/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 头部样式 */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 15px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 24px;
    font-weight: bold;
    text-decoration: none;
    color: white;
}

.logo img {
    height: 45px;
    width: auto;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 25px;
    flex-wrap: wrap;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
    padding: 5px 10px;
}

nav a:hover {
    opacity: 0.8;
    background-color: rgba(255,255,255,0.1);
    border-radius: 5px;
}

/* 搜索框样式 */
.search-container {
    width: 100%;
    max-width: 600px;
    margin: 20px auto;
    padding: 0 20px;
}

.search-box {
    position: relative;
    width: 100%;
}

.search-box input {
    width: 100%;
    padding: 12px 50px 12px 20px;
    border: 2px solid #e0e0e0;
    border-radius: 25px;
    font-size: 16px;
    transition: all 0.3s;
    background-color: white;
}

.search-box input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-box button {
    position: absolute;
    right: 5px;
    top: 50%;
    transform: translateY(-50%);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 500;
    transition: opacity 0.3s;
}

.search-box button:hover {
    opacity: 0.9;
}

/* 主内容区域 */
main {
    padding: 30px 0;
}

/* Hero区域 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 60px 20px;
    text-align: center;
    border-radius: 15px;
    margin-bottom: 40px;
}

.hero h1 {
    font-size: 2.5em;
    margin-bottom: 20px;
    line-height: 1.3;
}

.hero p {
    font-size: 1.2em;
    margin-bottom: 30px;
    opacity: 0.95;
}

.cta-button {
    display: inline-block;
    background: white;
    color: #667eea;
    padding: 12px 35px;
    border-radius: 25px;
    text-decoration: none;
    font-weight: bold;
    transition: transform 0.3s;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

/* 视频卡片网格 */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 25px;
    margin: 30px 0;
}

.video-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

.video-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.video-thumbnail {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
    background-color: #f0f0f0;
}

.video-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

.video-card:hover .video-thumbnail img {
    transform: scale(1.05);
}

.play-button {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    background: rgba(102, 126, 234, 0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s;
}

.video-card:hover .play-button {
    opacity: 1;
}

.play-button::after {
    content: "";
    width: 0;
    height: 0;
    border-left: 20px solid white;
    border-top: 12px solid transparent;
    border-bottom: 12px solid transparent;
    margin-left: 5px;
}

.video-info {
    padding: 15px;
}

.video-title {
    font-size: 1.1em;
    font-weight: 600;
    margin-bottom: 8px;
    color: #333;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.video-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.9em;
    color: #666;
}

.video-stats {
    display: flex;
    gap: 15px;
}

.video-duration {
    position: absolute;
    bottom: 10px;
    right: 10px;
    background: rgba(0,0,0,0.8);
    color: white;
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 0.85em;
}

/* 内容区块 */
.content-section {
    background: white;
    padding: 40px;
    border-radius: 12px;
    margin-bottom: 30px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.content-section h2 {
    font-size: 2em;
    margin-bottom: 20px;
    color: #333;
    border-bottom: 3px solid #667eea;
    padding-bottom: 10px;
}

.content-section h3 {
    font-size: 1.5em;
    margin: 25px 0 15px;
    color: #444;
}

.content-section p {
    margin-bottom: 15px;
    line-height: 1.8;
}

/* 专家卡片 */
.expert-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 25px;
    margin: 30px 0;
}

.expert-card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    transition: transform 0.3s;
}

.expert-card:hover {
    transform: translateY(-5px);
}

.expert-avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    margin: 0 auto 15px;
    object-fit: cover;
    border: 4px solid #667eea;
}

.expert-name {
    font-size: 1.3em;
    font-weight: bold;
    margin-bottom: 8px;
    color: #333;
}

.expert-title {
    color: #667eea;
    font-weight: 500;
    margin-bottom: 12px;
}

.expert-bio {
    font-size: 0.95em;
    color: #666;
    line-height: 1.6;
}

/* 合作伙伴 */
.partner-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.partner-logo {
    background: white;
    padding: 20px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    transition: transform 0.3s;
}

.partner-logo:hover {
    transform: scale(1.05);
}

/* 用户评价 */
.testimonial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 25px;
    margin: 30px 0;
}

.testimonial-card {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 12px;
    border-left: 4px solid #667eea;
}

.testimonial-text {
    font-style: italic;
    margin-bottom: 15px;
    color: #555;
    line-height: 1.7;
}

.testimonial-author {
    font-weight: bold;
    color: #333;
}

.testimonial-rating {
    color: #ffc107;
    margin-top: 8px;
}

/* FAQ样式 */
.faq-item {
    background: white;
    padding: 20px;
    margin-bottom: 15px;
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.faq-question {
    font-weight: bold;
    font-size: 1.1em;
    margin-bottom: 10px;
    color: #333;
}

.faq-answer {
    color: #666;
    line-height: 1.7;
}

/* 联系信息 */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 25px;
    margin: 30px 0;
}

.contact-card {
    background: white;
    padding: 25px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
}

.contact-icon {
    font-size: 2.5em;
    margin-bottom: 15px;
    color: #667eea;
}

.contact-title {
    font-weight: bold;
    margin-bottom: 10px;
    color: #333;
}

.contact-info {
    color: #666;
}

.qr-code {
    width: 150px;
    height: 150px;
    margin: 15px auto;
    border-radius: 8px;
}

/* 社交分享 */
.social-share {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin: 30px 0;
}

.social-button {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: 25px;
    text-decoration: none;
    color: white;
    font-weight: 500;
    transition: transform 0.3s;
}

.social-button:hover {
    transform: translateY(-2px);
}

.social-wechat { background: #09BB07; }
.social-weibo { background: #E6162D; }
.social-douyin { background: #000; }
.social-bilibili { background: #00A1D6; }

/* 页脚样式 */
footer {
    background: #2c3e50;
    color: white;
    padding: 40px 0 20px;
    margin-top: 50px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}

.footer-section h3 {
    margin-bottom: 15px;
    color: #667eea;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 8px;
}

.footer-section a {
    color: #bbb;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #444;
    color: #999;
}

.footer-qr {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-top: 20px;
}

.footer-qr-item {
    text-align: center;
}

.footer-qr-item img {
    width: 100px;
    height: 100px;
    border-radius: 8px;
    margin-bottom: 8px;
}

/* 面包屑导航 */
.breadcrumb {
    padding: 15px 0;
    font-size: 0.9em;
}

.breadcrumb a {
    color: #667eea;
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

.breadcrumb span {
    margin: 0 8px;
    color: #999;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 15px;
    }
    
    nav ul {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }
    
    .hero h1 {
        font-size: 1.8em;
    }
    
    .video-grid {
        grid-template-columns: 1fr;
    }
    
    .content-section {
        padding: 25px 20px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(102, 126, 234, 0.3);
    border-radius: 50%;
    border-top-color: #667eea;
    animation: spin 1s ease-in-out infinite;
}

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

/* 懒加载图片 */
img[data-src] {
    opacity: 0;
    transition: opacity 0.3s;
}

img[data-src].loaded {
    opacity: 1;
}