:root{color-scheme:light;font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.7;color:#202124;background:#f7f8fa}
*{box-sizing:border-box}
body{margin:0}
header,main,footer{max-width:780px;margin:auto;padding:1.25rem}
header{padding-top:2rem}
main{background:white;border:1px solid #e5e7eb;border-radius:12px;margin-top:1rem;margin-bottom:1rem;padding:2rem}
nav a{margin-right:1rem}
h1{line-height:1.3;margin-top:.5rem}
h2{font-size:1.2rem;margin-top:2rem}
a{color:#1765c1}
.note{color:#555}
footer{font-size:.9rem;color:#555}
@media(max-width:600px){main{border-radius:0;padding:1.25rem}}