.overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.7);
            z-index: 9999;
            display: none;
            overflow-y: auto; /* 允许遮罩层内部滚动 */
        }

        /* 遮罩层内容容器 */
        .overlay-content {
            position: absolute;
            top: 20%;
            left: 50%;
            transform: translate(-50%, -50%);
            background-color: white;
            padding: 10px;
            border-radius: 8px;
            width: 80%;
            max-width: 500px;
            max-height: 90vh;
            overflow-y: auto;
        }

        /* 关闭按钮 */
        .close-btn {
            position: absolute;
            top: 10px;
            right: 10px;
            font-size: 24px;
            cursor: pointer;
        }

        /* 禁止滚动条滚动的类 */
        .no-scroll {
            overflow: hidden;
            /*position: fixed;*/
            
        }

        /* 内容区域样式 - 仅用于演示 */
        
        /* 显示遮罩层的按钮样式 */
        .show-overlay-btn {
            padding: 10px 20px;
            background-color: #4CAF50;
            color: white;
            border: none;
            cursor: pointer;
            font-size: 16px;
        }
        #register{
            display: none;
        }
        #login{
            display: none;
        }