:root { --bg: #f6f5f1; --card: #ffffff; --ink: #1d1f22; --muted: #5d636b; --line: #e3e1da; --accent: #2f5d50; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #15171a; --card: #1e2125; --ink: #e8e6e1; --muted: #a3a8ae; --line: #2e3237; --accent: #7fb8a4; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 17px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
main { max-width: 640px; margin: 0 auto; padding: 64px 20px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 36px 32px; }
h1 { font-size: 1.6rem; margin: 0 0 6px; letter-spacing: -0.01em; }
h2 { font-size: 1.05rem; margin: 28px 0 6px; }
.sub { color: var(--muted); margin: 0 0 24px; }
p, li { margin: 0 0 12px; }
ul { padding-left: 20px; }
a { color: var(--accent); }
footer { color: var(--muted); font-size: 0.9rem; margin-top: 24px; text-align: center; }