/* =========================================
   基础重置 (Reset & Base)
   ========================================= */
   * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* IE11 HTML5 元素兼容 */
article, aside, details, figcaption, figure, footer, header, main, nav, section, summary {
    display: block;
}

body {
    font-family: "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s;
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* =========================================
   通用工具类 (Utilities)
   ========================================= */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
}

.section {
    padding: 40px 0; /* PC端间距从 60px 减小到 40px */
}

.section-header {
    text-align: center;
    margin-bottom: 40px; /* 标题下间距从 60px 减小到 40px */
    position: relative;
    padding: 10px;
    cursor: default;
    
    /* 滚动入场动画初始状态 */
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1), 
                transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}

.section-header.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.section-header h2 {
    font-size: 38px; /* 微调字号 */
    margin-bottom: 18px;
    color: #004a99; /* 新华蓝 */
    font-weight: 800;
    letter-spacing: -0.5px;
    position: relative;
    display: inline-block;
    transition: transform 0.3s ease, color 0.3s ease, text-shadow 0.3s ease;
}

/* 悬停特效：文字上浮与光晕 */
.section-header:hover h2 {
    transform: translateY(-2px);
    color: #005bb5;
    text-shadow: 0 4px 12px rgba(0, 74, 153, 0.15);
}

/* 点击反馈：微缩 */
.section-header:active h2 {
    transform: scale(0.98);
}

.header-line {
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, #004a99, #0072e5); /* 渐变色线条 */
    margin: 0 auto;
    border-radius: 2px;
    position: relative;
    transition: width 0.4s cubic-bezier(0.34, 1.56, 0.64, 1), 
                box-shadow 0.3s ease,
                background 0.3s ease;
}

/* 悬停特效：线条展开 */
.section-header:hover .header-line {
    width: 120px;
    box-shadow: 0 4px 8px rgba(0, 74, 153, 0.25);
}

/* 专家库背景重置为白色 */
.experts-section {
    background-color: #fff;
}

/* 行业动态背景改为灰色 */
.news-section {
    background-color: #f7f8fa;
}

/* 占位图样式 */
.placeholder-img {
    background-color: #eee;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #999;
    font-size: 14px;
    position: relative;
    overflow: hidden;
}

.placeholder-img::after {
    content: attr(data-text);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

/* =========================================
   头部导航 (Header)
   ========================================= */
.site-header {
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    height: 80px;
    border-top: 4px solid #004a99; /* 顶部蓝条 */
}

.site-header .container {
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo a {
    font-size: 24px;
    font-weight: bold;
    color: #004a99;
    display: block;
}

.main-nav ul {
    display: flex;
}

.main-nav li {
    margin-left: 40px;
}

.main-nav a {
    font-size: 16px;
    color: #333;
    padding: 10px 0;
    font-weight: 500;
}

.main-nav a:hover,
.main-nav a.active {
    color: #004a99;
    border-bottom: 2px solid #004a99;
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
}

.mobile-menu-btn .bar {
    display: block;
    width: 25px;
    height: 3px;
    background-color: #004a99;
    margin: 5px 0;
    transition: 0.3s;
}

/* =========================================
   Banner Section (Hero)
   ========================================= */
.hero-section {
    /* 模拟科技感/产业感的渐变背景 */
    background: linear-gradient(135deg, #003366 0%, #005bb5 100%);
    color: #fff;
    /* 固定高度 600px */
    height: 520px;
    padding: 0;
    /* Flexbox 垂直居中 */
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    overflow: hidden;
    z-index: 1;
}

/* 移除旧的伪元素背景，改用新的 DOM 结构实现更复杂的动画 */
.hero-section::before {
    display: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    padding-top: 60px;
}

/* 标题样式升级 */
.main-title {
    font-family: "Inter", "Helvetica Neue", Helvetica, Arial, sans-serif; /* 无衬线字体 */
    font-size: 64px; /* 增大字号 */
    font-weight: 700; /* 加粗 */
    margin-bottom: 24px;
    letter-spacing: 1px;
    line-height: 1.2;
    /* 文字渐变效果 (现代浏览器) */
    background: linear-gradient(to right, #ffffff, #e0e0e0);
    -webkit-background-clip: text;
    /* -webkit-text-fill-color: transparent; */
    /* IE11 回退阴影 */
    text-shadow: 0 4px 12px rgba(0,0,0,0.4);
    
    /* 动画 */
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease-out forwards;
}

/* 副标题样式升级 */
.sub-title {
    font-family: "Inter", "Helvetica Neue", Helvetica, Arial, sans-serif;
    font-size: 32px; /* 增大字号 */
    font-weight: 500;
    opacity: 0; /* 初始隐藏 */
    line-height: 1.5;
    color: rgba(255, 255, 255, 0.95);
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
    
    /* 动画延迟 */
    transform: translateY(20px);
    animation: fadeInUp 0.8s ease-out 0.3s forwards;
}

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

/* =========================================
   三大服务矩阵 (Service Matrix)
   ========================================= */
.grid-row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
}

.grid-item {
    flex: 0 0 33.3333%;
    max-width: 33.3333%;
    padding: 0 15px;
    margin-bottom: 30px;
}

.service-card {
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    height: 100%;
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid #eee;
    display: flex;
    flex-direction: column;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.card-header {
    padding: 30px 20px;
    color: #fff;
    text-align: center;
}

.service-card.blue-theme .card-header { background: linear-gradient(to right, #005bb5, #0072e5); }
.service-card.red-theme .card-header { background: linear-gradient(to right, #c0392b, #e74c3c); }
.service-card.gold-theme .card-header { background: linear-gradient(to right, #d4ac0d, #f1c40f); }

.card-header h3 {
    font-size: 22px;
    margin-bottom: 5px;
}

.card-subtitle {
    font-size: 12px;
    opacity: 0.8;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.card-body {
    padding: 30px 20px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
}

.service-list {
    text-align: center;
    width: 100%;
}

.service-list li {
    padding: 10px 0;
    border-bottom: 1px dashed #eee;
    color: #555;
    font-size: 15px;
}

.service-list li:last-child {
    border-bottom: none;
}

.btn-text {
    color: #004a99;
    font-weight: bold;
    font-size: 14px;
}

.btn-text:hover {
    text-decoration: underline;
}

/* =========================================
   专家库 (Experts Grid)
   ========================================= */
.experts-grid {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
    perspective: 1000px; /* 增加透视感 */
}

.expert-card {
    flex: 0 0 25%;
    max-width: 25%;
    padding: 0 15px;
    margin-bottom: 30px;
    text-align: center;
    
    /* 视觉特效增强 */
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1), 
                box-shadow 0.4s ease, 
                border-color 0.3s ease;
    border: 1px solid transparent;
    border-radius: 12px; /* 增加圆角 */
    background: #fff;
    padding-top: 20px; /* 增加内部空间 */
    padding-bottom: 20px;
}

/* 专家卡片悬停效果 */
.expert-card:hover {
    transform: translateY(-12px) scale(1.02); /* 上浮 + 微放大 */
    box-shadow: 0 20px 40px rgba(0, 74, 153, 0.15); /* 柔和的深色投影 */
    border-color: rgba(0, 74, 153, 0.3); /* 边框高亮 */
    z-index: 2; /* 确保浮起时在最上层 */
}

.expert-img {
    width: 160px;
    height: 160px;
    border-radius: 50%;
    margin: 0 auto 20px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    object-fit: cover;
    transition: transform 0.4s ease;
}

/* 头像微动特效 */
.expert-card:hover .expert-img {
    transform: rotate(5deg) scale(1.05);
}

.expert-info h3 {
    font-size: 18px;
    color: #333;
    margin-bottom: 5px;
    transition: color 0.3s;
}

.expert-card:hover .expert-info h3 {
    color: #004a99;
}

.expert-info .title {
    color: #004a99;
    font-weight: bold;
    font-size: 14px;
    margin-bottom: 10px;
}

.expert-info .desc {
    font-size: 13px;
    color: #666;
    line-height: 1.5;
}

/* =========================================
   行业动态 (News List - 左图右文)
   ========================================= */
.news-list {
    max-width: 1000px;
    margin: 0 auto;
    perspective: 2000px; /* 为3D翻转提供透视 */
}

/* 新闻条目容器 */
.news-item {
    margin-bottom: 30px;
    /* 移除原有边框和padding，移交给 inner/front 处理 */
    border: none;
    padding: 0;
    cursor: pointer;
    
    /* 渐进式加载初始状态 */
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s cubic-bezier(0.215, 0.610, 0.355, 1.000);
}

/* 加载完成状态 */
.news-item.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* 3D 翻转容器 */
.news-item-inner {
    position: relative;
    width: 100%;
    transform-style: preserve-3d;
    transition: transform 0.8s cubic-bezier(0.4, 0.2, 0.2, 1);
    border-radius: 8px;
}

/* 翻转激活状态 */
.news-item.is-flipped .news-item-inner {
    transform: rotateX(180deg);
}

/* 正面和背面公共样式 */
.news-front, .news-back {
    width: 100%;
    backface-visibility: hidden; /* 隐藏背面 */
    -webkit-backface-visibility: hidden;
    border-radius: 8px;
    overflow: hidden;
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

/* 正面样式 */
.news-front {
    display: flex;
    padding: 20px;
    border-bottom: 1px solid #eee;
    z-index: 2;
}

.news-item:hover .news-front {
    box-shadow: 0 10px 25px rgba(0,0,0,0.08);
}

/* 背面样式 */
.news-back {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    transform: rotateX(180deg); /* 初始翻转180度 */
    background: linear-gradient(135deg, #004a99 0%, #003366 100%);
    color: #fff;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 40px;
    z-index: 1;
}

.news-back h4 {
    font-size: 24px;
    margin-bottom: 15px;
    font-weight: bold;
}

.news-back p {
    margin-bottom: 25px;
    opacity: 0.9;
    max-width: 80%;
}

.read-more-btn {
    display: inline-block;
    padding: 10px 30px;
    background: #fff;
    color: #004a99;
    border-radius: 25px;
    font-weight: bold;
    text-decoration: none;
    transition: transform 0.2s, box-shadow 0.2s;
}

.read-more-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.news-front > a {
    display: block;
    flex-shrink: 0;
    margin-right: 30px;
    width: 260px;
    height: 146px; /* 16:9 比例 */
    border-radius: 4px;
    overflow: hidden;
}

.news-thumb {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: transform 0.3s ease;
}

.news-front > a:hover .news-thumb {
    transform: scale(1.05);
}

.news-content {
    flex-grow: 1;
}

.news-content h3 {
    font-size: 20px;
    margin-bottom: 10px;
    line-height: 1.4;
}

.news-content h3 a {
    color: #333;
}

.news-content h3 a:hover {
    color: #004a99;
}

.news-date {
    font-size: 14px;
    color: #999;
    margin-bottom: 15px;
}

.news-summary {
    color: #666;
    font-size: 15px;
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
    background-color: #004a99;
    color: #fff;
    text-align: center;
    padding: 40px 0;
    font-size: 14px;
    line-height: 1.8;
}

.site-footer p {
    margin: 0;
}

/* ==========================================================================
   Responsive & Mobile
   ========================================================================== */
@media (max-width: 992px) {
    .grid-item {
        flex: 0 0 50%;
        max-width: 50%;
    }
    
    .expert-card {
        flex: 0 0 50%;
        max-width: 50%;
    }
}

@media (max-width: 768px) {
    /* 移动端间距进一步压缩 */
    .section {
        padding: 30px 0;
    }
    
    .section-header {
        margin-bottom: 25px;
    }

    .site-header {
        height: 60px;
    }
    
    .mobile-menu-btn {
        display: block;
        z-index: 1002;
    }
    
    .main-nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 250px;
        height: 100%;
        background-color: #fff;
        box-shadow: -2px 0 10px rgba(0,0,0,0.1);
        padding-top: 70px;
        transition: right 0.3s ease-in-out;
        z-index: 1001;
    }
    
    .main-nav.active {
        right: 0;
    }
    
    .main-nav ul {
        display: block;
    }
    
    .main-nav li {
        margin: 0;
        border-bottom: 1px solid #f0f0f0;
    }
    
    .main-nav a {
        display: block;
        padding: 15px 20px;
    }
    
    .main-title {
        font-size: 36px; /* 移动端字号调整 */
        line-height: 1.3;
    }
    
    .sub-title {
        font-size: 18px; /* 移动端字号调整 */
    }
    
    .grid-item {
        flex: 0 0 100%;
        max-width: 100%;
    }
    
    .expert-card {
        flex: 0 0 100%; /* 手机端一行一个 */
        max-width: 100%;
    }

    .expert-img {
        width: 150px; /* 限制手机端头像大小 */
        /* padding-bottom: 150px; */
        margin: 0 auto 20px;
    }
    
    .news-item {
        display: block;
    }
    .news-front {
        display: flex;
        flex-wrap: wrap;
    }
    .news-front > a {
        width: 100%;
        height: 200px;
        margin-right: 0;
        margin-bottom: 15px;
    }
    .news-thumb {
        width: 100%;
        height: 100%;
    }
    
    .footer-content {
        display: block;
        text-align: center;
    }
    
    .footer-links ul {
        justify-content: center;
        margin-top: 20px;
    }
    
    .footer-links li {
        margin: 0 10px;
    }
    .site-footer  {
       font-size: 10px;
    }
}