:root {
  --bg: #f4f6fb;
  --panel: #ffffff;
  --text: #182033;
  --muted: #5d667a;
  --faint: #9aa3b5;
  --line: #e2e7f0;
  --blue: #2f5bea;
  --blue-soft: #eaf0ff;
  --navy: #141925;
  --shadow: 0 10px 30px rgba(28, 45, 95, 0.12), 0 1px 3px rgba(28, 45, 95, 0.08);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  color: var(--text);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); }
a { color: var(--blue); text-decoration: none; }
code { font: 0.92em ui-monospace, SFMono-Regular, Menlo, monospace; background: var(--blue-soft); padding: 1px 5px; border-radius: 5px; }

/* ---------- top bar ---------- */
.nav { position: fixed; top: 0; left: 0; right: 0; z-index: 20; display: flex; align-items: center; justify-content: space-between; height: 64px; padding: 0 28px; background: rgba(255, 255, 255, 0.82); backdrop-filter: blur(10px); border-bottom: 1px solid rgba(226, 231, 240, 0.8); }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); }
.brand svg { width: 26px; height: 29px; }
.brand b { font-size: 19px; letter-spacing: -0.3px; }
.brand .beta { padding: 2px 7px; border-radius: 6px; background: var(--blue-soft); color: var(--blue); font-size: 11px; font-weight: 700; letter-spacing: 0.6px; text-transform: uppercase; }
.nav nav { display: flex; align-items: center; gap: 26px; }
.nav nav a { color: var(--muted); font-size: 14px; font-weight: 500; }
.nav nav a:hover { color: var(--text); }
.nav nav a.cta { color: #fff; background: var(--blue); padding: 8px 16px; border-radius: 9px; font-weight: 600; }

/* ---------- hero: the live city behind ---------- */
.hero { position: relative; height: 100vh; min-height: 620px; overflow: hidden; background: #e6ebf6; }
.hero .city { position: absolute; inset: 0; opacity: 0; transition: opacity 1.5s ease; }
.hero .city.ready { opacity: 1; }
.hero .city canvas { display: block; }
.hero .city .labels { display: none; }
.hero .shade { position: absolute; inset: 0; pointer-events: none; background: linear-gradient(90deg, rgba(244, 246, 251, 0.95) 0%, rgba(244, 246, 251, 0.78) 34%, rgba(244, 246, 251, 0) 62%), linear-gradient(0deg, var(--bg) 0%, rgba(244, 246, 251, 0) 22%); }
.hero .pitch { position: absolute; left: max(28px, 7vw); top: 50%; transform: translateY(-46%); max-width: 560px; }
.kicker { font-size: 12.5px; font-weight: 700; letter-spacing: 1px; text-transform: uppercase; color: var(--blue); }
.hero h1 { margin: 14px 0 18px; font-size: clamp(40px, 5.6vw, 70px); line-height: 1.02; letter-spacing: -2px; }
.hero p { margin: 0 0 28px; font-size: 18px; line-height: 1.55; color: var(--muted); }
.acts { display: flex; gap: 12px; flex-wrap: wrap; }
.acts.center { justify-content: center; margin-top: 26px; }
.btn { display: inline-block; padding: 13px 24px; border-radius: 11px; background: var(--blue); color: #fff; font-weight: 600; font-size: 15px; box-shadow: 0 6px 18px rgba(47, 91, 234, 0.3); }
.btn.ghost { background: var(--panel); color: var(--blue); box-shadow: var(--shadow); }
.live { display: inline-flex; align-items: center; gap: 8px; margin-top: 26px; font-size: 13px; color: var(--muted); }
.live i { width: 8px; height: 8px; border-radius: 50%; background: #1f9d55; box-shadow: 0 0 0 4px rgba(31, 157, 85, 0.18); animation: pulse 1.6s ease-in-out infinite; }
.hero .beta-note { margin: 18px 0 0; padding: 10px 14px; max-width: 460px; font-size: 14px; line-height: 1.5; color: var(--text); background: rgba(255, 255, 255, 0.72); border: 1px solid var(--line); border-left: 3px solid var(--blue); border-radius: 9px; }
@keyframes pulse { 50% { box-shadow: 0 0 0 7px rgba(31, 157, 85, 0.05); } }

/* ---------- sections ---------- */
.band { padding: 96px max(28px, 7vw); text-align: center; }
.band h2 { margin: 0 0 12px; font-size: clamp(30px, 3.6vw, 44px); letter-spacing: -1px; }
.lead { margin: 0 auto 42px; max-width: 640px; font-size: 17px; line-height: 1.55; color: var(--muted); }
.legend { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 14px; max-width: 1180px; margin: 0 auto; text-align: left; }
.lg { display: flex; flex-direction: column; gap: 6px; padding: 18px 20px; background: var(--panel); border-radius: 14px; box-shadow: var(--shadow); }
.lg b { font-size: 15px; }
.lg span { font-size: 14px; line-height: 1.5; color: var(--muted); }
.feat { display: grid; grid-template-columns: 1.4fr 1fr; gap: 48px; align-items: center; max-width: 1180px; margin: 0 auto; padding: 46px 28px; }
.feat.flip { grid-template-columns: 1fr 1.4fr; }
.feat.flip img { order: 2; }
.feat img { width: 100%; border-radius: 16px; box-shadow: var(--shadow); }
.feat h3 { margin: 0 0 12px; font-size: 28px; letter-spacing: -0.6px; }
.feat p { margin: 0; font-size: 16.5px; line-height: 1.6; color: var(--muted); }
.band.dark { background: var(--navy); color: #e6e9f0; margin-top: 50px; }
.band.dark .lead { color: #a0a9bb; }
.layers { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; max-width: 1180px; margin: 0 auto; text-align: left; }
.layers div { display: flex; flex-direction: column; gap: 8px; padding: 20px 22px; border: 1px solid #2d3445; border-radius: 14px; background: #1b2130; }
.layers b { font-size: 16px; color: #fff; }
.layers span { font-size: 14px; line-height: 1.55; color: #a0a9bb; }
.code { max-width: 860px; margin: 0 auto; padding: 20px 22px; text-align: left; background: var(--navy); color: #dfe6f5; border-radius: 14px; font: 13.5px/1.65 ui-monospace, SFMono-Regular, Menlo, monospace; overflow-x: auto; }
.code .c { color: #6f7a8f; }
.foot { display: flex; justify-content: space-between; padding: 28px max(28px, 7vw); border-top: 1px solid var(--line); font-size: 13.5px; color: var(--muted); }

/* ---------- docs ---------- */
.docs { display: grid; grid-template-columns: 210px minmax(0, 820px); gap: 48px; justify-content: center; padding: 110px 28px 60px; }
.docs aside { position: sticky; top: 96px; align-self: start; display: flex; flex-direction: column; gap: 4px; }
.docs aside a { padding: 6px 10px; border-radius: 7px; color: var(--muted); font-size: 14px; }
.docs aside a:hover { background: var(--blue-soft); color: var(--blue); }
.docs h1 { margin: 0 0 14px; font-size: 38px; letter-spacing: -1px; }
.docs h2 { margin: 42px 0 12px; font-size: 23px; letter-spacing: -0.4px; scroll-margin-top: 90px; }
.docs p, .docs li { font-size: 15.5px; line-height: 1.65; color: #2c3446; }
.docs .code { margin: 14px 0; max-width: none; }
.docs .note { padding: 10px 14px; background: var(--blue-soft); border-left: 3px solid var(--blue); border-radius: 9px; }
.docs table { width: 100%; border-collapse: collapse; margin: 14px 0; background: var(--panel); border-radius: 12px; overflow: hidden; box-shadow: var(--shadow); font-size: 14px; }
.docs th, .docs td { padding: 9px 12px; text-align: left; border-bottom: 1px solid var(--line); vertical-align: top; }
.docs th { background: #f8f9fc; font-size: 12.5px; text-transform: uppercase; letter-spacing: 0.5px; color: var(--muted); }

@media (max-width: 860px) {
  .nav nav a:not(.cta) { display: none; }
  .hero .shade { background: linear-gradient(0deg, rgba(244, 246, 251, 0.96) 30%, rgba(244, 246, 251, 0.5) 70%, rgba(244, 246, 251, 0.2)); }
  .hero .pitch { top: auto; bottom: 48px; transform: none; right: 28px; }
  .feat, .feat.flip { grid-template-columns: 1fr; gap: 20px; }
  .feat.flip img { order: 0; }
  .docs { grid-template-columns: 1fr; }
  .docs aside { display: none; }
}

/* ---------- logo cube spin (site.js) ---------- */
.nav .brand svg { cursor: pointer; }
.cube3d { position: fixed; z-index: 40; width: 0; height: 0; perspective: 900px; pointer-events: none; }
.cube3d .c { position: absolute; width: var(--a); height: var(--a); left: calc(var(--a) / -2); top: calc(var(--a) / -2); transform-style: preserve-3d; animation: cube3d 1s cubic-bezier(0.35, 0.6, 0.25, 1) both; }
.cube3d i { position: absolute; inset: 0; backface-visibility: hidden; }
.cube3d .f { background: #2348c9; transform: translateZ(calc(var(--a) / 2)); }
.cube3d .b { background: #2348c9; transform: rotateY(180deg) translateZ(calc(var(--a) / 2)); }
.cube3d .r { background: #2f5bea; transform: rotateY(90deg) translateZ(calc(var(--a) / 2)); }
.cube3d .l { background: #2f5bea; transform: rotateY(-90deg) translateZ(calc(var(--a) / 2)); }
.cube3d .t { background: #6f8ff5; transform: rotateX(90deg) translateZ(calc(var(--a) / 2)); }
.cube3d .u { background: #1b3aa8; transform: rotateX(-90deg) translateZ(calc(var(--a) / 2)); }
@keyframes cube3d { from { transform: rotateX(-35.26deg) rotateY(45deg); } to { transform: rotateX(-35.26deg) rotateY(405deg); } }