:root {
  --bg: #fafaf7;
  --bg-2: #ffffff;
  --ink: #16181d;
  --ink-2: #4b5160;
  --ink-3: #8a90a0;
  --line: #e5e6ea;
  --accent: #1a56db;
  --accent-ink: #ffffff;
  --accent-soft: #e8efff;
  --bar: #1a56db;
  --bar-cur: #f0a202;
  --shadow: 0 10px 40px rgba(20, 30, 60, 0.10);
  --radius: 14px;
  color-scheme: light;
}
:root[data-theme="dark"] {
  --bg: #0f1115;
  --bg-2: #171a21;
  --ink: #eef0f4;
  --ink-2: #b6bcc9;
  --ink-3: #7e869a;
  --line: #262b36;
  --accent: #7aa2ff;
  --accent-ink: #0f1115;
  --accent-soft: #1b2440;
  --bar: #7aa2ff;
  --bar-cur: #ffc857;
  --shadow: 0 10px 40px rgba(0, 0, 0, 0.45);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 17px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { margin: 0; letter-spacing: -0.01em; line-height: 1.15; }
h1 { font-size: clamp(2.2rem, 4.5vw, 3.6rem); font-weight: 700; }
h2 { font-size: clamp(1.7rem, 3vw, 2.4rem); font-weight: 700; }
h3 { font-size: 1.15rem; font-weight: 600; }
p { margin: 0; }
code { font-family: "JetBrains Mono", ui-monospace, monospace; font-size: 0.9em; background: var(--accent-soft); padding: 0.1em 0.4em; border-radius: 6px; }

.eyebrow { font-size: 0.85rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--accent); margin-bottom: 0.9rem; }
.lead { font-size: 1.15rem; color: var(--ink-2); max-width: 46rem; }
.fine { font-size: 0.9rem; color: var(--ink-3); }
.section-head { max-width: 52rem; margin-bottom: 2.5rem; }
.section-head .lead { margin-top: 1rem; }

/* header */
.top {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 2rem;
  padding: 0.8rem clamp(1rem, 5vw, 4rem);
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 0.6rem; font-weight: 700; color: var(--ink); font-size: 1.05rem; }
.brand:hover { text-decoration: none; }
.nav { display: flex; gap: 1.6rem; margin-left: auto; }
.nav a { color: var(--ink-2); font-size: 0.95rem; font-weight: 500; }
.nav a:hover { color: var(--ink); text-decoration: none; }
.controls { display: flex; align-items: center; gap: 0.5rem; }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 0.55rem 1.05rem; border-radius: 10px; font-weight: 600; font-size: 0.95rem;
  border: 1px solid var(--line); color: var(--ink); background: var(--bg-2);
  transition: transform .12s ease, box-shadow .12s ease, background .12s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); box-shadow: 0 4px 14px rgba(0,0,0,.08); }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: transparent; }
.btn.lg { padding: 0.85rem 1.5rem; font-size: 1.05rem; border-radius: 12px; }
.ghost { border: 1px solid var(--line); background: transparent; color: var(--ink-2); border-radius: 10px; padding: 0.45rem 0.7rem; cursor: pointer; font: inherit; font-size: 0.85rem; font-weight: 600; display: inline-flex; align-items: center; }
.ghost:hover { color: var(--ink); background: var(--bg-2); }
:root[data-theme="dark"] .sun { display: none; }
:root:not([data-theme="dark"]) .moon { display: none; }

main { padding: 0 clamp(1rem, 5vw, 4rem); }
section { padding: clamp(3rem, 7vw, 6rem) 0; border-bottom: 1px solid var(--line); }
section:last-of-type { border-bottom: 0; }

/* hero */
.hero { display: grid; grid-template-columns: 1.05fr 1fr; gap: 3rem; align-items: center; padding-top: clamp(3rem, 8vw, 6rem); }
.hero-text .lead { margin-top: 1.4rem; }
.cta { display: flex; gap: 0.8rem; flex-wrap: wrap; margin-top: 2rem; }
.hero .fine { margin-top: 1rem; }

.window { background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.window-bar { display: flex; align-items: center; gap: 6px; padding: 10px 14px; border-bottom: 1px solid var(--line); }
.window-bar span { width: 10px; height: 10px; border-radius: 50%; background: var(--line); }
.window-bar em { margin-left: auto; font-style: normal; font-size: 0.8rem; color: var(--ink-3); }
.window-body { padding: 16px 18px 12px; }
.ask-row { display: flex; align-items: center; gap: 10px; border: 1px solid var(--line); border-radius: 10px; padding: 8px 12px; background: var(--bg); }
.spark { color: var(--accent); }
.ask-text { flex: 1; font-size: 0.95rem; color: var(--ink); white-space: nowrap; overflow: hidden; }
.ask-text::after { content: "▏"; color: var(--accent); animation: blink 1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }
.ask-btn { background: var(--accent); color: var(--accent-ink); font-size: 0.8rem; font-weight: 600; padding: 4px 10px; border-radius: 7px; }
.chips { display: flex; gap: 8px; flex-wrap: wrap; margin: 12px 0 6px; }
.chips span { font-size: 0.78rem; color: var(--ink-2); border: 1px solid var(--line); border-radius: 999px; padding: 3px 10px; }
.chips b { color: var(--ink); font-weight: 600; }
.chart { width: 100%; height: auto; display: block; margin-top: 6px; }
.chart .grid line { stroke: var(--line); stroke-width: 1; }
.chart .bars rect { fill: var(--bar); rx: 4; transform-origin: bottom; transform-box: fill-box; animation: grow .9s cubic-bezier(.2,.8,.2,1) both; }
.chart .bars rect.cur { fill: var(--bar-cur); }
.chart .bars rect:nth-child(2) { animation-delay: .05s } .chart .bars rect:nth-child(3) { animation-delay: .1s } .chart .bars rect:nth-child(4) { animation-delay: .15s } .chart .bars rect:nth-child(5) { animation-delay: .2s } .chart .bars rect:nth-child(6) { animation-delay: .25s } .chart .bars rect:nth-child(7) { animation-delay: .3s }
@keyframes grow { from { transform: scaleY(0); } }
.chart text { font-family: Inter, sans-serif; font-size: 11px; fill: var(--ink-3); text-anchor: middle; }
.chart .values text { fill: var(--ink-2); font-weight: 600; }
.chart-note { font-size: 0.72rem; color: var(--ink-3); margin-top: 4px; }

/* numbers */
.numbers { display: grid; grid-template-columns: repeat(5, 1fr); gap: 1.5rem; }
.num b { display: block; font-size: clamp(1.6rem, 2.6vw, 2.3rem); font-weight: 700; letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
.num span { display: block; color: var(--ink-2); font-size: 0.95rem; margin-top: 0.2rem; }

/* ask */
.examples { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; margin-bottom: 3rem; }
.example {
  text-align: left; background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.1rem 1.3rem; cursor: pointer; font: inherit; color: var(--ink);
  transition: border-color .15s ease, transform .15s ease;
}
.example:hover { border-color: var(--accent); transform: translateY(-2px); }
.example .q { display: block; font-size: 1.05rem; font-weight: 600; }
.example .a { display: block; margin-top: 0.5rem; font-size: 0.85rem; color: var(--ink-3); }
.example .a i { font-style: normal; color: var(--ink-2); background: var(--accent-soft); padding: 1px 8px; border-radius: 999px; }
.features3, .grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; }
.f p, .int p { color: var(--ink-2); margin-top: 0.5rem; font-size: 1rem; }

/* inside */
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.2rem; }
.grid article { background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.4rem 1.5rem; }
.grid article p { color: var(--ink-2); margin-top: 0.6rem; font-size: 1rem; }

/* who */
.cols { display: grid; grid-template-columns: repeat(4, 1fr); gap: 2rem; }
.cols p { color: var(--ink-2); margin-top: 0.5rem; font-size: 1rem; }

/* final */
.final { text-align: center; }
.final .lead { margin: 1rem auto 2rem; }
.final .fine { margin-top: 1.2rem; }

footer { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; padding: 1.5rem clamp(1rem, 5vw, 4rem); border-top: 1px solid var(--line); color: var(--ink-3); font-size: 0.9rem; }

@media (max-width: 1000px) {
  .hero { grid-template-columns: 1fr; }
  .numbers { grid-template-columns: repeat(2, 1fr); }
  .features3, .grid3, .grid { grid-template-columns: 1fr 1fr; }
  .cols { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .nav { display: none; }
  .numbers, .features3, .grid3, .grid, .cols, .examples { grid-template-columns: 1fr; }
  .top { gap: 0.8rem; }
  .controls .btn { display: none; }
}