ackground: linear-gradient(135deg, #5433FF 0%, #20BDFF 50%, #A5FECB 100%); /* 靛蓝 -> 亮蓝 -> 薄荷绿 */
        }
        /* 左下角：上次刷新时间卡片 */
        .last-refresh-box {
            background: linear-gradient(135deg, #00b09b 0%, #96c93d 50%, #00d2ff 100%); /* 青绿 -> 亮青柠 -> 海洋蓝 */
        }
        /* 右上角：预计下次刷新卡片 */
        .next-refresh-box {
            background: linear-gradient(135deg, #6a11cb 0%, #fc00ff 50%, #00dbde 100%); /* 深�