:root {
  --bg: #060a12;
  --bg-soft: #0c1220;
  --bg-soft-2: #131b2c;
  --border: #1c2638;
  --fg: #e6ebf5;
  --fg-dim: #9aa6bd;
  --fg-faint: #5c6781;
  --accent: #22d3ee;
  --accent-2: #0891b2;
  --accent-soft: rgba(34, 211, 238, 0.14);
  --pink: #f472b6;
  --green: #34d399;
  --code-bg: #060a14;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg); color: var(--fg);
  line-height: 1.65; -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(ellipse 60% 50% at 80% 0%, rgba(34, 211, 238, 0.07), transparent 60%),
    radial-gradient(ellipse 50% 40% at 10% 100%, rgba(8, 145, 178, 0.05), transparent 60%);
  background-attachment: fixed;
  display: flex; flex-direction: column; min-height: 100vh;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code, pre { font-family: 'JetBrains Mono', ui-monospace, monospace; }
code { font-size: 0.9em; background: var(--bg-soft); padding: 0.1em 0.35em; border-radius: 4px; color: #fde0a3; }
pre { background: var(--code-bg); border: 1px solid var(--border); border-radius: 10px; padding: 16px 18px; overflow-x: auto; line-height: 1.55; }
pre code { background: transparent; padding: 0; color: inherit; font-size: 0.86em; }

/* top nav */
.topnav {
  position: sticky; top: 0; z-index: 50; height: 60px;
  backdrop-filter: blur(10px);
  background: rgba(6, 10, 18, 0.75);
  border-bottom: 1px solid var(--border);
}
.topnav-inner {
  max-width: 1240px; margin: 0 auto; height: 100%;
  display: flex; align-items: center; gap: 18px; padding: 0 24px;
}
.topnav .brand { display: flex; align-items: center; gap: 10px; color: var(--fg); font-weight: 600; font-size: 1.05rem; letter-spacing: -0.01em; }
.topnav .brand:hover { text-decoration: none; }
.topnav .brand img { width: 32px; height: 32px; }
.topnav .brand .ark { color: var(--accent); }
.topnav .spacer { flex: 1; }
.topnav nav { display: flex; gap: 4px; }
.topnav nav a {
  color: var(--fg-dim); padding: 6px 12px; border-radius: 6px; font-size: 0.92rem; font-weight: 500;
}
.topnav nav a:hover { color: var(--fg); background: var(--bg-soft); text-decoration: none; }
.topnav nav a.active { color: var(--accent); }
.topnav .gh { display: flex; align-items: center; color: var(--fg-dim); padding: 6px; border-radius: 6px; }
.topnav .gh:hover { color: var(--fg); background: var(--bg-soft); }
.topnav .gh svg { width: 22px; height: 22px; display: block; }

/* hero */
.hero {
  flex: 1;
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 48px; align-items: center;
  max-width: 1240px; margin: 0 auto; padding: 80px 32px 120px;
  width: 100%;
}
.hero-text h1 {
  font-size: clamp(3.5rem, 8vw, 6rem); margin: 0 0 12px;
  letter-spacing: -0.04em; line-height: 1;
  background: linear-gradient(120deg, #67e8f9 0%, #22d3ee 50%, #0891b2 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-text .tagline { font-size: 1.25rem; color: var(--fg-dim); margin: 0 0 28px; max-width: 460px; }
.hero-cta { display: flex; gap: 10px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 10px 22px; border-radius: 999px;
  font-weight: 600; font-size: 0.92rem; transition: transform 0.08s ease, background 0.15s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn.primary { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #021018; box-shadow: 0 4px 24px -8px rgba(34, 211, 238, 0.6); }
.btn.primary:hover { background: linear-gradient(135deg, #67e8f9, var(--accent)); }
.btn.secondary { background: var(--bg-soft-2); color: var(--fg); border: 1px solid var(--border); }
.btn.secondary:hover { background: var(--bg-soft); border-color: #2a3850; }
.hero-art {
  display: flex; justify-content: center; align-items: center;
  filter: drop-shadow(0 24px 64px rgba(34, 211, 238, 0.18));
}
.hero-art img {
  width: 100%; max-width: 380px; height: auto;
  animation: float 6s ease-in-out infinite;
}
@keyframes float {
  0%, 100% { transform: translateY(0) rotate(-2deg); }
  50% { transform: translateY(-12px) rotate(2deg); }
}

/* feature row */
.features {
  max-width: 1240px; margin: 0 auto; padding: 0 32px 80px;
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}
.feature { background: var(--bg-soft); border: 1px solid var(--border); border-radius: 12px; padding: 20px; }
.feature h3 { margin: 0 0 6px; font-size: 1rem; color: var(--fg); display: flex; align-items: center; gap: 8px; }
.feature h3 .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 12px var(--accent); }
.feature p { margin: 0; font-size: 0.88rem; color: var(--fg-faint); }

/* docs shell (api + guide) */
.shell { display: grid; grid-template-columns: 260px minmax(0, 1fr); gap: 0; flex: 1; max-width: 1240px; width: 100%; margin: 0 auto; }
.shell.no-sidebar { grid-template-columns: minmax(0, 1fr); }
aside.sidebar {
  position: sticky; top: 60px; align-self: start; height: calc(100vh - 60px); overflow-y: auto;
  padding: 28px 22px 60px; border-right: 1px solid var(--border);
}
aside.sidebar h4 { text-transform: uppercase; font-size: 0.7rem; letter-spacing: 0.08em; color: var(--fg-faint); margin: 18px 0 6px; }
aside.sidebar h4:first-child { margin-top: 0; }
aside.sidebar a { display: block; padding: 4px 8px; margin: 1px -8px; border-radius: 5px; font-size: 0.88rem; color: var(--fg-dim); }
aside.sidebar a:hover { color: var(--fg); background: var(--bg-soft-2); text-decoration: none; }
aside.sidebar a.active { color: var(--accent); background: var(--accent-soft); }

main.docs { max-width: 880px; padding: 48px 56px 96px; }
main.docs h1 { font-size: 2.4rem; line-height: 1.1; letter-spacing: -0.03em; margin: 0 0 8px; }
main.docs h2 { font-size: 1.55rem; margin: 56px 0 18px; letter-spacing: -0.02em; border-bottom: 1px solid var(--border); padding-bottom: 8px; }
main.docs h3 { font-size: 1.05rem; margin: 32px 0 6px; }
main.docs h3 code { background: transparent; color: var(--accent); padding: 0; font-size: inherit; }
main.docs p { color: var(--fg-dim); }
main.docs p strong { color: var(--fg); font-weight: 600; }
main.docs ul, main.docs ol { color: var(--fg-dim); padding-left: 22px; }
main.docs ul li, main.docs ol li { margin: 4px 0; }
main.docs hr { border: none; border-top: 1px solid var(--border); margin: 48px 0; }
.lede { font-size: 1.1rem; color: var(--fg-dim); margin: 0 0 28px; }
.api-sig {
  display: inline-block; background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: 6px; padding: 2px 8px; font-family: 'JetBrains Mono', monospace;
  font-size: 0.85em; color: var(--fg-dim); margin-bottom: 6px;
}
.callout { border-left: 3px solid var(--accent); background: rgba(34, 211, 238, 0.06); padding: 12px 16px; border-radius: 0 6px 6px 0; margin: 14px 0; color: var(--fg-dim); }
.callout.warn { border-color: #ffb86b; background: rgba(255, 184, 107, 0.05); }

/* footer */
.footer {
  border-top: 1px solid var(--border); padding: 24px 32px;
  text-align: center; color: var(--fg-faint); font-size: 0.85rem;
}
.footer a { color: var(--fg-dim); }

@media (max-width: 920px) {
  .hero { grid-template-columns: 1fr; padding: 48px 24px 64px; gap: 32px; }
  .hero-art { order: -1; }
  .hero-art img { max-width: 240px; }
  .shell { grid-template-columns: 1fr; }
  aside.sidebar { position: static; height: auto; border-right: none; border-bottom: 1px solid var(--border); }
  main.docs { padding: 32px 22px; }
  .topnav nav a { padding: 6px 8px; font-size: 0.85rem; }
}