:root { color-scheme: light; font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif; line-height: 1.75; color: #243142; background: #f6f8fb; }
body { margin: 0; }
main { max-width: 48rem; margin: 3rem auto; padding: 2.5rem; background: #fff; border-radius: 1rem; box-shadow: 0 8px 30px #1420380b; }
h1 { line-height: 1.3; margin-top: 0; }
h2 { margin-top: 2rem; font-size: 1.2rem; }
nav { display: flex; flex-wrap: wrap; gap: 1.5rem; margin-top: 2.5rem; padding-top: 1rem; border-top: 1px solid #e3e8ef; }
a { color: #175c9f; }
@media (max-width: 52rem) { main { margin: 0; padding: 1.5rem; border-radius: 0; box-shadow: none; } }