/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, 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-color: #4a6fa5;
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

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

header h1 a {
    color: white;
    text-decoration: none;
    font-size: 1.8rem;
    font-weight: 600;
}

.language-switcher {
    display: flex;
    list-style: none;
}

.language-switcher li {
    margin-left: 1rem;
}

.language-switcher a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
}

.language-switcher a:hover {
    opacity: 0.8;
}

.language-switcher .active {
    font-weight: bold;
    text-decoration: underline;
}

/* 主内容区域样式 */
main {
    padding: 2rem 0 4rem;
}

/* 语言选择页面样式 */
.language-selection-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 70vh;
    text-align: center;
}

.language-selection-container h1 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: #4a6fa5;
}

.language-selection-container p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    color: #666;
}

.language-options {
    display: flex;
    gap: 1.5rem;
}

.language-btn {
    background-color: #4a6fa5;
    color: white;
    padding: 1rem 2rem;
    border-radius: 4px;
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 500;
    transition: background-color 0.3s, transform 0.3s;
}

.language-btn:hover {
    background-color: #3a5a8a;
    transform: translateY(-3px);
}

/* 分类页面样式 */
.categories-container h2,
.section-container h2,
.article-container h2,
.single-article-container h1 {
    margin-bottom: 1.5rem;
    color: #2c3e50;
    font-weight: 600;
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.category-card {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 3px 10px rgba(0,0,0,0.08);
    transition: transform 0.3s, box-shadow 0.3s;
}

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

.category-card h3 {
    margin-bottom: 0.8rem;
    font-size: 1.3rem;
    color: #4a6fa5;
}

.category-card h3 a {
    color: inherit;
    text-decoration: none;
}

.category-card p {
    color: #666;
    font-size: 0.95rem;
}

/* 章节页面样式 */
.sections-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.section-card {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 3px 10px rgba(0,0,0,0.08);
}

.section-card h3 {
    margin-bottom: 0.8rem;
    font-size: 1.2rem;
    color: #4a6fa5;
}

.section-card h3 a {
    color: inherit;
    text-decoration: none;
}

.section-description {
    margin-bottom: 1rem;
    color: #666;
    font-size: 0.95rem;
}

.section-articles h4 {
    margin: 1rem 0 0.5rem;
    font-size: 1rem;
    color: #333;
}

.section-articles ul {
    list-style-position: inside;
    margin-bottom: 0.8rem;
}

.section-articles li {
    margin-bottom: 0.4rem;
}

.section-articles a {
    color: #4a6fa5;
    text-decoration: none;
}

.section-articles a:hover {
    text-decoration: underline;
}

.view-all {
    display: inline-block;
    font-size: 0.9rem;
    color: #4a6fa5;
    font-weight: 500;
}

/* 文章列表样式 */
.articles-list ul {
    list-style: none;
}

.articles-list li {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid #eee;
}

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

.articles-list h3 {
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
}

.articles-list h3 a {
    color: #4a6fa5;
    text-decoration: none;
}

.article-excerpt {
    color: #666;
    font-size: 0.95rem;
}

/* 单篇文章样式 */
.breadcrumbs {
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    color: #666;
}

.breadcrumbs a {
    color: #4a6fa5;
    text-decoration: none;
}

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

.single-article-container h1 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
}

.article-content {
    background-color: white;
    border-radius: 8px;
    padding: 2rem;
    box-shadow: 0 3px 10px rgba(0,0,0,0.08);
}

.article-content p {
    margin-bottom: 1rem;
}

.article-content a {
    color: #4a6fa5;
    text-decoration: underline;
}

/* 底部样式 */
footer {
    background-color: #2c3e50;
    color: white;
    padding: 1.5rem 0;
    margin-top: 2rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        text-align: center;
    }

    .language-switcher {
        margin-top: 1rem;
    }

    .language-switcher li {
        margin: 0 0.5rem;
    }

    .categories-grid,
    .sections-grid {
        grid-template-columns: 1fr;
    }

    .article-content {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    header h1 a {
        font-size: 1.5rem;
    }

    .container {
        padding: 0 15px;
    }

    .single-article-container h1 {
        font-size: 1.5rem;
    }
}