:root {
  --primary: #2f6df6;
  --bg: #f5f6f8;
  --card: #ffffff;
  --text: #1f2329;
  --muted: #8a909c;
  --border: #e8eaed;
  --radius: 12px;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}
.wrap { max-width: 1120px; margin: 0 auto; padding: 24px 20px 48px; }

/* 顶部：单一分类标题 + 排序选择 */
.head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 24px;
}
.cat {
  display: flex;
  align-items: center;
  gap: 10px;
}
.logo-mark {
  width: 26px; height: 26px; border-radius: 7px;
  background: var(--primary);
  display: inline-block;
}
.cat h1 {
  font-size: 20px;
  margin: 0;
  font-weight: 700;
}
.sort {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--muted);
}
.sort select {
  font-size: 14px;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  min-width: 180px;
}
.sort select:focus { outline: 2px solid rgba(47,109,246,.25); border-color: var(--primary); }

/* 图纸网格：每页 4 列 x 3 行 = 12 张 */
.grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: transform .15s ease, box-shadow .15s ease;
  display: flex;
  flex-direction: column;
}
.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(20,30,60,.12);
}
.thumb {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  background: #eef0f3;
}
.meta { padding: 10px 12px 12px; }
.meta .t { font-size: 14px; font-weight: 600; margin: 0 0 6px; }
.meta .sub {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--muted);
}
.count { color: var(--primary); font-weight: 600; }
.empty { color: var(--muted); padding: 40px 0; text-align: center; }

/* 分页 */
.pager {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}
.p-info { font-size: 13px; color: var(--muted); }
.p-nav { display: flex; gap: 10px; }
.p-btn {
  font-size: 14px;
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card);
  color: var(--text);
  cursor: pointer;
}
.p-btn:hover:not(:disabled) { border-color: var(--primary); color: var(--primary); }
.p-btn:disabled { opacity: .45; cursor: not-allowed; }

@media (max-width: 768px) {
  .grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 560px) {
  .grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .head { flex-direction: column; align-items: stretch; }
  .sort select { width: 100%; }
  .pager { flex-direction: column; align-items: stretch; }
  .p-nav { justify-content: center; }
}

/* 灯箱：点击后加载原图 */
.lightbox {
  position: fixed; inset: 0; z-index: 50;
  display: flex; align-items: center; justify-content: center;
  flex-direction: column; gap: 12px;
  background: rgba(15, 22, 40, .82);
  padding: 24px;
}
.lightbox[hidden] { display: none; }
.lightbox img {
  max-width: 92vw; max-height: 80vh;
  border-radius: 10px; background: #fff;
  box-shadow: 0 12px 40px rgba(0, 0, 0, .4);
}
.lightbox .lb-cap { color: #e8ecf4; font-size: 14px; }
.lb-close {
  position: absolute; top: 16px; right: 20px;
  width: 38px; height: 38px; border-radius: 50%;
  border: none; cursor: pointer;
  background: rgba(255, 255, 255, .15); color: #fff;
  font-size: 20px; line-height: 1;
}
.lb-close:hover { background: rgba(255, 255, 255, .3); }

/* 页脚：备案信息 + 版权，简洁清晰，与整体风格协调 */
.site-foot {
  margin-top: 40px;
  border-top: 1px solid var(--border);
  background: var(--card);
  color: var(--muted);
  font-size: 13px;
}
.foot-wrap {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: center;
  gap: 6px 18px;
  padding: 18px 20px;
  text-align: center;
}
.site-foot p { margin: 0; }
.site-foot .icp { color: var(--text); font-weight: 600; }
.site-foot .copy { color: var(--text); }
.site-foot a { color: var(--primary); text-decoration: none; }
.site-foot .gongan { color: var(--muted); }
@media (max-width: 560px) {
  .foot-wrap { flex-direction: column; gap: 6px; }
}