/* ── Self-hosted fonts ─── */
@font-face {
    font-family: 'Monomakh';
    src: url('fonts/MonomakhUnicode-Regular.woff2') format('woff2');
    font-weight: normal;
    font-style: normal;
    font-display: swap;
    unicode-range: U+0000-007F, U+0080-00FF, U+0300-036F, U+0400-04FF,
        U+0500-052F, U+1C80-1C8F, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F;
}

/* ── Design tokens ───────────────────────────────────────────────────── */
:root {
    --bg:          #111827;
    --bg-panel:    #1f2937;
    --bg-section:  #1a2333;
    --bg-input:    #111827;
    --bg-hover:    #2a3a52;
    --text:        #e2e8f0;
    --text-muted:  #64748b;
    --text-dim:    #94a3b8;
    --accent:      #e94560;
    --accent-hover:#ff6b81;
    --primary:     #3b82f6;
    --primary-hover:#60a5fa;
    --success:     #22c55e;
    --warning:     #f59e0b;
    --danger:      #ef4444;
    --border:      #2d3f59;
    --border-light:#3a4f6e;
    --radius:      6px;
    --radius-lg:   10px;
    --font:        'Segoe UI', system-ui, -apple-system, sans-serif;
    --font-mono:   'Consolas', 'Fira Code', 'Cascadia Code', monospace;
    --header-h:    44px;
    --tabs-h:      56px;
    --shadow:      0 4px 20px rgba(0,0,0,0.4);
}

/* ── Reset & base ───────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { height: 100%; }

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    height: 100%;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* ── Header ─────────────────────────────────────────────────────────── */
#header {
    height: var(--header-h);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 14px;
    background: var(--bg-panel);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    gap: 12px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 8px;
    min-width: 0;
}

.header-logo {
    font-size: 1.3rem;
    color: var(--primary);
    line-height: 1;
}

#header h1 {
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: 0.3px;
    white-space: nowrap;
}

.header-sub {
    font-weight: 400;
    color: var(--text-muted);
    font-size: 0.9rem;
    letter-spacing: 2px;
    margin-left: 2px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}

.gpu-badge {
    font-size: 0.75rem;
    padding: 3px 10px;
    border-radius: 12px;
    background: var(--bg-input);
    color: var(--text-muted);
    border: 1px solid var(--border);
    white-space: nowrap;
    max-width: 280px;
    overflow: hidden;
    text-overflow: ellipsis;
}

.btn-icon {
    width: 30px;
    height: 30px;
    border: 1px solid var(--border);
    border-radius: 50%;
    background: var(--bg-input);
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: border-color 0.15s, color 0.15s;
}
.btn-icon:hover { border-color: var(--primary); color: var(--primary); }

/* ── GPU widget ─────────────────────────────────────────────────────── */
.gpu-widget {
    display: flex;
    gap: 8px;
    align-items: center;
}
.gpu-card {
    display: flex;
    flex-direction: column;
    gap: 3px;
    font-size: 0.7rem;
    color: var(--text-muted);
    min-width: 90px;
    max-width: 160px;
}
.gpu-card-name {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 4px;
    white-space: nowrap;
    overflow: hidden;
}
.gpu-card-name span { overflow: hidden; text-overflow: ellipsis; }
.gpu-util-pct {
    font-size: 0.68rem;
    color: var(--text-dim);
    flex-shrink: 0;
}
.gpu-mem-bar {
    height: 4px;
    background: var(--bg-input);
    border-radius: 2px;
    overflow: hidden;
}
.gpu-mem-fill {
    height: 100%;
    border-radius: 2px;
    background: var(--primary);
    transition: width 0.5s ease;
}
.gpu-mem-fill.warm  { background: var(--warning); }
.gpu-mem-fill.hot   { background: var(--danger); }
.gpu-mem-label {
    font-size: 0.65rem;
    color: var(--text-muted);
}

/* ── Toast notifications ─────────────────────────────────────────────── */
#toast-container {
    position: fixed;
    bottom: 20px;
    right: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    z-index: 9999;
    pointer-events: none;
}
.toast {
    padding: 10px 16px;
    border-radius: var(--radius);
    font-size: 0.85rem;
    box-shadow: var(--shadow);
    pointer-events: auto;
    animation: toast-in 0.2s ease;
    max-width: 320px;
}
.toast-error   { background: #7f1d1d; color: #fca5a5; border: 1px solid #991b1b; }
.toast-success { background: #14532d; color: #86efac; border: 1px solid #15803d; }
.toast-info    { background: #1e3a5f; color: #93c5fd; border: 1px solid #1d4ed8; }
@keyframes toast-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

/* ── Main layout (3 columns) ────────────────────────────────────────── */
#app {
    display: grid;
    grid-template-columns: var(--panel-left, 260px) 5px 1fr 5px var(--panel-right, 360px);
    grid-template-rows: 1fr;
    gap: 0;
    flex: 1;
    min-height: 0;
    background: var(--border);
}
.panel-resize-handle {
    background: var(--border);
    cursor: col-resize;
    transition: background 0.15s;
    z-index: 10;
    position: relative;
}
.panel-resize-handle:hover,
.panel-resize-handle.dragging {
    background: var(--primary);
}
.panel-resize-handle::after {
    content: '';
    position: absolute;
    inset: 0 -4px; /* wider hit area */
}

.panel {
    background: var(--bg-panel);
    overflow-y: auto;
    overflow-x: hidden;
    min-height: 0;
}

/* Left panel flex column */
#engine-panel {
    display: flex;
    flex-direction: column;
    gap: 0;
    padding: 0;
}

.panel-section {
    padding: 12px 12px 8px;
    display: flex;
    flex-direction: column;
    gap: 7px;
}

.panel-footer {
    padding: 10px 12px;
    border-top: 1px solid var(--border);
    margin-top: auto;
}
.footer-btn-row {
    display: flex;
    gap: 6px;
}
.footer-btn-row .btn {
    flex: 1;
}

.panel h2 {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--text-muted);
    margin-bottom: 2px;
}

#engine-panel hr {
    border: none;
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}

/* ── Form elements ──────────────────────────────────────────────────── */
label {
    font-size: 0.78rem;
    color: var(--text-dim);
}

select,
input[type="text"],
input[type="number"],
input[type="password"] {
    width: 100%;
    padding: 6px 9px;
    background: var(--bg-input);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.83rem;
    font-family: var(--font);
    transition: border-color 0.15s;
}

select:focus, input:focus, textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(59,130,246,0.12);
}

textarea {
    width: 100%;
    padding: 6px 9px;
    background: var(--bg-input);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.83rem;
    font-family: var(--font);
    transition: border-color 0.15s;
    box-sizing: border-box;
}

input::placeholder,
textarea::placeholder {
    color: var(--text-dim);
    font-style: italic;
    opacity: 0.65;
}

select option { background: var(--bg-panel); color: var(--text); }

/* Config form fields */
.config-field {
    display: flex;
    flex-direction: column;
    gap: 3px;
}

/* Select + refresh button row */
.select-row {
    display: flex;
    gap: 4px;
    align-items: center;
}
.select-row select { flex: 1; min-width: 0; width: auto; }

.btn-refresh {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-input);
    color: var(--text-muted);
    font-size: 1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.btn-refresh:hover:not(:disabled) { background: var(--bg-hover); border-color: var(--primary); color: var(--primary); }
.btn-refresh:disabled { opacity: 0.5; cursor: not-allowed; }

.dynamic-hint {
    font-size: 0.7rem;
    color: var(--text-muted);
    min-height: 1em;
}

.config-field label { font-size: 0.75rem; color: var(--text-muted); }

.config-field-checkbox {
    flex-direction: row;
    align-items: center;
    gap: 7px;
}
.config-field-checkbox input[type="checkbox"] {
    width: auto;
    accent-color: var(--primary);
    cursor: pointer;
}
.config-field-checkbox label { font-size: 0.82rem; color: var(--text); cursor: pointer; }

#blla-options {
    display: flex;
    align-items: center;
    gap: 8px;
}
#blla-options label { flex-shrink: 0; }
#blla-options input { width: 64px; }

/* ── Buttons ────────────────────────────────────────────────────────── */
.btn {
    padding: 8px 14px;
    border: none;
    border-radius: var(--radius);
    font-size: 0.83rem;
    font-family: var(--font);
    cursor: pointer;
    transition: background 0.15s, transform 0.1s;
    white-space: nowrap;
}
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn:disabled { opacity: 0.38; cursor: not-allowed; }

.btn-full { width: 100%; }

.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover:not(:disabled) { background: var(--primary-hover); }

.btn-accent { background: var(--accent); color: white; }
.btn-accent:hover:not(:disabled) { background: var(--accent-hover); }

.btn-small {
    padding: 5px 10px;
    font-size: 0.78rem;
    background: var(--bg-input);
    color: var(--text-dim);
    border: 1px solid var(--border);
}
.btn-small:hover:not(:disabled) { background: var(--bg-hover); border-color: var(--border-light); color: var(--text); }

.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    cursor: pointer;
    border-radius: var(--radius);
    display: inline-flex;
    align-items: center;
    font-size: 0.78rem;
    color: var(--text-dim);
    padding: 4px 8px;
    transition: background 0.15s, border-color 0.15s;
}
.btn-outline:hover { background: var(--bg-hover); border-color: var(--primary); color: var(--text); }

.btn-row {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    margin-top: 6px;
}

/* Save key row */
.key-save-row {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-top: 4px;
    font-size: 0.76rem;
    color: var(--text-muted);
}
.key-save-row input[type="checkbox"] { width: auto; margin: 0; accent-color: var(--primary); }
.key-save-row label { cursor: pointer; }

input[disabled] { opacity: 0.45; cursor: not-allowed; }

/* ── Upload area ────────────────────────────────────────────────────── */
.upload-area {
    border: 2px dashed var(--border);
    border-radius: var(--radius-lg);
    padding: 18px 12px;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
    font-size: 0.83rem;
    color: var(--text-muted);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}
.upload-area:hover, .upload-area.dragover {
    border-color: var(--primary);
    background: rgba(59,130,246,0.06);
    color: var(--text-dim);
}
.upload-icon {
    width: 28px;
    height: 28px;
    opacity: 0.5;
}
.upload-area:hover .upload-icon,
.upload-area.dragover .upload-icon { opacity: 0.8; }

/* XML row */
.xml-row {
    display: flex;
    align-items: center;
    gap: 8px;
}
.xml-row .muted {
    flex: 1;
    font-size: 0.78rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.xml-ok { color: var(--success) !important; }

/* ── Image viewer (center) ──────────────────────────────────────────── */
#viewer-panel {
    padding: 0;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

/* Zoom toolbar */
.zoom-toolbar {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 5px 8px;
    background: var(--bg-panel);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    z-index: 2;
}
.zoom-btn {
    width: 26px;
    height: 26px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-input);
    color: var(--text-dim);
    font-size: 1rem;
    line-height: 1;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.15s, border-color 0.15s;
}
.zoom-btn:hover { background: var(--bg-hover); border-color: var(--border-light); color: var(--text); }
.zoom-fit { font-size: 0.8rem; width: auto; padding: 0 7px; }
.zoom-toolbar-sep { width: 1px; background: var(--border); margin: 0 4px; align-self: stretch; }
.nav-btn { padding: 2px 8px; font-size: .8rem; line-height: 1.6; }
.nav-btn:disabled { opacity: 0.3; cursor: default; }
.batch-nav-label-toolbar { font-size: .78rem; color: var(--text-muted); min-width: 36px; text-align: center; }
.zoom-level {
    font-size: 0.75rem;
    color: var(--text-muted);
    min-width: 3.5em;
    text-align: center;
    font-family: var(--font-mono);
}

/* Scrollable image area */
#viewer-scroll {
    flex: 1;
    overflow: auto;
    display: flex;
    align-items: flex-start;
    justify-content: flex-start;
    min-height: 0;
    position: relative;
}

/* Placeholder — fills scroll area and centers content */
.viewer-placeholder {
    width: 100%;
    height: 100%;
    min-height: 200px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 14px;
    color: var(--text-muted);
    font-size: 0.9rem;
    user-select: none;
}
.viewer-placeholder.dragover {
    color: var(--primary);
    background: rgba(59, 130, 246, 0.08);
}
.viewer-placeholder svg {
    width: 56px;
    height: 56px;
    opacity: 0.25;
}
.viewer-placeholder p { opacity: 0.6; }

/* Image container — only shows when image is loaded */
#image-container {
    position: relative;
    flex-shrink: 0;
    line-height: 0;
}

#page-image {
    display: block;
    /* width controlled by zoom JS; height auto */
    transition: width 0.08s ease-out, height 0.08s ease-out;
}

#overlay-canvas {
    position: absolute;
    top: 0;
    left: 0;
    pointer-events: auto;
    cursor: crosshair;
    transition: width 0.08s ease-out, height 0.08s ease-out;
}

/* ── Results panel (right) ──────────────────────────────────────────── */
#results-panel {
    display: flex;
    flex-direction: column;
}

.results-header {
    padding: 12px 12px 8px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}
.results-header-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0;
}
.results-header-row h2 { margin-bottom: 0; }
.results-header-controls {
    display: flex;
    align-items: center;
    gap: 5px;
}
.btn-icon.active { border-color: var(--primary); color: var(--primary); background: rgba(59,130,246,0.1); }

/* Font selector in results header */
.font-select {
    width: auto !important;
    padding: 3px 5px !important;
    font-size: 0.72rem !important;
    height: 26px;
    border-radius: var(--radius);
    color: var(--text-muted);
    max-width: 140px;
}

#transcription-lines {
    flex: 1;
    overflow-y: auto;
    font-family: var(--font-results, var(--font-mono));
    font-size: 0.83rem;
    line-height: 1.5;
    padding: 4px 0;
}

.line-result {
    padding: 5px 10px;
    border-bottom: 1px solid rgba(45,63,89,0.5);
    cursor: pointer;
    transition: background 0.1s;
}
.line-result:last-child { border-bottom: none; }
.line-result:hover { background: var(--bg-hover); }

.line-num {
    color: var(--text-muted);
    font-size: 0.68rem;
    margin-right: 7px;
    user-select: none;
    display: inline-block;
    min-width: 2.2em;
    text-align: right;
}

.confidence {
    float: right;
    font-size: 0.68rem;
    padding: 1px 6px;
    border-radius: 8px;
    margin-left: 6px;
    margin-top: 2px;
}
.conf-high { background: rgba(34,197,94,0.15);  color: var(--success); }
.conf-mid  { background: rgba(245,158,11,0.15); color: var(--warning); }
.conf-low  { background: rgba(239,68,68,0.15);  color: var(--danger);  }

.line-result.line-active {
    background: rgba(233,69,96,0.12);
    border-left: 3px solid var(--accent);
}
.line-result.highlight {
    background: rgba(59,130,246,0.12);
    border-left: 3px solid var(--primary);
}

/* Dimmed lines (below confidence threshold) */
.line-result.line-dimmed {
    opacity: 0.28;
}

/* Inline editing */
.line-text {
    display: inline;
    outline: none;
    border-radius: 2px;
}
.line-text[contenteditable="true"] {
    background: rgba(58, 134, 255, 0.08);
    outline: 1px dashed var(--primary);
    padding: 0 3px;
    cursor: text;
}
/* Gemini thinking/reasoning block */
.thinking-block {
    display: block;
    width: 100%;
    margin-top: 4px;
}
.thinking-toggle {
    font-size: 0.7rem;
    color: var(--text-dim);
    cursor: pointer;
    user-select: none;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}
.thinking-toggle:hover { color: var(--primary); }
.thinking-text {
    margin: 4px 0 0 0;
    padding: 6px 10px;
    font-size: 0.72rem;
    font-family: monospace;
    white-space: pre-wrap;
    word-break: break-word;
    background: var(--bg-input);
    border-left: 2px solid var(--border);
    color: var(--text-dim);
    border-radius: 0 3px 3px 0;
    max-height: 300px;
    overflow-y: auto;
}

.line-result.line-edited .line-num::after {
    content: '✎';
    color: var(--primary);
    font-size: 0.6rem;
    margin-left: 2px;
}

/* Confidence filter row */
.results-search-row {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 0;
}
.results-search-row input[type="search"] {
    flex: 1;
    min-width: 0;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text);
    font-size: 0.8rem;
    padding: 3px 8px;
}
.results-search-row input[type="search"]:focus {
    outline: none;
    border-color: var(--primary);
}
#results-search-count {
    font-size: 0.72rem;
    white-space: nowrap;
}
.line-result.line-hidden { display: none; }
.line-result mark { background: color-mix(in srgb, var(--accent) 35%, transparent); border-radius: 2px; }

/* Thinking / reasoning block (Gemini, Claude) */
.thinking-block {
    margin-top: 4px;
    border-left: 2px solid var(--accent);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    background: color-mix(in srgb, var(--accent) 6%, var(--bg-secondary));
    font-size: 0.75rem;
}
.thinking-toggle {
    cursor: pointer;
    padding: 2px 6px;
    color: var(--accent);
    user-select: none;
    font-style: italic;
    list-style: none;
}
.thinking-toggle::marker,
.thinking-toggle::-webkit-details-marker { display: none; }
.thinking-toggle::before {
    content: '▶ ';
    font-style: normal;
    font-size: 0.65rem;
    transition: transform 0.15s;
}
details[open] > .thinking-toggle::before { content: '▼ '; }
.thinking-text {
    margin: 0;
    padding: 4px 8px 6px;
    white-space: pre-wrap;
    word-break: break-word;
    color: var(--text-secondary);
    font-family: inherit;
    line-height: 1.45;
    max-height: 200px;
    overflow-y: auto;
}

.conf-filter-row {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 0 6px;
    font-size: 0.75rem;
    color: var(--text-muted);
}
.conf-filter-row input[type="range"] {
    flex: 1;
    width: auto;
    height: 3px;
    cursor: pointer;
    accent-color: var(--primary);
    padding: 0;
    background: none;
    border: none;
}

/* Batch queue */
#batch-queue-section {
    margin-top: 6px;
    border-top: 1px solid var(--border);
    padding-top: 8px;
}
.batch-queue-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 4px;
}
.section-label {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: .06em;
    color: var(--text-muted);
}
.batch-overall-progress {
    font-size: 0.72rem;
    font-family: var(--font-mono);
    color: var(--accent);
    background: color-mix(in srgb, var(--accent) 12%, transparent);
    padding: 1px 7px;
    border-radius: 10px;
}
.batch-item {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 2px;
    font-size: 0.78rem;
    border-bottom: 1px solid rgba(45,63,89,0.4);
}
.batch-item:last-child { border-bottom: none; }
.batch-drag-handle {
    cursor: grab;
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1;
    padding: 0 2px;
    flex-shrink: 0;
    user-select: none;
}
.batch-drag-handle:active { cursor: grabbing; }
.batch-item.batch-dragging { opacity: 0.4; }
.batch-item.batch-drag-over {
    border-top: 2px solid var(--accent);
    margin-top: -1px;
}
.batch-item-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    color: var(--text);
}
.batch-status {
    font-size: 0.68rem;
    flex-shrink: 0;
    min-width: 56px;
    text-align: right;
    color: var(--text-muted);
}
.batch-status.done   { color: var(--success); }
.batch-status.error  { color: var(--danger); }
.batch-status.active { color: var(--primary); }

.batch-nav-row {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-top: 6px;
}
.batch-options-row {
    display: flex;
    gap: 14px;
    align-items: center;
    margin-top: 6px;
    flex-wrap: wrap;
}
.checkbox-label {
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: .8rem;
    color: var(--text-muted);
    cursor: pointer;
    user-select: none;
}
.checkbox-label input[type="checkbox"] { cursor: pointer; }

/* Column layout (multi-region side-by-side) */
#transcription-lines.col-layout {
    display: flex;
    flex-direction: row;
    align-items: flex-start;  /* columns grow to their content height */
    overflow-x: auto;
    /* overflow-y stays 'auto' from the base rule — unified scroll */
    padding: 0;
    gap: 0;
}
.region-column {
    flex: 0 0 auto;       /* don't shrink; grow to content */
    min-width: 220px;
    width: max-content;   /* each column as wide as its widest line */
    max-width: min(520px, 75vw);
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border);
    /* No overflow-y — parent handles the single scrollbar */
}
.region-column:last-child { border-right: none; }
/* Prevent line text from wrapping inside column cells */
.region-column .line-result { white-space: nowrap; }
.region-col-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 4px;
    padding: 4px 8px;
    font-size: 0.68rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--text-muted);
    background: var(--bg-section);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1;
}
.region-col-close {
    flex-shrink: 0;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 1rem;
    line-height: 1;
    padding: 0 2px;
    border-radius: 3px;
    transition: color 0.1s, background 0.1s;
}
.region-col-close:hover { color: var(--danger); background: rgba(239,68,68,0.1); }

/* Detected region list (below segmentation controls) */
#seg-regions-list {
    margin: 0 12px 8px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-section);
    overflow: hidden;
}
.seg-regions-header {
    padding: 5px 10px;
    font-size: 0.68rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border);
}
.seg-region-row {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 5px 10px;
    border-bottom: 1px solid rgba(45,63,89,0.4);
    font-size: 0.78rem;
}
.seg-region-row:last-child { border-bottom: none; }
.seg-region-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    flex-shrink: 0;
}
.seg-region-label { font-weight: 600; color: var(--text); min-width: 2em; }
.seg-region-count { flex: 1; color: var(--text-muted); }
.seg-region-del {
    width: 22px !important;
    height: 22px !important;
    font-size: 0.9rem !important;
    flex-shrink: 0;
}

/* Region separator */
.region-separator {
    padding: 4px 10px;
    font-size: 0.68rem;
    color: var(--text-muted);
    background: var(--bg-section);
    border-bottom: 1px solid var(--border);
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

#results-footer {
    padding: 8px 12px;
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}

/* ── Progress bar ───────────────────────────────────────────────────── */
.progress-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    margin-top: 4px;
}

#progress-bar {
    height: 4px;
    background: var(--bg-input);
    border-radius: 2px;
    overflow: hidden;
    margin-top: 8px;
}
#progress-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transition: width 0.25s ease;
    border-radius: 2px;
}

/* ── Status badges ──────────────────────────────────────────────────── */
.status-badge {
    font-size: 0.78rem;
    padding: 4px 10px;
    border-radius: var(--radius);
    text-align: center;
}
.status-loaded  { background: rgba(34,197,94,0.12);  color: var(--success); border: 1px solid rgba(34,197,94,0.25); }
.status-loading { background: rgba(59,130,246,0.12); color: var(--primary); border: 1px solid rgba(59,130,246,0.25); }

/* ── Spinner on buttons ─────────────────────────────────────────────── */
.btn.loading { pointer-events: none; opacity: 0.7; }
.btn.loading::after {
    content: '';
    display: inline-block;
    width: 11px;
    height: 11px;
    margin-left: 7px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    animation: spin 0.65s linear infinite;
    vertical-align: middle;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Utilities ──────────────────────────────────────────────────────── */
.muted   { color: var(--text-muted); font-size: 0.8rem; }
.hidden  { display: none !important; }

/* ── Help modal ─────────────────────────────────────────────────────── */
#help-modal {
    background: var(--bg-panel);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    padding: 0;
    width: min(680px, 96vw);
    max-height: 82vh;
    overflow: hidden;
}
#help-modal[open] {
    display: flex;
    flex-direction: column;
}
#help-modal::backdrop {
    background: rgba(0,0,0,0.65);
    backdrop-filter: blur(2px);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 18px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}
.modal-header h2 { font-size: 1rem; font-weight: 600; }

.modal-body {
    overflow-y: auto;
    padding: 18px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    font-size: 0.88rem;
    line-height: 1.6;
}

.modal-body h3 {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border);
    padding-bottom: 4px;
    margin-top: 4px;
}

.modal-body ol, .modal-body ul { padding-left: 1.4em; display: flex; flex-direction: column; gap: 5px; }
.modal-body li { color: var(--text-dim); }
.modal-body strong { color: var(--text); font-weight: 600; }

.modal-body table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.83rem;
}
.modal-body th, .modal-body td {
    padding: 5px 10px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}
.modal-body th { color: var(--text-muted); font-weight: 600; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.5px; }
.modal-body td:first-child { color: var(--text); font-weight: 500; white-space: nowrap; }
.modal-body tr:last-child td { border-bottom: none; }
.modal-body tr:hover td { background: var(--bg-hover); }

.modal-body kbd {
    display: inline-block;
    padding: 1px 6px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--text-dim);
}

.demo-badge {
    font-size: 0.72rem;
    padding: 1px 6px;
    border-radius: 8px;
    display: inline-block;
    margin: 0 2px;
}

/* ── Mobile tab bar ─────────────────────────────────────────────────── */
#mobile-tabs {
    display: none;   /* hidden on desktop */
    height: var(--tabs-h);
    background: var(--bg-panel);
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}

.tab-btn {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 3px;
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 0.68rem;
    cursor: pointer;
    padding: 6px 4px;
    transition: color 0.15s;
}
.tab-btn svg { width: 20px; height: 20px; }
.tab-btn.active { color: var(--primary); }
.tab-btn:hover { color: var(--text-dim); }
.tab-btn.active:hover { color: var(--primary-hover); }

/* ── Responsive — tablet (≤ 960px) ─────────────────────────────────── */
@media (max-width: 960px) {
    #app { grid-template-columns: var(--panel-left, 240px) 5px 1fr 5px var(--panel-right, 300px); }
    .gpu-badge { max-width: 160px; font-size: 0.7rem; }
}

@media (max-width: 780px) and (min-width: 641px) {
    #app { grid-template-columns: var(--panel-left, 200px) 5px 1fr 5px var(--panel-right, 240px); }
    .gpu-badge { max-width: 120px; font-size: 0.68rem; }
}

/* ── Responsive — mobile (≤ 640px) ─────────────────────────────────── */
@media (max-width: 640px) {
    :root { --header-h: 48px; }

    #header h1 { font-size: 0.9rem; }
    .gpu-badge { display: none; }      /* too little space */

    /* Single-column; tab bar controls which panel is visible */
    #app {
        grid-template-columns: 1fr;
        grid-template-rows: 1fr;
    }
    .panel-resize-handle { display: none; }

    #mobile-tabs { display: flex; }

    /* All panels are hidden by default; JS adds panel-active */
    [data-panel] {
        display: none;
    }
    [data-panel].panel-active {
        display: flex;
        flex-direction: column;
    }
    /* Engine panel needs special treatment (flex column) */
    [data-panel="settings"].panel-active {
        overflow-y: auto;
    }

    body { overflow: hidden; }
    /* Account for tab bar height */
    #app { height: calc(100vh - var(--header-h) - var(--tabs-h)); }

    /* Results panel: stack vertically */
    #results-panel.panel-active { gap: 0; }

    /* Larger touch targets */
    .btn { padding: 10px 16px; font-size: 0.9rem; }
    .btn-small { padding: 7px 12px; font-size: 0.82rem; }
    select, input[type="text"], input[type="number"], input[type="password"] {
        padding: 8px 10px;
        font-size: 0.9rem;
    }

    /* Upload area takes less vertical space */
    .upload-area { padding: 14px 10px; }

    /* Full-width help modal */
    #help-modal { width: 100vw; max-height: 90vh; border-radius: var(--radius-lg) var(--radius-lg) 0 0; }
}