/* ============================================================
   IMAGE UPSCALE LAB — Professional Design System v2
   A dark image-processing workstation
   ============================================================ */
:root {
  --bg-base: #08080a; --bg-surface: #101012; --bg-surface-2: #16161a;
  --bg-surface-3: #1c1c20; --bg-elevated: #222228; --bg-overlay: rgba(8,8,10,0.92);
  --border-subtle: #1a1a1e; --border-default: #26262c; --border-strong: #38383f; --border-focus: #5b8def;
  --text-primary: #ececee; --text-secondary: #9696a0; --text-muted: #5a5a64; --text-dim: #3a3a42;
  --accent: #5b8def; --accent-hover: #7ba5f7; --accent-active: #4a7ce0;
  --accent-subtle: rgba(91,141,239,0.10); --accent-text: #82aaf7;
  --success: #2dd4bf; --success-subtle: rgba(45,212,191,0.10);
  --warning: #fbbf24; --warning-subtle: rgba(251,191,36,0.10);
  --error: #f87171; --error-subtle: rgba(248,113,113,0.10);
  --info: #60a5fa; --info-subtle: rgba(96,165,250,0.10);
  --purple: #a78bfa; --purple-subtle: rgba(167,139,250,0.10);
  --font-sans: -apple-system,BlinkMacSystemFont,"Segoe UI",system-ui,sans-serif;
  --font-mono: "SF Mono","JetBrains Mono","Cascadia Code","Fira Code",ui-monospace,monospace;
  --font-size-xs: 10px; --font-size-sm: 11px; --font-size-base: 13px; --font-size-md: 14px;
  --font-size-lg: 16px; --font-size-xl: 20px; --font-size-2xl: 26px; --font-size-3xl: 34px;
  --sp-1: 4px; --sp-2: 8px; --sp-3: 12px; --sp-4: 16px; --sp-5: 20px; --sp-6: 24px;
  --sp-8: 32px; --sp-10: 40px; --sp-12: 48px; --sp-16: 64px;
  --radius-xs: 3px; --radius-sm: 5px; --radius: 7px; --radius-md: 9px; --radius-lg: 12px; --radius-xl: 16px; --radius-full: 9999px;
  --shadow-xs: 0 1px 2px rgba(0,0,0,0.24); --shadow-sm: 0 1px 3px rgba(0,0,0,0.32);
  --shadow: 0 2px 8px rgba(0,0,0,0.36); --shadow-md: 0 4px 16px rgba(0,0,0,0.42);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.55); --shadow-glow: 0 0 0 1px var(--accent-subtle),0 0 20px rgba(91,141,239,0.15);
  --ease: cubic-bezier(0.4,0,0.2,1); --ease-out: cubic-bezier(0.16,1,0.3,1); --ease-spring: cubic-bezier(0.34,1.56,0.64,1);
  --duration: 120ms; --duration-md: 200ms; --duration-slow: 350ms;
  --header-height: 46px; --status-bar-height: 30px; --left-panel-width: 264px; --right-panel-width: 300px; --toolbar-height: 38px;
  --z-canvas: 1; --z-toolbar: 10; --z-panel: 20; --z-overlay: 100; --z-modal: 200; --z-toast: 300;
}
*,*::before,*::after { box-sizing: border-box; margin: 0; padding: 0; }
html,body { height: 100%; overflow: hidden; }
body { font-family: var(--font-sans); font-size: var(--font-size-base); color: var(--text-primary); background: var(--bg-base); -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; line-height: 1.5; text-rendering: optimizeLegibility; }
button,input,select,textarea { font: inherit; color: inherit; background: none; border: none; }
button { cursor: pointer; }
a { color: var(--accent-text); text-decoration: none; }
a:hover { color: var(--accent-hover); }
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-default); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--border-strong); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: var(--radius-sm); }
:focus:not(:focus-visible) { outline: none; }

.app-shell { display: flex; flex-direction: column; height: 100vh; height: 100dvh; }
.app-body { flex: 1; display: flex; overflow: hidden; min-height: 0; }

/* Header */
.app-header { height: var(--header-height); display: flex; align-items: center; padding: 0 var(--sp-4); background: var(--bg-surface); border-bottom: 1px solid var(--border-subtle); gap: var(--sp-3); flex-shrink: 0; z-index: var(--z-panel); }
.brand { font-size: var(--font-size-md); font-weight: 600; letter-spacing: -0.01em; color: var(--text-primary); display: flex; align-items: center; gap: var(--sp-2); user-select: none; white-space: nowrap; }
.brand-mark { width: 24px; height: 24px; border-radius: var(--radius-sm); background: linear-gradient(135deg, var(--accent) 0%, #8b5cf6 100%); display: flex; align-items: center; justify-content: center; flex-shrink: 0; box-shadow: 0 0 12px rgba(91,141,239,0.25); }
.brand-mark svg { width: 14px; height: 14px; color: white; }
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-text .sub { font-size: var(--font-size-xs); font-weight: 400; color: var(--text-muted); letter-spacing: 0.06em; text-transform: uppercase; }
.nav { display: flex; gap: 1px; margin-left: var(--sp-3); }
.nav-item { padding: 5px 12px; font-size: var(--font-size-base); font-weight: 500; color: var(--text-secondary); background: transparent; border: none; border-radius: var(--radius-sm); transition: all var(--duration) var(--ease); white-space: nowrap; position: relative; }
.nav-item:hover { background: var(--bg-surface-2); color: var(--text-primary); }
.nav-item.active { background: var(--accent-subtle); color: var(--accent-text); }
.nav-item.active::after { content: ''; position: absolute; bottom: -1px; left: 8px; right: 8px; height: 1px; background: var(--accent); border-radius: var(--radius-full); }
.header-spacer { flex: 1; }
.header-status { display: flex; align-items: center; gap: var(--sp-3); font-size: var(--font-size-sm); color: var(--text-secondary); }
.device-badge { display: flex; align-items: center; gap: 6px; padding: 3px 8px; background: var(--bg-surface-2); border: 1px solid var(--border-subtle); border-radius: var(--radius-full); font-size: var(--font-size-sm); color: var(--text-secondary); white-space: nowrap; font-variant-numeric: tabular-nums; }
.device-badge .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--success); box-shadow: 0 0 6px rgba(45,212,191,0.6); flex-shrink: 0; transition: all var(--duration-md) var(--ease); }
.device-badge .dot.busy { background: var(--warning); box-shadow: 0 0 6px rgba(251,191,36,0.6); animation: pulse 1.2s infinite; }
.device-badge .dot.error { background: var(--error); box-shadow: 0 0 6px rgba(248,113,113,0.6); }
.device-badge .dot.idle { background: var(--text-muted); box-shadow: none; }
.status-text { color: var(--text-secondary); white-space: nowrap; font-weight: 500; }
.icon-btn { display: flex; align-items: center; justify-content: center; width: 32px; height: 32px; background: transparent; border: none; border-radius: var(--radius-sm); color: var(--text-secondary); cursor: pointer; transition: all var(--duration) var(--ease); }
.icon-btn:hover { background: var(--bg-surface-2); color: var(--text-primary); }
.icon-btn svg { width: 16px; height: 16px; }

/* Panels */
.panel { background: var(--bg-surface); display: flex; flex-direction: column; overflow-y: auto; overflow-x: hidden; }
.panel-left { width: var(--left-panel-width); border-right: 1px solid var(--border-subtle); flex-shrink: 0; }
.panel-right { width: var(--right-panel-width); border-left: 1px solid var(--border-subtle); flex-shrink: 0; }
.panel-section { padding: var(--sp-4); border-bottom: 1px solid var(--border-subtle); }
.panel-section:last-child { border-bottom: none; }
.panel-title { font-size: var(--font-size-xs); font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-muted); margin-bottom: var(--sp-3); display: flex; align-items: center; justify-content: space-between; gap: var(--sp-2); }
.panel-title .badge { margin-left: auto; }

/* Canvas */
.canvas-area { flex: 1; display: flex; flex-direction: column; overflow: hidden; background: var(--bg-base); position: relative; min-width: 0; }
.canvas-toolbar { display: flex; align-items: center; gap: 2px; padding: var(--sp-1) var(--sp-3); border-bottom: 1px solid var(--border-subtle); background: var(--bg-surface); flex-shrink: 0; min-height: var(--toolbar-height); }
.canvas-toolbar .spacer { flex: 1; }
.tb-btn { display: flex; align-items: center; justify-content: center; width: 28px; height: 28px; background: transparent; border: none; border-radius: var(--radius-sm); color: var(--text-secondary); cursor: pointer; transition: all var(--duration) var(--ease); position: relative; }
.tb-btn:hover { background: var(--bg-surface-2); color: var(--text-primary); }
.tb-btn:active { background: var(--bg-surface-3); }
.tb-btn.active { background: var(--accent-subtle); color: var(--accent-text); }
.tb-btn svg { width: 15px; height: 15px; }
.tb-btn:disabled { opacity: 0.35; cursor: not-allowed; }
.tb-btn:disabled:hover { background: transparent; }
.tb-divider { width: 1px; height: 18px; background: var(--border-default); margin: 0 var(--sp-1); }
.canvas-viewport { flex: 1; position: relative; overflow: hidden; display: flex; align-items: center; justify-content: center; }
.canvas-viewport::before { content: ''; position: absolute; inset: 0; background-image: linear-gradient(45deg, rgba(255,255,255,0.015) 25%, transparent 25%), linear-gradient(-45deg, rgba(255,255,255,0.015) 25%, transparent 25%), linear-gradient(45deg, transparent 75%, rgba(255,255,255,0.015) 75%), linear-gradient(-45deg, transparent 75%, rgba(255,255,255,0.015) 75%); background-size: 24px 24px; background-position: 0 0, 0 12px, 12px -12px, -12px 0; pointer-events: none; }
.canvas-img { max-width: 100%; max-height: 100%; object-fit: contain; user-select: none; -webkit-user-drag: none; position: relative; z-index: var(--z-canvas); transition: transform 80ms var(--ease-out); will-change: transform; }
.canvas-img.dragging { cursor: grabbing; transition: none; }
.canvas-info { position: absolute; bottom: var(--sp-3); left: var(--sp-3); display: flex; gap: var(--sp-2); z-index: var(--z-canvas); pointer-events: none; flex-wrap: wrap; max-width: calc(100% - var(--sp-6)); }
.info-chip { display: flex; align-items: center; gap: 5px; padding: 4px 9px; background: rgba(16,16,18,0.85); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border: 1px solid var(--border-subtle); border-radius: var(--radius-sm); font-size: var(--font-size-sm); color: var(--text-secondary); white-space: nowrap; font-variant-numeric: tabular-nums; }
.info-chip .label { color: var(--text-muted); font-weight: 500; }
.info-chip .value { color: var(--text-primary); font-weight: 500; }
.info-chip .arrow { color: var(--text-muted); }

/* Processing overlay */
.processing-overlay { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: var(--sp-3); z-index: var(--z-overlay); background: rgba(8,8,10,0.78); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); }
.processing-overlay.hidden { display: none; }
.spinner { width: 28px; height: 28px; border: 2px solid var(--border-default); border-top-color: var(--accent); border-radius: 50%; animation: spin 0.7s linear infinite; }
.processing-label { font-size: var(--font-size-md); font-weight: 600; color: var(--text-primary); letter-spacing: -0.01em; }
.processing-sub { font-size: var(--font-size-sm); color: var(--text-muted); font-variant-numeric: tabular-nums; }
.progress-bar { height: 3px; background: var(--bg-surface-3); border-radius: var(--radius-full); overflow: hidden; position: relative; }
.progress-bar-fill { height: 100%; background: var(--accent); border-radius: var(--radius-full); transition: width var(--duration-md) var(--ease); }
.progress-bar-fill.indeterminate { width: 35%; animation: indeterminate 1.4s ease-in-out infinite; }
@keyframes indeterminate { 0% { transform: translateX(-100%); } 50% { transform: translateX(200%); } 100% { transform: translateX(200%); } }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.4; } }

/* Drop zone */
.drop-zone { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: var(--sp-4); padding: var(--sp-12); cursor: pointer; transition: background var(--duration-md) var(--ease); position: relative; }
.drop-zone.dragover { background: var(--accent-subtle); }
.drop-zone.dragover .drop-zone-frame { border-color: var(--accent); background: var(--accent-subtle); transform: scale(1.02); }
.drop-zone-frame { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: var(--sp-5); padding: var(--sp-12) var(--sp-10); border: 2px dashed var(--border-default); border-radius: var(--radius-xl); transition: all var(--duration-md) var(--ease-out); max-width: 460px; background: var(--bg-surface); }
.drop-zone-icon { width: 52px; height: 52px; color: var(--text-muted); opacity: 0.7; transition: all var(--duration-md) var(--ease); }
.drop-zone.dragover .drop-zone-icon { color: var(--accent); opacity: 1; transform: translateY(-4px); }
.drop-zone-title { font-size: var(--font-size-xl); font-weight: 600; color: var(--text-primary); text-align: center; letter-spacing: -0.01em; }
.drop-zone-subtitle { font-size: var(--font-size-base); color: var(--text-muted); text-align: center; font-variant-numeric: tabular-nums; letter-spacing: 0.02em; }
.drop-zone-actions { display: flex; gap: var(--sp-3); margin-top: var(--sp-2); }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--sp-2); padding: 7px 14px; font-size: var(--font-size-base); font-weight: 500; border: 1px solid transparent; border-radius: var(--radius); cursor: pointer; white-space: nowrap; transition: all var(--duration) var(--ease); user-select: none; line-height: 1.4; }
.btn svg { width: 15px; height: 15px; flex-shrink: 0; }
.btn:active { transform: scale(0.97); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
.btn:disabled:active { transform: none; }
.btn-primary { background: var(--accent); color: white; border-color: var(--accent); }
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn-secondary { background: var(--bg-surface-2); color: var(--text-primary); border-color: var(--border-default); }
.btn-secondary:hover { background: var(--bg-surface-3); border-color: var(--border-strong); }
.btn-ghost { background: transparent; color: var(--text-secondary); border-color: transparent; }
.btn-ghost:hover { background: var(--bg-surface-2); color: var(--text-primary); }
.btn-danger { background: var(--error-subtle); color: var(--error); border-color: transparent; }
.btn-danger:hover { background: rgba(248,113,113,0.18); }
.btn-lg { padding: 10px 20px; font-size: var(--font-size-md); }
.btn-sm { padding: 4px 10px; font-size: var(--font-size-sm); }
.btn-block { width: 100%; }
.btn-row { display: flex; gap: var(--sp-2); flex-wrap: wrap; }

/* Segmented */
.segmented { display: flex; gap: 1px; background: var(--bg-surface-2); border: 1px solid var(--border-subtle); border-radius: var(--radius); padding: 2px; }
.segmented-item { flex: 1; padding: 5px 8px; font-size: var(--font-size-sm); font-weight: 500; color: var(--text-secondary); background: transparent; border: none; border-radius: var(--radius-sm); cursor: pointer; transition: all var(--duration) var(--ease); white-space: nowrap; text-align: center; }
.segmented-item:hover { color: var(--text-primary); }
.segmented-item.active { background: var(--bg-elevated); color: var(--text-primary); box-shadow: var(--shadow-xs); }

/* Sliders */
.slider-row { display: flex; align-items: center; gap: var(--sp-2); margin-bottom: var(--sp-3); }
.slider-row:last-child { margin-bottom: 0; }
.slider-label { font-size: var(--font-size-sm); color: var(--text-secondary); width: 72px; flex-shrink: 0; font-weight: 500; }
.slider-value { font-size: var(--font-size-sm); color: var(--text-primary); font-variant-numeric: tabular-nums; width: 42px; text-align: right; flex-shrink: 0; }
.slider { -webkit-appearance: none; appearance: none; flex: 1; height: 4px; background: var(--bg-surface-3); border-radius: var(--radius-full); outline: none; cursor: pointer; }
.slider::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 14px; height: 14px; border-radius: 50%; background: var(--accent); cursor: pointer; border: 2px solid var(--bg-surface); box-shadow: var(--shadow-sm); transition: all var(--duration) var(--ease); }
.slider::-webkit-slider-thumb:hover { background: var(--accent-hover); transform: scale(1.15); }
.slider::-webkit-slider-thumb:active { transform: scale(0.95); }
.slider::-moz-range-thumb { width: 14px; height: 14px; border-radius: 50%; background: var(--accent); cursor: pointer; border: 2px solid var(--bg-surface); box-shadow: var(--shadow-sm); }

/* Badges */
.badge { display: inline-flex; align-items: center; gap: 4px; padding: 2px 7px; font-size: var(--font-size-xs); font-weight: 600; border-radius: var(--radius-full); text-transform: uppercase; letter-spacing: 0.04em; white-space: nowrap; line-height: 1.4; }
.badge-success { background: var(--success-subtle); color: var(--success); }
.badge-warning { background: var(--warning-subtle); color: var(--warning); }
.badge-error { background: var(--error-subtle); color: var(--error); }
.badge-info { background: var(--info-subtle); color: var(--info); }
.badge-neutral { background: var(--bg-surface-3); color: var(--text-muted); }
.badge-purple { background: var(--purple-subtle); color: var(--purple); }

/* Tooltips */
[data-tooltip] { position: relative; }
[data-tooltip]::after { content: attr(data-tooltip); position: absolute; bottom: calc(100% + 6px); left: 50%; transform: translateX(-50%) translateY(2px); background: var(--bg-elevated); color: var(--text-primary); padding: 4px 8px; font-size: var(--font-size-sm); border-radius: var(--radius-sm); border: 1px solid var(--border-default); white-space: nowrap; pointer-events: none; opacity: 0; transition: all var(--duration) var(--ease); z-index: var(--z-toast); font-weight: 500; }
[data-tooltip]:hover::after { opacity: 1; transform: translateX(-50%) translateY(0); }
.tooltip-icon { display: inline-flex; align-items: center; justify-content: center; color: var(--text-muted); cursor: help; }
.tooltip-icon svg { width: 12px; height: 12px; }

/* Model list */
.model-list { display: flex; flex-direction: column; gap: 2px; }
.model-item { display: flex; align-items: center; gap: var(--sp-2); padding: 7px var(--sp-3); background: transparent; border: 1px solid transparent; border-radius: var(--radius-sm); cursor: pointer; transition: all var(--duration) var(--ease); }
.model-item:hover:not(.disabled) { background: var(--bg-surface-2); border-color: var(--border-subtle); }
.model-item.selected { background: var(--accent-subtle); border-color: rgba(91,141,239,0.25); }
.model-item.disabled { opacity: 0.45; cursor: not-allowed; }
.model-info { flex: 1; min-width: 0; }
.model-name { font-size: var(--font-size-base); font-weight: 500; color: var(--text-primary); }
.model-meta { font-size: var(--font-size-xs); color: var(--text-muted); font-family: var(--font-mono); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* Result stats */
.result-card { display: flex; flex-direction: column; gap: 0; }
.result-stat { display: flex; align-items: center; justify-content: space-between; padding: 6px 0; border-bottom: 1px solid var(--border-subtle); font-size: var(--font-size-sm); }
.result-stat:last-child { border-bottom: none; }
.stat-label { color: var(--text-muted); font-weight: 500; }
.stat-value { color: var(--text-primary); font-variant-numeric: tabular-nums; font-weight: 500; }

/* AI Router */
.router-panel { display: flex; flex-direction: column; gap: var(--sp-1); }
.router-row { display: flex; align-items: center; justify-content: space-between; padding: 4px 0; font-size: var(--font-size-sm); }
.r-label { color: var(--text-muted); font-weight: 500; }
.r-value { color: var(--text-primary); font-weight: 500; text-align: right; }
.confidence-bar { height: 3px; background: var(--bg-surface-3); border-radius: var(--radius-full); overflow: hidden; margin-top: var(--sp-2); }
.confidence-fill { height: 100%; background: var(--accent); border-radius: var(--radius-full); transition: width var(--duration-slow) var(--ease-out); }

/* Face restoration */
.face-panel { display: flex; flex-direction: column; gap: var(--sp-2); }
.face-info { display: flex; align-items: center; gap: var(--sp-2); flex-wrap: wrap; }
.face-info .hint { font-size: var(--font-size-sm); color: var(--text-muted); }

/* Collapsible */
.collapsible-trigger { display: flex; align-items: center; justify-content: space-between; width: 100%; padding: 6px 0; font-size: var(--font-size-xs); font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-muted); background: transparent; border: none; cursor: pointer; transition: color var(--duration) var(--ease); }
.collapsible-trigger:hover { color: var(--text-secondary); }
.collapsible-trigger .chevron { transition: transform var(--duration-md) var(--ease); }
.collapsible-trigger.open .chevron { transform: rotate(90deg); }
.collapsible-content { max-height: 0; overflow: hidden; transition: max-height var(--duration-slow) var(--ease-out); }
.collapsible-content.open { max-height: 600px; }

/* Status bar */
.status-bar { height: var(--status-bar-height); display: flex; align-items: center; padding: 0 var(--sp-4); gap: var(--sp-5); background: var(--bg-surface); border-top: 1px solid var(--border-subtle); flex-shrink: 0; font-size: var(--font-size-sm); color: var(--text-muted); }
.status-bar .spacer { flex: 1; }
.status-item { display: flex; align-items: center; gap: var(--sp-2); white-space: nowrap; font-variant-numeric: tabular-nums; }
.status-value { color: var(--text-secondary); font-weight: 500; }
.status-dot { width: 6px; height: 6px; border-radius: 50%; flex-shrink: 0; transition: all var(--duration-md) var(--ease); }
.status-dot.ready { background: var(--success); box-shadow: 0 0 4px rgba(45,212,191,0.4); }
.status-dot.busy { background: var(--warning); box-shadow: 0 0 4px rgba(251,191,36,0.4); animation: pulse 1.2s infinite; }
.status-dot.complete { background: var(--success); box-shadow: 0 0 4px rgba(45,212,191,0.4); }
.status-dot.error { background: var(--error); box-shadow: 0 0 4px rgba(248,113,113,0.4); }

/* Comparison */
.compare-container { display: flex; width: 100%; height: 100%; gap: 1px; background: var(--border-subtle); }
.compare-side { flex: 1; position: relative; overflow: hidden; display: flex; align-items: center; justify-content: center; background: var(--bg-base); }
.compare-side img { max-width: 100%; max-height: 100%; object-fit: contain; user-select: none; -webkit-user-drag: none; }
.compare-label { position: absolute; top: 8px; left: 8px; padding: 3px 8px; background: rgba(16,16,18,0.85); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border: 1px solid var(--border-subtle); border-radius: var(--radius-sm); font-size: var(--font-size-sm); font-weight: 600; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.05em; z-index: 5; pointer-events: none; }
.split-view { position: relative; width: 100%; height: 100%; overflow: hidden; display: flex; align-items: center; justify-content: center; }
.split-image-wrap { position: absolute; inset: 0; overflow: hidden; }
.split-image-wrap img { width: 100%; height: 100%; object-fit: contain; user-select: none; -webkit-user-drag: none; }
.split-image-wrap.right { clip-path: inset(0 0 0 50%); }
.split-divider { position: absolute; top: 0; bottom: 0; width: 2px; background: var(--accent); cursor: ew-resize; z-index: 10; box-shadow: 0 0 8px rgba(91,141,239,0.4); }
.split-divider::before { content: ''; position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%); width: 28px; height: 28px; background: var(--accent); border-radius: 50%; box-shadow: var(--shadow-md); }
.split-divider::after { content: '\21d4'; position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%); color: white; font-size: 14px; font-weight: 700; z-index: 1; }
.overlay-view { position: relative; width: 100%; height: 100%; overflow: hidden; display: flex; align-items: center; justify-content: center; }
.overlay-view img { position: absolute; max-width: 100%; max-height: 100%; object-fit: contain; user-select: none; -webkit-user-drag: none; }
.difference-view { width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; position: relative; }
.difference-view canvas { max-width: 100%; max-height: 100%; object-fit: contain; }

/* Tab bar */
.tab-bar { display: flex; gap: 2px; padding: var(--sp-2) var(--sp-3) 0; background: var(--bg-surface); border-bottom: 1px solid var(--border-subtle); flex-shrink: 0; }
.tab-item { padding: 5px 12px; font-size: var(--font-size-base); font-weight: 500; color: var(--text-secondary); background: transparent; border: none; border-bottom: 2px solid transparent; cursor: pointer; transition: all var(--duration) var(--ease); white-space: nowrap; margin-bottom: -1px; }
.tab-item:hover { color: var(--text-primary); }
.tab-item.active { color: var(--accent-text); border-bottom-color: var(--accent); }

/* Pages */
.page { flex: 1; overflow-y: auto; padding: var(--sp-6); max-width: 900px; margin: 0 auto; width: 100%; }
.page-header { margin-bottom: var(--sp-6); }
.page-title { font-size: var(--font-size-xl); font-weight: 600; color: var(--text-primary); letter-spacing: -0.01em; margin-bottom: var(--sp-1); }
.page-subtitle { font-size: var(--font-size-base); color: var(--text-muted); }

/* Empty states */
.empty-state { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: var(--sp-3); padding: var(--sp-12) var(--sp-6); text-align: center; }
.empty-state-icon { width: 48px; height: 48px; color: var(--text-dim); opacity: 0.6; }
.empty-state-icon svg { width: 48px; height: 48px; }
.empty-state-title { font-size: var(--font-size-lg); font-weight: 600; color: var(--text-secondary); }
.empty-state-text { font-size: var(--font-size-base); color: var(--text-muted); max-width: 360px; line-height: 1.6; }

/* History */
.history-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: var(--sp-4); }
.history-card { background: var(--bg-surface); border: 1px solid var(--border-subtle); border-radius: var(--radius-md); overflow: hidden; transition: all var(--duration) var(--ease); }
.history-card:hover { border-color: var(--border-default); box-shadow: var(--shadow); }
.history-thumb { width: 100%; aspect-ratio: 16/10; background: var(--bg-surface-2); overflow: hidden; display: flex; align-items: center; justify-content: center; }
.history-thumb img { max-width: 100%; max-height: 100%; object-fit: contain; }
.history-info { padding: var(--sp-3); }
.history-name { font-size: var(--font-size-base); font-weight: 500; color: var(--text-primary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; margin-bottom: 2px; }
.history-meta { font-size: var(--font-size-xs); color: var(--text-muted); }

/* Settings */
.settings-group { background: var(--bg-surface); border: 1px solid var(--border-subtle); border-radius: var(--radius-md); overflow: hidden; margin-bottom: var(--sp-4); }
.settings-group-title { padding: var(--sp-3) var(--sp-4); font-size: var(--font-size-sm); font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); background: var(--bg-surface-2); border-bottom: 1px solid var(--border-subtle); }
.setting-row { display: flex; align-items: center; justify-content: space-between; padding: var(--sp-3) var(--sp-4); border-bottom: 1px solid var(--border-subtle); gap: var(--sp-4); }
.setting-row:last-child { border-bottom: none; }
.setting-label { font-size: var(--font-size-base); font-weight: 500; color: var(--text-primary); }
.setting-hint { font-size: var(--font-size-sm); color: var(--text-muted); margin-top: 2px; }
.setting-control { flex-shrink: 0; }

/* Quality bars */
.quality-bar-row { display: flex; align-items: center; gap: var(--sp-3); margin-bottom: var(--sp-3); }
.quality-bar-row:last-child { margin-bottom: 0; }
.quality-label { font-size: var(--font-size-sm); color: var(--text-secondary); width: 80px; flex-shrink: 0; font-weight: 500; }
.quality-track { flex: 1; height: 6px; background: var(--bg-surface-3); border-radius: var(--radius-full); overflow: hidden; }
.quality-fill { height: 100%; border-radius: var(--radius-full); transition: width var(--duration-slow) var(--ease-out); }
.quality-fill.good { background: var(--success); }
.quality-fill.medium { background: var(--warning); }
.quality-fill.bad { background: var(--error); }
.quality-score { font-size: var(--font-size-sm); color: var(--text-primary); font-variant-numeric: tabular-nums; width: 28px; text-align: right; flex-shrink: 0; font-weight: 600; }

/* Candidates */
.candidate-list { display: flex; flex-direction: column; gap: var(--sp-2); }
.candidate-item { display: flex; align-items: center; gap: var(--sp-3); padding: var(--sp-3); background: var(--bg-surface-2); border: 1px solid var(--border-subtle); border-radius: var(--radius); transition: all var(--duration) var(--ease); }
.candidate-item.best { border-color: var(--accent); box-shadow: var(--shadow-glow); }
.candidate-item.running { border-color: var(--warning); }
.candidate-model { font-size: var(--font-size-base); font-weight: 500; color: var(--text-primary); }
.candidate-score { font-size: var(--font-size-sm); color: var(--text-muted); font-variant-numeric: tabular-nums; }
.candidate-badge { margin-left: auto; }

/* Modals */
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.6); backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); display: flex; align-items: center; justify-content: center; z-index: var(--z-modal); animation: fadeIn var(--duration) var(--ease); }
.modal { background: var(--bg-surface); border: 1px solid var(--border-default); border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); max-width: 500px; width: 90%; max-height: 80vh; overflow-y: auto; animation: modalIn var(--duration-md) var(--ease-spring); }
.modal-header { display: flex; align-items: center; justify-content: space-between; padding: var(--sp-4) var(--sp-5); border-bottom: 1px solid var(--border-subtle); }
.modal-title { font-size: var(--font-size-md); font-weight: 600; color: var(--text-primary); }
.modal-body { padding: var(--sp-5); display: flex; flex-direction: column; gap: var(--sp-2); }
@keyframes fadeIn { from { opacity: 0; } }
@keyframes modalIn { from { opacity: 0; transform: scale(0.95) translateY(8px); } to { opacity: 1; transform: scale(1) translateY(0); } }

/* Shortcuts */
.shortcut-row { display: flex; align-items: center; justify-content: space-between; padding: 6px 0; font-size: var(--font-size-base); }
.shortcut-label { color: var(--text-secondary); }
.kbd { display: inline-flex; align-items: center; justify-content: center; min-width: 24px; height: 24px; padding: 0 6px; background: var(--bg-surface-2); border: 1px solid var(--border-default); border-bottom-width: 2px; border-radius: var(--radius-sm); font-size: var(--font-size-sm); font-family: var(--font-mono); color: var(--text-secondary); font-weight: 600; }

/* Error box */
.error-box { background: var(--error-subtle); border: 1px solid rgba(248,113,113,0.25); border-radius: var(--radius-md); padding: var(--sp-4); }
.error-title { display: flex; align-items: center; gap: var(--sp-2); font-size: var(--font-size-md); font-weight: 600; color: var(--error); margin-bottom: var(--sp-2); }
.error-title svg { width: 18px; height: 18px; }
.error-detail { margin-top: var(--sp-3); font-size: var(--font-size-sm); }
.error-detail summary { cursor: pointer; color: var(--text-muted); user-select: none; }
.error-detail summary:hover { color: var(--text-secondary); }
.error-detail pre { margin-top: var(--sp-2); padding: var(--sp-3); background: var(--bg-surface-2); border-radius: var(--radius-sm); font-family: var(--font-mono); font-size: var(--font-size-xs); color: var(--text-muted); overflow-x: auto; white-space: pre-wrap; word-break: break-all; }

/* Utilities */
.hidden { display: none !important; }
.mt-2 { margin-top: var(--sp-2); } .mt-3 { margin-top: var(--sp-3); } .mt-4 { margin-top: var(--sp-4); } .mt-5 { margin-top: var(--sp-5); } .mt-6 { margin-top: var(--sp-6); }
.text-center { text-align: center; } .text-muted { color: var(--text-muted); } .text-secondary { color: var(--text-secondary); } .text-mono { font-family: var(--font-mono); }
.flex { display: flex; } .flex-col { flex-direction: column; } .items-center { align-items: center; } .justify-between { justify-content: space-between; }
.gap-1 { gap: var(--sp-1); } .gap-2 { gap: var(--sp-2); } .gap-3 { gap: var(--sp-3); } .gap-4 { gap: var(--sp-4); }
.flex-wrap { flex-wrap: wrap; } .w-full { width: 100%; }

/* Reduced motion */
@media (prefers-reduced-motion: reduce) { *,*::before,*::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; } }

/* Responsive */
@media (max-width: 1024px) {
  :root { --left-panel-width: 240px; --right-panel-width: 260px; }
  .nav-item { padding: 5px 8px; font-size: var(--font-size-sm); }
  .header-status .status-text { display: none; }
}
@media (max-width: 860px) {
  .panel-right { display: none; }
}
@media (max-width: 640px) {
  :root { --left-panel-width: 100%; --right-panel-width: 100%; }
  .app-body { flex-direction: column; }
  .panel-left { width: 100%; border-right: none; border-bottom: 1px solid var(--border-subtle); max-height: 40vh; flex-shrink: 0; }
  .panel-right { display: none; }
  .nav-item { padding: 5px 6px; font-size: var(--font-size-xs); }
  .brand .brand-text { display: none; }
  .device-badge { font-size: var(--font-size-xs); padding: 2px 6px; }
  .status-bar { font-size: var(--font-size-xs); gap: var(--sp-3); padding: 0 var(--sp-2); }
  .status-bar .status-item:nth-child(n+4) { display: none; }
  .page { padding: var(--sp-4); }
  .history-grid { grid-template-columns: 1fr; }
  .drop-zone-frame { padding: var(--sp-8) var(--sp-4); }
  .drop-zone-title { font-size: var(--font-size-lg); }
  .drop-zone-actions { flex-direction: column; width: 100%; }
}
@media print { .app-header, .status-bar, .panel-left, .panel-right, .canvas-toolbar { display: none; } }

/* Fallback Warning */
.fallback-warning {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  margin-top: var(--sp-2);
  background: rgba(245, 158, 11, 0.08);
  border: 1px solid rgba(245, 158, 11, 0.25);
  border-radius: var(--radius-md);
}
.fallback-icon { font-size: 1.1rem; line-height: 1.4; }
.fallback-title { font-size: var(--font-size-sm); font-weight: 600; color: var(--text-primary); }
.fallback-reason { font-size: var(--font-size-xs); color: var(--text-secondary); margin-top: 2px; }