.page-tool--heading-structure-visualizer .tool-page {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.page-tool--heading-structure-visualizer .tool-workspace {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 16px;
    align-items: stretch;
}

.page-tool--heading-structure-visualizer .tool-pane {
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.page-tool--heading-structure-visualizer .tool-pane__body {
    display: flex;
    flex-direction: column;
    flex: 1 1 auto;
    min-height: 30rem;
}

.page-tool--heading-structure-visualizer .tool-textarea {
    display: block;
    flex: 1 1 auto;
    min-height: 0;
    padding: 14px 16px;
    border: 0;
    border-radius: 0;
    background: var(--surface);
    resize: none;
}

.page-tool--heading-structure-visualizer .tool-textarea:focus {
    box-shadow: none;
}

.page-tool--heading-structure-visualizer .tool-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 11px 16px;
    border-top: 1px solid var(--line);
    background: var(--surface-2);
}

.page-tool--heading-structure-visualizer .tool-hint {
    margin: 0;
    color: var(--muted);
    font-size: 0.8rem;
}

.page-tool--heading-structure-visualizer .tool-hint--note {
    padding: 11px 16px;
    border-top: 1px solid var(--line);
    background: var(--surface-2);
}

.page-tool--heading-structure-visualizer .tool-status {
    min-height: 0;
    margin: 0;
    padding: 11px 16px;
    border-bottom: 1px solid var(--line);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--muted);
}

.page-tool--heading-structure-visualizer .tool-status.status {
    margin: 0;
    border: 0;
    border-bottom: 1px solid var(--line);
    border-radius: 0;
    background: transparent;
}

.page-tool--heading-structure-visualizer .tool-status.status--error {
    background: var(--danger-soft);
    color: var(--danger);
}

.page-tool--heading-structure-visualizer .tool-status.status--warning {
    background: var(--warning-soft);
    color: var(--warning);
}

.page-tool--heading-structure-visualizer .tool-status.status--success {
    background: var(--success-soft);
    color: var(--success);
}

.page-tool--heading-structure-visualizer .tool-summary {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 12px 16px;
    border-bottom: 1px solid var(--line);
    background: var(--surface-2);
}

.page-tool--heading-structure-visualizer .tool-summary[hidden] {
    display: none;
}

.page-tool--heading-structure-visualizer .heading-chip {
    display: inline-flex;
    align-items: center;
    padding: 0.2rem 0.55rem;
    border: 1px solid var(--line);
    border-radius: var(--radius-pill);
    background: var(--surface);
    color: var(--muted);
    font-family: var(--font-mono);
    font-size: 0.68rem;
    white-space: nowrap;
}

.page-tool--heading-structure-visualizer .heading-chip--error {
    border-color: var(--danger);
    background: var(--danger-soft);
    color: var(--danger);
}

.page-tool--heading-structure-visualizer .heading-chip--warning {
    border-color: var(--warning);
    background: var(--warning-soft);
    color: var(--warning);
}

.page-tool--heading-structure-visualizer .heading-chip--muted {
    color: var(--faint);
}

.page-tool--heading-structure-visualizer .tool-outline {
    flex: 1 1 auto;
    min-height: 0;
    max-height: 34rem;
    overflow: auto;
    background: var(--surface);
}

.page-tool--heading-structure-visualizer .tool-outline .empty-state {
    border: 0;
    border-radius: 0;
    background: transparent;
    padding: 3rem 1.25rem;
}

.page-tool--heading-structure-visualizer .heading-tree {
    display: flex;
    flex-direction: column;
    padding: 8px 0;
}

.page-tool--heading-structure-visualizer .heading-node {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 7px 16px 7px calc(16px + var(--heading-depth, 0) * 20px);
    border-bottom: 1px solid var(--line);
    font-size: 0.85rem;
}

.page-tool--heading-structure-visualizer .heading-node:last-child {
    border-bottom: 0;
}

.page-tool--heading-structure-visualizer .heading-node__level {
    flex: 0 0 auto;
    padding: 0.1rem 0.4rem;
    border: 1px solid var(--line-2);
    border-radius: var(--radius-xs);
    background: var(--surface-2);
    color: var(--muted);
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-weight: 600;
}

.page-tool--heading-structure-visualizer .heading-node__level--h1 {
    border-color: var(--accent-line);
    background: var(--accent-soft);
    color: var(--accent);
}

.page-tool--heading-structure-visualizer .heading-node__level--h2 {
    color: var(--ink);
}

.page-tool--heading-structure-visualizer .heading-node__level--h5,
.page-tool--heading-structure-visualizer .heading-node__level--h6 {
    color: var(--faint);
}

.page-tool--heading-structure-visualizer .heading-node__order {
    flex: 0 0 auto;
    color: var(--faint);
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-variant-numeric: tabular-nums;
}

.page-tool--heading-structure-visualizer .heading-node__text {
    min-width: 0;
    color: var(--ink);
    overflow-wrap: anywhere;
}

.page-tool--heading-structure-visualizer .heading-node--h1 .heading-node__text {
    font-weight: 600;
}

.page-tool--heading-structure-visualizer .heading-node__text--empty {
    color: var(--danger);
    font-style: italic;
}

.page-tool--heading-structure-visualizer .tool-issues-panel .panel__body {
    padding: 16px;
}

.page-tool--heading-structure-visualizer .tool-issues-panel .empty-state {
    border: 0;
    background: transparent;
    padding: 1.5rem;
}

.page-tool--heading-structure-visualizer .tool-issues-panel .status {
    margin: 0;
}

.page-tool--heading-structure-visualizer .heading-issues {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin: 0;
    padding: 0;
    list-style: none;
    counter-reset: issue;
}

.page-tool--heading-structure-visualizer .heading-issue {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 10px 14px;
    border: 1px solid var(--line);
    border-left: 3px solid var(--line-strong);
    border-radius: var(--radius-sm);
    background: var(--surface-2);
    font-size: 0.86rem;
    counter-increment: issue;
}

.page-tool--heading-structure-visualizer .heading-issue--error {
    border-left-color: var(--danger);
}

.page-tool--heading-structure-visualizer .heading-issue--warning {
    border-left-color: var(--warning);
}

.page-tool--heading-structure-visualizer .heading-issue__severity {
    flex: 0 0 auto;
    padding: 0.1rem 0.45rem;
    border-radius: var(--radius-pill);
    font-family: var(--font-mono);
    font-size: 0.64rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.page-tool--heading-structure-visualizer .heading-issue--error .heading-issue__severity {
    background: var(--danger-soft);
    color: var(--danger);
}

.page-tool--heading-structure-visualizer .heading-issue--warning .heading-issue__severity {
    background: var(--warning-soft);
    color: var(--warning);
}

.page-tool--heading-structure-visualizer .heading-issue__body {
    min-width: 0;
    color: var(--ink);
}

.page-tool--heading-structure-visualizer .tool-about__text {
    max-width: 80ch;
    margin: 0;
    color: var(--muted);
    font-size: 0.9rem;
}

.page-tool--heading-structure-visualizer .tool-about__text code {
    padding: 0.05rem 0.3rem;
    border-radius: var(--radius-xs);
    background: var(--surface-3);
    color: var(--ink-2);
    font-family: var(--font-mono);
}

@media (max-width: 860px) {
    .page-tool--heading-structure-visualizer .tool-workspace {
        grid-template-columns: 1fr;
    }

    .page-tool--heading-structure-visualizer .tool-pane__body {
        min-height: 0;
    }

    .page-tool--heading-structure-visualizer .tool-textarea {
        min-height: 16rem;
    }

    .page-tool--heading-structure-visualizer .tool-outline {
        max-height: 24rem;
    }
}

@media (max-width: 640px) {
    .page-tool--heading-structure-visualizer .heading-node {
        flex-wrap: wrap;
        row-gap: 3px;
    }

    .page-tool--heading-structure-visualizer .heading-node__text {
        flex: 1 1 100%;
    }
}