:root {
    --primary-color: #2563eb;
    --text-color: #333333;
    --bg-color: #f9fafb;
    --card-bg: #ffffff;
    --border-color: #e5e7eb;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

a {
    color: var(--primary-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: var(--card-bg);
    padding: 40px 0;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 40px;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    color: #111827;
}

header p {
    font-size: 1.2rem;
    color: #6b7280;
}

.article-list {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 30px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.card h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.card h2 a {
    color: #111827;
}

.card h2 a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

.meta {
    font-size: 0.9rem;
    color: #6b7280;
    margin-bottom: 15px;
}

.summary {
    color: #4b5563;
    margin-bottom: 20px;
}

.read-more {
    font-weight: 600;
}

footer {
    text-align: center;
    padding: 40px 0;
    margin-top: 60px;
    color: #6b7280;
    font-size: 0.9rem;
    border-top: 1px solid var(--border-color);
}

/* 文章详情页样式 */
.article-header {
    margin-bottom: 30px;
}

.article-header h1 {
    font-size: 2.2rem;
    color: #111827;
    margin-bottom: 15px;
}

.article-content {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 40px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.article-content h2 {
    margin-top: 30px;
    margin-bottom: 15px;
    color: #111827;
}

.article-content p {
    margin-bottom: 20px;
    color: #4b5563;
}

.back-link {
    display: inline-block;
    margin-bottom: 20px;
    font-weight: 600;
}

/* 分类标签与过滤器样式 */
.category-badge {
    display: inline-block;
    background-color: #f3f4f6;
    color: #4b5563;
    padding: 2px 10px;
    border-radius: 9999px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 10px;
    border: 1px solid #e5e7eb;
}

.filter-bar {
    margin-bottom: 25px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.filter-btn {
    background-color: #ffffff;
    border: 1px solid var(--border-color);
    padding: 6px 14px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    color: #4b5563;
    transition: all 0.2s ease;
}

.filter-btn.active, .filter-btn:hover {
    background-color: var(--primary-color);
    color: #ffffff;
    border-color: var(--primary-color);
}

/* 导航栏样式 */
.navbar {
    background-color: var(--card-bg);
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.nav-logo {
    font-size: 1.2rem;
    font-weight: bold;
    color: #111827;
}

.nav-links a {
    margin-left: 20px;
    color: #4b5563;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--primary-color);
    text-decoration: none;
}

/* 封面主页样式 */
.landing-page header {
    display: none; /* 主页隐藏默认header */
}

.hero {
    min-height: calc(100vh - 160px);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 40px 20px;
}

.hero h1 {
    font-size: 3rem;
    color: #111827;
    margin-bottom: 20px;
}

.hero p {
    font-size: 1.2rem;
    color: #6b7280;
    margin-bottom: 40px;
}

.hero-buttons .btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 30px;
    font-size: 1.1rem;
    font-weight: 600;
    margin: 0 10px;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background-color: #1d4ed8;
    color: #ffffff;
    transform: translateY(-2px);
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: #ffffff;
    transform: translateY(-2px);
}