/* 页面基础样式 */
        body {
            margin: 0;
            min-height: 100vh;
            font-family: Arial, sans-serif;
            background: #f8f9fa;
        }

        /* 弹窗核心样式 - 固定右下角 */
        .popup {
            position: fixed;
            bottom: 20px;
            right: 20px;
            width: 300px;
            padding: 20px;
            background: #fff;
            border-radius: 10px;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.12);
            z-index: 9999;
            transition: all 0.5s ease;
            opacity: 1;
            transform: translateY(0);
            box-sizing: border-box;
        }

        /* 弹窗关闭状态 */
        .popup.close {
            opacity: 0;
            transform: translateY(30px);
            pointer-events: none;
        }

        /* 弹窗标题 */
        .popup-title {
            font-size: 18px;
            font-weight: 600;
            color: #333;
            margin: 0 0 12px 0;
            padding-bottom: 8px;
            border-bottom: 1px solid #eee;
        }

        /* 弹窗内容 */
        .popup-content {
            font-size: 14px;
            color: #666;
            line-height: 1.6;
            margin-bottom: 15px;
        }

        /* 倒计时高亮 */
        #countdown {
            color: #e53e3e;
            font-weight: bold;
            font-size: 16px;
        }

        /* 按钮样式 */
        .popup-btn-group {
            display: flex;
            justify-content: flex-end;
            gap: 8px;
        }
        .close-btn, .confirm-btn {
            padding: 6px 16px;
            border: none;
            border-radius: 6px;
            cursor: pointer;
            font-size: 14px;
            transition: background 0.3s;
        }
        .close-btn {
            background: #f5f5f5;
            color: #666;
        }
        .close-btn:hover {
            background: #e9e9e9;
        }
        .confirm-btn {
            background: #4299e1;
            color: #fff;
        }
        .confirm-btn:hover {
            background: #3182ce;
        }