/* ===============================================
   增强样式 - 特效和动画
   =============================================== */

/* CSS 变量 */
:root {
    --primary-blue: #1a5490;
    --accent-blue: #2980b9;
    --light-blue: #3498db;
    --shadow-sm: 0 2px 8px rgba(26, 84, 144, 0.1);
    --shadow-md: 0 4px 16px rgba(26, 84, 144, 0.15);
    --shadow-lg: 0 8px 32px rgba(26, 84, 144, 0.2);
    --duration: 0.4s;
    --timing: cubic-bezier(0.4, 0, 0.2, 1);
    --ease: var(--duration) var(--timing);
}

/* 字体 */
html {
    overflow-y: scroll;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

.header h1, .page-header h1, .section-header h2, .overview-text h2 {
    font-family: 'Noto Serif SC', 'SimSun', serif;
    font-weight: 600;
    letter-spacing: 0.05em;
}

/* 动画定义 */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideInLeft {
    from { opacity: 0; transform: translateX(-50px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
    from { opacity: 0; transform: translateX(50px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes bannerReveal {
    from {
        opacity: 0;
        transform: scale(1.02);
        clip-path: inset(5% 10% 5% 10%);
    }
    to {
        opacity: 1;
        transform: scale(1);
        clip-path: inset(0% 0% 0% 0%);
    }
}

@keyframes bannerShine {
    from {
        left: -100%;
    }
    to {
        left: 100%;
    }
}

/* 背景装饰 */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(41, 128, 185, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(26, 84, 144, 0.03) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

main, header, nav, footer { position: relative; z-index: 1; }

/* 头部 */
.header {
    background: #fff;
    box-shadow: var(--shadow-sm);
}

.header-content { opacity: 0; }
.header h1, .header .subtitle { opacity: 0; }

body.content-loaded .header-content { animation: fadeInUp 0.6s var(--timing) forwards; }
body.content-loaded .header h1 { animation: fadeInUp 0.6s var(--timing) 0.1s forwards; }
body.content-loaded .header .subtitle { animation: fadeInUp 0.6s var(--timing) 0.2s forwards; }

/* The shared header stays visible between pages in the same language. */
html[data-header-motion="skip"] body .header-content,
html[data-header-motion="skip"] body .header h1,
html[data-header-motion="skip"] body .header .subtitle {
    opacity: 1;
    transform: none;
    animation: none;
}

.header h1 {
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-logo { transition: transform var(--ease); }
.header-logo:hover { transform: scale(1.05); }

/* 导航栏 */
.navbar {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
}


/* 轮播图 */
.banner {
    box-shadow: var(--shadow-md);
    opacity: 0;
    position: relative;
    overflow: hidden;
}

body.content-loaded .banner {
    animation: bannerReveal 1s var(--timing) 0.2s forwards;
}

/* 轮播图光泽效果 */
body.content-loaded .banner::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.15),
        transparent
    );
    z-index: 10;
    pointer-events: none;
    animation: bannerShine 1.2s var(--timing) 0.8s forwards;
}

.banner-dots .dot {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    transition: all var(--ease);
}

.banner-prev, .banner-next {
    backdrop-filter: blur(5px);
    transition: all var(--ease);
}

/* 主内容区 */
.main-content {
    position: relative;
    min-height: 100vh;
}

body.content-loaded .main-content { min-height: calc(100vh - 350px); }

/* 课题组介绍 */
.overview-card {
    background: linear-gradient(135deg, #fff, #f8f9fa);
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(26, 84, 144, 0.08);
    transition: all var(--ease);
    opacity: 0;
}

body.content-loaded .overview-card { animation: fadeInUp 0.6s var(--timing) 0.3s forwards; }

.overview-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.overview-image { overflow: hidden; border-radius: 8px; }
.overview-image img { transition: transform var(--ease); }
.overview-image:hover img { transform: scale(1.05); }

/* 内容区域入场 */
.col-left, .col-right { opacity: 0; }
.col-right > * { opacity: 0; }

body.content-loaded .col-left { animation: slideInLeft 0.6s var(--timing) 0.4s forwards; }
body.content-loaded .col-right { animation: slideInRight 0.6s var(--timing) 0.4s forwards; }
body.content-loaded .col-right > *:nth-child(1) { animation: fadeInUp 0.6s var(--timing) 0.5s forwards; }
body.content-loaded .col-right > *:nth-child(2) { animation: fadeInUp 0.6s var(--timing) 0.7s forwards; }

/* 内容页面 */
.content-page { opacity: 0; }
body.content-loaded .content-page { animation: fadeInUp 0.6s var(--timing) 0.3s forwards; }

/* 文章区块 */
.article-section, .quick-links {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(26, 84, 144, 0.08);
    transition: all var(--ease);
}

.article-section:hover, .quick-links:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

/* 新闻列表 */
.news-list-item {
    position: relative;
    transition: all var(--ease);
}

.news-list-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 0;
    background: linear-gradient(180deg, var(--accent-blue), var(--light-blue));
    transition: height var(--ease);
}

.news-list-item:hover::before { height: 80%; }
.news-list-item:hover .date-box .day { transform: scale(1.1); color: var(--accent-blue); }

.date-box .day { transition: all var(--ease); }

/* 研究方向卡片 */
.research-card {
    background: linear-gradient(145deg, #fff, #f8f9fa);
    box-shadow: var(--shadow-sm);
    transition: all var(--ease);
}

.research-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-lg);
}

/* 组员卡片 */
.member-card {
    background: linear-gradient(145deg, #fff, #fafafa);
    box-shadow: var(--shadow-sm);
    transition: all var(--ease);
    overflow: hidden;
}

.member-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-blue), var(--accent-blue), var(--light-blue));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--ease);
}

.member-card:hover::before { transform: scaleX(1); }
.member-card:hover { transform: translateY(-10px); box-shadow: var(--shadow-lg); }

.member-photo { overflow: hidden; border-radius: 8px; }
.member-photo img { transition: transform var(--ease); }
.member-card:hover .member-photo img { transform: scale(1.1); }
.member-card:hover .member-name { color: var(--accent-blue); }

/* 论文卡片 */
.paper-item {
    background: linear-gradient(145deg, #fff, #fafafa);
    border: 1px solid rgba(26, 84, 144, 0.08);
    transition: all var(--ease);
}

.paper-item:hover {
    border-color: rgba(41, 128, 185, 0.2);
    box-shadow: var(--shadow-md);
}

.year-group {
    background: linear-gradient(145deg, #f9f9f9, #fff);
}

/* 侧边栏 */
.sidebar-sticky {
    background: linear-gradient(145deg, #fff, #f8f9fa);
    box-shadow: var(--shadow-md);
}

.toc-item { transition: all var(--ease); }
.toc-item:hover { background: rgba(41, 128, 185, 0.1); }
.toc-item.active { background: rgba(26, 84, 144, 0.1); }

/* 联系信息 */
.contact-info {
    background: linear-gradient(145deg, #f9f9f9, #fff);
    box-shadow: var(--shadow-sm);
}

.contact-item { transition: all var(--ease); border-radius: 5px; }
.contact-item:hover { background: rgba(41, 128, 185, 0.05); transform: translateX(10px); }

/* 介绍文本 */
.intro-text {
    background: linear-gradient(135deg, #f9f9f9, #fff);
}

/* 分页 */
.pagination-btn {
    background: linear-gradient(145deg, #fff, #f8f9fa);
    box-shadow: var(--shadow-sm);
    transition: all var(--ease);
}

.pagination-btn:hover, .pagination-btn.active {
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-blue));
    color: #fff;
    box-shadow: var(--shadow-md);
}

/* 更多链接 */
.more-link {
    position: relative;
    padding-right: 20px;
    transition: all var(--ease);
}

.more-link::after {
    content: '→';
    position: absolute;
    right: 0;
    transition: all var(--ease);
}

.more-link:hover { padding-right: 25px; }
.more-link:hover::after { right: -5px; }

/* 返回顶部 */
.go-top {
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-blue));
    box-shadow: 0 4px 20px rgba(26, 84, 144, 0.3);
}

.go-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 30px rgba(26, 84, 144, 0.4);
}

/* 页脚 */
.footer {
    background: linear-gradient(135deg, var(--primary-blue), #0d3a6f);
}

.footer-links a { transition: all var(--ease); }
.footer-links a:hover { transform: translateY(-2px); }



/* 文字选中 */
::selection { background: rgba(41, 128, 185, 0.3); }

/* 焦点样式 */
a:focus-visible, button:focus-visible {
    outline: 2px solid var(--accent-blue);
    outline-offset: 2px;
}


/* 打印 */
@media print {
    .go-top, .banner, .navbar { display: none !important; }
    body::before { display: none !important; }
    * { animation: none !important; }
}

/* Keep the requested page-entry effects enabled; print remains static. */
@media print {
  .header-content, .header h1, .header .subtitle, .banner, .overview-card, .col-left, .col-right, .col-right > *, .content-page { opacity: 1 !important; animation: none !important; transform: none !important; }
}