:root{--bg:#f5f7fb;--card:#fff;--ink:#1d2433;--muted:#667085;--line:#e4e8f0;
--brand:#2f4bd8;--brand-soft:#eef1ff;--ok:#0f7b4f;--ok-soft:#e8f7ef;--warn:#a35b00;--warn-soft:#fff4e2}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);
font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Noto Sans CJK SC","Source Han Sans SC",sans-serif;
line-height:1.75;font-size:16px}
a{color:var(--brand);text-decoration:none}a:hover{text-decoration:underline}
.wrap{max-width:960px;margin:0 auto;padding:0 20px}
header.top{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}
header.top .wrap{display:flex;align-items:center;gap:22px;min-height:60px;flex-wrap:wrap}
.logo{font-weight:700;font-size:18px;color:var(--ink);letter-spacing:.5px}
nav{display:flex;gap:18px;flex-wrap:wrap;font-size:15px}
nav a.active{font-weight:700;color:var(--brand)}
main{padding:28px 0 60px}
h1{font-size:28px;margin:0 0 8px;line-height:1.35}h2{font-size:21px;margin:34px 0 14px}h3{font-size:17px;margin:22px 0 10px}
p{margin:10px 0}.muted{color:var(--muted);font-size:14px}
.hero{background:linear-gradient(135deg,#2f4bd8,#5b76ee);color:#fff;border-radius:16px;padding:30px 32px;margin-bottom:26px}
.hero h1{color:#fff;font-size:30px}.hero p{color:#e7ecff;margin:6px 0 0}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:12px;margin:18px 0 28px}
.stat{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:16px 18px}
.stat b{display:block;font-size:26px;color:var(--brand);line-height:1.3}.stat span{color:var(--muted);font-size:13px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px 22px;margin:16px 0}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px}
.cards .card{margin:0}.cards .card h3{margin:0 0 6px}
.badge{display:inline-block;background:var(--brand-soft);color:var(--brand);border-radius:6px;
padding:1px 9px;font-size:12px;font-weight:600;vertical-align:middle}
.badge.judge{background:#f3ecff;color:#6d3fc4}.badge.multiple{background:#e7f6f6;color:#0b6f75}
.searchbar{display:flex;gap:10px;margin:18px 0 10px;flex-wrap:wrap}
.searchbar input{flex:1;min-width:220px;padding:11px 14px;border:1px solid var(--line);border-radius:10px;
font-size:15px;font-family:inherit;background:#fff;color:var(--ink)}
.searchbar input:focus{outline:2px solid var(--brand);border-color:transparent}
.toolbar{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin:10px 0 18px;font-size:14px;color:var(--muted)}
.q-card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:18px 20px;margin:14px 0;
scroll-margin-top:78px}
.q-head{display:flex;align-items:center;gap:10px;flex-wrap:wrap;font-size:13px;color:var(--muted);margin-bottom:10px}
.q-id{font-weight:700;font-size:14px;color:var(--brand);font-family:ui-monospace,Menlo,Consolas,monospace}
.q-stem{font-size:16px;font-weight:600;margin:0 0 12px;line-height:1.8}
.q-opts{list-style:none;margin:0 0 12px;padding:0}
.q-opts li{display:flex;gap:10px;padding:6px 10px;border-radius:8px;margin:3px 0;align-items:baseline}
.q-opts li.correct{background:var(--ok-soft);color:#0b5e3c}
.q-opts .k{font-weight:700;min-width:20px;font-family:ui-monospace,Menlo,Consolas,monospace}
.q-ans{background:var(--ok-soft);border-left:3px solid var(--ok);border-radius:6px;padding:8px 12px;font-size:15px}
.q-ans strong{color:var(--ok);font-size:17px}
.q-foot{margin-top:10px;font-size:13px;color:var(--muted);display:flex;gap:14px;flex-wrap:wrap}
.note{background:var(--warn-soft);border-left:3px solid var(--warn);border-radius:6px;padding:8px 12px;
font-size:13px;color:var(--warn);margin:8px 0}
.fml{max-height:44px;vertical-align:middle;margin:0 3px;mix-blend-mode:multiply}
.img-missing{background:var(--warn-soft);color:var(--warn);padding:1px 6px;border-radius:5px;font-size:13px}
table{width:100%;border-collapse:collapse;font-size:14px;margin:12px 0}
th,td{border:1px solid var(--line);padding:8px 10px;text-align:left}th{background:#f0f3fa}
code{background:#f0f3fa;border-radius:5px;padding:1px 6px;font-size:13px}
ul.clean{padding-left:20px}ul.clean li{margin:5px 0}
.ref-img{max-width:100%;border:1px solid var(--line);border-radius:10px;margin:10px 0}
footer{border-top:1px solid var(--line);background:#fff;color:var(--muted);font-size:13px;padding:22px 0;margin-top:40px}
.pager{display:flex;justify-content:space-between;gap:12px;margin:24px 0;flex-wrap:wrap}
.btn{display:inline-block;background:var(--brand);color:#fff;border-radius:9px;padding:9px 16px;font-weight:600}
.btn:hover{text-decoration:none;opacity:.92}
.btn.ghost{background:#fff;color:var(--brand);border:1px solid var(--line)}
.hidden{display:none!important}
@media(max-width:620px){.hero{padding:22px}.wrap{padding:0 14px}h1{font-size:23px}.hero h1{font-size:24px}}