/* ------------------------------------------------------------
   竞赛资料站 · 基础样式
   设计原则：无框架、纯 CSS、移动优先、首屏渲染快
   ------------------------------------------------------------ */

:root {
  --ink: #1a1a18;
  --ink2: #5a5955;
  --ink3: #8d8b84;
  --line: #e8e6e0;
  --line2: #d6d3cb;
  --bg: #ffffff;
  --bg2: #f7f7f5;
  --accent: #185fa5;
  --accent-d: #0c447c;
  --accent-bg: #eaf3fb;
  --r: 12px;
  --wrap: 880px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { -webkit-text-size-adjust: 100%; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 20px; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-d); text-decoration: underline; }
b, strong { font-weight: 600; }

/* ----------------------------- 头部 ----------------------------- */

.hd {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.94);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.hd-in { display: flex; align-items: center; gap: 18px; height: 62px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand-mark {
  width: 34px; height: 34px; flex: 0 0 34px; border-radius: 9px;
  background: var(--accent); color: #fff;
  display: grid; place-items: center;
  font-size: 12px; font-weight: 600; letter-spacing: .5px;
}
.brand-txt { display: flex; flex-direction: column; line-height: 1.25; }
.brand-txt b { font-size: 15px; font-weight: 600; white-space: nowrap; }
.brand-txt i {
  font-style: normal; font-size: 11.5px; color: var(--ink3);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 240px;
}
.nav { display: flex; gap: 2px; margin-left: auto; flex-wrap: wrap; }
.nav a {
  padding: 6px 11px; border-radius: 8px; font-size: 14px;
  color: var(--ink2); white-space: nowrap;
}
.nav a:hover { background: var(--bg2); color: var(--ink); text-decoration: none; }
.nav a.on { background: var(--accent-bg); color: var(--accent-d); font-weight: 500; }
.cta {
  flex: 0 0 auto; padding: 8px 18px; border-radius: 99px;
  background: var(--accent); color: #fff; font-size: 14px; font-weight: 500;
}
.cta:hover { background: var(--accent-d); color: #fff; text-decoration: none; }

/* ----------------------------- 区块 ----------------------------- */

.sec { padding: 40px 0; }
.sec + .sec { border-top: 1px solid var(--line); }
h1 { font-size: 30px; line-height: 1.35; font-weight: 600; letter-spacing: -.4px; }
h2 { font-size: 21px; font-weight: 600; margin: 34px 0 16px; letter-spacing: -.2px; }
h3 { font-size: 17px; font-weight: 600; margin: 22px 0 10px; }
.sec > h2:first-child { margin-top: 0; }
.lede { font-size: 17px; color: var(--ink2); margin-top: 14px; max-width: 680px; }
.meta-line { font-size: 14px; color: var(--ink3); margin-top: 12px; }
.more { margin-top: 20px; font-size: 14.5px; }
.prose p { margin-bottom: 14px; color: #33322f; }
.prose p + p { margin-top: 0; }
.note {
  margin-top: 20px; padding: 14px 18px; border-radius: 10px;
  background: #fdf6e3; border: 1px solid #f0e0b8;
  font-size: 13.5px; color: #6b5410;
}

/* ----------------------------- 面包屑 ----------------------------- */

.crumbs { font-size: 13px; color: var(--ink3); margin-bottom: 18px; display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.crumbs a { color: var(--ink3); }
.crumbs a:hover { color: var(--accent); }
.crumbs i { font-style: normal; opacity: .5; }
.crumbs span { color: var(--ink2); }

/* ----------------------------- 首屏 ----------------------------- */

.hero {
  background: var(--bg2);
  border-bottom: 1px solid var(--line);
  padding: 34px 0 38px;
}
.hero h1 { margin-bottom: 4px; }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin-top: 26px; }
.stat {
  background: #fff; border: 1px solid var(--line); border-radius: var(--r);
  padding: 14px 16px; text-align: center;
}
.stat b { display: block; font-size: 24px; font-weight: 600; color: var(--accent-d); line-height: 1.3; }
.stat span { font-size: 12.5px; color: var(--ink3); }

/* ----------------------------- 速览表 ----------------------------- */

.facts {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px;
  background: var(--line); border: 1px solid var(--line);
  border-radius: var(--r); overflow: hidden;
}
.fact { background: #fff; padding: 14px 18px; }
.fact dt { font-size: 13px; color: var(--ink3); margin-bottom: 3px; }
.fact dd { font-size: 15.5px; font-weight: 500; }

/* ----------------------------- 时间轴 ----------------------------- */

.timeline { list-style: none; margin-top: 8px; }
.timeline li {
  position: relative; padding: 0 0 26px 26px;
  border-left: 2px solid var(--line2); margin-left: 5px;
}
.timeline li:last-child { border-left-color: transparent; padding-bottom: 0; }
.timeline li::before {
  content: ""; position: absolute; left: -6px; top: 8px;
  width: 10px; height: 10px; border-radius: 50%;
  background: #fff; border: 2px solid var(--accent);
}
.tl-time { display: block; font-size: 13px; color: var(--accent-d); font-weight: 500; margin-bottom: 2px; }
.timeline b { font-size: 16.5px; display: block; margin-bottom: 4px; }
.timeline p { font-size: 14.5px; color: var(--ink2); }

/* ----------------------------- 卡片网格 ----------------------------- */

.grid { display: grid; gap: 14px; }
.g2 { grid-template-columns: repeat(2, 1fr); }
.g3 { grid-template-columns: repeat(3, 1fr); }
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--r);
  padding: 18px 20px; display: block; color: inherit;
}
.card b { font-size: 16px; display: block; margin-bottom: 6px; }
.card p { font-size: 14px; color: var(--ink2); margin-top: 6px; }
.card dl { display: grid; grid-template-columns: 72px 1fr; gap: 2px 10px; font-size: 14px; margin-top: 10px; }
.card dt { color: var(--ink3); font-size: 13px; }
.card ul { list-style: none; display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.card ul li {
  font-size: 13px; background: var(--bg2); border: 1px solid var(--line);
  padding: 3px 10px; border-radius: 99px; color: var(--ink2);
}
.card .yr {
  display: inline-block; font-size: 12px; font-weight: 600; color: var(--accent-d);
  background: var(--accent-bg); padding: 2px 9px; border-radius: 99px; margin-bottom: 10px;
}
.link:hover { border-color: var(--accent); text-decoration: none; background: #fcfdfe; }
.link span { font-size: 13px; color: var(--ink3); display: block; margin-top: 4px; }

/* ----------------------------- 数据表 ----------------------------- */

.table-wrap { overflow-x: auto; margin-top: 6px; -webkit-overflow-scrolling: touch; }
table.data {
  width: 100%; border-collapse: collapse; font-size: 14.5px;
  border: 1px solid var(--line); border-radius: var(--r); overflow: hidden;
  min-width: 420px;
}
table.data thead th {
  background: var(--bg2); text-align: left; font-weight: 600; font-size: 13.5px;
  padding: 12px 16px; border-bottom: 1px solid var(--line2); color: var(--ink);
}
table.data tbody th {
  text-align: left; font-weight: 600; padding: 11px 16px;
  border-bottom: 1px solid var(--line); color: var(--ink);
}
table.data td {
  padding: 11px 16px; border-bottom: 1px solid var(--line); color: var(--ink2);
  font-variant-numeric: tabular-nums;
}
table.data tbody tr:last-child th, table.data tbody tr:last-child td { border-bottom: none; }
table.data tbody tr:nth-child(even) td,
table.data tbody tr:nth-child(even) th { background: #fcfcfb; }

/* ----------------------------- FAQ ----------------------------- */

.faq { border: 1px solid var(--line); border-radius: var(--r); overflow: hidden; }
.faq details { border-bottom: 1px solid var(--line); background: #fff; }
.faq details:last-child { border-bottom: none; }
.faq summary {
  padding: 16px 20px; font-weight: 500; font-size: 15.5px; cursor: pointer;
  list-style: none; position: relative; padding-right: 46px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; position: absolute; right: 20px; top: 50%; transform: translateY(-50%);
  font-size: 20px; color: var(--ink3); font-weight: 400; line-height: 1;
}
.faq details[open] summary::after { content: "−"; }
.faq summary:hover { background: var(--bg2); }
.faq details > div { padding: 0 20px 18px; font-size: 14.8px; color: var(--ink2); }

/* ----------------------------- 资讯 ----------------------------- */

.news-list { display: flex; flex-direction: column; gap: 1px; background: var(--line);
  border: 1px solid var(--line); border-radius: var(--r); overflow: hidden; }
.news-item { background: #fff; padding: 18px 20px; display: block; color: inherit; }
.news-item:hover { background: #fcfdfe; text-decoration: none; }
.news-item time { font-size: 12.5px; color: var(--ink3); font-variant-numeric: tabular-nums; }
.news-item b { display: block; font-size: 16px; margin: 4px 0 6px; }
.news-item span { font-size: 14px; color: var(--ink2); }

/* ----------------------------- 相关内容 ----------------------------- */

.related { border-top: 1px solid var(--line); background: var(--bg2); padding: 40px 0; }
.related .wrap { display: block; }
.related h2 { margin-top: 0; }
.related .grid { margin-top: 0; }
.related .card { background: #fff; }

/* ----------------------------- 页脚 ----------------------------- */

.ft { border-top: 1px solid var(--line); background: var(--bg2); padding: 32px 0 40px; margin-top: 0; }
.ft-links { display: flex; flex-wrap: wrap; gap: 6px 18px; margin-bottom: 16px; font-size: 14px; }
.ft-note { font-size: 12.5px; color: var(--ink3); line-height: 1.7; max-width: 660px; }
.ft-copy { font-size: 12.5px; color: var(--ink3); margin-top: 10px; }

/* ----------------------------- 响应式 ----------------------------- */

@media (max-width: 860px) {
  .brand-txt i { display: none; }
  .nav { gap: 0; }
  .nav a { padding: 6px 8px; font-size: 13.5px; }
}

@media (max-width: 700px) {
  body { font-size: 15.5px; }
  h1 { font-size: 24px; }
  h2 { font-size: 19px; }
  .sec { padding: 30px 0; }
  .hd-in { height: 56px; gap: 10px; }
  .cta { padding: 7px 14px; font-size: 13px; }
  .nav { width: 100%; order: 3; overflow-x: auto; padding-bottom: 8px;
    margin: 0; -webkit-overflow-scrolling: touch; }
  .hd-in { flex-wrap: wrap; height: auto; padding: 10px 0; }
  .nav::-webkit-scrollbar { display: none; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .facts { grid-template-columns: 1fr; }
  .g2, .g3 { grid-template-columns: 1fr; }
  .hero { padding: 24px 0 28px; }
}