:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --text-primary: #1a1a2e;
    --text-secondary: #6c757d;
    --accent: #667eea;
    --accent-hover: #5a6fd6;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
    --card-hover-shadow: 0 10px 30px rgba(0, 0, 0, 0.12);
    --border: #e9ecef;
}

[data-theme="dark"] {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --text-primary: #e8e8e8;
    --text-secondary: #a0a0b0;
    --accent: #7c8cf8;
    --accent-hover: #6b7bf7;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    --card-hover-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
    --border: #2a2a4a;
}

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

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background 0.3s, color 0.3s;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.9);
}

[data-theme="dark"] .navbar {
    background: rgba(26, 26, 46, 0.9);
}

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

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent);
}

.theme-btn {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: background 0.3s;
}

.theme-btn:hover {
    background: var(--bg-secondary);
}

/* Hero */
.hero {
    padding: 140px 0 80px;
    text-align: center;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--accent) 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.hero-tags {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

.tag {
    padding: 6px 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: 0.875rem;
    color: var(--text-secondary);
    transition: all 0.3s;
}

.tag:hover {
    border-color: var(--accent);
    color: var(--accent);
}

/* Posts Grid */
.posts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
    padding: 40px 0 80px;
}

.post-card {
    background: var(--bg-primary);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
    cursor: pointer;
    border: 1px solid var(--border);
}

.post-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--card-hover-shadow);
}

.post-image {
    height: 180px;
    display: flex;
    align-items: flex-end;
    padding: 16px;
}

.post-category {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    color: white;
    font-weight: 500;
}

.post-content {
    padding: 20px;
}

.post-date {
    font-size: 0.8rem;
    color: var(--text-secondary);
    display: block;
    margin-bottom: 8px;
}

.post-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
    line-height: 1.4;
}

.post-excerpt {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 16px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.post-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 16px;
    border-top: 1px solid var(--border);
}

.read-time {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.read-more {
    font-size: 0.875rem;
    color: var(--accent);
    font-weight: 500;
}

/* Footer */
.footer {
    background: var(--bg-secondary);
    padding: 40px 0;
    text-align: center;
    border-top: 1px solid var(--border);
}

.footer p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 24px;
}

.social-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s;
}

.social-links a:hover {
    color: var(--accent);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .posts-grid {
        grid-template-columns: 1fr;
    }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.post-card {
    animation: fadeInUp 0.5s ease forwards;
}

.post-card:nth-child(1) { animation-delay: 0.1s; }
.post-card:nth-child(2) { animation-delay: 0.2s; }
.post-card:nth-child(3) { animation-delay: 0.3s; }
.post-card:nth-child(4) { animation-delay: 0.4s; }