/* ============================================
   课程列表页面样式
   Courses Page Styles
   ============================================ */

/* 页面头部 */
.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-6);
}

.page-header-left {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.page-title {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
}

.page-subtitle {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.page-header-right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* 视图切换 */
.view-toggle {
  display: flex;
  background: var(--bg-tertiary);
  border-radius: var(--radius-lg);
  padding: var(--space-1);
}

.view-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.view-btn:hover {
  color: var(--text-primary);
  background: var(--bg-secondary);
}

.view-btn.active {
  color: var(--text-primary);
  background: var(--bg-secondary);
  box-shadow: var(--shadow-sm);
}

/* 筛选栏 */
.filter-bar {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
  padding: var(--space-4);
  background: var(--bg-secondary);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-primary);
  flex-wrap: wrap;
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.filter-group.search-group {
  flex: 1;
  min-width: 200px;
}

.filter-label {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  color: var(--text-secondary);
}

.filter-select {
  min-width: 140px;
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-sm);
  color: var(--text-primary);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-select:hover {
  border-color: var(--border-secondary);
}

.filter-select:focus {
  outline: none;
  border-color: var(--primary-500);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-box {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.search-box:focus-within {
  border-color: var(--primary-500);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-box svg {
  color: var(--text-tertiary);
  flex-shrink: 0;
}

.search-box input {
  flex: 1;
  border: none;
  background: transparent;
  font-size: var(--font-size-sm);
  color: var(--text-primary);
}

.search-box input::placeholder {
  color: var(--text-tertiary);
}

.search-box input:focus {
  outline: none;
}

/* 课程网格 */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-5);
  margin-bottom: var(--space-6);
}

/* 列表视图 */
.courses-grid.list-view {
  grid-template-columns: 1fr;
}

.courses-grid.list-view .course-card {
  display: flex;
  flex-direction: row;
}

.courses-grid.list-view .course-cover {
  width: 200px;
  height: auto;
  min-height: 160px;
}

.courses-grid.list-view .course-content {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.courses-grid.list-view .course-desc {
  flex: 1;
}

/* 课程卡片 */
.course-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.course-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-secondary);
}

.course-cover {
  position: relative;
  height: 160px;
  background: linear-gradient(135deg, var(--primary-600) 0%, var(--primary-500) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.course-cover-icon {
  font-size: 48px;
  opacity: 0.9;
}

.course-badge {
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  padding: var(--space-1) var(--space-2);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  border-radius: var(--radius-full);
}

.course-badge.hot {
  background: var(--danger-500);
  color: white;
}

.course-badge.new {
  background: var(--success-500);
  color: white;
}

.course-progress-overlay {
  position: absolute;
  bottom: var(--space-3);
  right: var(--space-3);
}

.progress-ring {
  position: relative;
  width: 48px;
  height: 48px;
}

.progress-ring svg {
  transform: rotate(-90deg);
  width: 100%;
  height: 100%;
}

.progress-ring-bg {
  fill: none;
  stroke: rgba(255, 255, 255, 0.2);
  stroke-width: 3;
}

.progress-ring-fill {
  fill: none;
  stroke: white;
  stroke-width: 3;
  stroke-linecap: round;
  transition: stroke-dasharray var(--transition-slow);
}

.progress-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-bold);
  color: white;
}

.course-content {
  padding: var(--space-4);
}

.course-tags {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.course-title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-2);
  line-height: 1.4;
}

.course-desc {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-4);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.course-meta {
  display: flex;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--border-primary);
}

.meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.meta-item svg {
  color: var(--text-tertiary);
}

.course-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.course-instructor {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.instructor-avatar {
  width: 28px;
  height: 28px;
  background: var(--primary-500);
  color: white;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
}

.instructor-name {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

/* 分页 */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
}

.pagination-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  height: 36px;
  padding: 0 var(--space-3);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--text-secondary);
  background: var(--bg-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.pagination-btn:hover:not(:disabled) {
  color: var(--text-primary);
  background: var(--bg-tertiary);
  border-color: var(--border-secondary);
}

.pagination-btn.active {
  color: white;
  background: var(--primary-500);
  border-color: var(--primary-500);
}

.pagination-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.pagination-ellipsis {
  color: var(--text-tertiary);
  padding: 0 var(--space-1);
}

/* 响应式适配 */
@media (max-width: 1024px) {
  .courses-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .filter-bar {
    gap: var(--space-3);
  }

  .filter-group {
    flex: 1;
    min-width: 140px;
  }

  .filter-group.search-group {
    width: 100%;
    min-width: 100%;
  }
}

@media (max-width: 768px) {
  .page-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-4);
  }

  .courses-grid {
    grid-template-columns: 1fr;
  }

  .courses-grid.list-view .course-card {
    flex-direction: column;
  }

  .courses-grid.list-view .course-cover {
    width: 100%;
    height: 160px;
  }

  .filter-bar {
    flex-direction: column;
    align-items: stretch;
  }

  .filter-group {
    width: 100%;
  }

  .filter-select {
    width: 100%;
  }
}