/* 更明显的入场动画 */
@keyframes slideInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

#announcement-section:not(.hidden) #announcement-box {
    animation: slideInDown 0.5s cubic-bezier(0.34, 1.2, 0.64, 1);
}

/* 或者使用弹跳效果 */
@keyframes bounceIn {
    0% {
        opacity: 0;
        transform: translateY(-30px);
    }
    60% {
        opacity: 1;
        transform: translateY(5px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

#announcement-section:not(.hidden) #announcement-box {
    animation: bounceIn 0.6s ease-out;
}