/* 网页通用样式 reset 和基础设置 */
* {
    margin: 0;
    padding: 0;
    border: 0;
    outline: 0;
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Roboto', 'Open Sans', sans-serif;
    line-height: 1.7;
    color: #333;
    background-color: #f4f4f4;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
}

ul, ol {
    list-style: none;
}

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

/* 颜色变量定义，符合未来科技风格 */
:root {
    --primary-color: #0A2463; /* 深蓝 */
    --secondary-color: #FFFFFF; /* 白色 */
    --accent-color: #FF5722; /* 橙红色 */
    --grey-color: #BDBDBD; /* 银灰色 */
    --success-color: #4CAF50; /* 绿色 */
    --gradient-primary: linear-gradient(to right, var(--primary-color), #1E3A8A); /* 深蓝渐变 */
    --gradient-secondary: linear-gradient(to right, var(--accent-color), #FF7043); /* 橙红渐变 */
}

/* 页面布局和通用组件样式 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section {
    padding: 60px 0;
}

.section-title {
    font-family: 'Poppins', 'Montserrat', sans-serif;
    font-size: 2.5rem;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 40px;
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--grey-color);
    text-align: center;
    margin-bottom: 60px;
}

/* 顶部导航栏样式 */
.navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--gradient-primary);
    color: var(--secondary-color);
    padding: 20px 0;
}

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

.navbar-brand {
    font-family: 'Poppins', 'Montserrat', sans-serif;
    font-size: 1.8rem;
    font-weight: bold;
}

.navbar-nav {
    display: flex;
}

.nav-item {
    margin-left: 30px;
}

.nav-link {
    font-size: 1rem;
    transition: color 0.3s ease;
}

.nav-link:hover {
    color: var(--accent-color);
}

/* 首页 Hero Section 样式 */
.hero-section {
    background: var(--gradient-primary);
    color: var(--secondary-color);
    padding: 120px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-family: 'Poppins', 'Montserrat', sans-serif;
    font-size: 3.5rem;
    font-weight: bold;
    margin-bottom: 20px;
    text-shadow: 2px 2px 5px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 40px;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.3);
}

.hero-image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.1; /* 降低背景图片透明度，增强文字可读性 */
}


/* 特色功能模块样式 */
.features-section {
    background-color: var(--secondary-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-item {
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
    background-color: #fff;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    margin-bottom: 20px;
    text-align: center;
}

.feature-icon img {
    width: 60px;
    height: 60px;
    object-fit: contain;
}

.feature-title {
    font-family: 'Poppins', 'Montserrat', sans-serif;
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--primary-color);
    text-align: center;
}

.feature-description {
    font-size: 1rem;
    color: #666;
    text-align: center;
}


/* 示例数据展示区域样式 */
.example-data-section {
    background-color: #f0f0f0;
    padding: 80px 0;
}

.example-data-container {
    background-color: var(--secondary-color);
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.example-data-title {
    font-family: 'Poppins', 'Montserrat', sans-serif;
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 30px;
    text-align: center;
}

.example-data-list {
    columns: 2; /* 两列布局 */
    -webkit-columns: 2;
    -moz-columns: 2;
    column-gap: 40px;
}

.example-data-item {
    margin-bottom: 20px;
    break-inside: avoid; /* 避免在列表项内部断列 */
}


/* 示例文章展示区域样式 */
.article-section {
    background-color: var(--secondary-color);
    padding: 60px 0;
}

.article-container {
    background-color: #fff;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

article h2 {
    font-family: 'Poppins', 'Montserrat', sans-serif;
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 25px;
}

article h3 {
    font-family: 'Poppins', 'Montserrat', sans-serif;
    font-size: 1.6rem;
    color: var(--primary-color);
    margin-top: 30px;
    margin-bottom: 20px;
}

article h4 {
    font-family: 'Poppins', 'Montserrat', sans-serif;
    font-size: 1.4rem;
    color: var(--primary-color);
    margin-top: 25px;
    margin-bottom: 15px;
}

article p {
    margin-bottom: 20px;
    color: #555;
}

article ul, article ol {
    margin-left: 25px;
    margin-bottom: 20px;
}

article li {
    margin-bottom: 10px;
    color: #555;
}

article b {
    font-weight: bold;
    color: var(--primary-color);
}

article pre {
    background-color: #f7f7f7;
    padding: 15px;
    border-radius: 6px;
    overflow-x: auto; /* 代码块水平滚动 */
    font-size: 0.9rem;
    line-height: 1.5;
    color: #333;
    margin-bottom: 20px;
    white-space: pre-wrap; /* 代码换行 */
    word-wrap: break-word;
}

article code {
    font-family: monospace, monospace;
}


/* 页脚样式 */
.footer {
    background: var(--primary-color);
    color: var(--secondary-color);
    padding: 40px 0;
    text-align: center;
}

.footer-content {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.footer-text {
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.footer-links {
    display: flex;
    justify-content: center;
}

.footer-link-item {
    margin: 0 15px;
}

.footer-link-icon {
    width: 24px;
    height: 24px;
    object-fit: contain;
    opacity: 0.7;
    transition: opacity 0.3s ease;
}

.footer-link-icon:hover {
    opacity: 1;
}

/* 响应式设计 */
@media screen and (max-width: 768px) {
    .section {
        padding: 40px 0;
    }

    .section-title {
        font-size: 2rem;
        margin-bottom: 30px;
    }

    .section-subtitle {
        font-size: 1rem;
        margin-bottom: 40px;
    }

    .navbar-container {
        flex-direction: column;
        align-items: flex-start;
    }

    .navbar-brand {
        margin-bottom: 15px;
    }

    .navbar-nav {
        flex-direction: column;
    }

    .nav-item {
        margin-left: 0;
        margin-bottom: 15px;
    }

    .hero-section {
        padding: 80px 0;
    }

    .hero-title {
        font-size: 2.8rem;
    }

    .hero-subtitle {
        font-size: 1.3rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .example-data-list {
        columns: 1; /* 移动设备上单列布局 */
    }

    .example-data-container, .article-container {
        padding: 30px;
    }

    article h2 {
        font-size: 1.8rem;
    }

    article h3 {
        font-size: 1.4rem;
    }

    article h4 {
        font-size: 1.2rem;
    }
}

@media screen and (max-width: 480px) {
    .hero-title {
        font-size: 2.4rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }
}

/* 特殊样式，例如提示文字 */
.reference-tip {
    text-align: center;
    padding: 20px 0;
    font-size: 1.1rem;
    color: var(--accent-color);
    background-color: #fffbe6;
    border-bottom: 1px solid #ffe0b2;
}