:root {
  --bg: #161618;
  --bg-2: #1d1d20;
  --panel: #222226;
  --border: #2e2e33;
  --text: #ececec;
  --muted: #9a9aa2;
  --accent: #5b9dff;
  --accent-2: #4ec98e;

  /* Syntax-token colours — matched to the app. */
  --tok-num: #f2f2f2;
  --tok-var: #5b9dff;
  --tok-kw: #ff6b9d;
  --tok-unit: #34c7c0;
  --tok-cur: #4ec98e;
  --tok-fn: #b08cff;
  --tok-com: #74747e;
  --tok-res: #e9e9ee;
  --tok-hint: #74747e;

  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 1040px; margin: 0 auto; padding: 0 24px; }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 10;
  backdrop-filter: blur(12px);
  background: rgba(22, 22, 24, 0.75);
  border-bottom: 1px solid var(--border);
}
.nav .wrap { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--text); }
.brand:hover { text-decoration: none; }
.brand .mark {
  width: 28px; height: 28px; border-radius: 7px;
  background: linear-gradient(135deg, var(--accent), var(--tok-fn));
  display: grid; place-items: center; color: #fff; font-family: var(--mono); font-weight: 700; font-size: 15px;
}
.nav-links { display: flex; gap: 26px; align-items: center; }
.nav-links a { color: var(--muted); font-size: 15px; }
.nav-links a:hover { color: var(--text); text-decoration: none; }

/* Buttons */
.btn {
  display: inline-block; padding: 12px 22px; border-radius: 10px;
  font-weight: 700; font-size: 15px; cursor: pointer; border: 1px solid transparent;
  transition: background .15s ease, border-color .15s ease, transform .05s ease;
}
.btn-primary { background: #2b66d6; color: #ffffff; box-shadow: 0 6px 20px rgba(43, 102, 214, .4); }
.btn-primary:hover { background: #3b76e6; text-decoration: none; }
.btn-primary:active { transform: translateY(1px); }
.btn-ghost { background: rgba(255, 255, 255, .05); border-color: #3a3a42; color: var(--text); }
.btn-ghost:hover { border-color: #565660; background: rgba(255, 255, 255, .08); text-decoration: none; }

/* Hero */
.hero { padding: 80px 0 60px; }
.hero-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.eyebrow { color: var(--accent); font-weight: 600; font-size: 14px; letter-spacing: .04em; text-transform: uppercase; }
.hero h1 { font-size: 52px; line-height: 1.05; margin: 14px 0 18px; letter-spacing: -0.02em; }
.hero p.lead { font-size: 19px; color: var(--muted); margin: 0 0 28px; }
.cta-row { display: flex; gap: 14px; flex-wrap: wrap; }
.cta-note { color: var(--muted); font-size: 13px; margin-top: 14px; }

/* Calc panel (used in hero + docs) */
.calc {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px 6px 18px 18px;
  font-family: var(--mono);
  font-size: 15px;
  box-shadow: 0 24px 60px rgba(0,0,0,.4);
  overflow: hidden;
}
.calc .row { display: grid; grid-template-columns: 1fr auto; gap: 20px; padding: 2px 14px 2px 0; }
.calc .expr { white-space: pre; overflow: hidden; text-overflow: ellipsis; }
.calc .res { color: var(--tok-res); text-align: right; white-space: nowrap; }
.calc .res.hint { color: var(--tok-hint); }

.num { color: var(--tok-num); }
.var { color: var(--tok-var); }
.kw  { color: var(--tok-kw); }
.unit{ color: var(--tok-unit); }
.cur { color: var(--tok-cur); }
.fn  { color: var(--tok-fn); }
.com { color: var(--tok-com); }
.op  { color: var(--muted); }

/* Sections */
section { padding: 64px 0; border-top: 1px solid var(--border); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 44px; }
.section-head h2 { font-size: 34px; margin: 0 0 12px; letter-spacing: -0.01em; }
.section-head p { color: var(--muted); font-size: 17px; margin: 0; }

/* Feature grid */
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.feature {
  background: var(--panel); border: 1px solid var(--border);
  border-radius: 14px; padding: 22px;
}
.feature .ic { font-size: 22px; }
.feature h3 { margin: 12px 0 8px; font-size: 17px; }
.feature p { margin: 0; color: var(--muted); font-size: 14.5px; }
.mono { font-family: var(--mono); font-size: 0.92em; color: var(--text); background: rgba(255,255,255,.06); padding: 1px 5px; border-radius: 5px; }

/* CTA band */
.cta-band { text-align: center; }
.cta-band h2 { font-size: 32px; margin: 0 0 10px; }
.cta-band p { color: var(--muted); margin: 0 0 26px; font-size: 17px; }

/* Footer */
footer { border-top: 1px solid var(--border); padding: 34px 0; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; }

/* Docs */
.doc { padding: 56px 0; }
.doc h1 { font-size: 40px; margin: 0 0 8px; }
.doc .lead { color: var(--muted); font-size: 18px; margin: 0 0 40px; }
.doc h2 { font-size: 24px; margin: 44px 0 8px; }
.doc h2 .ic { margin-right: 8px; }
.doc p.note { color: var(--muted); margin: 0 0 16px; }
.doc .calc { margin: 12px 0 8px; }

@media (max-width: 820px) {
  .hero-grid { grid-template-columns: 1fr; gap: 32px; }
  .hero h1 { font-size: 40px; }
  .features { grid-template-columns: 1fr; }
  .nav-links a:not(.btn) { display: none; }
}