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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.7;
    color: #333;
    background-color: #f8f9fa;
}

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

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
}

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

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

.nav-links a:hover {
    opacity: 0.8;
}

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

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

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

article {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.07);
    padding: 2.5rem;
    margin-bottom: 2rem;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

.article-nav {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.07);
    padding: 1.5rem 2.5rem;
    margin-bottom: 2rem;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

.article-nav h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: #2d3748;
}

.article-list {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1.5rem;
}

.article-list li {
    position: relative;
}

.article-list li::before {
    content: "•";
    color: #667eea;
    font-weight: bold;
    margin-right: 0.5rem;
}

.article-list a {
    color: #4a5568;
    text-decoration: none;
    transition: color 0.3s;
}

.article-list a:hover {
    color: #667eea;
}

.article-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    align-items: center;
}

.tag {
    background: #667eea;
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.date {
    color: #666;
    font-size: 0.9rem;
}

h2 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: #2d3748;
}

h3 {
    font-size: 1.3rem;
    margin: 2rem 0 1rem;
    color: #4a5568;
}

.summary {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 2rem;
    line-height: 1.8;
}

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

.article-content ul {
    margin: 1rem 0 1rem 1.5rem;
}

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

.article-content strong {
    color: #2d3748;
}

.about-section {
    max-width: 900px;
    margin: 0 auto 3rem;
    padding: 0 2rem;
}

.about-section h2 {
    margin-bottom: 1rem;
}

footer {
    background: #2d3748;
    color: #a0aec0;
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 1.8rem;
    }

    article {
        padding: 1.5rem;
        margin: 0 1rem 2rem;
    }

    nav {
        flex-direction: column;
        gap: 1rem;
    }
}