/* ========================================
   课程列表页样式 - 优超医学英语
   ======================================== */

.courses-page {
    --primary: #FA5A5A;
    --primary-light: #FFF0F0;
    --secondary: #00BE64;
    --secondary-light: #E8F9F0;
    --bg-warm: linear-gradient(180deg, #F0F7F0 0%, #F5F0EB 100%);
    --text-dark: #2D2D2D;
    --text-mid: #666666;
    --text-light: #999999;
    --card-bg: #FFFFFF;
    --shadow: 0 4px 20px rgba(0,0,0,0.06);
    --shadow-hover: 0 8px 30px rgba(0,0,0,0.10);
    --radius: 16px;
    --radius-sm: 10px;
}

.courses-page {
    background: var(--bg-warm);
    min-height: 100vh;
    padding-bottom: 80px;
}

/* 页面标题 */
.courses-hero {
    background: linear-gradient(135deg, #FA5A5A 0%, #FF8A8A 100%);
    padding: 50px 20px 40px;
    text-align: center;
}
.courses-hero h1 {
    font-size: 2rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
}
.courses-hero p {
    font-size: 1rem;
    color: rgba(255,255,255,0.9);
}

/* 筛选栏 */
.filter-bar {
    max-width: 1200px;
    margin: 0 auto;
    padding: 24px 20px;
}
.filter-group {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
    margin-bottom: 16px;
}
.filter-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-mid);
    margin-right: 6px;
    white-space: nowrap;
}
.filter-btn {
    padding: 8px 18px;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    border: 1.5px solid #E0E0E0;
    background: #fff;
    color: var(--text-mid);
    transition: all 0.25s ease;
}
.filter-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}
.filter-btn.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
    box-shadow: 0 3px 12px rgba(250,90,90,0.25);
}

/* 结果计数 */
.result-count {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 20px;
}
.result-count strong {
    color: var(--primary);
    font-weight: 700;
}

/* 课程网格 */
.courses-grid {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}
@media (max-width: 900px) {
    .courses-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
    .courses-grid { grid-template-columns: 1fr; }
}

/* 课程卡片 */
.course-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.35s ease;
    position: relative;
}
.course-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}
.course-card.hidden {
    display: none;
}

.course-thumbnail {
    width: 100%;
    height: 170px;
    position: relative;
    overflow: hidden;
}

/* 封面占位 */
.course-cover-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #555;
    font-size: 1.5rem;
    font-weight: 700;
    text-align: center;
    padding: 10px;
}

/* 角标 */
.course-type-badge {
    position: absolute;
    top: 12px;
    left: 12px;
    padding: 5px 14px;
    border-radius: 50px;
    font-size: 0.72rem;
    font-weight: 600;
    color: #fff;
    z-index: 2;
}
.course-type-badge.vocab { background: linear-gradient(135deg, #8B5CF6, #A78BFA); }
.course-type-badge.knowledge { background: linear-gradient(135deg, #00BE64, #4DD88A); }
.course-type-badge.sentence { background: linear-gradient(135deg, #5B8DEF, #8AB4F8); }

/* 状态标签 */
.course-status {
    position: absolute;
    top: 12px;
    right: 12px;
    padding: 4px 12px;
    border-radius: 50px;
    font-size: 0.7rem;
    font-weight: 600;
    z-index: 2;
}
.status-1 { background: #FCE7F3; color: #EC4899; }
.status-2 { background: #FFF3E0; color: #F57C00; }

/* 信息区 */
.course-info {
    padding: 18px 20px 16px;
}
.course-info h3 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 10px;
    line-height: 1.4;
}
.course-meta {
    display: flex;
    gap: 16px;
    margin-bottom: 4px;
}
.course-meta span {
    font-size: 0.8rem;
    color: var(--text-light);
    display: flex;
    align-items: center;
    gap: 4px;
}
.course-meta svg {
    width: 14px;
    height: 14px;
    opacity: 0.5;
}

/* 按钮 */
.course-action {
    padding: 0 20px 20px;
}
.course-btn {
    display: block;
    width: 100%;
    padding: 12px;
    border-radius: var(--radius-sm);
    text-align: center;
    font-size: 0.9rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}
.course-btn.primary {
    background: linear-gradient(135deg, #FA5A5A, #E04A4A);
    color: #fff;
}
.course-btn.primary:hover {
    background: linear-gradient(135deg, #E04A4A, #D04040);
}

/* 空状态 */
.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 80px 20px;
    color: var(--text-light);
}
.empty-state svg {
    width: 80px;
    height: 80px;
    margin-bottom: 20px;
    opacity: 0.25;
}
.empty-state h3 {
    font-size: 1.2rem;
    color: var(--text-mid);
    margin-bottom: 8px;
}