/* ── Layout ──────────────────────────────────────────────────────────────── */

html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    overflow: hidden;
    font-family: var(--font);
    color: var(--text);
    background-color: var(--bg);
}

#appMain {
    position: relative;
    height: calc(100vh - 2.65rem); /* clear .app-header */
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.browse-root {
    display: flex;
    flex-direction: column;
    flex: 1;
    height: 100%;
    overflow: hidden;
    background: var(--bg);
}

/* ── Toolbar ─────────────────────────────────────────────────────────────── */

.browse-toolbar {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.4rem 1rem;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.view-mode-toggle {
    display: inline-flex;
    gap: 0;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}

.view-mode-toggle .btn {
    border-radius: 0;
    border: none;
    border-right: 1px solid var(--border);
}

.view-mode-toggle .btn:last-child {
    border-right: none;
}

.view-mode-toggle .btn[aria-selected="true"] {
    background: var(--primary);
    color: var(--text-light);
}

/* Breadcrumbs */
.breadcrumbs {
    flex: 1;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.15rem 0.4rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    min-width: 0;
}

.breadcrumbs a,
.breadcrumbs button {
    color: var(--text-muted);
    background: none;
    border: 0;
    padding: 0.1rem 0.3rem;
    border-radius: var(--radius);
    cursor: pointer;
    text-decoration: none;
    font: inherit;
}

.breadcrumbs a:hover,
.breadcrumbs button:hover {
    color: var(--text);
    background: var(--bg-hover);
}

.breadcrumbs .bc-sep {
    color: var(--text-muted);
    user-select: none;
}

.breadcrumbs .bc-current {
    color: var(--text);
    font-weight: 600;
    padding: 0.1rem 0.3rem;
}

.bc-home-icon {
    width: 1em;
    height: 1em;
    vertical-align: -0.15em;
}

.toolbar__count {
    font-size: 0.8rem;
    color: var(--text-muted);
    white-space: nowrap;
}

/* ── Two-pane browse view ────────────────────────────────────────────────── */

.browse-view {
    display: flex;
    flex: 1;
    overflow: hidden;
    min-height: 0;
}

.pane {
    overflow: hidden;
    background: var(--bg);
    display: flex;
    flex-direction: column;
}

.tree-pane {
    width: 360px;
    min-width: 200px;
    max-width: 60%;
    border-right: 1px solid var(--border);
    flex-shrink: 0;
}

.tree-pane__body {
    flex: 1;
    overflow: auto;
    padding: 0.25rem 0;
    font-size: 0.875rem;
}

/* Pane resizer — 4px grab handle between tree and preview */
.pane-resizer {
    width: 4px;
    background: transparent;
    cursor: col-resize;
    flex-shrink: 0;
    position: relative;
    z-index: 1;
}

.pane-resizer:hover,
.pane-resizer.is-dragging {
    background: var(--primary);
}

.preview-pane {
    flex: 1;
    min-width: 0;
}

.preview-pane__header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 0.75rem;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    min-height: 2.1rem;
}

.preview-pane__title {
    flex: 1;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    min-width: 0;
}

.preview-pane__meta {
    font-size: 0.8rem;
    color: var(--text-muted);
    white-space: nowrap;
}

.preview-pane__body {
    flex: 1;
    overflow: auto;
    display: flex;
    flex-direction: column;
    background: var(--bg);
}

/* The body's children fill the available space. Plugins inject
   different content here — img, iframe, pre, custom markdown editor. */
.preview-pane__body > * {
    flex: 1;
    min-height: 0;
}

.preview-empty {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 0.95rem;
    padding: 2rem;
    text-align: center;
}

.preview-pane__body img.preview-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    margin: auto;
    display: block;
    flex: none; /* avoid flex sizing interfering with object-fit */
}

.preview-pane__body iframe.preview-iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.preview-pane__body pre.preview-text {
    padding: 1rem;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    white-space: pre-wrap;
    word-wrap: break-word;
    margin: 0;
    overflow: auto;
    background: var(--bg);
    color: var(--text);
}

/* ── Tree (vertical, file-explorer style) ───────────────────────────────── */

.tree-row {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.15rem 0.5rem;
    cursor: pointer;
    user-select: none;
    border-radius: 0;
    color: var(--text);
}

.tree-row:hover {
    background: var(--bg-hover);
}

.tree-row.is-selected {
    background: var(--bg-selected);
    color: var(--text);
}

.tree-row.is-selected .tree-name__label {
    color: var(--text);
}

.tree-name__chevron {
    display: inline-block;
    width: 1rem;
    text-align: center;
    color: var(--text-muted);
    flex-shrink: 0;
    font-family: monospace;
    font-size: 0.65rem;
}

.tree-row[data-isdir="true"] .tree-name__chevron::before,
.tree-row[data-iszip="true"] .tree-name__chevron::before {
    content: "▸";
}

.tree-row[data-isdir="true"].expanded .tree-name__chevron::before,
.tree-row[data-iszip="true"].expanded .tree-name__chevron::before {
    content: "▾";
}

.tree-name__chevron--leaf::before {
    content: "";
}

.tree-name__icon {
    flex-shrink: 0;
    font-size: 0.95rem;
}

.tree-name__label {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    color: var(--text);
}

.tree-row[data-isdir="true"] .tree-name__label,
.tree-row[data-iszip="true"] .tree-name__label {
    font-weight: 500;
}

/* ── Grid view (Phase C) ─────────────────────────────────────────────────── */

.grid-view {
    flex: 1;
    overflow: auto;
    background: var(--bg);
    padding: 0;
}

.grid-empty {
    padding: 3rem;
    text-align: center;
    color: var(--text-muted);
}

/* ── Status bar ──────────────────────────────────────────────────────────── */

.status-bar {
    padding: 0.4rem 1rem;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    font-size: 0.8rem;
    color: var(--text-muted);
    min-height: 1.6rem;
    flex-shrink: 0;
}

.status-bar.is-error { color: var(--danger); }
.status-bar.is-info  { color: var(--text); }

/* ── Markdown plugin (right-pane internals when a .md is selected) ──────── */

/* Editor toolbar (above the editor+TOC split): Save + dirty marker +
   status + source hint. Sticks to the top of the pane body. */
.md-toolbar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.35rem 0.75rem;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    font-size: 0.85rem;
}

.md-toolbar__dirty {
    color: var(--text-muted);
    font-size: 0.85rem;
    min-width: 6rem;
}

.md-toolbar__status {
    flex: 1;
    text-align: right;
    color: var(--text-muted);
    font-size: 0.85rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.md-toolbar__source {
    color: var(--text-muted);
    font-size: 0.75rem;
    font-style: italic;
    margin-left: 0.5rem;
    padding: 0.15rem 0.4rem;
    border-radius: var(--radius);
    background: var(--bg);
    border: 1px solid var(--border);
}

/* Editor + TOC two-pane split inside the preview body. */
.md-split {
    flex: 1;
    display: flex;
    flex-direction: row;
    min-height: 0;
    overflow: hidden;
}

.md-editor-host {
    flex: 1;
    min-width: 0;
    min-height: 0;
    overflow: hidden;
}

/* TOC pane sits on the right. Fixed width by default; the user can't
   resize it (yet) — kept simple in v1. */
.md-toc-pane {
    width: 220px;
    flex-shrink: 0;
    border-left: 1px solid var(--border);
    background: var(--bg);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.md-toc-pane__header {
    padding: 0.35rem 0.75rem;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    flex-shrink: 0;
}

.md-toc-pane__body {
    flex: 1;
    overflow-y: auto;
    padding: 0.4rem 0;
    font-size: 0.85rem;
    line-height: 1.4;
}

.toc-empty {
    color: var(--text-muted);
    font-style: italic;
    padding: 0.5rem 0.75rem;
    margin: 0;
    font-size: 0.85rem;
}

.toc-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.toc-item {
    margin: 0;
}

.toc-item a {
    display: block;
    padding: 0.2rem 0.75rem;
    text-decoration: none;
    color: var(--text);
    border-left: 2px solid transparent;
    transition: background 0.1s, border-color 0.1s;
}

.toc-item a:hover {
    background: var(--bg-hover);
    border-left-color: var(--primary);
}

.toc-item a:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: -2px;
}

.toc-level-1 a { padding-left: 0.75rem;  font-weight: 600; }
.toc-level-2 a { padding-left: 1.4rem; }
.toc-level-3 a { padding-left: 2.05rem; }
.toc-level-4 a { padding-left: 2.7rem;  color: var(--text-muted); }
.toc-level-5 a { padding-left: 3.35rem; color: var(--text-muted); font-size: 0.8rem; }
.toc-level-6 a { padding-left: 4rem;    color: var(--text-muted); font-size: 0.8rem; }

/* ── Sort control ────────────────────────────────────────────────────────── */
.sort-control {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.8rem;
    color: var(--text-muted);
    white-space: nowrap;
}

.sort-control__label {
    user-select: none;
}

.sort-control__select {
    font-family: var(--font);
    font-size: 0.8rem;
    padding: 0.2rem 0.4rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg);
    color: var(--text);
    cursor: pointer;
}

.sort-control__select:focus {
    outline: 2px solid var(--primary);
    outline-offset: -1px;
}

/* Front-matter display section inside the TOC pane. */
.md-fm-section {
    border-bottom: 1px solid var(--border);
    max-height: 40%;
    overflow-y: auto;
}

.md-fm-body {
    padding: 0.4rem 0.75rem;
    font-size: 0.85rem;
    line-height: 1.4;
}

.fm-empty {
    color: var(--text-muted);
    font-style: italic;
    font-size: 0.85rem;
    margin: 0;
}

.fm-list {
    margin: 0;
    display: grid;
    grid-template-columns: minmax(5rem, max-content) 1fr;
    gap: 0.15rem 0.5rem;
}

.fm-list dt {
    font-weight: 600;
    color: var(--text-muted);
    font-size: 0.8rem;
    text-transform: lowercase;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.fm-list dd {
    margin: 0;
    color: var(--text);
    font-size: 0.85rem;
    overflow-wrap: anywhere;
}

/* TOC pane resizer — narrower than the main one. */
.md-toc-resizer {
    width: 4px;
}