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

:root {
    --primary-color: #2563eb;
    --secondary-color: #64748b;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-color: #1e293b;
    --light-text: #64748b;
    --border-color: #e2e8f0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 2rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

nav h1 {
    font-size: 1.8rem;
    font-weight: 600;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
}

nav ul li a:hover {
    opacity: 0.8;
}

main {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
}

.hero {
    text-align: center;
    padding: 4rem 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 12px;
    margin-bottom: 3rem;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.9;
}

section {
    margin-bottom: 3rem;
}

section h3 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

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

.post-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    transition: transform 0.3s, box-shadow 0.3s;
}

.post-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
}

.post-card h4 {
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.post-card h4 a {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.3s;
}

.post-card h4 a:hover {
    color: var(--primary-color);
}

.post-card .date {
    color: var(--light-text);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.post-card .excerpt {
    color: var(--light-text);
    margin-bottom: 1rem;
}

.read-more {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.read-more:hover {
    color: #1e40af;
}

.post-content {
    background: var(--card-bg);
    padding: 3rem;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.post-content h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.post-meta {
    color: var(--light-text);
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.post-content p {
    margin-bottom: 1.5rem;
    line-height: 1.8;
    font-size: 1.1rem;
}

.post-content h2 {
    font-size: 1.8rem;
    margin: 2rem 0 1rem 0;
    color: var(--text-color);
}

.post-content ul {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
}

.post-content li {
    margin-bottom: 0.5rem;
}

.back-link {
    display: inline-block;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.back-link:hover {
    color: #1e40af;
}

footer {
    text-align: center;
    padding: 2rem;
    color: var(--light-text);
    border-top: 1px solid var(--border-color);
    margin-top: 3rem;
}

@media (max-width: 768px) {
    nav {
        flex-direction: column;
        gap: 1rem;
    }
    
    nav h1 {
        font-size: 1.5rem;
    }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .posts-grid {
        grid-template-columns: 1fr;
    }
    
    .post-content {
        padding: 2rem 1.5rem;
    }
}