/* 全局样式 */
body {
    background-color: #1d1d1f;
    color: #f5f5f7;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}

.countdown-container {
    display: flex;
    text-align: center;
}

.time-unit {
    display: flex;
    align-items: center; /* 确保数字和单位基线对齐 */
    margin-right: 32px;
}

.time-unit:last-child {
    margin-right: 0;
}

.digit-group {
    display: flex;
    margin-right: 8px; /* 数字组合和单位之间的间距 */
}

.number {
    font-family: "SF Mono", "Menlo", "Monaco", "Consolas", "Liberation Mono", "Courier New", monospace;
    font-size: 4rem;
    font-weight: 600;
    transition: opacity 0.3s ease-in-out; /* 动画效果 */
}

.unit {
    font-size: 1.5rem;
    font-weight: 300;
}

/* 动画类 */
.changing {
    opacity: 0;
}

/* 响应式设计 */
@media (max-width: 480px) {
    .countdown-container {
        flex-direction: column;
        align-items: center;
    }

    .time-unit {
        margin-right: 0;
        margin-bottom: 24px;
    }

    .time-unit:last-child {
        margin-bottom: 0;
    }

    .number {
        font-size: 3rem;
    }

    .unit {
        font-size: 1rem;
    }
}