/* ========== 全局变量 ========== */
:root {
  --primary: #1a6fc4;
  --primary-dark: #155a9c;
  --primary-light: #4a9de6;
  --primary-soft: #eaf3fb;
  --bg: #f5f7fa;
  --card-bg: #ffffff;
  --text-main: #111111;
  --text-sub: #333333;
  --text-light: #666666;
  --border: #ebeef2;
  --table-head: #f2f6fa;
  --table-hover: #f8fafc;
  --link: #1a6fc4;
  --link-hover: #155a9c;
  --radius: 6px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text-main);
  font-size: 14px;
  line-height: 1.6;
}

a { text-decoration: none; color: var(--link); transition: color .2s; }
a:hover { color: var(--link-hover); text-decoration: underline; }

/* ========== 顶部 Banner ========== */
.hero-banner {
  position: relative;
  height: 180px;
  background: linear-gradient(135deg, #2b7de1 0%, #1a6fc4 50%, #0d5aa8 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; }
.orbit {
  position: absolute;
  border: 1px solid rgba(255,255,255,.15);
  border-radius: 50%;
}
.orbit-1 { width: 420px; height: 420px; top: -120px; right: 10%; }
.orbit-2 { width: 300px; height: 300px; top: -60px; right: 15%; }
.dot {
  position: absolute;
  width: 8px; height: 8px;
  background: rgba(255,255,255,.7);
  border-radius: 50%;
}
.dot-1 { top: 35px; right: 22%; }
.dot-2 { top: 70px; right: 28%; }
.dot-3 { top: 55px; right: 16%; }
.cube {
  position: absolute;
  font-size: 40px;
  opacity: .55;
  filter: drop-shadow(0 6px 12px rgba(0,0,0,.15));
}
.cube-left { left: 8%; bottom: 20px; }
.cube-right { right: 7%; bottom: 25px; }

.hero-content { position: relative; z-index: 2; text-align: center; color: #fff; }
.hero-content h1 { font-size: 32px; font-weight: bold; margin-bottom: 10px; letter-spacing: 1px; }
.hero-content p { font-size: 15px; opacity: .92; }

/* ========== 主内容区 ========== */
.knowledge-main {
  max-width: 1200px;
  margin: 28px auto;
  padding: 0 24px;
  min-height: 60vh;
}

/* 分组卡片 */
.group-section {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 20px 24px 16px;
  margin-bottom: 24px;
  box-shadow: 0 1px 4px rgba(0,0,0,.06);
}
.group-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
  padding-left: 12px;
  border-left: 4px solid var(--primary);
}
.group-title {
  font-size: 17px;
  font-weight: bold;
  color: var(--text-main);
}
.group-count {
  font-size: 12px;
  color: var(--text-light);
  background: var(--primary-soft);
  padding: 3px 10px;
  border-radius: 12px;
}

/* 表格 */
.km-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}
.km-table th {
  background: var(--table-head);
  color: var(--text-main);
  font-weight: normal;
  text-align: left;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  border-top: 1px solid var(--border);
}
.km-table th:first-child { text-align: center; width: 70px; border-left: 1px solid var(--border); }
.km-table th:last-child { text-align: center; border-right: 1px solid var(--border); }
.km-table td {
  padding: 13px 16px;
  border-bottom: 1px solid var(--border);
  color: var(--text-sub);
}
.km-table td:first-child { text-align: center; color: var(--text-light); border-left: 1px solid var(--border); }
.km-table td:last-child { text-align: center; border-right: 1px solid var(--border); }
.km-table tbody tr:nth-child(odd) { background: #fff; }
.km-table tbody tr:nth-child(even) { background: #fafbfc; }
.km-table tbody tr:hover { background: var(--table-hover); }
.km-table tbody tr:hover a { text-decoration: underline; }

.file-link { display: inline-flex; align-items: center; gap: 6px; cursor: pointer; }
.file-ico {
  display: inline-flex; align-items: center; justify-content: center;
  width: 20px; height: 20px;
  background: var(--primary-soft);
  color: var(--primary);
  border-radius: 4px;
  font-size: 11px;
  flex-shrink: 0;
}
.no-file { color: var(--text-sub); cursor: default; }

.loading-tip {
  text-align: center;
  color: var(--text-light);
  padding: 80px 0;
  font-size: 14px;
}

/* 页脚 */
.page-footer { text-align: center; color: var(--text-light); font-size: 12px; padding: 24px 0 32px; }

/* 滚动条 */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-thumb { background: #c8ccd2; border-radius: 4px; }
::-webkit-scrollbar-track { background: transparent; }

/* ========== 响应式 ========== */
@media (max-width: 900px) {
  .hero-content h1 { font-size: 24px; }
  .km-table th, .km-table td { padding: 10px 8px; }
}