* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  overflow: hidden;
  display: flex;
  flex-direction: column;
  height: 100vh;
  font-family: 'Segoe UI', Tahoma, Verdana, sans-serif;
  font-size: 11px;
  color: var(--sz-color-button-text);
  background: var(--sz-color-button-face);
  user-select: none;
}

/* ==== Quick Access Toolbar ==== */

.qat {
  display: flex;
  align-items: center;
  padding: 1px 4px;
  background: var(--sz-color-active-title);
  gap: 1px;
  flex-shrink: 0;
  min-height: 20px;
}

.qat-btn {
  width: 20px;
  height: 18px;
  border: none;
  background: transparent;
  cursor: default;
  font-size: 11px;
  line-height: 18px;
  text-align: center;
  color: var(--sz-color-title-text);
  border-radius: 2px;
  padding: 0;
}

.qat-btn:hover { background: rgba(255,255,255,0.25); }
.qat-btn:active { background: rgba(0,0,0,0.15); }

/* ==== Ribbon Tab Bar ==== */

.ribbon-tabs {
  flex-shrink: 0;
  background: var(--sz-color-button-face);
  border-bottom: 1px solid var(--sz-color-button-shadow);
}

.ribbon-tab-bar {
  display: flex;
  align-items: flex-end;
  padding: 0 2px;
}

.ribbon-file-btn {
  padding: 4px 14px;
  font-size: 11px;
  font-weight: bold;
  border: none;
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
  cursor: default;
  border-radius: 3px 3px 0 0;
  margin-right: 2px;
}

.ribbon-file-btn:hover { filter: brightness(1.1); }

.ribbon-tab {
  padding: 4px 12px;
  font-size: 11px;
  border: 1px solid transparent;
  border-bottom: none;
  background: transparent;
  color: var(--sz-color-button-text);
  cursor: default;
  border-radius: 3px 3px 0 0;
  position: relative;
  top: 1px;
}

.ribbon-tab:hover {
  background: var(--sz-color-button-highlight);
  border-color: var(--sz-color-button-shadow);
}

.ribbon-tab.active {
  background: var(--sz-color-window);
  border-color: var(--sz-color-button-shadow);
  color: var(--sz-color-window-text);
  font-weight: bold;
}

/* ==== Backstage (File menu) ==== */

.backstage {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  z-index: 5000;
  background: rgba(0,0,0,0.3);
}

.backstage.visible { display: flex; }

.backstage-sidebar {
  width: 220px;
  background: var(--sz-color-highlight);
  display: flex;
  flex-direction: column;
  padding: 4px 0;
  box-shadow: 2px 0 8px rgba(0,0,0,0.3);
}

.backstage-back {
  border: none;
  background: transparent;
  color: var(--sz-color-highlight-text);
  font-size: 18px;
  padding: 8px 16px;
  text-align: left;
  cursor: default;
}

.backstage-back:hover { background: rgba(255,255,255,0.15); }

.backstage-item {
  border: none;
  background: transparent;
  color: var(--sz-color-highlight-text);
  font-size: 12px;
  padding: 8px 24px;
  text-align: left;
  cursor: default;
  width: 100%;
}

.backstage-item:hover { background: rgba(255,255,255,0.15); }
.backstage-sep { height: 1px; background: rgba(255,255,255,0.2); margin: 4px 12px; }
.backstage-spacer { flex: 1; }

/* ==== Ribbon Panels ==== */

.ribbon-panel {
  display: none;
  flex-direction: row;
  align-items: stretch;
  padding: 2px 4px 0;
  background: var(--sz-color-window);
  border-bottom: 1px solid var(--sz-color-button-shadow);
  flex-shrink: 0;
  min-height: 82px;
  overflow-x: auto;
  overflow-y: hidden;
}

.ribbon-panel.active { display: flex; }

.ribbon-panel::-webkit-scrollbar { height: 4px; }
.ribbon-panel::-webkit-scrollbar-thumb { background: var(--sz-color-button-shadow); border-radius: 2px; }

/* ==== Ribbon Groups ==== */

.ribbon-group {
  display: flex;
  flex-direction: column;
  padding: 2px 4px 0;
  min-width: 0;
  flex-shrink: 0;
}

.ribbon-group-content {
  display: flex;
  align-items: flex-start;
  gap: 2px;
  flex: 1;
  min-height: 0;
}

.ribbon-group-label {
  text-align: center;
  font-size: 9px;
  color: var(--sz-color-gray-text);
  padding: 1px 4px 2px;
  white-space: nowrap;
  border-top: 1px solid var(--sz-color-button-light, transparent);
}

.ribbon-sep {
  width: 1px;
  background: var(--sz-color-button-shadow);
  margin: 2px 3px;
  align-self: stretch;
  flex-shrink: 0;
  opacity: 0.4;
}

/* ==== Ribbon Buttons ==== */

.rb-btn {
  border: 1px solid transparent;
  background: transparent;
  cursor: default;
  color: var(--sz-color-button-text);
  font-size: 11px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 1px 3px;
  border-radius: 2px;
  white-space: nowrap;
}

.rb-btn:hover {
  background: var(--sz-color-button-highlight);
  border-color: var(--sz-color-button-shadow);
}

.rb-btn:active { background: var(--sz-color-button-shadow); }

.rb-btn.active {
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
  border-color: var(--sz-color-button-shadow);
}

.rb-btn.disabled {
  color: var(--sz-color-gray-text);
  pointer-events: none;
}

.rb-btn-lg {
  flex-direction: column;
  padding: 4px 8px;
  min-width: 44px;
  height: 100%;
  gap: 2px;
}

.rb-btn-lg .rb-icon-lg { font-size: 20px; line-height: 1; }
.rb-btn-lg .rb-label { font-size: 9px; }

.rb-btn-sm {
  gap: 4px;
  padding: 1px 4px;
  min-height: 20px;
  justify-content: flex-start;
}

.rb-btn-sm .rb-icon { font-size: 12px; width: 16px; text-align: center; flex-shrink: 0; }
.rb-btn-sm .rb-label { font-size: 10px; }

.rb-stack {
  display: flex;
  flex-direction: column;
  gap: 1px;
  justify-content: flex-start;
}

.rb-row {
  display: flex;
  align-items: center;
  gap: 2px;
  flex-wrap: nowrap;
}

/* ==== Ribbon Sliders ==== */

.rb-slider-row {
  display: flex;
  align-items: center;
  gap: 4px;
  min-height: 20px;
}

.rb-slider-row label { font-size: 10px; white-space: nowrap; min-width: 30px; }
.rb-slider-row input[type="range"] { width: 80px; height: 14px; cursor: default; }
.rb-slider-row span { font-size: 10px; min-width: 28px; text-align: center; }

/* ==== Tool Grid (4x2 in Home ribbon) ==== */

.tool-grid-4x2 {
  display: grid;
  grid-template-columns: repeat(4, 22px);
  gap: 1px;
}

.tool-grid-4x2 .rb-btn {
  width: 22px;
  height: 22px;
  padding: 0;
  font-size: 11px;
}

/* ==== Color swatches in ribbon ==== */

.rb-color-block {
  display: flex;
  flex-direction: column;
  gap: 2px;
  align-items: center;
}

.rb-fg-bg {
  position: relative;
  width: 30px;
  height: 30px;
}

.rb-fg-swatch {
  position: absolute;
  top: 0; left: 0;
  width: 20px; height: 20px;
  border: 1px solid var(--sz-color-button-shadow);
  z-index: 1;
  cursor: default;
}

.rb-fg-swatch.active {
  outline: 2px solid var(--sz-color-highlight);
  outline-offset: 1px;
}

.rb-bg-swatch {
  position: absolute;
  bottom: 0; right: 0;
  width: 20px; height: 20px;
  border: 1px solid var(--sz-color-button-shadow);
  cursor: default;
}

.rb-bg-swatch.active {
  outline: 2px solid var(--sz-color-highlight);
  outline-offset: 1px;
}

.rb-palette-mini {
  display: grid;
  grid-template-columns: repeat(7, 14px);
  grid-template-rows: repeat(2, 14px);
  gap: 1px;
}

.rb-palette-mini .color-swatch {
  width: 14px;
  height: 14px;
  border: 1px solid var(--sz-color-button-shadow);
  cursor: default;
}

.rb-palette-mini .color-swatch:hover {
  border-color: var(--sz-color-highlight-text);
}

/* ==== Ribbon checkbox labels ==== */

.rb-check-label {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 10px;
  padding: 2px 4px;
  cursor: default;
  white-space: nowrap;
  min-height: 18px;
}

.rb-check-label:hover {
  background: var(--sz-color-button-highlight);
  border-radius: 2px;
}

/* ==== Brush preview (in ribbon) ==== */

.brush-preview {
  width: 100%;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 2px;
}

.brush-preview canvas {
  image-rendering: pixelated;
  border: 1px solid var(--sz-color-button-shadow);
  background: var(--sz-color-window);
}

/* ==== Shape / Brush ribbon group visibility ==== */

.ribbon-group#tool-options { display: none; }
.ribbon-group#tool-options.visible { display: flex; }
.ribbon-group#brush-size-options { display: none; }
.ribbon-group#brush-size-options.visible { display: flex; }

/* Hide separators adjacent to hidden ribbon groups */
.ribbon-sep:has(+ .ribbon-group:not(.visible)) { display: none; }
.ribbon-group:not(.visible) + .ribbon-sep { display: none; }

/* ==== Main 3-column layout ==== */
.main-area {
  flex: 1;
  display: flex;
  overflow: hidden;
  min-height: 0;
}

/* ==== Left sidebar (Image List) ==== */
.sidebar-left {
  width: 110px;
  min-width: 80px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  background: var(--sz-color-button-face);
  border-right: 1px solid var(--sz-color-button-shadow);
}

.sidebar-title {
  padding: 3px 6px;
  font-weight: bold;
  font-size: 10px;
  background: var(--sz-color-button-face);
  border-bottom: 1px solid var(--sz-color-button-shadow);
  color: var(--sz-color-button-text);
  user-select: none;
}

.image-list {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  background: var(--sz-color-window);
}

.image-list-item {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px 6px;
  cursor: default;
  border-bottom: 1px solid var(--sz-color-button-shadow);
  user-select: none;
}

.image-list-item:hover {
  background: rgba(0, 0, 0, 0.04);
}

.image-list-item.selected {
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
}

.image-list-thumb {
  width: 36px;
  height: 36px;
  border: 1px solid var(--sz-color-button-shadow);
  image-rendering: pixelated;
  background-image:
    linear-gradient(45deg, #ccc 25%, transparent 25%),
    linear-gradient(-45deg, #ccc 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #ccc 75%),
    linear-gradient(-45deg, transparent 75%, #ccc 75%);
  background-size: 8px 8px;
  background-position: 0 0, 0 4px, 4px -4px, -4px 0;
  flex-shrink: 0;
}

.image-list-label {
  font-size: 10px;
  line-height: 1.2;
  overflow: hidden;
  text-overflow: ellipsis;
}

.image-list-buttons {
  display: flex;
  gap: 2px;
  padding: 3px 4px;
  background: var(--sz-color-button-face);
  border-top: 1px solid var(--sz-color-button-shadow);
}

.image-list-buttons button {
  flex: 1;
  padding: 2px 0;
  font-size: 12px;
  cursor: default;
  min-width: 0;
}

/* ==== Center canvas area ==== */
.canvas-area {
  flex: 1;
  overflow: auto;
  background: var(--sz-color-app-workspace, #808080);
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
}

.canvas-wrapper {
  display: inline-block;
  padding: 16px;
}

.canvas-container {
  position: relative;
  line-height: 0;
  box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.3);
}

.canvas-container canvas {
  position: absolute;
  top: 0;
  left: 0;
  image-rendering: pixelated;
}

#checker-canvas {
  position: relative;
  z-index: 0;
}

#main-canvas {
  z-index: 1;
}

#overlay-canvas {
  z-index: 2;
  pointer-events: none;
}

.canvas-container.show-grid::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 3;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(0,0,0,0.15) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0,0,0,0.15) 1px, transparent 1px);
  background-size: var(--grid-size, 8px) var(--grid-size, 8px);
}

/* ==== Right sidebar (Colors + Palette + Info) ==== */
.sidebar-right {
  width: 140px;
  min-width: 120px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  background: var(--sz-color-button-face);
  border-left: 1px solid var(--sz-color-button-shadow);
  overflow-y: auto;
  overflow-x: hidden;
  padding-right: 8px;
  scrollbar-gutter: stable;
}

/* ==== Palette (sidebar) ==== */
.palette-grid {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 1px;
  padding: 4px 6px 6px 4px;
  overflow-x: hidden;
}

.palette-swatch {
  width: 100%;
  aspect-ratio: 1 / 1;
  min-width: 0;
  border: 1px solid var(--sz-color-button-shadow);
  cursor: default;
}

.palette-swatch:hover {
  border-color: var(--sz-color-button-text);
}

.palette-swatch.active {
  outline: 2px solid var(--sz-color-highlight);
  outline-offset: -1px;
}

.palette-swatch.fg {
  box-shadow: inset 0 0 0 2px #ffffff;
}

.palette-swatch.bg {
  box-shadow: inset 0 0 0 2px #000000;
}

/* ==== Image Info ==== */
.image-info {
  padding: 4px 6px;
  font-size: 10px;
}

.info-row {
  display: flex;
  justify-content: space-between;
  padding: 1px 0;
  color: var(--sz-color-button-text);
}

.depth-select-row {
  padding: 2px 6px 6px;
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 10px;
}

.depth-select-row label {
  color: var(--sz-color-button-text);
}

.depth-select-row select {
  flex: 1;
  font-size: 10px;
  padding: 1px 2px;
}

/* ==== Status bar ==== */
.status-bar {
  display: flex;
  align-items: center;
  padding: 2px 8px;
  background: var(--sz-color-button-face);
  border-top: 1px solid var(--sz-color-button-shadow);
  font-size: 10px;
  color: var(--sz-color-button-text);
  flex-shrink: 0;
  user-select: none;
  gap: 4px;
  min-height: 22px;
}

.status-section {
  white-space: nowrap;
  padding: 0 6px;
}

.status-spacer { flex: 1; }

.status-section:not(:last-child) {
  border-right: 1px solid var(--sz-color-button-shadow);
}

/* ==== Dialogs ==== */
.dialog-overlay {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.3);
  z-index: 4000;
  justify-content: center;
  align-items: center;
}

.dialog-overlay.visible {
  display: flex;
}

.dialog {
  background: var(--sz-color-button-face);
  border: 1px solid var(--sz-color-button-shadow);
  min-width: 260px;
  max-width: 450px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
  border-radius: 4px;
}

.dialog-title {
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
  padding: 6px 12px;
  font-weight: bold;
  font-size: 11px;
  user-select: none;
  border-radius: 4px 4px 0 0;
}

.dialog-body {
  padding: 12px;
  font-size: 11px;
}

.dialog-body p {
  margin-bottom: 8px;
}

/* (depth-reduce styles removed -- unified into dq-picker below) */

.dialog-body input[type="text"],
.dialog-body input[type="number"] {
  padding: 2px 4px;
  font-size: 11px;
}

.dialog-buttons {
  display: flex;
  justify-content: flex-end;
  gap: 6px;
  padding: 8px 12px;
  border-top: 1px solid var(--sz-color-button-shadow);
}

.dialog-buttons button {
  min-width: 72px;
  padding: 4px 14px;
  font-size: 11px;
  cursor: default;
  border: 1px solid var(--sz-color-button-shadow);
  background: var(--sz-color-button-face);
  color: var(--sz-color-button-text);
  border-radius: 3px;
}

.dialog-buttons button:hover { background: var(--sz-color-button-highlight); }

.dialog-buttons button:first-child {
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
  border-color: var(--sz-color-highlight);
}

.dialog-buttons button:first-child:hover { filter: brightness(1.1); }

.settings-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  font-size: 11px;
}

.settings-row label {
  min-width: 60px;
}

.settings-row select,
.settings-row input[type="number"] {
  padding: 2px 4px;
  font-size: 11px;
}

.preset-sizes {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 8px;
}

.preset-sizes button {
  padding: 2px 8px;
  font-size: 10px;
  cursor: default;
}

/* ==== Slider rows (HSL dialog) ==== */
.slider-row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
  font-size: 11px;
}

.slider-row label {
  min-width: 70px;
}

.slider-row input[type="range"] {
  flex: 1;
}

.slider-row span {
  min-width: 30px;
  text-align: right;
}

/* ==== Import/Favicon checkbox lists ==== */
.favicon-sizes,
.import-sizes {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 12px;
  font-size: 11px;
}

.favicon-sizes label,
.import-sizes label {
  display: flex;
  align-items: center;
  gap: 3px;
  cursor: default;
}

/* ==== PE Resource Browser ==== */
.pe-browser-dialog {
  min-width: 480px;
  max-width: 640px;
}

.pe-browser-body {
  max-height: 400px;
  overflow-y: auto;
}

.pe-browser-info {
  font-size: 11px;
  margin-bottom: 8px;
  color: var(--sz-color-button-text);
}

.pe-browser-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 4px;
}

.pe-browser-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 6px 4px;
  border: 2px solid transparent;
  cursor: default;
  user-select: none;
}

.pe-browser-card:hover {
  border-color: var(--sz-color-button-shadow);
  background: var(--sz-color-button-highlight);
}

.pe-browser-card.selected {
  border-color: var(--sz-color-highlight);
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
}

.pe-browser-thumb {
  width: 48px;
  height: 48px;
  image-rendering: pixelated;
  background-image:
    linear-gradient(45deg, #ccc 25%, transparent 25%),
    linear-gradient(-45deg, #ccc 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #ccc 75%),
    linear-gradient(-45deg, transparent 75%, #ccc 75%);
  background-size: 8px 8px;
  background-position: 0 0, 0 4px, 4px -4px, -4px 0;
  margin-bottom: 4px;
}

.pe-browser-label {
  font-size: 9px;
  text-align: center;
  line-height: 1.2;
  word-break: break-word;
}

/* ==== DQ Picker Dialog (shared by depth-reduce + add-image-fill) ==== */
.dq-picker-dialog {
  min-width: 700px;
  max-width: 90vw;
  max-height: 85vh;
  display: flex;
  flex-direction: column;
}

.dq-picker-dialog .dialog-body {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  flex: 1;
  min-height: 0;
}

.dq-picker-info {
  margin: 0 0 6px;
  font-size: 10px;
  opacity: 0.85;
}

.dq-picker-info:empty {
  display: none;
}

.dq-columns {
  display: flex;
  gap: 8px;
  flex: 1;
  min-height: 0;
}

.dq-column-left {
  width: 210px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
}

.dq-column-right {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.dq-column-title {
  font-size: 10px;
  font-weight: bold;
  margin-bottom: 3px;
  opacity: 0.8;
}

/* -- Quantizer list -- */
.dq-quant-list {
  flex: 1;
  overflow-y: auto;
  border: 1px inset var(--sz-color-button-shadow);
  background: var(--sz-color-window);
  min-height: 80px;
}

.dq-quant-item {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 2px 4px;
  cursor: default;
  font-size: 10px;
  user-select: none;
}

.dq-quant-item:hover {
  background: var(--sz-color-button-highlight);
}

.dq-quant-item.selected {
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
}

.dq-quant-item canvas {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  border: 1px solid var(--sz-color-button-shadow);
  background: repeating-conic-gradient(#d8d8d8 0% 25%, #f0f0f0 0% 50%) 0 0 / 6px 6px;
}

/* -- Combined preview -- */
#dq-combined-preview {
  width: 100%;
  max-width: 192px;
  height: auto;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  border: 1px solid var(--sz-color-button-shadow);
  background: repeating-conic-gradient(#d8d8d8 0% 25%, #f0f0f0 0% 50%) 0 0 / 8px 8px;
  margin-top: 4px;
}

/* -- Ditherer grid -- */
.dq-dither-wrap {
  flex: 1;
  overflow-y: auto;
  border: 1px inset var(--sz-color-button-shadow);
  background: var(--sz-color-window);
  padding: 4px;
}

.dq-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
  gap: 4px;
}

.dq-cell {
  display: flex;
  flex-direction: column;
  align-items: center;
  cursor: default;
  padding: 3px;
  border: 2px solid transparent;
  user-select: none;
}

.dq-cell:hover {
  border-color: var(--sz-color-button-shadow);
  background: var(--sz-color-button-highlight);
}

.dq-cell.selected {
  border-color: var(--sz-color-highlight);
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
}

.dq-cell canvas {
  width: 48px;
  height: 48px;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  border: 1px solid var(--sz-color-button-shadow);
  background: repeating-conic-gradient(#d8d8d8 0% 25%, #f0f0f0 0% 50%) 0 0 / 6px 6px;
}

.dq-cell-label {
  font-size: 9px;
  margin-top: 2px;
  text-align: center;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 76px;
}