.back-to-top-btn {
            width: 100%;
            max-width: 800px;
            height: 48px;
            /* 背景色改为白色 */
            background-color: #ffffff;
            /* 字体颜色改为黑色 */
            color: #000000;
            font-size: 16px;
            border: none;
            border-radius: 4px;
            cursor: pointer;
            transition: background 0.3s;
            text-align: center;
            line-height: 48px;
            display: block;
            margin: 0 auto;
            /* 添加微软雅黑字体，兼容不同系统 */
            font-family: "Microsoft YaHei", "微软雅黑", Arial, sans-serif;
            /* 字体加粗 */
            font-weight: bold;
            /* 可选：添加浅灰色边框，让白色按钮更明显 */
            border: 1px solid #e0e0e0;
        }

        .back-to-top-btn:hover {
            /* 鼠标悬浮时背景色改为浅灰色，提升交互体验 */
            background-color: #f5f5f5;
        }

        .back-to-top-wrapper {
            margin-top: 50px;
            margin-bottom: 30px;
            padding: 0 20px;
            width: 100%;
            box-sizing: border-box;
        }

        @media (max-width: 768px) {
            .back-to-top-btn {
                max-width: 90%;
                height: 44px;
                font-size: 14px;
                line-height: 44px;
            }
        }