:root {
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --accent-color: #e74c3c;
    --dark-color: #2c3e50;
    --light-color: #ecf0f1;
    --gray-color: #95a5a6;
    --transition-speed: 0.3s;
    --box-shadow: 0 0.625rem 1.875rem rgba(0, 0, 0, 0.1);
    --gradient-bg: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    /* 基础字体大小，用于rem计算 */
    font-size: 16px;
}

body {
    font-family: 'Roboto', 'Noto Sans SC', sans-serif;
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
    overflow-x: hidden;
    margin: 0;
    padding: 0;
    font-size: 1rem; /* 16px */
}

/* 自定义滚动条 */
::-webkit-scrollbar {
    width: 0.625rem; /* 10px */
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 0.3125rem; /* 5px */
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}

/* 导航栏样式优化 */
.site-header {
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 0.125rem 0.9375rem rgba(0, 0, 0, 0.1); /* 0 2px 15px */
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(0.625rem); /* 10px */
    transition: all var(--transition-speed) ease;
    width: 100vw;
    max-width: 100vw;
    padding: 0;
    margin: 0;
    left: 0;
    right: 0;
    overflow-x: hidden;
    /* 确保移动端菜单能正确定位 */
    position: relative;
}

/* 导航栏平滑过渡效果 */
.site-header, .header-bar {
    transition: all 0.3s ease-in-out;
}

/* collapsed-nav 样式，确保在首页正确显示 */
.site-header.collapsed-nav {
    position: absolute;
    width: 100%;
    background: rgba(255, 255, 255, 0);
    z-index: 999;
}

.header-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.3125rem 0; /* 5px 0 */
    width: 100%;
    margin: 0;
    background: rgba(255, 255, 255, 0.45);
    border-radius: 0;
    box-shadow: 0 0.0625rem 0.3125rem rgba(0, 0, 0, 0.15); /* 0 1px 5px */
}

.site-header .container {
    width: 100%;
    max-width: 100%;
    padding-left: 0;
    padding-right: 0;
    margin: 0;
}

.branding {
    display: flex;
    align-items: center;
    text-decoration: none;
    transition: transform var(--transition-speed);
    flex: 0 0 auto;
    margin-left: 1.25rem; /* 20px */
}

.branding:hover {
    transform: scale(1.05);
}

.logo {
    width: 50px;
    height: 50px;
    margin-right: 10px;
    object-fit: contain; /* 防止图标变形 */
}

.site-title {
    font-size: 1.5rem; /* 24px */
    font-weight: 700;
    color: var(--dark-color);
    margin: 0;
    background: var(--gradient-bg);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0.0625rem 0.125rem rgba(255, 255, 255, 0.5); /* 0 1px 2px */
}

.site-description {
    font-size: 0.875rem; /* 14px */
    color: var(--gray-color);
    text-shadow: 0 0.0625rem 0.0625rem rgba(255, 255, 255, 0.8); /* 0 1px 1px */
}

/* 导航菜单 */
.main-navigation {
    margin-right: 0;
    display: flex;
    justify-content: flex-end;
    flex: 1;
    padding-right: 0;
    width: auto;
    /* 移除相对定位，让移动端菜单相对于site-header定位 */
}

/* 移动端菜单 - 完全独立定位，脱离导航栏约束，但不覆盖导航栏 */
.mobile-navigation {
    display: none;
    position: fixed;
    top: var(--header-height); /* 使用动态计算的导航栏高度 */
    left: 0;
    right: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: 0 0.5rem 1.5rem rgba(0, 0, 0, 0.15);
    z-index: 999;
    border-radius: 0 0 1rem 1rem;
    transform: translateY(-100%);
    opacity: 0;
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    border-top: 2px solid var(--primary-color);
    height: auto;
    min-height: auto;
    max-height: calc(100vh - var(--header-height)); /* 使用动态高度 */
    overflow-y: auto;
    padding-bottom: 1rem;
    padding-left: 0;
    padding-right: 0;
}

.mobile-navigation.show {
    display: block;
    transform: translateY(0);
    opacity: 1;
}

.mobile-navigation .menu {
    display: flex;
    flex-direction: column;
    padding: 1rem 0; /* 适中的垂直内边距 */
    margin: 0;
    list-style: none;
    gap: 0.25rem; /* 菜单项之间的小间距 */
    /* 添加水平容器边距，与页面内容保持一致 */
    max-width: 100%;
    padding-left: 1.25rem; /* 与branding的margin-left保持一致 */
    padding-right: 1.25rem;
}

.mobile-navigation .menu-item {
    margin: 0;
    width: 100%;
    opacity: 0;
    transform: translateY(-10px); /* 轻微的向上位移 */
    animation: slideInDown 0.3s ease forwards; /* 缩短动画时间 */
    overflow: visible;
    flex-shrink: 0;
}

.mobile-navigation .menu-item:nth-child(1) { animation-delay: 0.05s; }
.mobile-navigation .menu-item:nth-child(2) { animation-delay: 0.1s; }
.mobile-navigation .menu-item:nth-child(3) { animation-delay: 0.15s; }
.mobile-navigation .menu-item:nth-child(4) { animation-delay: 0.2s; }
.mobile-navigation .menu-item:nth-child(5) { animation-delay: 0.25s; }

@keyframes slideInDown {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.mobile-navigation .menu-item a {
    padding: 0.875rem 1rem; /* 减少水平内边距 */
    color: var(--dark-color);
    font-weight: 500;
    text-decoration: none;
    display: flex;
    align-items: center;
    border-radius: 0.5rem; /* 适中的圆角 */
    border-left: 0.25rem solid transparent;
    transition: all 0.3s ease;
    position: relative;
    font-size: 1rem; /* 16px - 标准字体大小 */
    min-height: 3rem; /* 适中的最小高度 */
    white-space: nowrap;
    background: transparent;
    margin: 0; /* 移除左右边距，因为容器已有边距 */
    border-bottom: 1px solid rgba(0, 0, 0, 0.05); /* 轻微的分隔线 */
}

.mobile-navigation .menu-item:last-child a {
    border-bottom: none; /* 最后一项不显示分隔线 */
}

.mobile-navigation .menu-item a:hover,
.mobile-navigation .current-menu-item a {
    border-left: 0.25rem solid var(--primary-color);
    background: linear-gradient(135deg, rgba(52, 152, 219, 0.1), rgba(46, 204, 113, 0.05));
    color: var(--primary-color);
    transform: translateX(5px); /* 轻微的右移效果 */
    box-shadow: 0 2px 10px rgba(52, 152, 219, 0.15);
}

.mobile-navigation .menu-item a:active {
    background: linear-gradient(135deg, rgba(52, 152, 219, 0.15), rgba(46, 204, 113, 0.1));
    transform: scale(0.98) translateX(5px);
}

/* 为移动端菜单项添加图标 */
.mobile-navigation .menu-item a::before {
    content: '';
    width: 0.5rem; /* 8px */
    height: 0.5rem; /* 8px */
    border-radius: 50%;
    background-color: var(--gray-color);
    margin-right: 0.75rem; /* 12px */
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.mobile-navigation .menu-item a:hover::before,
.mobile-navigation .current-menu-item a::before {
    background-color: var(--primary-color);
    transform: scale(1.2);
    box-shadow: 0 0 8px rgba(52, 152, 219, 0.4);
}

/* 响应式媒体查询优化 - 下拉菜单适配 */
@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
        margin-right: 1rem;
    }
    
    .main-navigation .menu {
        display: none !important; /* 强制隐藏主导航菜单 */
    }
    
    .mobile-navigation {
        max-height: calc(100vh - 100px);
    }
    
    .mobile-navigation .menu {
        padding-left: 1rem;
        padding-right: 1rem;
        display: block !important; /* 确保移动端菜单可见 */
    }
    
    .mobile-navigation .menu-item a {
        padding: 0.75rem 0.875rem;
        font-size: 0.9375rem;
        min-height: 2.75rem;
    }
    
    .mobile-navigation .menu-item a::before {
        width: 0.4375rem;
        height: 0.4375rem;
        margin-right: 0.625rem;
    }
}

@media (max-width: 576px) {
    .mobile-navigation {
        max-height: calc(100vh - 90px);
    }
    
    .mobile-navigation .menu {
        padding: 0.75rem 0;
        padding-left: 0.75rem; /* 进一步减少容器边距 */
        padding-right: 0.75rem;
    }
    
    .mobile-navigation .menu-item a {
        padding: 0.625rem 0.75rem; /* 调整内边距 */
        font-size: 0.875rem; /* 14px */
        min-height: 2.5rem;
    }
    
    .mobile-navigation .menu-item a::before {
        width: 0.375rem; /* 6px */
        height: 0.375rem;
        margin-right: 0.5rem; /* 8px */
    }
}

/* 超小屏幕优化 */
@media (max-width: 375px) {
    .mobile-navigation {
        max-height: calc(100vh - 80px);
    }
    
    .mobile-navigation .menu {
        padding: 0.5rem 0;
        padding-left: 0.5rem; /* 最小容器边距 */
        padding-right: 0.5rem;
    }
    
    .mobile-navigation .menu-item a {
        padding: 0.5rem 0.625rem; /* 调整内边距 */
        font-size: 0.8125rem; /* 13px */
        min-height: 2.25rem;
    }
    
    .mobile-navigation .menu-item a::before {
        width: 0.3125rem; /* 5px */
        height: 0.3125rem;
        margin-right: 0.375rem; /* 6px */
    }
}

/* 确保全屏菜单在所有情况下都正确显示 */
.mobile-navigation {
    position: fixed !important;
    z-index: 9999 !important;
}

/* 防止菜单被其他元素遮挡 */
.site-header {
    position: relative;
    z-index: 1000;
}

.main-navigation .menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    justify-content: flex-end;
    width: 100%;
}

.main-navigation .menu-item:last-child a {
    margin-right: 0;
    padding-right: 10px !important;
    position: relative;
    right: 0;
}

.main-navigation .menu-item {
    margin: 0 10px;
    position: relative;
}

.main-navigation .menu-item a {
    padding: 0.625rem 1.25rem; /* 10px 20px */
    color: var(--dark-color);
    font-weight: 500;
    text-decoration: none;
    display: block;
    border-radius: 1.875rem; /* 30px */
    transition: all var(--transition-speed);
    min-width: 5rem; /* 80px */
    text-align: center;
    white-space: nowrap;
}

.main-navigation .menu-item a:hover,
.main-navigation .current-menu-item a {
    background: var(--gradient-bg);
    color: white;
    box-shadow: 0 0.25rem 0.625rem rgba(52, 152, 219, 0.3); /* 0 4px 10px */
    transform: translateY(-0.125rem); /* -2px */
}

/* 为当前选中的菜单项添加特殊样式 */
.main-navigation .current-menu-item a {
    position: relative;
    font-weight: 600;
}

/* 为当前选中的菜单项添加标记 */
.main-navigation .current-menu-item a::before {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 50%;
    transform: translateX(-50%);
    width: 6px;
    height: 6px;
    background-color: white;
    border-radius: 50%;
    box-shadow: 0 0 8px rgba(255, 255, 255, 0.8);
}

/* 增强导航菜单项悬停效果 */
.main-navigation .menu-item a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 0.125rem; /* 2px */
    background-color: white;
    transition: all 0.3s ease;
    transform: translateX(-50%);
    opacity: 0;
}

.main-navigation .menu-item a:hover::after,
.main-navigation .current-menu-item a::after {
    width: 70%;
    opacity: 1;
    box-shadow: 0 0 0.3125rem rgba(255, 255, 255, 0.5); /* 0 0 5px */
}

/* 菜单切换按钮 */
.menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;         /* 建议与导航高度一致 */
    height: 44px;
    padding: 0;          /* 去除多余内边距 */
    background: transparent;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: background 0.3s, transform 0.3s;
    position: relative;
    font-size: 24px;     /* 让图标大小适中 */
    line-height: 1;      /* 避免行高影响垂直居中 */
}

.menu-toggle:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.menu-toggle:active {
    transform: scale(0.95);
}

/* 汉堡菜单图标动画 */
.menu-toggle .fa-bars {
    font-size: 24px;     /* 明确指定图标大小 */
    line-height: 1;      /* 避免字体行高影响 */
    margin: 0;           /* 去除默认外边距 */
    display: block;      /* 保证flex下居中 */
}

.menu-toggle.active .fa-bars {
    transform: rotate(90deg);
}

/* 进度阅读滚动条 */
.progress-container {
    position: fixed;
    top: 0;
    width: 100%;
    height: 0.25rem; /* 4px */
    z-index: 1001;
}

.progress-bar {
    height: 0.25rem; /* 4px */
    background: var(--gradient-bg);
    width: 0%;
    box-shadow: 0 0 0.625rem rgba(52, 152, 219, 0.5); /* 0 0 10px */
}

/* 回到顶部按钮 */
.scroll-top {
    position: fixed;
    bottom: 1.875rem; /* 30px */
    right: 1.875rem; /* 30px */
    width: 3.125rem; /* 50px */
    height: 3.125rem; /* 50px */
    background: var(--gradient-bg);
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-speed);
    box-shadow: 0 0.1875rem 0.9375rem rgba(52, 152, 219, 0.3); /* 0 3px 15px */
    z-index: 1000;
}

.scroll-top.active {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    transform: translateY(-0.3125rem); /* -5px */
    box-shadow: 0 0.3125rem 1.25rem rgba(52, 152, 219, 0.5); /* 0 5px 20px */
}

/* 容器样式 */
.container {
    width: 90%;
    max-width: 75rem; /* 1200px */
    margin: 0 auto;
    padding: 0 0.625rem; /* 0 10px */
}

/* 轮播图/hero区域 */
.hero {
    position: relative;
    overflow: hidden;
    margin-bottom: 3.125rem; /* 50px */
    height: 800px; /* 默认高度 500px + 300px */
}

.slides {
    list-style: none;
    margin: 0;
    padding: 0;
    position: relative;
    height: 100%;
}

.slides li {
    position: relative;
    height: 100%;
    width: 100%;
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 遮罩层样式 */
.slides li:before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, rgba(0,0,0,0.4), rgba(0,0,0,0.7));
    z-index: 1;
}

/* 轮播图文字内容 */
.slide-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: white;
    width: 90%;
    max-width: 50rem; /* 800px */
    padding: 2rem;
    margin: 0 auto;
    opacity: 1 !important;
    transform: none !important;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.slide-title {
    font-size: 3rem; /* 48px */
    font-weight: 700;
    margin-bottom: 1.25rem; /* 20px */
    line-height: 1.2;
    color: white;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.slide-content p {
    font-size: 1.25rem; /* 20px */
    margin-bottom: 1.875rem; /* 30px */
    line-height: 1.6;
    color: white;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
    max-width: 90%;
}

/* 研究方向卡片 */
.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.875rem; /* 30px */
    margin-bottom: 3.125rem; /* 50px */
}

.research-item {
    position: relative;
}

.research-card {
    display: block;
    border-radius: 0.9375rem; /* 15px */
    overflow: hidden;
    background: white;
    box-shadow: var(--box-shadow);
    height: 100%;
    transition: all var(--transition-speed);
}

.research-card:hover {
    transform: translateY(-0.3125rem); /* -5px */
    box-shadow: 0 0.9375rem 2.1875rem rgba(0, 0, 0, 0.15); /* 0 15px 35px */
}

.research-image-container {
    position: relative;
    width: 100%;
    height: 12.5rem; /* 200px */
    overflow: hidden;
}

.research-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.research-card:hover .research-image {
    transform: scale(1.1);
}

.research-badge {
    position: absolute;
    top: 0.9375rem; /* 15px */
    right: 0.9375rem; /* 15px */
    background: var(--gradient-bg);
    color: white;
    padding: 0.3125rem 0.625rem; /* 5px 10px */
    border-radius: 1.25rem; /* 20px */
    font-size: 0.75rem; /* 12px */
    font-weight: 500;
    box-shadow: 0 0.25rem 0.625rem rgba(52, 152, 219, 0.3); /* 0 4px 10px */
}

.research-content {
    padding: 1.25rem; /* 20px */
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.research-title {
    font-size: 1.25rem; /* 20px */
    font-weight: 700;
    margin-bottom: 0.625rem; /* 10px */
}

.research-desc {
    color: var(--gray-color);
    margin-bottom: 1.25rem; /* 20px */
    font-size: 0.9375rem; /* 15px */
    flex-grow: 1;
}

.research-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
}

.research-tag {
    color: var(--primary-color);
    font-size: 0.8125rem; /* 13px */
    font-weight: 500;
}

.research-more {
    color: var(--dark-color);
    font-weight: 500;
    font-size: 0.875rem; /* 14px */
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    transition: all var(--transition-speed);
    border-bottom: 0.0625rem solid transparent; /* 1px */
}

/* 响应式调整 */
@media (max-width: 992px) {
    .hero {
        height: 700px; /* 400px + 300px */
    }
    
    .slide-content {
        padding: 1.5rem;
    }
    
    .slide-title {
        font-size: 2.5rem; /* 40px */
        margin-bottom: 1rem;
    }
    
    .slide-content p {
        font-size: 1.125rem; /* 18px */
        margin-bottom: 1.25rem;
    }
}

@media (max-width: 768px) {
    .hero {
        height: 650px; /* 350px + 300px */
    }
    
    .slide-content {
        padding: 1.25rem;
        width: 95%;
    }
    
    .slide-title {
        font-size: 2rem; /* 32px */
        margin-bottom: 0.875rem;
    }
    
    .slide-content p {
        font-size: 1rem; /* 16px */
        margin-bottom: 1rem;
        line-height: 1.5;
    }
}

@media (max-width: 576px) {
    .hero {
        height: 600px; /* 300px + 300px */
        margin-bottom: 2rem;
    }
    
    .slide-content {
        padding: 1rem;
        padding-bottom: 3rem; /* 为导航点留出空间 */
    }
    
    .slide-title {
        font-size: 1.5rem; /* 24px */
        margin-bottom: 0.75rem;
    }
    
    .slide-content p {
        font-size: 0.875rem; /* 14px */
        margin-bottom: 0.75rem;
        line-height: 1.4;
    }
    
    /* 调整导航点位置 */
    .hero .flex-control-nav {
        bottom: 10px;
    }
    
    /* 调整箭头按钮位置 */
    .hero .flex-direction-nav {
        padding: 0 10px;
    }
}

@media (max-width: 375px) {
    .hero {
        height: 550px; /* 250px + 300px */
    }
    
    .slide-content {
        padding: 0.75rem;
        padding-bottom: 2.5rem;
    }
    
    .slide-title {
        font-size: 1.25rem; /* 20px */
        margin-bottom: 0.5rem;
    }
    
    .slide-content p {
        font-size: 0.8125rem; /* 13px */
        margin-bottom: 0.5rem;
        line-height: 1.3;
    }
    
    /* 进一步调整导航点 */
    .hero .flex-control-nav {
        bottom: 5px;
        padding: 3px 10px;
    }
    
    .hero .flex-control-nav li a {
        width: 6px;
        height: 6px;
    }
}

/* 通用响应式图片 */
img, video, iframe {
    max-width: 100%;
    height: auto;
}

/* 确保内容不会溢出 */
.site-content {
    overflow-x: hidden;
    width: 100%;
    position: relative;
}

/* 增强触摸设备体验 */
@media (hover: none) {
    .research-card:hover {
        transform: none;
    }
    
    .research-card:active {
        transform: translateY(-0.3125rem); /* -5px */
    }
}

/* 自定义滚动条 */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}

/* 新闻列表样式 */
.news-section {
    padding: 50px 0;
}

.news-container {
    max-width: 1200px;
    margin: 0 auto;
}

.news-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr); /* 每行显示2篇新闻 */
    grid-gap: 30px;
    margin-bottom: 40px;
}

.news-item {
    display: flex;
    flex-direction: column;
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--box-shadow);
    transition: all var(--transition-speed);
    height: 100%;
}

.news-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

.news-image {
    position: relative;
    overflow: hidden;
    height: 200px; /* 固定图片高度 */
}

.news-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.news-item:hover .news-image img {
    transform: scale(1.1);
}

.news-content {
    flex: 1;
    padding: 20px;
    display: flex;
    flex-direction: column;
}

.news-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--dark-color);
    line-height: 1.4;
}

.news-meta {
    display: flex;
    gap: 15px;
    margin-bottom: 12px;
    color: var(--gray-color);
    font-size: 14px;
}

.news-date {
    display: flex;
    align-items: center;
}

.news-date:before {
    content: '\f073';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    margin-right: 5px;
}

.news-category {
    display: flex;
    align-items: center;
}

.news-category:before {
    content: '\f02b';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    margin-right: 5px;
}

.news-excerpt {
    margin-bottom: 15px;
    color: #555;
    line-height: 1.6;
    flex-grow: 1; /* 让摘要占据剩余空间 */
}

.news-more {
    display: inline-block;
    color: var(--primary-color);
    font-weight: 500;
    text-decoration: none;
    transition: all var(--transition-speed);
    position: relative;
    align-self: flex-start; /* 保持在底部 */
    margin-top: auto; /* 推到底部 */
}

.news-more:after {
    content: '\f061';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    margin-left: 5px;
    transition: transform 0.3s ease;
    display: inline-block;
}

.news-more:hover {
    color: var(--secondary-color);
}

.news-more:hover:after {
    transform: translateX(5px);
}

/* 分页控件样式 */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 5px;
    margin-top: 40px;
}

.pagination .page-link {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: white;
    color: var(--dark-color);
    text-decoration: none;
    font-weight: 500;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
    transition: all var(--transition-speed);
}

.pagination .page-link:hover {
    background: linear-gradient(135deg, rgba(52, 152, 219, 0.1), rgba(46, 204, 113, 0.1));
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
}

.pagination .page-link.active {
    background: var(--gradient-bg);
    color: white;
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3);
}

.pagination .next,
.pagination .last {
    font-weight: bold;
}

/* 研究方向卡片链接样式 */
.research-card-link {
    text-decoration: none;
    color: inherit;
    display: block;
    width: 100%;
    height: 100%;
    transition: all 0.3s ease;
}

.research-card-link:hover {
    text-decoration: none;
    color: inherit;
}

.research-card-link:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.3);
    border-radius: 12px;
}

/* 研究方向卡片布局 */
.research-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr); /* 修改为2列布局 */
    gap: 30px;
    margin-top: 40px;
}

.research-item {
    transition: all 0.3s ease;
}

.research-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    height: 100%;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.research-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.research-image-container {
    position: relative;
    overflow: hidden;
    height: 180px;
}

.research-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.research-card:hover .research-image {
    transform: scale(1.1);
}

.research-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: var(--gradient-bg);
    color: white;
    padding: 5px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
    box-shadow: 0 3px 10px rgba(52, 152, 219, 0.3);
}

.research-content {
    padding: 20px;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.research-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--dark-color);
}

.research-desc {
    color: #555;
    margin-bottom: 20px;
    flex-grow: 1;
    font-size: 14px;
    line-height: 1.6;
}

.research-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
}

.research-tag {
    background: rgba(52, 152, 219, 0.1);
    color: var(--primary-color);
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
}

.research-more {
    color: var(--primary-color);
    font-weight: 500;
    font-size: 14px;
    position: relative;
    transition: all 0.3s ease;
    border-bottom: 1px solid transparent;
}

/* 媒体查询 - 研究方向卡片响应式布局 */
@media (max-width: 992px) {
    .research-grid {
        grid-template-columns: repeat(2, 1fr); /* 保持2列布局 */
        gap: 20px;
    }
    
    .news-list {
        grid-template-columns: 1fr; /* 平板设备上单列显示 */
    }
    
    .news-title {
        font-size: 16px;
    }
    
    .news-image {
        height: 180px;
    }
}

@media (max-width: 768px) {
    .research-grid {
        grid-template-columns: 1fr; /* 单列布局 */
        gap: 15px;
    }
    
    .research-image-container {
        height: 160px; /* 减小图片高度 */
    }
}

/* 响应式设计 */
@media (max-width: 576px) {
    .news-meta {
        flex-direction: column;
        gap: 5px;
    }
    
    /* 页面边距优化 */
    .container {
        padding-left: 15px;
        padding-right: 15px;
    }
    
    /* 页头部分更紧凑 */
    .header-bar {
        padding: 3px 0;
    }
    
    /* 轮播图内容进一步适配 */
    .slide-content {
        max-width: 100%;
        padding: 0 15px;
    }
    
    .slide-content h2 {
        font-size: 20px;
    }
    
    /* 回到顶部按钮缩小 */
    .scroll-top {
        width: 40px;
        height: 40px;
        bottom: 20px;
        right: 20px;
    }
    
    /* 研究方向卡片标题适配 */
    .research-title {
        font-size: 16px;
    }
    
    .research-desc {
        font-size: 14px;
    }
    
    /* 新闻项更紧凑 */
    .news-content {
        padding: 15px;
    }
    
    .news-excerpt {
        font-size: 14px;
    }
}

/* 适配超小屏幕设备 */
@media (max-width: 375px) {
    .site-title {
        font-size: 18px;
    }
    
    .site-description {
        display: none; /* 隐藏描述文字 */
    }
    
    .logo {
        width: 50px;
        height: 50px;
        margin-right: 10px;
        object-fit: contain; /* 防止图标变形 */
    }
    
    .news-title {
        font-size: 15px;
    }
    
    /* 更紧凑的标题 */
    .section-heading {
        font-size: 20px;
        margin-bottom: 15px;
    }
    
    /* 分页按钮缩小 */
    .pagination .page-link {
        width: 30px;
        height: 30px;
        font-size: 12px;
    }
}

/* 确保内容不超出容器 */
img, video, iframe {
    max-width: 100%;
    height: auto;
}

/* 添加视口控制，防止缩放问题 */
@viewport {
    width: device-width;
    zoom: 1.0;
}

/* 幻灯片和轮播图样式 */
.hero {
    position: relative;
    margin-top: 0; /* 保持为0，避免负margin导致内容被导航栏遮挡 */
    margin-bottom: 50px;
}

.slides {
    list-style: none;
    padding: 0;
    margin: 0;
    position: relative;
}

.slides li {
    position: relative;
    height: 500px;
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    padding-top: 90px; /* 添加顶部内边距，为导航栏留出空间 */
}

.slides li:before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
}

.slide-content {
    position: relative;
    z-index: 2;
    max-width: 700px;
    color: white;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.slide-title {
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 20px;
}

.slide-content p {
    font-size: 18px;
    line-height: 1.8;
    margin-bottom: 30px;
}

/* 媒体查询 - 针对轮播图的响应式适配 */
@media (max-width: 992px) {
    .slides li {
        height: 400px;
    }
    
    .slide-title {
        font-size: 32px;
    }
    
    .slide-content p {
        font-size: 16px;
    }
}

@media (max-width: 768px) {
    .slides li {
        height: 350px;
    }
    
    .slide-title {
        font-size: 28px;
    }
    
    .slide-content p {
        font-size: 14px;
    }
}

@media (max-width: 576px) {
    .slides li {
        height: 300px;
    }
    
    .slide-title {
        font-size: 24px;
    }
    
    .slide-content p {
        font-size: 14px;
        line-height: 1.6;
    }
    
    .hero {
        margin-bottom: 30px;
    }
}

@media (max-width: 375px) {
    .slides li {
        height: 250px;
    }
    
    .slide-title {
        font-size: 20px;
        margin-bottom: 10px;
    }
    
    .slide-content p {
        font-size: 13px;
        line-height: 1.5;
    }
}

/* 页面加载动画 */
.site-content {
    opacity: 0;
    animation: fadeIn 0.5s ease-in-out forwards;
    animation-delay: 0.1s; /* 减少延迟时间，让页面更快显示 */
}

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

/* 图片延迟加载效果 */
.lazy {
    opacity: 0;
    transition: opacity 0.5s ease-in-out;
}

img.lazy.loaded {
    opacity: 1;
}

/* 页面平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 新闻项和研究方向卡片悬停效果优化 */
.news-item, .research-card {
    transition: transform 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94),
                box-shadow 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    will-change: transform, box-shadow;
}

/* 响应式图片 */
.responsive-img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* 移动设备上的触摸优化 */
@media (hover: none) {
    .news-item:hover, .research-card:hover {
        transform: none;
    }
    
    .news-item:active, .research-card:active {
        transform: scale(0.98);
    }
}

/* 确保内容不超出容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
    box-sizing: border-box;
}

/* 防止移动设备上的字体过小 */
@media (max-width: 576px) {
    html {
        font-size: 16px; /* 确保基础字体大小合适 */
    }
    
    .container {
        padding: 0 10px; /* 减少边距以增加内容空间 */
    }
}

/* 修复浏览器兼容性问题 */
* {
    -webkit-tap-highlight-color: transparent; /* 移除移动设备上点击时的高亮 */
}

input, 
textarea, 
button, 
select, 
a {
    -webkit-tap-highlight-color: transparent;
}

/* 添加打印媒体查询 */
@media print {
    .site-header, 
    .progress-container, 
    .scroll-top, 
    .mobile-navigation {
        display: none !important;
    }
    
    .site-content {
        opacity: 1;
        animation: none;
    }
    
    body {
        background: white;
        color: black;
    }
}

/* 屏幕阅读器专用样式 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Body状态样式已移除，因为直接展示菜单不需要锁定页面滚动 */

/* 紧凑模式 - 当菜单项较多时自动启用 */
.mobile-navigation.compact-mode .menu {
    padding: 0.25rem 0; /* 进一步减小垂直内边距 */
}

.mobile-navigation.compact-mode .menu-item a {
    padding: 0.4rem 1rem; /* 紧凑的内边距 */
    font-size: 0.8125rem; /* 13px */
    min-height: 2rem; /* 紧凑的高度 */
}

.mobile-navigation.compact-mode .menu-item a:hover,
.mobile-navigation.compact-mode .current-menu-item a {
    padding-left: 1.25rem; /* 20px */
}

.mobile-navigation.compact-mode .menu-item a::before {
    width: 0.375rem; /* 6px */
    height: 0.375rem; /* 6px */
    margin-right: 0.5rem; /* 8px */
}

/* 确保紧凑模式下的边框也相应调整 */
.mobile-navigation.compact-mode .menu-item a {
    border-bottom: 1px solid rgba(0, 0, 0, 0.03);
}

.mobile-navigation.compact-mode .menu-item:last-child a {
    border-bottom: none;
}

/* 超紧凑模式 - 针对极小屏幕 */
@media (max-width: 320px) {
    .mobile-navigation .menu-item a {
        padding: 0.35rem 0.5rem;
        font-size: 0.7rem; /* 11px */
        min-height: 1.8rem;
    }
    
    .mobile-navigation .menu-item a:hover,
    .mobile-navigation .current-menu-item a {
        padding-left: 0.75rem; /* 12px */
    }
    
    .mobile-navigation .menu-item a::before {
        width: 0.25rem; /* 4px */
        height: 0.25rem; /* 4px */
        margin-right: 0.375rem; /* 6px */
    }
}

/* 确保菜单在所有情况下都完全可见的额外保障 */
.mobile-navigation {
    position: absolute !important;
    overflow: visible !important;
    max-height: none !important;
    height: auto !important;
}

/* 防止菜单被截断 */
.site-header {
    position: relative;
    z-index: 1000;
}

.mobile-navigation {
    z-index: 1001;
}

/* 轮播图样式增强 - 确保与SimpleSlider插件兼容 */
.hero {
    position: relative;
    overflow: hidden;
    margin-bottom: 50px;
    height: 500px; /* 默认高度 */
}

.hero .slides {
    position: relative;
    width: 100%;
    height: 100%;
    list-style: none;
    margin: 0;
    padding: 0;
}

.hero .slides li {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0;
    transition: opacity 0.8s ease-in-out;
}

.hero .slides li:first-child {
    opacity: 1;
}

/* 轮播图遮罩层 */
.hero .slides li:before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, rgba(0,0,0,0.0), rgba(0,0,0,0));
    z-index: 1;
}

/* 轮播图内容 */
.hero .slide-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: white;   
    max-width: 800px;
    padding: 0 20px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.hero .slide-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero .slide-content p {
    font-size: 20px;
    line-height: 1.6;
    margin-bottom: 30px;
}

/* 导航点样式 */
.hero .flex-control-nav {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    list-style: none;
    margin: 0;
    padding: 5px 15px;
    z-index: 3;
    background: none; /* 移除背景色 */
    border-radius: 20px;
}

.hero .flex-control-nav li {
    margin: 0;
}

.hero .flex-control-nav li a {
    display: block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    text-indent: -9999px;
    transition: all 0.3s ease;
    cursor: pointer;
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.2); /* 添加轻微阴影 */
}

.hero .flex-control-nav li a:hover,
.hero .flex-control-nav li a.flex-active {
    background: white;
    transform: scale(1.2);
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

/* 左右箭头样式 */
.hero .flex-direction-nav {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    transform: translateY(-50%);
    display: flex;
    justify-content: space-between;
    list-style: none;
    margin: 0;
    padding: 0 30px;
    pointer-events: none;
    z-index: 10;
    opacity: 0; /* 默认隐藏 */
    transition: opacity 0.3s ease; /* 添加过渡效果 */
}

.hero:hover .flex-direction-nav {
    opacity: 1; /* 鼠标悬停时显示 */
}

.hero .flex-direction-nav li {
    pointer-events: auto;
}

.hero .flex-direction-nav a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: rgba(0, 0, 0, 0.3);
    color: white;
    text-decoration: none;
    border-radius: 50%;
    transition: all 0.3s ease;
    position: relative;
}

.hero .flex-direction-nav a:before {
    content: '';
    width: 10px;
    height: 10px;
    border-top: 2px solid white;
    border-right: 2px solid white;
    position: absolute;
}

.hero .flex-direction-nav a.flex-prev:before {
    transform: rotate(-135deg);
    margin-left: 4px;
}

.hero .flex-direction-nav a.flex-next:before {
    transform: rotate(45deg);
    margin-right: 4px;
}

.hero .flex-direction-nav a:hover {
    background: rgba(0, 0, 0, 0.6);
    transform: scale(1.1);
}

.hero .flex-direction-nav a:active {
    transform: scale(0.95);
}

/* 响应式轮播图样式 */
@media (max-width: 992px) {
    .hero {
        height: 700px; /* 400px + 300px */
    }
    
    .hero .slide-title {
        font-size: 36px;
    }
    
    .hero .slide-content p {
        font-size: 18px;
    }
    
    .hero .flex-direction-nav a {
        width: 40px;
        height: 40px;
        font-size: 20px;
    }
}

@media (max-width: 768px) {
    .hero {
        height: 650px; /* 350px + 300px */
    }
    
    .hero .slide-title {
        font-size: 28px;
    }
    
    .hero .slide-content p {
        font-size: 16px;
    }
    
    .hero .flex-direction-nav {
        padding: 0 15px;
    }
    
    .hero .flex-direction-nav a {
        width: 36px;
        height: 36px;
    }
    
    .hero .flex-direction-nav a:before {
        width: 8px;
        height: 8px;
    }
}

@media (max-width: 576px) {
    .hero {
        height: 600px; /* 300px + 300px */
    }
    
    .hero .slide-title {
        font-size: 24px;
        margin-bottom: 15px;
    }
    
    .hero .slide-content p {
        font-size: 14px;
        margin-bottom: 20px;
    }
    
    .hero .flex-control-nav {
        bottom: 10px;
        padding: 3px 10px;
    }
    
    .hero .flex-control-nav li a {
        width: 6px;
        height: 6px;
    }
    
    .hero .flex-direction-nav {
        padding: 0 10px;
    }
    
    .hero .flex-direction-nav a {
        width: 32px;
        height: 32px;
    }
    
    .hero .flex-direction-nav a:before {
        width: 7px;
        height: 7px;
    }
}

@media (max-width: 375px) {
    .hero {
        height: 550px; /* 250px + 300px */
    }
    
    .hero .slide-title {
        font-size: 20px;
        margin-bottom: 10px;
    }
    
    .hero .slide-content p {
        font-size: 13px;
        margin-bottom: 15px;
    }
}

/* 轮播图加载动画 */
.hero .slides li {
    opacity: 0;
    transition: opacity 0.8s ease-in-out;
}

.hero .slides li.active {
    opacity: 1;
}

/* 防止轮播图在加载时闪烁 */
.hero.loading .slides li:not(:first-child) {
    display: none;
}

/* 轮播图性能优化 */
.hero .slides li {
    will-change: opacity;
    backface-visibility: hidden;
    transform: translateZ(0);
}

/* 确保轮播图在所有设备上正确显示 */
.hero {
    min-height: 250px;
    max-height: 600px;
}

/* 触摸设备优化 */
@media (hover: none) {
    .hero .flex-direction-nav a:hover {
        transform: none;
        background: rgba(0, 0, 0, 0.5);
    }
    
    .hero .flex-direction-nav a:active {
        background: rgba(0, 0, 0, 0.8);
        transform: scale(0.95);
    }
}

/* 确保文字内容始终可见 */
.slide-content .slide-title,
.slide-content p {
    margin-left: auto;
    margin-right: auto;
    max-width: 90%;
    opacity: 1 !important;
}

@media (max-width: 576px) {
    .menu-toggle {
        width: 38px;
        height: 38px;
        font-size: 20px;
    }
    .menu-toggle .fa-bars {
        font-size: 20px;
    }
}