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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-color);
    min-height: 100vh;
    padding: 0;
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 24px;
}

header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 24px 0;
    margin-bottom: 32px;
    box-shadow: var(--shadow-sm);
}

header h1 {
    font-size: 28px;
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
}

.tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
    flex-wrap: wrap;
    background: var(--card-bg);
    padding: 8px;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.tab-btn {
    padding: 10px 20px;
    background: transparent;
    border: none;
    border-radius: 8px;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s ease;
    position: relative;
}

.tab-btn:hover {
    background: var(--bg-color);
    color: var(--text-primary);
}

.tab-btn.active {
    background: var(--primary-color);
    color: white;
    box-shadow: var(--shadow-sm);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: box-shadow 0.2s ease;
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.card h2 {
    color: var(--text-primary);
    margin-bottom: 20px;
    font-size: 20px;
    font-weight: 600;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border-color);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 14px;
}

.form-group input[type="text"],
.form-group input[type="number"],
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.2s ease;
    font-family: inherit;
    background: var(--card-bg);
    color: var(--text-primary);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 13px;
}

.form-group small {
    color: var(--text-secondary);
    font-size: 12px;
    margin-top: 4px;
    display: block;
}

.form-group input[type="checkbox"] {
    width: auto;
    margin-right: 8px;
    cursor: pointer;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--secondary-color);
    color: white;
}

.btn-secondary:hover {
    background: #475569;
}

.btn-warning {
    background: var(--warning-color);
    color: white;
}

.btn-warning:hover {
    background: #d97706;
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}

.result {
    margin-top: 20px;
    padding: 16px;
    border-radius: 8px;
    display: none;
    font-size: 14px;
    line-height: 1.6;
}

.result.success {
    background: #ecfdf5;
    color: #065f46;
    border: 1px solid #a7f3d0;
    display: block;
}

.result.error {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
    display: block;
}

.result pre {
    background: rgba(0, 0, 0, 0.05);
    padding: 12px;
    border-radius: 6px;
    overflow-x: auto;
    margin-top: 12px;
    font-size: 13px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    line-height: 1.5;
}

.domains-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 16px;
}

.domain-item {
    background: var(--bg-color);
    padding: 16px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: all 0.2s ease;
}

.domain-item:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

.domain-item h3 {
    color: var(--primary-color);
    margin-bottom: 12px;
    font-size: 16px;
    font-weight: 600;
}

.domain-item p {
    margin: 6px 0;
    color: var(--text-secondary);
    font-size: 13px;
}

.domain-item .nameservers {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border-color);
}

.domain-item .nameservers strong {
    display: block;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-size: 13px;
}

.domain-item .nameserver {
    background: var(--card-bg);
    padding: 4px 8px;
    border-radius: 4px;
    display: inline-block;
    margin: 4px 4px 4px 0;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 11px;
    border: 1px solid var(--border-color);
}

.loading {
    text-align: center;
    padding: 24px;
    color: var(--primary-color);
    font-size: 14px;
}

.page-rule-item {
    background: var(--bg-color);
    padding: 16px;
    margin: 12px 0;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    border-left: 3px solid var(--primary-color);
}

.page-rule-item pre {
    background: var(--card-bg);
    padding: 10px;
    border-radius: 6px;
    margin: 8px 0;
    font-size: 12px;
    border: 1px solid var(--border-color);
    overflow-x: auto;
}

@media (max-width: 768px) {
    .container {
        padding: 16px;
    }

    header h1 {
        font-size: 24px;
    }

    .tabs {
        flex-direction: column;
        gap: 4px;
    }

    .tab-btn {
        width: 100%;
        text-align: left;
    }

    .card-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .domains-list {
        grid-template-columns: 1fr;
    }

    .card {
        padding: 16px;
    }
}