:root { --bg: #ffffff; --text: #1d2125; --muted: #5b636b; --accent: #1f6f5c; --line: #dfe3e6; --card: #f6f8f8; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #15181b; --text: #e8eaec; --muted: #a2a9b0; --accent: #5cc4a8; --line: #2d3338; --card: #1c2024; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
main { max-width: 720px; margin: 0 auto; padding: 48px 20px 64px; }
header { border-bottom: 1px solid var(--line); padding-bottom: 16px; margin-bottom: 28px; }
header a.brand { color: var(--text); font-weight: 700; font-size: 20px; text-decoration: none; letter-spacing: .2px; }
header nav { margin-top: 6px; font-size: 14px; }
header nav a { color: var(--muted); margin-right: 16px; text-decoration: none; }
header nav a:hover, a { color: var(--accent); }
h1 { font-size: 28px; line-height: 1.25; margin: 0 0 8px; }
h2 { font-size: 19px; margin: 32px 0 8px; }
p, li { color: var(--text); }
.muted { color: var(--muted); font-size: 14px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 18px 20px; margin: 20px 0; }
.button { display: inline-block; background: var(--accent); color: var(--bg); padding: 10px 18px; border-radius: 8px; text-decoration: none; font-weight: 600; }
footer { border-top: 1px solid var(--line); margin-top: 48px; padding-top: 16px; }
.card > p:first-child { margin-top: 0; }