/* —————————— 左侧全新大气设计 —————————— */
        .left-box {
            flex: 1;
            min-width: 300px;
            background: var(--white);
            border-radius: 12px;
            padding: 10px;
            box-shadow: 0 5px 20px rgba(0,0,0,0.06);
        }
        .class-title {
            font-size: 24px;
            color: var(--tsinghua-purple);
            margin-bottom: 30px;
            padding-bottom: 15px;
            border-bottom: 3px solid var(--tsinghua-purple);
            font-weight: bold;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .class-title::before {
            content: "";
            width: 6px;
            height: 24px;
            background: var(--tsinghua-purple);
            display: inline-block;
        }

        /* 课程卡片（带图片 图文大气版） */
        .course-card {
            background: #fff;
            border-radius: 12px;
            margin-bottom: 25px;
            border: 1px solid #eee;
            overflow: hidden;
            transition: all 0.3s ease;
            box-shadow: 0 2px 8px rgba(0,0,0,0.04);
        }
        .course-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(110,0,153,0.1);
            border-color: #d9b3e6;
        }

        /* 课程内容 */
        .course-content {
            padding: 25px;
        }
        .course-content h3 {
            font-size: 19px;
            color: var(--tsinghua-purple);
            margin-bottom: 12px;
            font-weight: bold;
        }
        .course-content .desc {
            color: #555;
            line-height: 1.8;
            font-size: 14px;
            margin-bottom: 18px;
        }
        .course-content .info {
            display: flex;
            flex-wrap: wrap;
            gap: 16px;
            margin-bottom: 20px;
            font-size: 14px;
            color: #666;
        }
        .course-content .info span {
            padding-right: 16px;
            border-right: 1px solid #ddd;
        }
        .course-content .info span:last-child {
            border-right: 0;
        }
        .course-content .price {
            font-size: 19px;
            font-weight: bold;
            color: #c40000;
        }
        .course-content .btn {
            display: inline-block;
            padding: 10px 24px;
            background: var(--tsinghua-purple);
            color: #fff;
            border-radius: 6px;
            text-decoration: none;
            font-size: 14px;
            transition: 0.25s;
        }
        .course-content .btn:hover {
            background: var(--tsinghua-dark);
        }
		
		 /* ===================== 底部：课堂风采 相册（一行6张） ===================== */
        .photo-section {
            max-width: 1200px;
            margin: 20px auto 40px;
            padding: 0 15px;
        }
        .photo-title {
            font-size: 24px;
            color: var(--tsinghua-purple);
            text-align: center;
            margin-bottom: 30px;
            font-weight: bold;
            position: relative;
        }
        .photo-title::after {
            content: "";
            width: 60px;
            height: 3px;
            background: var(--tsinghua-purple);
            display: block;
            margin: 10px auto 0;
        }

        /* 相册网格：一行 6 张 */
        .photo-grid {
            display: grid;
            grid-template-columns: repeat(6, 1fr);
            gap: 12px;
        }
        .photo-item {
            background: #fff;
            border-radius: 8px;
            overflow: hidden;
            box-shadow: 0 3px 10px rgba(0,0,0,0.05);
            transition: 0.3s;
        }
        .photo-item:hover {
            transform: translateY(-4px);
            box-shadow: 0 8px 20px rgba(110,0,153,0.1);
        }
        .photo-item img {
            width: 100%;
            height: 110px;
            object-fit: cover;
            display: block;
        }
        .photo-item p {
            text-align: center;
            padding: 8px 5px;
            font-size: 13px;
            color: #555;
        }