/**
 * 过渡动画样式
 * 提供文章内容渐变效果和页面切换效果
 */

/* 文章内容渐变效果 */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 文章容器进入/退出效果 */
.article-content {
    transition: opacity 0.2s ease;
}

.article-content.fade-out {
    opacity: 0;
}

/* 加载状态渐变效果 */
.loading {
    opacity: 0.7;
    transition: opacity 0.3s ease;
}

/* 页面切换效果 */
.page-transition {
    position: relative;
    transition: opacity 0.4s ease;
}

.page-transition.hidden {
    opacity: 0;
}

/* 优化 TOC 渐变 */
.toc-link {
    transition: color 0.3s ease, border-left 0.3s ease;
}

/* 渐现渐退动画 */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeOut {
    from { opacity: 1; transform: translateY(0); }
    to { opacity: 0; transform: translateY(-10px); }
}

.animate-fade-in {
    animation: fadeIn 0.6s ease forwards;
}

.animate-fade-out {
    animation: fadeOut 0.4s ease forwards;
}