/* =================================================================
   Paint — Ribbon-style UI with Layer Panel
   Uses OS skin colors via --sz-color-* custom properties
   ================================================================= */

* { 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-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-fmt {
  min-width: 22px;
  height: 22px;
  padding: 0 3px;
  font-size: 12px;
  line-height: 22px;
}

.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;
}

.rb-sep-v {
  width: 1px;
  height: 18px;
  background: var(--sz-color-button-shadow);
  margin: 0 2px;
  opacity: 0.3;
  flex-shrink: 0;
}

/* -- Ribbon Selects ---------------------------------------------- */

.rb-select {
  height: 22px;
  padding: 1px 4px;
  font-size: 11px;
  border: 1px solid var(--sz-color-button-shadow);
  background: var(--sz-color-window);
  color: var(--sz-color-window-text);
  cursor: default;
  border-radius: 2px;
}

.rb-narrow { width: 100px; }

/* -- 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 (4x4 in Home ribbon) ------------------------------ */

.tool-grid-4x4 {
  display: grid;
  grid-template-columns: repeat(4, 22px);
  gap: 1px;
}

.tool-grid-4x4 .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-bg-swatch {
  position: absolute;
  bottom: 0; right: 0;
  width: 20px; height: 20px;
  border: 1px solid var(--sz-color-button-shadow);
  cursor: default;
}

.rb-swap-btn {
  border: none;
  background: transparent;
  cursor: default;
  font-size: 10px;
  padding: 0 2px;
  color: var(--sz-color-button-text);
}

.rb-swap-btn:hover { color: var(--sz-color-highlight); }

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

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

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

/* -- Main Content Area ------------------------------------------- */

.main-area {
  flex: 1;
  display: flex;
  overflow: hidden;
  min-height: 0;
}

/* -- Canvas Area ------------------------------------------------- */

.canvas-area {
  flex: 1;
  overflow: auto;
  background: #808080;
  display: flex;
  justify-content: flex-start;
  align-items: flex-start;
  min-width: 0;
}

.canvas-wrapper {
  padding: 4px;
  display: inline-block;
}

.canvas-container {
  position: relative;
  border: 1px solid var(--sz-color-window-text);
  border-top-color: var(--sz-color-button-shadow);
  border-left-color: var(--sz-color-button-shadow);
  border-bottom-color: var(--sz-color-button-highlight);
  border-right-color: var(--sz-color-button-highlight);
  display: inline-block;
  line-height: 0;
  cursor: crosshair;
}

#display-canvas {
  display: block;
  image-rendering: pixelated;
}

#overlay-canvas {
  position: absolute;
  top: 0; left: 0;
  pointer-events: none;
  image-rendering: pixelated;
}

/* -- Pixel Grid (visible at high zoom) --------------------------- */

.canvas-container.show-pixel-grid #overlay-canvas {
  /* Grid drawn via CSS background-image set in JS */
}

/* -- Text input overlay ------------------------------------------ */

.text-input-overlay {
  position: absolute;
  display: none;
  z-index: 10;
}

.text-input-overlay textarea {
  border: 1px dashed #000;
  background: rgba(255,255,255,0.9);
  font-family: Arial, sans-serif;
  font-size: 14px;
  color: #000;
  resize: both;
  padding: 2px;
  outline: none;
  min-width: 60px;
  min-height: 20px;
  overflow: hidden;
}

/* -- Layer Panel (right sidebar) --------------------------------- */

.layer-panel {
  width: 180px;
  background: var(--sz-color-button-face);
  border-left: 1px solid var(--sz-color-button-shadow);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
}

.layer-panel-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);
}

.layer-controls {
  display: flex;
  padding: 2px 4px;
  gap: 2px;
  border-bottom: 1px solid var(--sz-color-button-shadow);
  flex-wrap: wrap;
}

.layer-controls button {
  border: 1px solid transparent;
  background: transparent;
  cursor: default;
  font-size: 10px;
  padding: 1px 4px;
  color: var(--sz-color-button-text);
  border-radius: 2px;
}

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

.layer-props {
  padding: 4px 6px;
  border-bottom: 1px solid var(--sz-color-button-shadow);
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.layer-props label {
  font-size: 10px;
  display: flex;
  align-items: center;
  gap: 4px;
}

.layer-props input[type="range"] { flex: 1; height: 12px; cursor: default; }
.layer-props select { flex: 1; font-size: 10px; }
.layer-props .opacity-val { font-size: 10px; min-width: 26px; text-align: right; }

.layer-list {
  flex: 1;
  overflow-y: auto;
  padding: 2px;
}

.layer-entry {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 2px 4px;
  border: 1px solid transparent;
  border-radius: 2px;
  cursor: default;
  margin-bottom: 1px;
}

.layer-entry:hover { background: var(--sz-color-button-highlight); }

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

.layer-eye {
  width: 16px;
  height: 16px;
  text-align: center;
  font-size: 11px;
  line-height: 16px;
  cursor: default;
  flex-shrink: 0;
  opacity: 0.7;
}

.layer-eye:hover { opacity: 1; }
.layer-eye.hidden { opacity: 0.3; }

.layer-thumb {
  width: 48px;
  height: 36px;
  border: 1px solid var(--sz-color-button-shadow);
  flex-shrink: 0;
  image-rendering: pixelated;
}

.layer-name {
  flex: 1;
  font-size: 10px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.layer-name-input {
  flex: 1;
  font-size: 10px;
  border: 1px solid var(--sz-color-button-shadow);
  padding: 0 2px;
  background: var(--sz-color-window);
  color: var(--sz-color-window-text);
}

/* -- 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: 12px;
  min-height: 22px;
}

.status-bar .status-section {
  white-space: nowrap;
}

.status-spacer { flex: 1; }

/* -- 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: 300px;
  max-width: 500px;
  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;
  border-radius: 4px 4px 0 0;
}

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

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

.dialog-body label {
  display: block;
  margin-bottom: 2px;
  font-size: 11px;
}

.dialog-body input[type="text"],
.dialog-body input[type="number"] {
  width: 80px;
  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); }

/* -- Effect Dialogs ---------------------------------------------- */

.effect-preview {
  border: 1px solid var(--sz-color-button-shadow);
  display: block;
  margin-bottom: 8px;
  image-rendering: pixelated;
}

.effect-controls {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.effect-controls label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
}

.effect-controls input[type="range"] {
  flex: 1;
  height: 14px;
  cursor: default;
}

.effect-controls span {
  min-width: 30px;
  text-align: right;
  font-size: 10px;
}

/* -- Resize row (legacy) ----------------------------------------- */

.resize-row {
  display: flex;
  gap: 12px;
  margin-bottom: 8px;
  align-items: center;
}

.resize-row label {
  display: inline;
  min-width: 50px;
}

/* -- Scaler Picker Dialog ---------------------------------------- */

.scaler-picker-dialog { min-width: 480px; max-width: 540px; }

.scaler-mode-tabs {
  display: flex;
  gap: 0;
  margin-bottom: 6px;
}

.scaler-mode-tab {
  padding: 3px 12px;
  font-size: 11px;
  border: 1px solid var(--sz-color-button-shadow);
  background: var(--sz-color-button-face);
  cursor: default;
}

.scaler-mode-tab:first-child { border-radius: 3px 0 0 3px; }
.scaler-mode-tab:last-child { border-radius: 0 3px 3px 0; border-left: none; }

.scaler-mode-tab.active {
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
  border-color: var(--sz-color-highlight);
}

.scaler-dims {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-bottom: 4px;
  flex-wrap: wrap;
}

.scaler-dims label { display: flex; align-items: center; gap: 4px; font-size: 11px; }
.scaler-dims input[type="number"] { width: 64px; }
.scaler-dims > span { font-size: 12px; opacity: 0.6; }
.scaler-lock { margin-left: auto; }
.scaler-lock input { margin-right: 3px; }

.scaler-info {
  font-size: 10px;
  color: var(--sz-color-gray-text);
  margin: 2px 0 6px;
  min-height: 14px;
}

.scaler-columns {
  display: flex;
  gap: 8px;
  min-height: 210px;
}

.scaler-list-col {
  flex: 1 1 auto;
  min-width: 0;
}

.scaler-list {
  overflow-y: auto;
  max-height: 240px;
  border: 1px solid var(--sz-color-button-shadow);
  background: var(--sz-color-window);
  padding: 2px;
}

.scaler-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 3px 4px;
  cursor: default;
  border: 1px solid transparent;
  border-radius: 2px;
}

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

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

.scaler-thumb {
  width: 48px;
  height: 48px;
  flex-shrink: 0;
  border: 1px solid var(--sz-color-button-shadow);
  image-rendering: pixelated;
}

.scaler-label {
  flex: 1 1 auto;
  font-size: 11px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.scaler-badge {
  flex-shrink: 0;
  font-size: 9px;
  padding: 1px 4px;
  border-radius: 3px;
  font-weight: bold;
}

.scaler-badge.pixel-art { background: #d4a017; color: #fff; }
.scaler-badge.resampler { background: #5078c0; color: #fff; }

.scaler-preview-col {
  flex: 0 0 200px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.scaler-preview-title {
  font-size: 10px;
  margin-bottom: 4px;
  opacity: 0.7;
}

#scaler-preview {
  width: 192px;
  height: 192px;
  border: 1px solid var(--sz-color-button-shadow);
  image-rendering: pixelated;
}

.scaler-params {
  margin-top: 6px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.scaler-param-row {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
}

.scaler-param-row label {
  min-width: 80px;
  white-space: nowrap;
  display: inline;
}

.scaler-param-row input[type="range"] {
  flex: 1;
  height: 14px;
  cursor: default;
}

.scaler-param-row span {
  min-width: 36px;
  text-align: right;
  font-size: 10px;
}

/* -- Zoom controls in ribbon ------------------------------------- */

.rb-zoom-row { align-items: center; gap: 4px; }
.rb-zoom-slider { width: 100px; height: 14px; cursor: default; }
.rb-zoom-value { font-size: 10px; min-width: 36px; text-align: center; }

/* -- Checkboxes in ribbon ---------------------------------------- */

.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;
}