:root {
  --bg: #09090b;
  --bg-soft: #0c0c0f;
  --panel: #101014;
  --line: #26262c;
  --line-soft: #1a1a1f;
  --fg: #e8e8ec;
  --muted: #a3a3ad;
  --dim: #7a7a84;
  --accent: #818cf8;
  --accent-soft: rgba(129, 140, 248, 0.1);
  --ok: #4ade80;
  --bad: #f87171;
  --warn: #fbbf24;
  --radius: 8px;
  --mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

::selection { background: rgba(129, 140, 248, 0.25); }

.wrap { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 1.25rem; }

main, header, footer { position: relative; z-index: 1; }

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

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

h1, h2, h3 { line-height: 1.25; letter-spacing: -0.02em; margin: 0; color: var(--fg); }

code, kbd, pre { font-family: var(--mono); }

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--fg);
  color: var(--bg);
  padding: 0.6rem 1rem;
  border-radius: 0 0 6px 0;
  font-weight: 600;
  z-index: 99;
}
.skip:focus { left: 0; }

/* ---------- nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(9, 9, 11, 0.86);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line-soft);
}
.nav-in { display: flex; align-items: center; gap: 1rem; height: 60px; }
.brand { display: flex; align-items: center; gap: 0.6rem; color: var(--fg); font-weight: 650; font-size: 0.95rem; }
.brand:hover { text-decoration: none; }
.mark {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--panel);
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--fg);
}
.nav-links { margin-left: auto; display: flex; align-items: center; gap: 1.4rem; }
.nav-links a { color: var(--muted); font-size: 0.88rem; }
.nav-links a:hover { color: var(--fg); text-decoration: none; }
.nav-ver {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--muted);
  border: 1px solid var(--line);
  padding: 0.12rem 0.5rem;
  border-radius: 999px;
}
@media (max-width: 820px) { .nav-links a.hide-sm { display: none; } }

/* ---------- buttons ---------- */
.btns { display: flex; flex-wrap: wrap; gap: 0.65rem; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.05rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.92rem;
  border: 1px solid transparent;
  transition: background 0.15s ease, border-color 0.15s ease;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--fg); color: var(--bg); }
.btn-primary:hover { background: #d4d4d8; }
.btn-ghost { background: transparent; border-color: var(--line); color: var(--fg); }
.btn-ghost:hover { border-color: #3f3f46; background: rgba(255, 255, 255, 0.03); }

/* ---------- section shell ---------- */
section { padding: 3.5rem 0; border-top: 1px solid var(--line-soft); }
section:first-of-type { border-top: 0; }
.eyebrow {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dim);
  margin-bottom: 0.75rem;
}
.h2 { font-size: clamp(1.4rem, 3vw, 1.85rem); }
.lead { color: var(--muted); max-width: 64ch; margin: 0.85rem 0 0; }