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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

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

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.logo {
    font-size: 1.8rem;
    font-weight: bold;
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    transition: opacity 0.3s;
    font-size: 1rem;
}

.nav-link:hover,
.nav-link.active {
    opacity: 0.8;
}

.main {
    min-height: calc(100vh - 160px);
    padding: 3rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 2rem;
    color: #333;
    font-size: 2rem;
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.article-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

.article-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.article-card-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 1.5rem;
    color: white;
}

.article-card-category {
    font-size: 0.85rem;
    opacity: 0.9;
    margin-bottom: 0.5rem;
}

.article-card-title {
    font-size: 1.3rem;
    font-weight: bold;
    line-height: 1.4;
}

.article-card-body {
    padding: 1.5rem;
}

.article-card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.article-card-excerpt {
    color: #555;
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.blog-detail {
    max-width: 900px;
    margin: 0 auto;
}

.back-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    margin-bottom: 2rem;
    transition: opacity 0.3s;
}

.back-btn:hover {
    opacity: 0.9;
}

.article-content {
    background: white;
    border-radius: 12px;
    padding: 3rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.article-content h1 {
    color: #333;
    margin-bottom: 1rem;
    font-size: 2.2rem;
    line-height: 1.3;
}

.article-content .article-meta {
    color: #666;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid #f0f0f0;
}

.article-content .category-badge {
    display: inline-block;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    margin-right: 15px;
}

.article-content .article-body {
    color: #444;
    line-height: 1.8;
    font-size: 1.05rem;
}

.article-content .article-body h2 {
    color: #333;
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-size: 1.6rem;
}

.article-content .article-body p {
    margin-bottom: 1.2rem;
}

.article-content .article-body code {
    background: #f5f5f5;
    padding: 2px 8px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

.footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 1rem;
    }

    .logo {
        font-size: 1.5rem;
    }

    .nav {
        gap: 1rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .articles-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .article-content {
        padding: 1.5rem;
    }

    .article-content h1 {
        font-size: 1.6rem;
    }

    .main {
        padding: 2rem 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .logo {
        font-size: 1.3rem;
    }

    .nav-link {
        font-size: 0.9rem;
    }

    .article-card-header {
        padding: 1.2rem;
    }

    .article-card-title {
        font-size: 1.1rem;
    }

    .article-card-body {
        padding: 1.2rem;
    }
}