* { margin:0; padding:0; box-sizing:border-box; }
:root {
  --primary:#1d4ed8; --primary-deep:#1e3a8a; --accent:#0ea5e9;
  --dark:#0f172a; --text:#334155; --muted:#64748b;
  --bg:#f8fafc; --border:#e2e8f0; --panel:#fff;
}
body { font-family:"PingFang SC","Microsoft YaHei",Arial,sans-serif; background:var(--bg); color:var(--text); line-height:1.7; }
.container { max-width:1600px; margin:0 auto; padding:0 28px; }
a { color:var(--primary); text-decoration:none; }
a:hover { text-decoration:underline; }
.btn { display:inline-flex; align-items:center; justify-content:center; min-height:42px; padding:0 18px; border-radius:999px; font-weight:600; border:0; cursor:pointer; }
.btn-primary { background:linear-gradient(90deg,var(--primary),var(--accent)); color:#fff; }
.btn-line { background:#fff; border:1px solid var(--border); color:var(--dark); }
.header { background:linear-gradient(100deg,#0f172a,#1e3a8a 55%,#1d4ed8); color:#dbeafe; position:sticky; top:0; z-index:20; }
.header .container { display:flex; align-items:center; justify-content:space-between; min-height:70px; gap:16px; }
.logo { display:flex; gap:12px; align-items:center; color:#fff; text-decoration:none; }
.logo-mark { width:40px; height:40px; border-radius:12px; background:linear-gradient(135deg,#38bdf8,#2563eb); display:flex; align-items:center; justify-content:center; font-weight:800; }
.logo b { display:block; font-size:16px; } .logo small { font-size:11px; opacity:.75; }
.nav { display:flex; gap:16px; list-style:none; flex-wrap:wrap; }
.nav a { color:#bfdbfe; font-size:14px; text-decoration:none; }
.nav a:hover { color:#fff; }
.hero { padding:48px 0 28px; text-align:center; background:linear-gradient(180deg,#eff6ff,var(--bg)); }
.hero h1 { font-size:clamp(28px,3vw,40px); color:var(--dark); }
.hero p { margin:12px auto 0; max-width:760px; color:var(--muted); }
.section { padding:24px 0; }
.section h2 { font-size:22px; color:var(--dark); margin-bottom:14px; }
.grid { display:grid; grid-template-columns:repeat(3,1fr); gap:14px; }
.card { background:var(--panel); border:1px solid var(--border); border-radius:14px; padding:18px; transition:.2s; }
.card:hover { transform:translateY(-2px); box-shadow:0 10px 24px rgba(37,99,235,.08); }
.card .cat { font-size:12px; color:var(--primary); font-weight:700; }
.card b { display:block; margin:6px 0; color:var(--dark); font-size:16px; }
.card p { font-size:13px; color:var(--muted); }
.breadcrumb { padding:16px 0 0; font-size:13px; color:var(--muted); }
.breadcrumb a { color:var(--primary-deep); }
.article-wrap { display:grid; grid-template-columns:1fr 300px; gap:24px; padding:20px 0 40px; }
.article { background:#fff; border:1px solid var(--border); border-radius:16px; padding:32px; }
.article h1 { font-size:30px; color:var(--dark); line-height:1.35; margin-bottom:10px; }
.article .meta { font-size:13px; color:var(--muted); margin-bottom:22px; }
.article h2 { font-size:20px; margin:22px 0 10px; color:var(--dark); }
.article ul,.article ol { padding-left:20px; margin:8px 0 14px; }
.article li { margin:6px 0; }
.article p { margin:10px 0; }
.side .card { margin-bottom:12px; }
.cta-box { background:#eff6ff; border:1px solid #bfdbfe; border-radius:14px; padding:16px; margin-top:24px; }
.friend-links { background:#fff; border-top:1px solid var(--border); padding:24px 0; }
.friend-links-title { font-size:15px; font-weight:700; color:var(--dark); margin-bottom:12px; }
.friend-links-list { list-style:none; display:flex; flex-wrap:wrap; gap:10px 18px; }
.friend-links-list a { color:var(--muted); font-size:13px; }
.footer { background:#0f172a; color:#94a3b8; padding:36px 0 0; margin-top:20px; }
.footer-grid { display:grid; grid-template-columns:2fr 1fr 1fr; gap:20px; padding-bottom:24px; }
.footer b,.footer h4 { color:#e2e8f0; display:block; margin-bottom:10px; }
.footer a { color:#93c5fd; display:block; margin:6px 0; font-size:14px; }
.footer-copy { border-top:1px solid #1e293b; text-align:center; padding:16px 0 24px; font-size:13px; }
.page-404 { padding:70px 0; text-align:center; }
.page-404-box { max-width:640px; margin:0 auto; background:#fff; border:1px solid var(--border); border-radius:16px; padding:40px 24px; }
.page-404-code { font-size:72px; font-weight:800; color:var(--primary); }
@media (max-width:1000px) {
  .grid,.article-wrap,.footer-grid { grid-template-columns:1fr; }
}