@keyframes slideDownFade {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideUpFade {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* 初始状态设置 */
.brand,
.slogan-line,
.download-title,
.download-btn,
.screenshots {
    opacity: 0;
}

/* 品牌标题动画 */
.brand {
    animation: slideDownFade 0.8s ease forwards;
}

/* 标语动画 */
.slogan-line:first-child {
    animation: slideDownFade 0.8s ease forwards;
    animation-delay: 0.3s;
}

.slogan-line:last-child {
    animation: slideDownFade 0.8s ease forwards;
    animation-delay: 0.6s;
}

/* 下载标题动画 */
.download-title {
    animation: slideDownFade 0.8s ease forwards;
    animation-delay: 0.9s;
}

/* 下载按钮动画 */
.download-btn {
    animation: fadeIn 0.8s ease forwards;
}

.download-btn.windows {
    animation-delay: 1.2s;
}

.download-btn.unreleased {
    animation-delay: 1.5s;
}

/* 截图区域动画 */
.screenshots {
    animation: fadeIn 1s ease forwards;
    animation-delay: 1.8s;
}