/* 基础工具类（多页面复用） */
@layer utilities {
    .content-auto {
        content-visibility: auto;
    }
}

/* 期刊系列下拉菜单样式 */
.series-group {
    position: relative;
}

/* 确保下拉菜单默认隐藏及动画基础样式 */
.series-group .series-dropdown {
    display: none;
    opacity: 0;
    visibility: hidden;
    transform: translateY(5px);
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
    
}

/* 鼠标悬停时显示下拉菜单并应用动画 */
.series-group:hover .series-dropdown {
    display: block;
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    transition-delay: 0s; /* 显示时立即执行 */
}

/* 鼠标离开时延迟隐藏，给用户足够时间点击子选项 */
.series-group:not(:hover) .series-dropdown {
    transition-delay: 1s; /* 延长隐藏延迟到0.8秒 */
}

/* 确保鼠标在下拉菜单上时保持显示 */
.series-dropdown:hover {
    opacity: 1 !important;
    visibility: visible !important;
    transform: translateY(0) !important;
}

/* 下拉菜单项样式 */
.series-dropdown a {
    pointer-events: auto !important;
    transition: all 0.2s ease;
}

/* 确保主标题有悬停效果提示可交互 */
.series-group > div {
    transition: color 0.2s ease;
}

.series-group > div:hover {
    color: #1A73E8;
}

/* 通用渐变背景（多页面复用） */
.bg-gradient-primary {
    background: linear-gradient(135deg, #0F3460 0%, #1A73E8 100%);
}

/* 卡片悬停动画（多页面复用） */
.scholar-card, .contact-card, .stat-card {
    transition: all 0.3s ease;
}
.scholar-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}
.contact-card:hover, .stat-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

/* 图标动画（index.html复用） */
.feature-icon {
    transition: transform 0.3s ease;
}
.feature-card:hover .feature-icon {
    transform: scale(1.1);
}

/* 时间线元素过渡（about.html复用） */
.timeline-item {
    transition: transform 0.3s ease, opacity 0.3s ease;
}

/* 标签页样式（information.html复用） */
.tab-content {
    display: none;
    animation: fadeIn 0.5s ease;
}
.tab-content.active {
    display: block;
}
.nav-tab {
    transition: all 0.3s ease;
}
.nav-tab.active {
    border-color: #1A73E8;
    color: #1A73E8;
    background-color: rgba(26, 115, 232, 0.1);
}

/* 标题层级样式（information.html复用） */
h3 {
    font-size: 1.5rem; /* 24px */
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
}
h4 {
    font-size: 1.25rem; /* 20px */
    margin-top: 1rem;
    margin-bottom: 0.5rem;
}

/* 动画关键帧（information.html复用） */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 联系卡片动画基础样式（contact.html复用） */
.contact-card {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.timeline-item {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.timeline-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.stat-card {
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}

.stat-card.visible {
    opacity: 1;
    transform: scale(1);
}
.stat-number {
    font-variant-numeric: tabular-nums;
}
.stat-counter {
    counter-reset: count 0;
    animation: countUp 2s forwards;
}

/* 导航栏样式优化 */
#navbar {
    background-color: #E8F0FE !important;; /* 淡蓝色背景 */
    transition: all 0.3s ease; /* 平滑过渡效果 */
}

/* 导航链接悬停效果增强 */
.desktop-nav a:hover, .mobile-nav a:hover {
    color: #0D47A1;
    transform: translateY(-1px);
}

/* 页脚样式优化 */
footer {
    background-color: #1E40AF !important; /* 较浅的蓝色，替换原来的深色 */
    background-image: linear-gradient(135deg, #1E40AF 0%, #3B82F6 100%);
}

/* 页脚链接交互效果 */
footer a {
    position: relative;
}

footer a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 1px;
    bottom: -2px;
    left: 0;
    background-color: white;
    transition: width 0.3s ease;
}

footer a:hover::after {
    width: 100%;
}

/* 增强导航栏滚动效果 */
#navbar.scrolled {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}