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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

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

header {
    text-align: center;
    color: white;
    margin-bottom: 40px;
    padding: 40px 20px;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.subtitle {
    font-size: 1.2em;
    opacity: 0.9;
}

main {
    background: white;
    border-radius: 10px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    margin-bottom: 30px;
}

.gateway-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.gateway-card {
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 20px;
    transition: transform 0.2s, box-shadow 0.2s;
    background: #fafafa;
}

.gateway-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    background: white;
}

.gateway-card h2 {
    margin-bottom: 10px;
    font-size: 1.3em;
}

.gateway-card h2 a {
    color: #667eea;
    text-decoration: none;
    transition: color 0.2s;
}

.gateway-card h2 a:hover {
    color: #764ba2;
    text-decoration: underline;
}

.gateway-card p {
    color: #666;
    font-size: 0.95em;
}

.detail-page {
    background: white;
    border-radius: 10px;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    margin-bottom: 30px;
}

.detail-page h1 {
    color: #667eea;
    margin-bottom: 20px;
    font-size: 2.2em;
    border-bottom: 3px solid #667eea;
    padding-bottom: 10px;
}

.detail-page h2 {
    color: #764ba2;
    margin-top: 30px;
    margin-bottom: 15px;
    font-size: 1.5em;
}

.detail-page p {
    margin-bottom: 15px;
    line-height: 1.8;
    color: #555;
}

.detail-page ul {
    margin-left: 30px;
    margin-bottom: 20px;
}

.detail-page li {
    margin-bottom: 10px;
    color: #555;
}

.detail-page code {
    background: #f4f4f4;
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    color: #e83e8c;
}

.detail-page pre {
    background: #f4f4f4;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
    margin: 15px 0;
    border-left: 4px solid #667eea;
}

.detail-page pre code {
    background: transparent;
    padding: 0;
    color: #333;
}

.detail-page a {
    color: #667eea;
    text-decoration: none;
}

.detail-page a:hover {
    text-decoration: underline;
}

.back-link {
    display: inline-block;
    margin-bottom: 20px;
    color: #667eea;
    text-decoration: none;
    font-weight: bold;
    transition: color 0.2s;
}

.back-link:hover {
    color: #764ba2;
    text-decoration: underline;
}

.feature-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
    margin: 20px 0;
}

.feature-item {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 5px;
    border-left: 4px solid #667eea;
}

.feature-item strong {
    display: block;
    margin-bottom: 8px;
    color: #667eea;
}

footer {
    text-align: center;
    color: white;
    padding: 20px;
    opacity: 0.9;
}

@media (max-width: 768px) {
    .gateway-grid {
        grid-template-columns: 1fr;
    }
    
    header h1 {
        font-size: 2em;
    }
    
    .detail-page {
        padding: 20px;
    }
}