/* 基础样式重置和变量 */
:root {
    --primary-color: #1a73e8;
    --secondary-color: #4285f4;
    --dark-color: #202124;
    --light-color: #f8f9fa;
    --text-color: #3c4043;
    --border-color: #dadce0;
    --spacing-unit: 1rem;
    --section-padding: 5rem 0;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #fff;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-unit);
}

/* 全局元素样式 */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-unit);
}

h1 {
    font-size: 3rem;
}

h2 {
    font-size: 2.5rem;
}

h3 {
    font-size: 1.75rem;
}

p {
    margin-bottom: var(--spacing-unit);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--secondary-color);
}

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

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--secondary-color);
    color: white;
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

.btn-secondary:hover {
    background-color: rgba(26, 115, 232, 0.1);
}

.section {
    padding: var(--section-padding);
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
}

.bg-light {
    background-color: var(--light-color);
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    color: var(--dark-color);
    font-weight: 500;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* 主横幅样式 */
.hero {
    height: 100vh;
    padding-top: 5rem;
    display: flex;
    align-items: center;
    background: linear-gradient(rgba(255,255,255,0.9), rgba(255,255,255,0.9)), 
                url('../images/hero-bg.jpg') no-repeat center center/cover;
    text-align: center;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.hero .subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.cta-buttons {
    margin-top: 2rem;
}

.cta-buttons .btn {
    margin: 0 0.5rem;
}

/* 概述部分样式 */
.overview-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 比例 */
    height: 0;
    overflow: hidden;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* 数据集部分样式 */
.stats-container {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    margin-bottom: 3rem;
}

.stat-item {
    text-align: center;
    padding: 1.5rem;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.2rem;
}

.features-list {
    list-style-position: inside;
    margin-bottom: 2rem;
}

.features-list li {
    margin-bottom: 0.5rem;
}

.dataset-visual {
    margin: 2rem 0;
    text-align: center;
}

/* 示例浏览器样式 */
.examples-browser {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 2rem;
}

.filter-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.filter-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.examples-list {
    max-height: 500px;
    overflow-y: auto;
    border: 1px solid var(--border-color);
    border-radius: 4px;
}

.example-item {
    display: flex;
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.example-item:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.thumbnail {
    width: 80px;
    height: 80px;
    margin-right: 1rem;
    overflow: hidden;
    border-radius: 4px;
}

.thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.example-info {
    flex: 1;
}

.scene-container {
    height: 400px;
    background-color: #f0f0f0;
    border-radius: 4px;
    margin-bottom: 1.5rem;
}

.example-details {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.question-box, .answer-box {
    padding: 1.5rem;
    border-radius: 4px;
    background-color: white;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

/* 基准测试部分样式 */
.results-table-container {
    overflow-x: auto;
    margin: 2rem 0;
}

.results-table {
    width: 100%;
    border-collapse: collapse;
}

.results-table th, .results-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.results-table th {
    background-color: rgba(0, 0, 0, 0.05);
    font-weight: 500;
}

.results-table tr:hover {
    background-color: rgba(0, 0, 0, 0.02);
}

/* 下载部分样式 */
.download-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.download-card {
    padding: 2rem;
    border-radius: 8px;
    background-color: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    text-align: center;
}

.download-card h3 {
    margin-bottom: 1rem;
}

.download-card .btn {
    margin-top: 1.5rem;
}

.code-block {
    background-color: var(--dark-color);
    border-radius: 4px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow-x: auto;
}

.code-block pre {
    margin: 0;
}

.code-block code {
    color: white;
    font-family: monospace;
    line-height: 1.4;
}

/* 页脚样式 */
.footer {
    background-color: var(--dark-color);
    color: white;
    padding: 3rem 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer h3 {
    color: white;
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.footer a {
    color: var(--secondary-color);
}

.institutions {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    margin: 2rem 0;
}

.institutions img {
    height: 60px;
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.institutions img:hover {
    opacity: 1;
}

.copyright {
    text-align: center;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.6);
    margin-top: 2rem;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .overview-content {
        grid-template-columns: 1fr;
    }
    
    .examples-browser {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
    }
    
    .nav-links {
        margin-top: 1rem;
    }
    
    .nav-links li {
        margin: 0 0.5rem;
    }
    
    .hero h1 {
        font-size: 3rem;
    }
    
    .example-details {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 576px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .cta-buttons .btn {
        display: block;
        width: 100%;
        margin: 0.5rem 0;
    }
    
    .stats-container {
        flex-direction: column;
    }
    
    .stat-item {
        width: 100%;
    }
}

/* 视频容器样式 */
.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 比例 */
    height: 0;
    overflow: hidden;
}

/* HTML5 视频样式 */
.video-container video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #000; /* 视频加载时的背景色 */
}

/* 全宽视频区域样式 */
.full-width-video-section {
    width: 100%;
    margin: 2rem 0 0 0;
    background-color: #f0f0f0; /* 可选: 给视频区域添加背景色 */
    padding: 2rem 0;
}

/* 视频容器样式 */
.full-width-video-section .video-container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    padding-bottom: 56.25%; /* 16:9 比例 */
    height: 0;
    overflow: hidden;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.full-width-video-section .video-container video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #000; /* 视频加载时的背景色 */
}

/* 修改概述内容部分样式 */
.overview-content {
    /* 移除原来的网格布局 */
    display: block;
    max-width: 100%;
}

.text-content {
    width: 100%;
    margin-bottom: 1rem;
}
/* 响应式调整 */
@media (max-width: 768px) {
    .full-width-video-section {
        padding: 1.5rem 0;
    }
    
    .full-width-video-section .video-container {
        width: 95%;
        border-radius: 4px;
    }
}

@media (max-width: 480px) {
    .full-width-video-section .video-container {
        padding-bottom: 62.5%; /* 移动设备上更高一点 */
    }
}