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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    background-color: #fff;
    padding: 20px 40px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header h1 {
    font-size: 24px;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 15px;
    text-align: center;
}

.nav-tabs {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
    overflow-x: auto;
    padding: 5px;
}

.tab-btn {
    padding: 10px 20px;
    border: none;
    background-color: #e9ecef;
    color: #495057;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.tab-btn:hover {
    background-color: #dee2e6;
}

.tab-btn.active {
    background-color: #3498db;
    color: white;
}

.main-content {
    flex: 1;
    padding: 30px 40px;
    max-width: 1400px;
    margin: 0 auto;
    width: 100%;
}

.site-section {
    margin-bottom: 40px;
}

.section-title {
    font-size: 18px;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3498db;
    display: inline-block;
}

.site-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 15px;
}

.site-card {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px 15px;
    background-color: #fff;
    border-radius: 12px;
    text-decoration: none;
    color: #333;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    min-height: 80px;
    text-align: center;
    word-break: break-word;
}

.site-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
    background-color: #3498db;
    color: white;
}

.site-name {
    font-size: 14px;
    font-weight: 500;
}

.site-section.hidden {
    display: none;
}

.footer {
    background-color: #2c3e50;
    color: #ecf0f1;
    text-align: center;
    padding: 20px;
    margin-top: auto;
}

.footer p {
    font-size: 14px;
}

@media (max-width: 768px) {
    .header {
        padding: 15px 20px;
    }

    .header h1 {
        font-size: 20px;
    }

    .nav-tabs {
        gap: 8px;
    }

    .tab-btn {
        padding: 8px 15px;
        font-size: 13px;
    }

    .main-content {
        padding: 20px;
    }

    .site-grid {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: 10px;
    }

    .site-card {
        padding: 15px 10px;
        min-height: 70px;
    }

    .site-name {
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .tab-btn {
        padding: 6px 12px;
        font-size: 12px;
    }

    .site-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}