*{box-sizing:border-box}
:root{--bg:#f6f7fb;--text:#171923;--muted:#6b7280;--accent:#ff1744;--border:#e5e7eb}
body{margin:0;font-family:Arial,Helvetica,sans-serif;background:var(--bg);color:var(--text)}
a{text-decoration:none;color:inherit}
.top{background:linear-gradient(135deg,#111827,#252a38);color:#fff;font-size:13px;text-align:center;padding:8px}
header{background:#fff;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:20}
.nav{max-width:1180px;margin:auto;display:flex;align-items:center;justify-content:space-between;padding:15px 18px;gap:20px;flex-wrap:wrap}
.logo{font-size:28px;font-weight:900;letter-spacing:-1px}.logo span{color:var(--accent)}
nav{display:flex;gap:20px;font-size:14px;font-weight:700;flex-wrap:wrap}nav a:hover{color:var(--accent)}
.wrap{max-width:860px;margin:36px auto;padding:0 18px}
.article{background:#fff;border-radius:16px;padding:36px;box-shadow:0 8px 30px rgba(0,0,0,.07)}
.badge{display:inline-block;background:var(--accent);color:#fff;padding:6px 12px;border-radius:20px;font-size:12px;font-weight:800}
h1{font-size:38px;line-height:1.15;margin:16px 0 8px}
h2{font-size:22px;margin:30px 0 8px}
.meta{color:var(--muted);font-size:14px;margin-bottom:22px}
p,li{font-size:18px;line-height:1.75;color:#333}
.article img,.article iframe,.article video{max-width:100%;border-radius:10px}
.video{position:relative;padding-top:56.25%;margin:18px 0}.video iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.todo{background:#fff8d6;border:1px dashed #d4b106;border-radius:8px;padding:12px 14px;font-size:15px;color:#6b5600}
.next{margin-top:34px;border-top:1px solid var(--border);padding-top:8px}
.next a{display:block;padding:10px 0;font-weight:700;border-bottom:1px solid var(--border)}.next a:hover{color:var(--accent)}
.back{display:inline-block;margin-top:24px;font-weight:800;color:var(--accent)}
footer{background:#111827;color:#cbd5e1;margin-top:45px}
.foot{max-width:1180px;margin:auto;padding:30px 18px;display:flex;gap:22px;flex-wrap:wrap;justify-content:center;font-size:14px}
.foot a:hover{color:#fff}
.copy{border-top:1px solid #374151;text-align:center;padding:16px;font-size:12px}
@media(max-width:600px){h1{font-size:28px}.article{padding:22px}p,li{font-size:17px}}