header{border-bottom:1px solid var(--border);margin-bottom:1rem}footer{border-top:1px solid var(--border);margin-top:1rem}:root{color-scheme:light dark;--bg: #ffffff;--text: #222222;--link: #0000ee;--border: #222222}@media(prefers-color-scheme:dark){:root{--bg: #111111;--text: #e6e6e6;--link: #8ab4f8;--border: #444444}}body{background-color:var(--bg);color:var(--text);font-family:sans-serif;line-height:1.5;margin:1rem;max-width:768px}a{color:var(--link);text-decoration:none}