:root{--ink:#111;--muted:#666;--bg:#fafafa;--card:#fff;--line:#e8e8e8;}
*{box-sizing:border-box}html,body{margin:0;padding:0;font-family:ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Inter,Helvetica,Arial,sans-serif;color:var(--ink);background:var(--bg);}
a{color:#0a58f7;text-decoration:none}a:hover{text-decoration:underline}
.container{max-width:980px;margin:0 auto;padding:22px}
nav{display:flex;gap:14px;flex-wrap:wrap;align-items:center;justify-content:center;padding:14px 0;border-bottom:1px solid var(--line);background:#fff;position:sticky;top:0;z-index:5}
nav a{padding:8px 12px;border-radius:10px}
nav a.active{background:#f3f5ff}
.hero{max-width:980px;margin:18px auto 8px;padding:16px}
.hero img{display:block;width:100%;height:auto;border-radius:18px;background:#fff;border:1px solid var(--line);}
h1{font-size:38px;line-height:1.15;margin:16px 0 8px;text-align:center}
.sub{color:var(--muted);text-align:center;margin:0 0 22px}
.ribbon{height:3px;width:82px;margin:12px auto 28px;background:linear-gradient(90deg,#8a5bff,#5fd6ff,#8dff8a,#8a5bff);border-radius:3px}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:22px;margin:20px 0}
.center{text-align:center}
.grid{display:grid;gap:14px}
@media(min-width:800px){.grid{grid-template-columns:repeat(2,1fr)}}
footer{margin:40px 0 18px;color:#888;text-align:center;font-size:14px}
small.note{display:block;margin-top:8px;color:#777}
pre.code{background:#0a0a0a;color:#f3f3f3;padding:12px 14px;border-radius:10px;overflow:auto;font-size:13px}
ul{margin:0 0 10px 20px}