.course-detail-page {
  display: grid;
  gap: 18px;
  width: min(var(--shell), calc(100vw - 32px));
  margin: 0 auto;
}

.breadcrumb {
  color: #64748b;
  font-size: 14px;
}

.breadcrumb a {
  color: #073b66;
  font-weight: 700;
  text-decoration: none;
}

.breadcrumb span {
  margin: 0 8px;
  color: #94a3b8;
}

.course-detail-main {
  overflow: hidden;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
  box-shadow: var(--shadow);
}

.course-detail-top {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  padding: 24px;
  background: linear-gradient(180deg, #f8fbfe, #fff);
}

.course-detail-top h1 {
  margin: 0;
  color: var(--blue-deep);
  font-size: 26px;
}

.course-detail-cover {
  min-height: 218px;
  border-radius: 12px;
  background: #dbe8f5 center/cover;
  box-shadow: inset 0 0 0 1px rgba(7,59,102,.08);
}

.course-info-table {
  width: 100%;
  margin-top: 16px;
  border-collapse: collapse;
  font-size: 14px;
}

.course-info-table th,
.course-info-table td {
  padding: 10px 12px;
  border: 1px solid #e5edf5;
  text-align: left;
  vertical-align: top;
}

.course-info-table th {
  width: 92px;
  color: #536b85;
  background: #f6f9fc;
  font-weight: 700;
}

.course-teacher-summary {
  margin: 0;
  color: #536b85;
  font-size: 13px;
  line-height: 1.6;
}

.course-tabs {
  display: flex;
  gap: 10px;
  margin: 0;
  padding: 0 24px;
  border-bottom: 1px solid #dbe7f1;
}

.course-tab {
  min-height: 42px;
  padding: 0 18px;
  border: 0;
  border-bottom: 3px solid transparent;
  background: transparent;
  color: #536b85;
  font-weight: 800;
}

.course-tab.active {
  color: var(--blue);
  border-bottom-color: var(--blue);
}

.course-tab-panel {
  padding: 18px 24px 24px;
}

.course-detail-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 18px;
  align-items: start;
}

.admin-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  padding: 16px;
}

.chapter-list {
  display: grid;
  gap: 8px;
}

.chapter-row {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) 112px;
  gap: 10px;
  align-items: center;
  min-height: 48px;
  padding: 10px 12px;
  border: 1px solid #e2edf6;
  border-radius: 10px;
  background: #fff;
  color: inherit;
  text-decoration: none;
}

.chapter-list.has-progress .chapter-row {
  grid-template-columns: 44px minmax(0, 1fr) 112px 58px;
}

.chapter-row.folder {
  background: #f5f9fd;
  font-weight: 800;
}

.chapter-row.leaf:hover {
  border-color: rgba(13,79,136,.28);
  box-shadow: 0 12px 28px rgba(7,59,102,.08);
  transform: translateY(-1px);
}

.chapter-name {
  min-width: 0;
  color: var(--blue-deep);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chapter-name small {
  display: inline-flex;
  margin-right: 8px;
  padding: 2px 7px;
  border-radius: 999px;
  background: #eaf2fb;
  color: var(--blue);
  font-size: 12px;
}

.chapter-sequence,
.chapter-hours,
.chapter-percent {
  min-width: 0;
  text-align: center;
  white-space: nowrap;
}

.chapter-sequence {
  color: #64748b;
  font-weight: 800;
}

.chapter-hours {
  color: #334155;
}

.learn-side {
  display: grid;
  gap: 14px;
}

.learn-box {
  padding: 14px;
  border-radius: 8px;
  background: #f7fbfe;
  border: 1px solid #e2edf6;
}

.course-intro {
  color: #334155;
  line-height: 1.8;
}

@media (max-width: 980px) {
  .course-detail-top,
  .course-detail-body,
  .chapter-row {
    grid-template-columns: 1fr;
  }
}