:root{--bg:#fff;--text:#1f2937;--muted:#6b7280;--primary:#2878b5;--sec:#f4f6f8;color-scheme:light}
@media(prefers-color-scheme:dark){:root:not([data-theme="light"]){--bg:#12161c;--text:#f4f4f4;--muted:#a1a9b5;--sec:#1f2630;--primary:#4aa3e0;color-scheme:dark}}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:'Segoe UI',Tahoma,Geneva,Verdana,sans-serif;line-height:1.6;background:var(--bg);color:var(--text)}
.container{max-width:760px;margin:0 auto;padding:0 20px}
header{background:var(--sec);padding:1rem 0;box-shadow:0 2px 5px rgba(0,0,0,.1)}
.logo{font-size:1.4rem;font-weight:700;color:var(--primary);text-decoration:none}
main{padding:48px 0 64px}h1{margin-bottom:1rem}h2{margin:1.5rem 0 .5rem}p,li{margin-bottom:.75rem}ul{margin-left:1.2rem}
.muted{color:var(--muted)}a{color:var(--primary)}
.btn{display:inline-block;background:var(--primary);color:#fff;padding:10px 20px;border-radius:6px;text-decoration:none;font-size:1rem;margin-top:.5rem}
footer{text-align:center;padding:32px 0;background:var(--sec);color:var(--muted)}footer a{margin:0 .5rem}