:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --bg: #f6f8fb;
  --card: #ffffff;
  --text: #1f2937;
  --text-sub: #6b7280;
  --border: #e5e7eb;
  --red: #dc2626;
  --green: #16a34a;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}
a { text-decoration: none; color: inherit; }

/* 顶部导航 */
.site-header {
  background: linear-gradient(135deg, #1e40af, #2563eb);
  color: #fff;
  padding: 0 20px;
  box-shadow: 0 2px 8px rgba(0,0,0,.08);
}
.header-inner {
  max-width: 1080px; margin: 0 auto;
  display: flex; align-items: center; gap: 28px; height: 60px;
}
.logo { font-size: 20px; font-weight: 700; letter-spacing: 1px; display: flex; align-items: center; gap: 8px; }
.logo .dot { width: 10px; height: 10px; border-radius: 50%; background: #fbbf24; }
.nav { display: flex; gap: 4px; margin-left: auto; flex-wrap: wrap; }
.nav a {
  color: rgba(255,255,255,.85); padding: 6px 14px; border-radius: 8px; font-size: 15px;
  transition: background .2s;
}
.nav a:hover, .nav a.active { background: rgba(255,255,255,.18); color: #fff; }

/* Hero */
.hero { max-width: 1080px; margin: 36px auto 0; padding: 0 20px; text-align: center; }
.hero h1 { font-size: 30px; margin-bottom: 10px; }
.hero h1 em { font-style: normal; color: var(--primary); }
.hero p { color: var(--text-sub); font-size: 16px; }
.stats { display: flex; justify-content: center; gap: 40px; margin-top: 22px; }
.stats .num { font-size: 26px; font-weight: 700; color: var(--primary); }
.stats .lbl { font-size: 13px; color: var(--text-sub); }

/* 搜索与筛选 */
.toolbar {
  max-width: 1080px; margin: 28px auto 0; padding: 0 20px;
  display: flex; gap: 12px; flex-wrap: wrap; align-items: center;
}
.search-box { flex: 1; min-width: 240px; position: relative; }
.search-box input {
  width: 100%; padding: 11px 16px 11px 42px; border: 1px solid var(--border);
  border-radius: 10px; font-size: 15px; outline: none; background: var(--card);
  transition: border .2s, box-shadow .2s;
}
.search-box input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-light); }
.search-box .icon { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); color: var(--text-sub); }
.filter-tabs { display: flex; gap: 8px; }
.filter-tabs button {
  padding: 8px 18px; border: 1px solid var(--border); background: var(--card);
  border-radius: 999px; font-size: 14px; cursor: pointer; color: var(--text-sub);
  transition: all .2s;
}
.filter-tabs button.active { background: var(--primary); border-color: var(--primary); color: #fff; }

/* 试卷分组与卡片 */
.list { max-width: 1080px; margin: 24px auto 60px; padding: 0 20px; }
.group-title {
  font-size: 17px; font-weight: 700; margin: 26px 0 12px; display: flex; align-items: center; gap: 8px;
}
.group-title::before { content: ""; width: 4px; height: 18px; border-radius: 2px; background: var(--primary); }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 14px; }
.paper-card {
  background: var(--card); border: 1px solid var(--border); border-radius: 12px;
  padding: 16px 18px; display: flex; flex-direction: column; gap: 10px;
  transition: transform .15s, box-shadow .15s;
}
.paper-card:hover { transform: translateY(-3px); box-shadow: 0 8px 20px rgba(37,99,235,.10); }
.card-top { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.badge {
  font-size: 12px; padding: 2px 10px; border-radius: 999px; font-weight: 600;
}
.badge.zk { background: #fee2e2; color: var(--red); }
.badge.gk { background: #dcfce7; color: var(--green); }
.badge.ky { background: #ede9fe; color: #7c3aed; }
.badge.year { background: var(--primary-light); color: var(--primary-dark); }
.badge.prov { background: #f3f4f6; color: var(--text-sub); font-weight: 400; }
.card-title { font-size: 15px; font-weight: 600; flex: 1; }
.card-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: auto; }
.btn {
  display: inline-flex; align-items: center; gap: 5px; font-size: 13px;
  padding: 7px 14px; border-radius: 8px; cursor: pointer; border: none;
  transition: opacity .2s;
}
.btn:hover { opacity: .85; }
.btn.view { background: var(--primary); color: #fff; }
.btn.dl { background: #f3f4f6; color: var(--text); border: 1px solid var(--border); }
.empty-tip { text-align: center; color: var(--text-sub); padding: 60px 0; font-size: 15px; }

/* 页脚 */
.site-footer {
  border-top: 1px solid var(--border); background: var(--card);
  text-align: center; padding: 24px 20px; color: var(--text-sub); font-size: 13px;
}
@media (max-width: 640px) {
  .header-inner { height: auto; padding: 10px 0; flex-direction: column; align-items: flex-start; gap: 8px; }
  .nav { margin-left: 0; }
  .hero h1 { font-size: 22px; }
  .stats { gap: 24px; }
}