/* 课程封面卡片 + 专题计数 + 长图预览 */

/* 最新上架：2×2 */
.latest-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}
@media (max-width: 640px) {
  .latest-grid {
    grid-template-columns: 1fr;
  }
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
}

.course-card {
  background: var(--paper-deep, #ebe4d6);
  border-top: 2px solid var(--seal, #7a0c1e);
  cursor: pointer;
  overflow: hidden;
  transition: transform .15s, box-shadow .15s;
}

.course-card:hover,
.course-card:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(26, 22, 20, 0.12);
  outline: none;
}

.card-cover {
  width: 100%;
  /* 原来写死 height:200px —— 卡片只有 250-290px 宽，
     框的比例就变成 1.1:1~1.3:1，比封面图的 16:9 方得多，
     配上 object-fit:cover 就把封面左右各裁掉约 30%，标题两头被切。
     改成按 16:9 算高：图完整显示，不裁。 */
  aspect-ratio: 16 / 9;
  background: var(--ink, #1a1614);
  overflow: hidden;
}

.card-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center center;
  display: block;
}

.card-cover-empty {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--seal, #7a0c1e);
  color: var(--paper, #f4efe6);
  font-family: "Songti SC", "SimSun", serif;
  font-size: 36px;
}

.card-body {
  padding: 16px 16px 18px;
}

.card-body .tag {
  font-family: "Songti SC", "SimSun", serif;
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--seal, #7a0c1e);
}

.card-body h3 {
  font-family: "Songti SC", "SimSun", serif;
  font-size: 17px;
  letter-spacing: 1px;
  margin: 8px 0 10px;
  line-height: 1.35;
}

.card-body .chips {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.card-body .chip {
  font-size: 11px;
  border: 1px solid rgba(26, 22, 20, 0.15);
  border-radius: 999px;
  padding: 2px 8px;
  color: #666;
}

.card-hint {
  margin-top: 12px;
  font-size: 12px;
  color: var(--seal, #7a0c1e);
  letter-spacing: 1px;
}

/* 专题格子：课程数 + 可点击 */
.cat-cell {
  text-align: left;
  border: 0;
  font: inherit;
  color: inherit;
  background: var(--paper, #f4efe6);
  padding: 22px 18px;
  cursor: pointer;
  min-height: 96px;
  transition: background .2s, color .2s;
}

.cat-cell:hover,
.cat-cell.on {
  background: var(--ink, #1a1614);
  color: var(--paper, #f4efe6);
}

.cat-cell:hover .tag,
.cat-cell.on .tag {
  color: var(--gold, #c9a227);
  border-color: var(--gold, #c9a227);
}

.cat-cell .tag {
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border: 1px solid var(--red, #b71c2c);
  color: var(--red, #b71c2c);
  font-family: "Songti SC", "SimSun", serif;
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 12px;
}

.cat-cell h3 {
  font-family: "Songti SC", "SimSun", serif;
  font-size: 15px;
  letter-spacing: 1px;
}

.cat-cell p {
  font-size: 11px;
  opacity: 0.65;
  margin-top: 4px;
}

.cat-count {
  margin-top: 10px;
  font-family: "SF Mono", Consolas, monospace;
  font-size: 12px;
  color: var(--seal, #7a0c1e);
}

.cat-cell:hover .cat-count,
.cat-cell.on .cat-count {
  color: var(--gold, #c9a227);
}

/* 预览层 */
#viewer:empty { display: none; }
#viewer { position: fixed; inset: 0; z-index: 100; }
.viewer-mask {
  position: absolute; inset: 0;
  background: rgba(13, 13, 13, 0.78);
}
.viewer-panel {
  position: absolute;
  left: 50%; top: 3vh;
  transform: translateX(-50%);
  width: min(880px, 96vw);
  max-height: 94vh;
  background: var(--paper, #f4efe6);
  display: flex; flex-direction: column;
  border-top: 3px solid var(--seal, #7a0c1e);
}
.viewer-head {
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px; padding: 14px 16px;
  border-bottom: 1px solid rgba(26, 22, 20, 0.12);
}
.viewer-title {
  font-family: "Songti SC", "SimSun", serif;
  font-size: 16px; letter-spacing: 1px;
  flex: 1; min-width: 0;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.viewer-close {
  border: 1px solid rgba(26, 22, 20, 0.2);
  background: transparent;
  color: var(--ink, #1a1614);
  padding: 8px 14px; cursor: pointer; font-size: 13px;
}
.viewer-close:hover,
.viewer-close:focus-visible {
  background: var(--ink, #1a1614);
  color: var(--paper, #f4efe6);
  outline: none;
}
.viewer-tabs {
  display: flex;
  background: var(--paper-deep, #ebe4d6);
  border-bottom: 1px solid rgba(26, 22, 20, 0.12);
}
.viewer-tab {
  flex: 1; border: 0; background: transparent;
  padding: 12px 8px; cursor: pointer;
  font-family: "Songti SC", "SimSun", serif;
  font-size: 14px; letter-spacing: 2px;
  color: var(--mist, #8a8074);
}
.viewer-tab.on {
  color: var(--seal, #7a0c1e);
  box-shadow: inset 0 -2px 0 var(--seal, #7a0c1e);
}
.viewer-body {
  overflow: auto;
  padding: 12px 12px 28px;
  background: var(--paper, #f4efe6);
}
.stack-img {
  width: 100%;
  display: block;
  margin-bottom: 8px;
  background: #fff;
  cursor: zoom-in;
}
.empty-card {
  grid-column: 1 / -1;
  text-align: center;
  padding: 40px 16px;
  color: var(--mist, #8a8074);
}
.muted { color: var(--mist, #8a8074); font-size: 13px; }

@media (max-width: 640px) {
  .card-cover { aspect-ratio: 16 / 9; }
  .viewer-panel { top: 0; width: 100vw; max-height: 100vh; }
}