px; border-radius: 12px; background: var(--panel); border: 1px solid var(--border); position: relative; overflow: hidden; }
.queue-viz i { position: absolute; top: 50%; width: 7px; height: 7px; margin-top: -3.5px; border-radius: 50%; background: var(--muted); }
.you { padding: 12px 14px; border-radius: 12px; background: color-mix(in srgb, var(--c) 12%, transparent); border: 1px solid color-mix(in srgb, var(--c) 40%, transparent); font-size: 0.88rem; }

/* Ring lab */
.ring-svg { width: 100%; max-width: 440px; display: block; margin: 0 auto; }
.ring-svg .key { transition: fill .5s, r .3s; }
.ring-svg .key.moved { animation: moved 1s ease; }
@keyframes moved { 0%,100% { r: 4; } 30% { r: 9; } }
.dist { display: flex; flex-direction: column; gap: 8px; }
.dist .b { display: grid; grid-template-columns: 70px 1fr 40px; gap: 10px; align-items: center; font-size: 0.82rem; }
.dist .b .t { height: 10px; border-radius: 9px; background: var(--panel2); overflow: hidden; }
.dist .b .t i { display: block; height: 100%; border-radius: 9px; transition: width .5s cubic-bezier(.2,.8,.2,1); }

/* Stripe lab */
.bucket { position: relative; width: 150px; height: 190px; margin: 0 auto; border: 3px solid var(--border2); border-top: 0; border-radius: 0 0 26px 26px; display: flex; flex-wrap: wrap-reverse; align-content: flex-start; gap: 5px; padding: 10px; justify-content: center; }
.bucket i { width: 22px; height: 22px; border-radius: 50%; background: radial-gradient(circle at 30% 30%, #ffe08a, #f59e0b); box-shadow: 0 2px 6px rgba(245,158,11,.5); animation: pop .3s ease both; }
.bucket i.out { animation: tokenOut .35s ease forwards; }
@keyframes tokenOut { to { transform: translateY(-80px) scale(.3); opacity: 0; } }
.reqs { display: flex; gap: 4px; flex-wrap: wrap; min-height: 26px; margin-top: 12px; }
.reqs span { font-family: var(--mono); font-size: 0.68rem; font-weight: 700; padding: 3px 6px; border-radius: 6px; animation: pop .25s ease both; }
.reqs .ok { background: color-mix(in srgb, var(--ok) 20%, transparent); color: var(--ok); }
.reqs .no { background: color-mix(in srgb, var(--bad) 20%, transparent); color: var(--bad); }
.ledger { width: 100%; border-collapse: collapse; font-size: 0.84rem; margin-top: 10px; }
.ledger td, .ledger th { padding: 8px 10px; border-bottom: 1px solid var(--border); text-align: left; }
.ledger th { font-size: 0.72rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.ledger tr { animation: logIn .3s ease; }
.ledger tr.dup td { color: var(--bad); background: color-mix(in srgb, var(--bad) 8%, transparent); }
.flowline { position: relative; height: 70px; margin: 10px 0; }
.flowline .ep { position: absolute; top: 14px; padding: 8px 12px; border-radius: 12px; border: 1px solid var(--border2); background: var(--panel); font-size: 0.8rem; font-weight: 700; }
.flowline .ep.l { left: 0; } .flowline .ep.r { right: 0; }
.flowline .wire { position: absolute; left: 90px; right: 90px; top: 32px; height: 2px; background: repeating-linear-gradient(90deg, var(--border2) 0 6px, transparent 6px 12px); }

/* ── Trade-offs, takeaways ───────────────────────────── */
.trade { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.trade .card h4 { font-size: 1.02rem; margin-bottom: 14px; }
.trade .pc { display: flex; gap: 8px; font-size: 0.88rem; margin-top: 8px; }
.trade .pc span { flex: none; width: 20px; height: 20px; border-radius: 6px; display: grid; place-items: center; font-weight: 800; font-size: 0.75rem; }
.trade .pro span { background: color-mix(in srgb, var(--ok) 20%, transparent); color: var(--ok); }
.trade .con span { background: color-mix(in srgb, var(--bad) 20%, transparent); color: var(--bad); }
.takeaways { display: grid; gap: 12px; margin-top: 22px; }
.takeaways div { display: flex; gap: 14px; align-items: center; padding: 16px 18px; border-radius: 14px; background: linear-gradient(90deg, color-mix(in srgb, var(--c) 12%, transparent), transparent); border: 1px solid var(--border); font-weight: 600; }
.takeaways div span { font-size: 1.2rem; }

/* ── Quiz ───────────────────────────── */
.quiz { display: grid; gap: 16px; }
.q { padding: 22px; }
.q h4 { font-size: 1.05rem; margin-bottom: 14px; display: flex; gap: 10px; }
.q h4 .qn { flex: none; color: var(--c); font-family: var(--mono); }
.opts { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.opt { text-align: left; padding: 12px 14px; border-radius: 12px; border: 1px solid var(--border2); background: var(--panel); font-size: 0.92rem; transition: 0.2s; }
.opt:hover:not(:disabled) { border-color: var(--c); background: color-mix(in srgb, var(--c) 8%, transparent); transform: translateY(-1px); }
.opt.right { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 14%, transparent); animation: pop .35s ease; }
.opt.wrong { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 12%, transparent); animation: shake .4s ease; }
.opt:disabled { cursor: default; }
.why { margin-top: 12px; font-size: 0.9rem; color: var(--muted); padding: 12px 14px; border-radius: 10px; background: var(--panel); border-left: 3px solid var(--c); animation: logIn .3s ease; }
.score-card { text-align: center; padding: 34px; }
.score-card .big { font-size: 3.4rem; font-weight: 800; }
.confetti { position: fixed; top: -10px; width: 9px; height: 14px; z-index: 200; pointer-events: none; animation: fall linear forwards; }
@keyframes fall { to { transform: translateY(105vh) rotate(720deg); } }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 80px; }
.pager a { padding: 22px; border-radius: 18px; border: 1px solid var(--border); background: var(--panel); transition: .25s; }
.pager a:hover { border-color: var(--c); transform: translateY(-2px); }
.pager a.next { text-align: right; }
.pager small { color: var(--muted); display: block; }
.pager b { font-size: 1.1rem; }

/* ── Concepts page & drawer ───────────────────────────── */
.concept-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 14px; }
.concept-card { padding: 20px; cursor: pointer; transition: .25s; }
.concept-card:hover { transform: translateY(-3px); border-color: var(--border2); box-shadow: var(--shadow); }
.concept-card .ci { font-size: 1.7rem; }
.concept-card h4 { font-size: 1.05rem; margin: 10px 0 6px; }
.concept-card p { font-size: 0.88rem; color: var(--muted); margin: 0; }
.search-row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; margin-bottom: 22px; }
.search-row input { max-width: 340px; }
.drawer-bg { position: fixed; inset: 0; background: rgba(0,0,0,.5); backdrop-filter: blur(4px); z-index: 90; opacity: 0; pointer-events: none; transition: .3s; }
.drawer-bg.on { opacity: 1; pointer-events: auto; }
.drawer { position: fixed; top: 0; right: 0; bottom: 0; width: min(520px, 100vw); z-index: 100; background: var(--bg2); border-left: 1px solid var(--border); transform: translateX(100%); transition: transform .4s cubic-bezier(.2,.8,.2,1); overflow-y: auto; padding: 32px; }
.drawer.on { transform: none; }
.drawer .close { position: absolute; top: 20px; right: 20px; }
.drawer .ci { font-size: 2.6rem; }
.drawer h2 { font-size: 1.8rem; margin: 12px 0 10px; }
.drawer .one { font-size: 1.1rem; }
.drawer pre { font-family: var(--mono); font-size: .82rem; padding: 14px; border-radius: 12px; background: var(--panel2); border: 1px solid var(--border); white-space: pre-wrap; }
.drawer .used { display: grid; gap: 8px; margin-top: 10px; }
.drawer .used a { display: flex; gap: 12px; align-items: center; padding: 12px 14px; border-radius: 12px; border: 1px solid var(--border); background: var(--panel); transition: .2s; }
.drawer .used a:hover { border-color: var(--c); }

/* ── Toolkit ───────────────────────────── */
.framework { display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; }
.framework .card { padding: 20px; }
.framework .n { font-size: 2.2rem; font-weight: 800; background: linear-gradient(135deg, var(--accent), var(--accent2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.framework h4 { margin: 4px 0 4px; font-size: 1.02rem; }
.framework .m { font-size: .75rem; color: var(--muted); font-weight: 700; }
.framework p { font-size: .85rem; color: var(--muted); }
.framework .ex { font-size: .8rem; font-family: var(--mono); padding: 10px; border-radius: 10px; background: var(--panel2); }
.lat { display: flex; flex-direction: column; gap: 10px; }
.lat .lr { display: grid; grid-template-columns: 280px 1fr 90px; gap: 14px; align-items: center; font-size: .9rem; }
.lat .lt { height: 14px; border-radius: 9px; background: var(--panel2); overflow: hidden; }
.lat .lt i { display: block; height: 100%; width: 0; border-radius: 9px; background: linear-gradient(90deg, var(--accent2), var(--accent)); transition: width 1.2s cubic-bezier(.2,.8,.2,1); }
.lat .lv { text-align: right; font-family: var(--mono); font-size: .82rem; color: var(--muted); }
.calc { display: grid; grid-template-columns: 1fr 1.2fr; gap: 20px; }
.calc .inputs { display: grid; gap: 14px; }
.calc .outs { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; align-content: start; }
.blocks { width: 100%; border-collapse: collapse; font-size: .9rem; }
.blocks td, .blocks th { padding: 13px 14px; border-bottom: 1px solid var(--border); text-align: left; vertical-align: top; }
.blocks th { font-size: .74rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.blocks td:first-child { font-weight: 700; }
.blocks td:last-child { color: var(--muted); }

.footer { margin-top: 100px; padding: 30px 0; border-top: 1px solid var(--border); color: var(--dim); font-size: .82rem; display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; }

/* ── Responsive ───────────────────────────── */
@media (max-width: 1000px) {
  .hero { grid-template-columns: 1fr; padding-top: 50px; }
  .how, .framework { grid-template-columns: 1fr 1fr; }
  .case-layout { grid-template-columns: 1fr; }
  .toc { display: none; }
  .trade { grid-template-columns: 1fr; }
  .diagram-foot { grid-template-columns: 1fr; }
  .node-info { border-left: 0; border-top: 1px solid var(--border); }
  .chat-stage { grid-template-columns: 1fr 1fr; }
  .chat-stage .server-col { grid-column: 1 / -1; grid-row: 2; flex-direction: row; }
  .calc { grid-template-columns: 1fr; }
}
@media (max-width: 700px) {
  main { padding: 0 18px 80px; }
  .topbar { padding: 12px 18px; gap: 12px; }
  .nav a { padding: 6px 9px; font-size: .85rem; }
  .xp { display: none; }
  .stats, .grid2, .grid3, .req-grid, .naive, .opts, .how, .framework { grid-template-columns: 1fr; }
  .lat .lr { grid-template-columns: 1fr 70px; } .lat .lt { grid-column: 1 / -1; grid-row: 2; }
  .chat-stage { grid-template-columns: 1fr; }
  .timeline { padding-left: 0; } .timeline::before, .timeline .fill, .step .dot { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  .reveal, .stagger > * { opacity: 1; transform: none; }
}