:root {
  --blue: #0a6cff;
  --blue-dark: #0546e0;
  --cyan: #16c8ff;
  --ink: #0f172a;
  --muted: #5b6475;
  --bg: #ffffff;
  --soft: #f3f7ff;
  --line: #e3e9f5;
  --card: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e8edf7;
    --muted: #9aa6bd;
    --bg: #0b1220;
    --soft: #111b2e;
    --line: #1e2a42;
    --card: #121c30;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* Header */
.nav { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.nav .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand img { width: 34px; height: 34px; border-radius: 9px; }
.nav-links { display: flex; gap: 22px; font-size: 15px; }
.nav-links a { color: var(--muted); }
@media (max-width: 600px) { .nav-links .hide-sm { display: none; } }

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 13px 22px; border-radius: 12px; font-weight: 600; font-size: 16px; border: 0; cursor: pointer; font-family: inherit; }
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--blue); color: #fff; }
.btn-primary:hover { background: var(--blue-dark); }
.btn-ghost { background: var(--soft); color: var(--ink); border: 1px solid var(--line); }

/* Hero */
.hero { background: linear-gradient(135deg, var(--cyan) 0%, var(--blue) 55%, var(--blue-dark) 100%); color: #fff; }
.hero .wrap { display: grid; grid-template-columns: 1.2fr 1fr; gap: 40px; align-items: center; padding-top: 72px; padding-bottom: 80px; }
.hero h1 { font-size: clamp(34px, 6vw, 56px); line-height: 1.1; margin: 0 0 16px; letter-spacing: -0.02em; }
.hero p { font-size: 19px; opacity: 0.92; margin: 0 0 28px; max-width: 520px; }
.hero .btn-primary { background: #fff; color: var(--blue); }
.hero .btn-primary:hover { background: #eaf2ff; }
.hero .btn-ghost { background: rgba(255,255,255,0.14); color: #fff; border-color: rgba(255,255,255,0.35); }
.hero-art { display: flex; justify-content: center; }
.hero-art img { width: min(320px, 70vw); border-radius: 64px; box-shadow: 0 30px 60px rgba(3, 30, 110, 0.35); }
.actions { display: flex; flex-wrap: wrap; gap: 12px; }
@media (max-width: 820px) {
  .hero .wrap { grid-template-columns: 1fr; text-align: center; padding-top: 48px; }
  .hero p { margin-left: auto; margin-right: auto; }
  .actions { justify-content: center; }
  .hero-art { order: -1; }
  .hero-art img { width: 160px; border-radius: 36px; }
}

/* Sections */
section { padding: 72px 0; }
section.alt { background: var(--soft); }
h2 { font-size: clamp(26px, 4vw, 36px); margin: 0 0 12px; letter-spacing: -0.01em; }
.lead { color: var(--muted); font-size: 18px; margin: 0 0 36px; max-width: 640px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 18px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 24px; }
.card h3 { margin: 12px 0 6px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.icon { width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center; background: linear-gradient(135deg, var(--cyan), var(--blue)); color: #fff; }
.icon svg { width: 22px; height: 22px; }

/* Footer */
footer { border-top: 1px solid var(--line); padding: 32px 0; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 16px; justify-content: space-between; align-items: center; }
footer nav { display: flex; flex-wrap: wrap; gap: 18px; }
footer a { color: var(--muted); }

/* Document pages (privacy, terms) */
.doc { max-width: 760px; margin: 0 auto; padding: 48px 20px 72px; }
.doc h1 { font-size: clamp(30px, 5vw, 40px); margin: 0 0 6px; }
.doc .meta { color: var(--muted); margin: 0 0 32px; }
.doc h2 { font-size: 22px; margin: 36px 0 10px; }
.doc ul { padding-left: 22px; }
.doc li { margin: 6px 0; }

/* Link landing pages (/c/..., /join/..., /u/...) */
.landing { min-height: calc(100vh - 64px); display: grid; place-items: center; padding: 40px 20px; background: var(--soft); }
.landing .card { max-width: 440px; width: 100%; text-align: center; padding: 36px 28px; }
.landing .card img { width: 88px; height: 88px; border-radius: 22px; }
.landing h1 { font-size: 24px; margin: 18px 0 4px; word-break: break-word; }
.landing .sub { color: var(--muted); margin: 0 0 24px; }
.linkbox { display: flex; gap: 8px; align-items: center; background: var(--soft); border: 1px solid var(--line); border-radius: 12px; padding: 8px 8px 8px 14px; margin: 0 0 20px; }
.linkbox code { flex: 1; text-align: left; font-size: 14px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.linkbox button { padding: 8px 14px; font-size: 14px; border-radius: 9px; }
.steps { text-align: left; color: var(--muted); font-size: 15px; margin: 22px 0 0; padding-left: 20px; }
.landing .btn { width: 100%; justify-content: center; }
.landing .linkbox .btn { width: auto; flex: none; }
.linkbox code { min-width: 0; }