:root {
  --bg: #0a0e1a;
  --bg-elevated: #0f1424;
  --bg-panel: #141b2d;
  --panel: var(--bg-elevated);
  --text: #e8ecff;
  --muted: #a9b3da;
  --border: rgba(255, 255, 255, 0.1);
  --accent: #3b82f6;
}

/* Scrollbars - blueish dark theme */
.niivue-app,
.niivue-app * {
  scrollbar-width: thin;
  scrollbar-color: rgba(59, 130, 246, 0.45) var(--bg-elevated);
}
.niivue-app ::-webkit-scrollbar { width: 8px; height: 8px; }
.niivue-app ::-webkit-scrollbar-track { background: var(--bg-elevated); }
.niivue-app ::-webkit-scrollbar-thumb {
  background: rgba(59, 130, 246, 0.35);
  border-radius: 4px;
}
.niivue-app ::-webkit-scrollbar-thumb:hover { background: rgba(59, 130, 246, 0.55); }
.niivue-app ::-webkit-scrollbar-corner { background: var(--bg-elevated); }

.niivue-app {
  height: 100%;
  margin: 0;
  background: transparent;
  color: var(--text);
  font: 14px/1.4 system-ui, -apple-system, Segoe UI, Roboto, Helvetica,
    Arial, "Apple Color Emoji", "Segoe UI Emoji";
}

.niivue-app .layout {
  height: 100%;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 12px;
  box-sizing: border-box;
}

/* Standalone layout: sidebar left, viewer right (like no-field) */
.niivue-app .layout.standalone-layout {
  flex-direction: row;
  gap: 0;
  padding: 0;
}
.niivue-app .layout.standalone-layout .standalone-sidebar {
  width: 338px;
  min-width: 260px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  background: var(--bg-elevated);
  border-right: 1px solid var(--border);
  overflow: hidden;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .tabbed-controls {
  display: flex;
  flex-direction: column;
  height: 100%;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .tabs-header {
  display: flex;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .tab-btn {
  flex: 1;
  padding: 10px 5px;
  background: transparent;
  border: none;
  color: var(--muted);
  cursor: pointer;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .tab-btn.active {
  color: var(--accent);
  border-bottom: 2px solid var(--accent);
  background: var(--bg-elevated);
}
.niivue-app .layout.standalone-layout .standalone-sidebar .tabs-content {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
  display: flex;
  flex-direction: column;
  background: var(--bg-elevated);
}
.niivue-app .layout.standalone-layout .standalone-sidebar .tabs-content.panel-collapsed {
  display: none !important;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .tab-pane {
  display: none;
  height: 100%;
  overflow-y: auto;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .tab-pane.active {
  display: flex;
  flex-direction: column;
}
.niivue-app .layout.standalone-layout > div:last-child {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: 12px;
}

/* Standalone sidebar: no-field-style buttons, volume rows, section headers */
.niivue-app .layout.standalone-layout .standalone-sidebar .btn,
.niivue-app .layout.standalone-layout .standalone-sidebar .btn.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(59, 130, 246, 0.4);
  background: rgba(59, 130, 246, 0.3);
  color: var(--text);
  border-radius: 4px;
  padding: 4px 8px;
  cursor: pointer;
  font-size: 11px;
  font-weight: 500;
  transition: all 0.2s ease;
  font-family: inherit;
  white-space: nowrap;
  user-select: none;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .btn:hover:not(:disabled),
.niivue-app .layout.standalone-layout .standalone-sidebar .btn.btn-secondary:hover:not(:disabled) {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .btn-sm {
  padding: 2px 6px;
  font-size: 10px;
  height: 20px;
  border-radius: 3px;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .btn-flex {
  flex: 1;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .section-header {
  font-size: 10px;
  font-weight: 700;
  color: var(--accent);
  margin-top: 8px;
  margin-bottom: 4px;
  padding-left: 4px;
  border-left: 2px solid var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 4px 8px;
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 4px;
  cursor: pointer;
  transition: background 0.2s ease;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row:hover {
  background: rgba(255, 255, 255, 0.05);
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row.selected {
  background: rgba(34, 197, 94, 0.15);
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row.scan-item {
  border-left: 3px solid #22c55e;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row.scan-item.selected {
  border-left: 4px solid #22c55e;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row.mask-item {
  border-left: 3px solid var(--accent);
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row-info {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row-title {
  font-size: 12px;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row-meta {
  font-size: 10px;
  color: var(--muted);
  margin-top: 1px;
  opacity: 0.8;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row-actions {
  display: flex;
  gap: 4px;
  align-items: center;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row-btn,
.niivue-app .layout.standalone-layout .standalone-sidebar .btn.volume-row-btn {
  width: 20px;
  min-width: 20px;
  height: 20px;
  padding: 0;
  font-size: 9px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-sizing: border-box;
}
.niivue-app .layout.standalone-layout .standalone-sidebar .volume-row-btn:hover:not(:disabled),
.niivue-app .layout.standalone-layout .standalone-sidebar .btn.volume-row-btn:hover:not(:disabled) {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

/* Multi-phantom group parent and sub-items */
.niivue-app .volume-group-parent {
  font-weight: 600;
  border-left: 2px solid var(--accent);
}
.niivue-app .volume-group-sub {
  font-weight: normal;
}

/* JSON choice dialog (body-level overlay) */
.json-choice-overlay {
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.json-choice-dialog .btn:hover:not(:disabled) {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.niivue-app .viewer {
  flex: 1;
  position: relative;
  background: #000;
  border: 1px solid var(--border);
  border-radius: 0;
  overflow: hidden;
  min-height: 400px;
}

.niivue-app .options-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  height: auto;
}

.niivue-app .panel {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 0;
  padding: 12px;
  overflow: auto;
}

.niivue-app .panel-flat {
  padding: 2px;
  overflow: auto;
  height: 100%;
}

.niivue-app .panel-title {
  font-size: 11px;
  font-weight: 600;
  margin: 0 0 4px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  display: flex;
  align-items: center;
}

.niivue-app .panel h1, .niivue-app .section-title {
  font-size: 0.9rem;
  font-weight: 600;
  margin: 0 0 10px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  display: flex;
  align-items: center;
}

.niivue-app .row {
  display: grid;
  gap: 8px;
  margin-bottom: 8px;
}

.niivue-app .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
  border-radius: 6px;
  padding: 4px 8px;
  cursor: pointer;
  font-size: 11px;
  font-weight: 500;
  transition: all 0.2s ease;
}

.niivue-app .btn.primary {
  background: var(--accent);
  border-color: rgba(0, 0, 0, 0.15);
  color: white;
}

.niivue-app .btn:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.12);
}

.niivue-app .btn.primary:hover:not(:disabled) {
  background: #2563eb;
}

.niivue-app .btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

@keyframes highlight-fade {
  0% { 
    outline: 2px solid #22c55e;
    outline-offset: -2px;
    background: rgba(34, 197, 94, 0.1);
  }
  100% { 
    outline: 2px solid transparent;
    outline-offset: -2px;
    background: transparent;
  }
}

.niivue-app .highlight-add,
.scan-preview-viewer.highlight-add {
  animation: highlight-fade 3s ease-out forwards;
}

.niivue-app .kv {
  margin-top: 8px;
  color: var(--muted);
  display: grid;
  gap: 4px;
  font-size: 11px;
}

.niivue-app .stateBox {
  margin-top: 10px;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.03);
  display: grid;
  gap: 4px;
  color: var(--muted);
  font-size: 11px;
}

.niivue-app .stateRow {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 6px;
  align-items: baseline;
}

.niivue-app .stateKey {
  color: var(--text);
  opacity: 0.8;
}

.niivue-app .stateVal {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.niivue-app .stateVal.auto-wrap {
  white-space: normal;
  overflow: visible;
  text-overflow: clip;
  word-break: break-all;
}

.niivue-app canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.niivue-app .status {
  position: absolute;
  bottom: 8px;
  left: 8px;
  padding: 0;
  background: transparent;
  border: none;
  border-radius: 0;
  color: #888;
  font-size: 11px;
  pointer-events: none;
  max-width: 80%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.niivue-app .hint {
  margin-top: 6px;
  color: var(--text);
  opacity: 0.95;
  font-size: 12px;
  line-height: 1.4;
  background: rgba(255, 255, 255, 0.03);
  padding: 6px;
  border-radius: 6px;
  border: 1px solid var(--border);
}

.niivue-app .toggle {
  display: flex;
  gap: 8px;
  align-items: center;
  color: var(--muted);
  font-size: 12px;
  user-select: none;
}

.niivue-app .toggle input {
  transform: translateY(0.5px);
}

.niivue-app .sliderGroup {
  display: grid;
  gap: 4px;
  padding: 6px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.03);
}

.niivue-app .sliderRow {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 6px;
  color: var(--muted);
  font-size: 11px;
}

.niivue-app .sliderRow input[type="range"] {
  width: 60px;
}

.niivue-app .num-input {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 4px;
  padding: 2px 4px;
  width: 45px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 11px;
  text-align: right;
}

.niivue-app .num-input::-webkit-inner-spin-button, 
.niivue-app .num-input::-webkit-outer-spin-button { 
  -webkit-appearance: none; 
  margin: 0; 
}

.niivue-app .num-input {
  -moz-appearance: textfield;
}

.niivue-app .input-sync {
  display: flex;
  align-items: center;
  gap: 6px;
}

.niivue-app .mono {
  font-variant-numeric: tabular-nums;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;
}

.niivue-app input[type="file"] {
  width: 100%;
}