.course-popup {
        position: fixed;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        background: white;
        border-radius: 12px;
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
        width: 90%;
        max-width: 500px;
        z-index: 1000000 !important;
        display: none;
        overflow: hidden;
    }

    .popup-header {
        padding: 15px 20px;
        background: linear-gradient(45deg, #3a7bd5, #00d2ff);
        color: white;
        display: flex;
        justify-content: space-between;
        align-items: center;
        z-index: 10000 !important;
        /* 确保标题栏在最上层 */
    }

    .popup-title {
        margin: 0;
        font-size: 1.2rem;
    }

    .popup-close {
        background: transparent;
        border: none;
        color: white;
        font-size: 1.2rem;
        cursor: pointer;
        z-index: 10001 !important;
        /* 确保关闭按钮在最上层 */
    }

    .popup-content {
        padding: 20px;
        max-height: 70vh;
        overflow-y: auto;
    }