:root {
  --bg: #FFFFFF; --surface: #FBFBFD; --line: #E7EAEF; --text: #1C2129; --sub: #5F6877; --hi: #0B0E14; --accent: #00704B;
  --font-ui: 'Inter var', 'Inter', ui-sans-serif, system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', Menlo, ui-monospace, monospace;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #07090D; --surface: #0C1016; --line: #1A2130; --text: #C6CCD6; --sub: #7C8596; --hi: #E9EDF3; --accent: #27C28A; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: var(--font-ui); font-size: 15px; line-height: 1.65; }
a { color: var(--hi); text-decoration: underline; text-underline-offset: 2px; }
a:hover { color: var(--accent); }
.wrap { max-width: 780px; margin: 0 auto; padding: 0 32px; }
header.top { border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--bg) 88%, transparent); position: sticky; top: 0; }
.top-in { display: flex; align-items: center; height: 60px; justify-content: space-between; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 600; color: var(--hi); text-decoration: none; letter-spacing: -0.01em; }
.brand-mark { width: 28px; height: 28px; border-radius: 6px; background: var(--accent); display: inline-flex; align-items: center; justify-content: center; color: white; font-family: var(--font-mono); font-weight: 700; }
.brand-mark .sigma-glyph { display: block; width: 20px; height: 20px; background-color: currentColor; -webkit-mask: url('/sigma-mark.png') center / contain no-repeat; mask: url('/sigma-mark.png') center / contain no-repeat; }
main { padding: 56px 0 96px; }
.label { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--sub); }
h1 { font-size: 36px; line-height: 1.2; color: var(--hi); letter-spacing: -0.02em; margin: 10px 0 8px; font-weight: 600; }
h2 { margin-top: 48px; font-size: 20px; color: var(--hi); letter-spacing: -0.01em; font-weight: 600; }
h3 { margin-top: 28px; font-size: 15px; color: var(--hi); font-weight: 600; }
p, li { color: var(--text); }
ul { padding-left: 22px; }
footer { border-top: 1px solid var(--line); padding: 32px 0; color: var(--sub); font-size: 13px; }
code { font-family: var(--font-mono); background: var(--surface); padding: 1px 6px; border: 1px solid var(--line); border-radius: 3px; font-size: 12.5px; }
.meta { color: var(--sub); font-size: 13px; font-family: var(--font-mono); }