:root{
  --ink:#141414;
  --ink-2:#5c5c5c;
  --ink-3:#9a9a9a;
  --line:#ececec;
  --bg:#fff;
  --bg-2:#fafafa;
  --accent:#141414;
}
*{margin:0;padding:0;box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  background:var(--bg);color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  font-size:15.5px;line-height:1.9;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto}

.site-head{border-bottom:1px solid var(--line);background:#fff}
.site-head .inner{max-width:880px;margin:0 auto;padding:0 24px;display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:60px}
.brand{font-size:16px;font-weight:600;letter-spacing:.2px;white-space:nowrap}
.brand span{color:var(--ink-3);font-weight:400;font-size:12.5px;margin-left:8px;letter-spacing:.4px}
.nav{display:flex;flex-wrap:wrap;gap:4px 18px;font-size:13.5px;color:var(--ink-2)}
.nav a{white-space:nowrap}
.nav a:hover{color:var(--ink)}
.nav a[aria-current="page"]{color:var(--ink);font-weight:600}

.wrap{max-width:760px;margin:0 auto;padding:56px 24px 72px}
.crumb{font-size:12.5px;color:var(--ink-3);margin-bottom:22px;letter-spacing:.2px}
.crumb a:hover{color:var(--ink-2)}

h1{font-size:30px;line-height:1.35;font-weight:600;letter-spacing:-.2px}
.lead{margin-top:16px;color:var(--ink-2);font-size:15.5px}
.meta-line{margin-top:12px;font-size:12.5px;color:var(--ink-3);letter-spacing:.3px}

h2{font-size:20px;font-weight:600;margin:52px 0 16px;letter-spacing:-.1px;scroll-margin-top:80px}
h3{font-size:16px;font-weight:600;margin:28px 0 10px}
p{color:var(--ink-2);margin:14px 0}
p strong,li strong{color:var(--ink);font-weight:600}
ul,ol{margin:14px 0 14px 22px;color:var(--ink-2)}
li{margin:8px 0}
li::marker{color:var(--ink-3)}
blockquote{margin:22px 0;padding:16px 20px;background:var(--bg-2);border-left:3px solid var(--ink);border-radius:0 8px 8px 0;color:var(--ink-2);font-size:14.5px}
blockquote p{margin:0}

.card{display:block;border:1px solid var(--line);border-radius:12px;padding:20px 22px;margin:18px 0;transition:border-color .16s ease}
.card:hover{border-color:#d6d6d6}
.card .t{display:block;font-size:16px;font-weight:600;color:var(--ink)}
.card .d{display:block;margin-top:6px;font-size:13.5px;color:var(--ink-2);line-height:1.8}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:20px 0}

.btn-row{display:flex;flex-wrap:wrap;gap:12px;margin:28px 0 8px}
.btn{display:inline-block;padding:13px 22px;border-radius:10px;font-size:14.5px;font-weight:600;border:1px solid var(--line);transition:opacity .16s ease,border-color .16s ease}
.btn:hover{opacity:.75}
.btn.primary{background:var(--ink);border-color:var(--ink);color:#fff}

.table-wrap{overflow-x:auto;margin:20px 0;border:1px solid var(--line);border-radius:12px}
table{width:100%;border-collapse:collapse;font-size:13.5px;min-width:520px}
th,td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
th{background:var(--bg-2);font-weight:600;color:var(--ink);white-space:nowrap}
td{color:var(--ink-2)}
tr:last-child td{border-bottom:0}

.faq details{border-bottom:1px solid var(--line);padding:6px 0}
.faq summary{cursor:pointer;list-style:none;padding:14px 0;font-size:15px;font-weight:600;color:var(--ink);display:flex;justify-content:space-between;gap:16px;align-items:flex-start}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--ink-3);font-weight:400;font-size:18px;line-height:1.2;flex:none}
.faq details[open] summary::after{content:"−"}
.faq .a{padding:0 0 16px;color:var(--ink-2);font-size:14.5px}
.faq .a p{margin:0 0 8px}

.notice{margin:36px 0 0;padding:18px 20px;background:var(--bg-2);border-radius:10px;font-size:13px;line-height:1.85;color:var(--ink-3)}
.notice strong{color:var(--ink-2)}

.related{margin-top:56px;padding-top:28px;border-top:1px solid var(--line)}
.related h2{margin-top:0;font-size:14px;letter-spacing:2px;color:var(--ink-3);font-weight:600}
.related ul{list-style:none;margin:12px 0 0}
.related li{margin:10px 0}
.related a{color:var(--ink-2)}
.related a:hover{color:var(--ink)}

.site-foot{margin-top:64px;padding:28px 0 48px;border-top:1px solid var(--line);font-size:12.5px;color:var(--ink-3);text-align:center;line-height:2}
.site-foot a{color:var(--ink-3);margin:0 8px}
.site-foot a:hover{color:var(--ink-2)}

@media (max-width:640px){
  .site-head .inner{padding:0 18px;min-height:56px;flex-direction:column;align-items:flex-start;justify-content:center;gap:2px;padding-top:10px;padding-bottom:10px}
  .brand{font-size:15px}
  .brand span{display:none}
  .nav{gap:2px 14px;font-size:12.5px;padding-bottom:2px}
  .wrap{padding:36px 18px 56px}
  h1{font-size:25px}
  h2{font-size:18px;margin-top:42px}
  .grid{grid-template-columns:1fr}
  .btn-row .btn{flex:1 1 100%;text-align:center}
}