/* 全局原生样式 统一官网轻量化风格 */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
 
        :root {
            --primary: #1d4ed8;
            --secondary: #f59e0b;
            --light: #ffffff;
            --gray: #64748b;
            --shadow: 0 6px 24px rgba(29, 78, 216, 0.08);
            --hover-shadow: 0 12px 32px rgba(29, 78, 216, 0.18);
            --radius: 16px;
        }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 18px;
        }

        /* 顶部专题Banner */
        .top-banner {
            width: 100%;
            background: linear-gradient(120deg, #1d4ed8 0%, #3b82f6 100%);
            padding: 70px 0;
            text-align: center;
   
            position: relative;
            overflow: hidden;
        }
            .top-banner h1 {
                font-size: 2.6rem;
                margin-bottom: 16px;
                font-weight: 700;
                color: #fff;
            }
            .top-banner p {
                font-size: 1.15rem;
                opacity: 0.92;
                max-width: 850px;
                margin: 0 auto;
                color: #fff;
            }

        /* 固定导航栏 滚动高亮 */
        .nav-bar {
            background: #fff;
            box-shadow: 0 2px 15px rgba(0,0,0,0.06);
            position: sticky;
            top: 0;
            z-index: 999;
            padding: 16px 0;
        }
        .nav-list {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 10px;
            list-style: none;
        }
        .nav-list li a {
            padding: 9px 18px;
            text-decoration: none;
            color: var(--gray);
            border-radius: 30px;
            font-size: 0.96rem;
            transition: all 0.3s ease;
        }
        .nav-list li a.active,
        .nav-list li a:hover {
            background: var(--primary);
            color: #fff;
        }

        /* 主体通用卡片样式 */
        .main-wrap {
            padding: 55px 0;
        }
        .card {
            background: var(--light);
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            padding: 40px;
            margin-bottom: 35px;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .card:hover {
            transform: translateY(-6px);
            box-shadow: var(--hover-shadow);
        }
        .card-title {
            font-size: 1.9rem;
            color: var(--primary);
            border-left: 5px solid var(--secondary);
            padding-left: 16px;
            margin-bottom: 20px;
        }
        .card-desc {
            color: var(--gray);
            font-size: 1.05rem;
            margin-bottom: 28px;
        }
        .sub-title {
            font-size: 1.2rem;
            margin: 24px 0 12px;
            color: #222;
        }

        /* 图文自适应布局 */
        .row-box {
            display: grid;
            grid-template-columns: 1fr 1fr;
            
            gap: 35px;
            align-items: center;
            margin: 30px 0;
        }
.sub-container {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
 
    min-height: 400px;
}
            .img-placeholder {
                width: 100%;
                min-height: 240px;
                background: linear-gradient(145deg, #eff6ff, #dbeafe);
                border-radius: var(--radius);
                display: flex;
                align-items: center;
                justify-content: center;
                flex-wrap: wrap;
                color: var(--primary);
                font-size: 0.8rem;
                text-decoration: none;
            }
                .img-placeholder img {
            width: 100%;
            border-radius: 10px 10px 0 0;
           margin-bottom: 10px;

        }
          .img-placeholder>p{ padding: 0 8px 4px; box-sizing:border-box; letter-spacing: 2px;}
.list-item {
    padding-left: 22px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
 
    min-height: 300px;
}
        .list-item li {
            margin-bottom: 12px;
            color: #444;
        }
        .list-item li strong {
            color: var(--primary);
        }

        /* 动态课程、文章占位模块样式 */
        .dynamic-module {
            background: #f8faff;
            padding: 30px;
            border-radius: var(--radius);
            margin-top: 20px;
        }
        .dynamic-module h4 {
            font-size: 1.3rem;
            color: var(--primary);
            margin-bottom: 15px;
        }

        /* 转化引导底部模块 */
        .convert-block {
            background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
            padding: 45px;
            border-radius: var(--radius);
            text-align: center;
            margin-top: 20px;
        }
        .convert-block h3 {
            font-size: 1.4rem;
            color: var(--primary);
            margin-bottom: 15px;
        }
        .convert-block p {
            font-size: 1.08rem;
            color: #333;
        }

        /* 响应式适配 */
        @media (max-width: 992px) {
            .row-box {
                grid-template-columns: 1fr;
            }
            .top-banner h1 {
                font-size: 2.1rem;
            }

       
        }
@media (max-width: 576px) {
    .top-banner {
        padding: 45px 0;
    }

        .top-banner h1 {
            font-size: 1.7rem;
        }

    .card {
        padding: 22px;
    }

    .card-title {
        font-size: 1.5rem;
    }

    .nav-list li a {
        font-size: 0.85rem;
        padding: 7px 12px;
    }


    html {
        scroll-behavior: smooth;
    }
}

    .teachers-list li {
        width: 49%;
    }