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

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
    z-index: 1000;
    padding: 0.5rem 1rem;
    background: var(--accent);
    color: var(--bg-primary);
    text-decoration: none;
}

.skip-link:focus {
    left: 0;
}

:root {
    /* Light theme (default) */
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f0f1f3;
    --accent: #0077aa;
    --accent-dim: #005580;
    --text-primary: #1a1a2e;
    --text-secondary: #4b5563;
    --text-muted: #6b7280;
    --success: #059669;
    --success-bg: #d1fae5;
    --warning: #d97706;
    --warning-bg: #fef3c7;
    --error: #dc2626;
    --error-bg: #fee2e2;
    --dnssec: #7c3aed;
    --dnssec-bg: #ede9fe;
    --insecure: #b45309;
    --insecure-bg: #fef3c7;
    --border: #d1d5db;
    --radius: 8px;
    --radius-sm: 4px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #0f0f1a;
        --bg-secondary: #1a1a2e;
        --bg-tertiary: #252540;
        --accent: #00d4ff;
        --accent-dim: #0099bb;
        --text-primary: #f0f0f0;
        --text-secondary: #9ca3af;
        --text-muted: #6b7280;
        --success: #10b981;
        --success-bg: #064e3b;
        --warning: #f59e0b;
        --warning-bg: #78350f;
        --error: #ef4444;
        --error-bg: #7f1d1d;
        --dnssec: #8b5cf6;
        --dnssec-bg: #4c1d95;
        --insecure: #fbbf24;
        --insecure-bg: #78350f;
        --border: #374151;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.5;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 2rem;
}

.header h1 {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.header .subtitle {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.header .powered-by {
    font-size: 0.75rem;
    margin-top: 0.5rem;
}

.header .powered-by a {
    color: var(--accent-dim);
    text-decoration: none;
}

.header .powered-by a:hover {
    color: var(--accent);
    text-decoration: underline;
}

/* Query Form */
.query-form {
    margin-bottom: 1.5rem;
}

.input-row {
    display: flex;
    gap: 0.5rem;
    background: var(--bg-secondary);
    padding: 0.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

.input-row input[type="text"] {
    flex: 1;
    min-width: 0;
    padding: 0.625rem 0.875rem;
    font-size: 1rem;
    border: none;
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    outline: none;
}

.input-row input[type="text"]:focus {
    box-shadow: 0 0 0 2px var(--accent-dim);
}

.input-row input[type="text"]::placeholder {
    color: var(--text-muted);
}

.input-row select {
    padding: 0.625rem 0.75rem;
    font-size: 0.875rem;
    font-weight: 500;
    border: none;
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    cursor: pointer;
    outline: none;
}

.input-row select:focus {
    box-shadow: 0 0 0 2px var(--accent-dim);
}

.input-row button {
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    background: var(--accent);
    color: var(--bg-primary);
    cursor: pointer;
    transition: background 0.15s, transform 0.1s;
    white-space: nowrap;
}

.input-row button:hover {
    background: var(--accent-dim);
}

.input-row button:active {
    transform: scale(0.98);
}

.input-row button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Example Domains */
.example-domains {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.75rem;
    font-size: 0.8125rem;
    color: var(--text-muted);
    flex-wrap: wrap;
}

.example-btn {
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
    font-family: "SF Mono", Monaco, monospace;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--accent-dim);
    cursor: pointer;
    transition: background 0.15s, border-color 0.15s;
}

.example-btn:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent-dim);
    color: var(--accent);
}

/* Status Messages */
.status {
    display: none;
    align-items: center;
    gap: 0.625rem;
    padding: 0.75rem 1rem;
    border-radius: var(--radius);
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

.status.loading {
    display: flex;
    background: var(--bg-secondary);
    color: var(--accent);
    border: 1px solid var(--border);
}

.status.error {
    display: flex;
    background: var(--error-bg);
    color: var(--error);
    border: 1px solid var(--error);
}

.status .spinner {
    display: none;
}

.status.loading .spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid var(--accent-dim);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Results */
.results {
    background: var(--bg-secondary);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow: hidden;
}

.results.hidden {
    display: none;
}

.result-summary {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.25rem;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
    flex-wrap: wrap;
}

.result-query {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    min-width: 0;
}

.query-name {
    font-family: "SF Mono", Monaco, "Cascadia Code", monospace;
    font-size: 1rem;
    color: var(--text-primary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Copy Button */
.copy-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    padding: 0;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: background 0.15s, border-color 0.15s, color 0.15s;
    flex-shrink: 0;
}

.copy-btn:hover {
    background: var(--bg-primary);
    border-color: var(--accent-dim);
    color: var(--accent);
}

.copy-btn.copied {
    background: var(--success-bg);
    border-color: var(--success);
    color: var(--success);
}

/* Badges */
.result-badges {
    display: flex;
    gap: 0.375rem;
    flex-wrap: wrap;
}

.badge {
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.025em;
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    white-space: nowrap;
}

.badge.secure {
    background: linear-gradient(135deg, #0d9488, #0891b2);
    color: #fff;
    text-shadow: 0 1px 1px rgba(0,0,0,0.2);
}

.badge.secure::before {
    content: "\2713\0020";
}

.badge.insecure {
    background: var(--insecure-bg);
    color: var(--insecure);
}

.badge.insecure::before {
    content: "\26A0\0020";
}

.badge.bogus {
    background: var(--error-bg);
    color: var(--error);
}

.badge.bogus::before {
    content: "\2717\0020";
}

.badge.indeterminate {
    background: var(--warning-bg);
    color: var(--warning);
}

.badge.indeterminate::before {
    content: "?\0020";
}

.badge.validating {
    background: var(--bg-tertiary);
    color: var(--accent);
}

/* Chain Visualization - Vertical Tree */
.chain-visualization {
    display: flex;
    flex-direction: column;
    padding: 1rem 1.25rem;
    background: var(--bg-primary);
    font-family: "SF Mono", Monaco, monospace;
    font-size: 0.8125rem;
}

.zone-tree {
    display: flex;
    flex-direction: column;
}

.zone-item {
    display: flex;
    align-items: center;
    padding: 0.375rem 0;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: background 0.15s;
}

.zone-item:hover {
    background: var(--bg-secondary);
}

.zone-item.selected {
    background: var(--bg-tertiary);
}

.zone-indent {
    display: inline-flex;
    align-items: center;
    color: var(--border);
    white-space: pre;
    user-select: none;
}

.zone-status-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.25rem;
    height: 1.25rem;
    margin-right: 0.5rem;
    font-size: 0.875rem;
    flex-shrink: 0;
}

.zone-status-icon.secure { color: var(--success); }
.zone-status-icon.insecure { color: var(--insecure); }
.zone-status-icon.bogus { color: var(--error); }
.zone-status-icon.indeterminate { color: var(--warning); }
.zone-status-icon.validating { color: var(--accent); }

.zone-name {
    color: var(--text-primary);
    font-weight: 500;
}

.zone-item.cached .zone-name {
    color: var(--text-secondary);
}

.zone-cached-label {
    font-size: 0.6875rem;
    color: var(--text-muted);
    margin-left: 0.5rem;
    font-weight: normal;
}

.zone-rtt {
    font-size: 0.6875rem;
    color: var(--text-muted);
    margin-left: auto;
    padding-left: 1rem;
}

/* CNAME indicator */
.cname-indicator {
    display: flex;
    align-items: center;
    padding: 0.5rem 0;
    margin: 0.25rem 0;
}

.cname-indicator .zone-indent {
    color: var(--dnssec);
}

.cname-label {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.25rem 0.5rem;
    background: var(--dnssec-bg);
    border: 1px solid var(--dnssec);
    border-radius: var(--radius-sm);
    color: var(--dnssec);
    font-size: 0.75rem;
    font-weight: 500;
}

.cname-target {
    color: var(--text-primary);
    margin-left: 0.5rem;
}

/* Legacy card styles removed - using tree view now */
.zone-card {
    display: none;
}

.chain-arrow {
    display: none;
}

/* Result Timing */
.result-timing {
    display: flex;
    gap: 1.5rem;
    padding: 0.75rem 1.25rem;
    border-bottom: 1px solid var(--border);
    background: var(--bg-secondary);
}

.timing-item {
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

.timing-item strong {
    color: var(--text-primary);
    font-weight: 500;
}

/* Zone Details */
.zone-details {
    padding: 1rem 1.25rem;
}

.zone-tabs {
    display: flex;
    gap: 0.25rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.zone-tab {
    padding: 0.5rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 500;
    border: none;
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
}

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

.zone-tab.active {
    background: var(--accent);
    color: var(--bg-primary);
}

.zone-content {
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    padding: 1rem;
}

.zone-content h4 {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    margin-top: 1rem;
}

.zone-content h4:first-child {
    margin-top: 0;
}

/* Nameserver List */
.ns-list {
    list-style: none;
}

.ns-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.375rem 0;
    font-size: 0.8125rem;
    font-family: "SF Mono", Monaco, monospace;
    border-bottom: 1px solid var(--border);
}

.ns-item:last-child {
    border-bottom: none;
}

.ns-status {
    font-size: 0.75rem;
}

.ns-status.secure { color: var(--success); }
.ns-status.error { color: var(--error); }
.ns-status.warning { color: var(--warning); }

.ns-name {
    color: var(--text-primary);
}

.ns-ip {
    color: var(--text-secondary);
}

.ns-rtt {
    color: var(--text-muted);
    margin-left: auto;
}

/* Record Cards */
.record-card {
    background: var(--bg-primary);
    border-radius: var(--radius-sm);
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    font-family: "SF Mono", Monaco, monospace;
    font-size: 0.75rem;
}

.record-card:last-child {
    margin-bottom: 0;
}

.record-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.375rem;
}

.record-type {
    color: var(--accent);
    font-weight: 600;
}

.record-tag {
    color: var(--text-muted);
}

.record-data {
    color: var(--text-primary);
    word-break: break-all;
}

.record-meta {
    color: var(--text-muted);
    margin-top: 0.25rem;
    font-size: 0.6875rem;
}

/* RDAP verification badges */
.rdap-badge {
    font-size: 0.6875rem;
    font-weight: 600;
    padding: 0.125rem 0.375rem;
    border-radius: var(--radius-sm);
    margin-left: 0.5rem;
    white-space: nowrap;
}

.rdap-badge.match {
    background: var(--success-bg);
    color: var(--success);
}

.rdap-badge.mismatch {
    background: var(--error-bg);
    color: var(--error);
}

.rdap-badge.warning {
    background: var(--warning-bg);
    color: var(--warning);
}

/* RDAP-only record styling */
.record-card.rdap-only {
    border-left: 3px solid var(--warning);
    opacity: 0.85;
}

/* RDAP status summary */
.rdap-summary {
    margin-top: 0.75rem;
    padding: 0.5rem 0.75rem;
    background: var(--bg-primary);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
}

.rdap-status {
    display: inline-flex;
    align-items: center;
}

.rdap-status.success {
    color: var(--success);
}

.rdap-status.warning {
    color: var(--warning);
}

.rdap-status.error {
    color: var(--error);
}

.rdap-status.muted {
    color: var(--text-muted);
}

/* Raw JSON */
.raw-json {
    border-top: 1px solid var(--border);
}

.raw-json summary {
    padding: 0.75rem 1.25rem;
    font-size: 0.8125rem;
    color: var(--text-muted);
    cursor: pointer;
    user-select: none;
    transition: background 0.15s;
}

.raw-json summary:hover {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
}

.raw-json pre {
    margin: 0;
    padding: 1rem 1.25rem;
    background: var(--bg-primary);
    font-family: "SF Mono", Monaco, "Cascadia Code", monospace;
    font-size: 0.75rem;
    line-height: 1.6;
    overflow-x: auto;
    white-space: pre-wrap;
    word-break: break-word;
    color: var(--text-secondary);
    max-height: 400px;
    overflow-y: auto;
}

/* About Section */
.about-section {
    margin-top: 2rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-secondary);
}

.about-section summary {
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    user-select: none;
    transition: background 0.15s;
}

.about-section summary:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.about-section[open] summary {
    border-bottom: 1px solid var(--border);
}

.about-content {
    padding: 1rem 1.25rem;
    font-size: 0.875rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

.about-content p {
    margin-bottom: 0.75rem;
}

.about-content ul {
    margin: 0.75rem 0;
    padding-left: 1.5rem;
}

.about-content li {
    margin-bottom: 0.375rem;
}

.about-content strong {
    color: var(--text-primary);
}

.about-content a {
    color: var(--accent-dim);
    text-decoration: none;
}

.about-content a:hover {
    color: var(--accent);
    text-decoration: underline;
}

.about-content .code-example {
    margin-top: 1rem;
    padding: 0.75rem 1rem;
    background: var(--bg-primary);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--accent-dim);
    overflow-x: auto;
}

.about-content .code-example code {
    font-family: "SF Mono", Monaco, "Cascadia Code", monospace;
    font-size: 0.8125rem;
    color: var(--accent);
    white-space: nowrap;
}

.about-content .badge {
    display: inline-block;
    vertical-align: middle;
    margin: 0 0.125rem;
}

/* Footer */
.footer {
    margin-top: 2rem;
    text-align: center;
}

.footer p {
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.footer a {
    color: var(--accent-dim);
    text-decoration: none;
}

.footer a:hover {
    color: var(--accent);
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 640px) {
    .container {
        padding: 1.5rem 1rem;
    }

    .input-row {
        flex-wrap: wrap;
    }

    .input-row input[type="text"] {
        width: 100%;
    }

    .input-row select,
    .input-row button {
        flex: 1;
    }

    .result-summary {
        flex-direction: column;
        align-items: flex-start;
    }

    .result-timing {
        flex-wrap: wrap;
        gap: 0.75rem 1.5rem;
    }

    .chain-visualization {
        padding: 1rem;
    }

    .zone-card {
        min-width: 60px;
        padding: 0.5rem 0.75rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
        animation: none !important;
    }
}

/* Focus states - use focus-visible for keyboard-only focus rings */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Zone cards need explicit focus styles since they're clickable */
.zone-card:focus {
    outline: none;
}

.zone-card:focus-visible {
    outline: 3px solid var(--accent);
    outline-offset: 2px;
    border-color: var(--accent);
    box-shadow: 0 0 0 4px rgba(0, 212, 255, 0.25);
}

/* Zone tabs keyboard navigation */
.zone-tab:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.2);
}

/* Example buttons keyboard navigation */
.example-btn:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    border-color: var(--accent);
}

/* Copy button keyboard navigation */
.copy-btn:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    border-color: var(--accent);
}

/* Raw JSON details focus */
.raw-json summary:focus-visible,
.about-section summary:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: -2px;
    background: var(--bg-tertiary);
}

/* Fallback for browsers without focus-visible support */
@supports not selector(:focus-visible) {
    a:focus,
    button:focus,
    input:focus,
    select:focus,
    .zone-card:focus,
    .zone-tab:focus,
    .example-btn:focus,
    .copy-btn:focus {
        outline: 2px solid var(--accent);
        outline-offset: 2px;
    }
}