/* ─── Variables ─────────────────────────────────────────────────── */
:root {
  --bg: #1a1a2e;
  --bg-panel: #16213e;
  --bg-card: #0f3460;
  --bg-hover: #1a4a7a;
  --border: #2a4a6a;
  --text: #e0e8f0;
  --text-muted: #7a9ab5;
  --accent: #4a9eff;
  --accent-hover: #6ab8ff;
  --btn-bg: #1e3a5f;
  --btn-hover: #2a5280;
  --danger: #e05555;
  --success: #55c080;
  --radius: 6px;
  --radius-sm: 4px;
  --panel-w: 160px;
  --header-h: 52px;
  --status-h: 28px;
  --gap: 10px;
}

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

body {
  font-family: system-ui, -apple-system, sans-serif;
  font-size: 13px;
  background: var(--bg);
  color: var(--text);
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  user-select: none;
}

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

.app-header h1 {
  font-size: 15px;
  font-weight: 600;
  color: var(--accent);
  flex: 1;
  min-width: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-actions {
  display: flex;
  gap: 6px;
  align-items: center;
  flex-shrink: 0;
}

/* ─── Body layout ────────────────────────────────────────────────── */
.app-body {
  flex: 1;
  display: flex;
  overflow: hidden;
  min-height: 0;
}

/* ─── Panels ─────────────────────────────────────────────────────── */
.left-panel,
.right-panel {
  width: var(--panel-w);
  background: var(--bg-panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: var(--gap);
  padding: 10px 8px;
  overflow-y: auto;
  flex-shrink: 0;
}

.right-panel {
  border-right: none;
  border-left: 1px solid var(--border);
}

.label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}

/* ─── Tools section ──────────────────────────────────────────────── */
.tools-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
}

.tool-btn {
  aspect-ratio: 1;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6px;
}

.tool-btn.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent-hover);
}

.rect-mode-section {
  min-height: 24px;
}

/* ─── Palette ─────────────────────────────────────────────────────── */
.color-section {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

#palette {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 3px;
  margin-bottom: 6px;
}

.palette-color {
  aspect-ratio: 1;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform 0.1s, border-color 0.1s;
  padding: 0;
}

.palette-color:hover {
  transform: scale(1.1);
  border-color: var(--text);
}

.palette-color.selected {
  border-color: var(--accent);
  transform: scale(1.05);
  box-shadow: 0 0 0 1px var(--accent-hover);
}

.color-picker-row {
  display: flex;
  align-items: center;
  gap: 6px;
}

.current-color-swatch {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  border: 2px solid var(--border);
  background: #000;
  flex-shrink: 0;
}

#color-picker {
  flex: 1;
  height: 28px;
  border: none;
  border-radius: var(--radius-sm);
  background: none;
  cursor: pointer;
  padding: 0;
}

/* ─── Canvas area ────────────────────────────────────────────────── */
.canvas-area {
  flex: 1;
  overflow: auto;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 20px;
  background: repeating-conic-gradient(#1e2030 0% 25%, #252840 0% 50%) 0 0 / 24px 24px;
}

.canvas-wrapper {
  position: relative;
  display: inline-block;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.6);
  border-radius: 2px;
}

#canvas,
#preview-canvas {
  display: block;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}

#preview-canvas {
  position: absolute;
  top: 0;
  left: 0;
  pointer-events: auto;
  cursor: crosshair;
}

/* ─── Right panel sections ───────────────────────────────────────── */
.settings-section {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.select {
  width: 100%;
  background: var(--btn-bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 4px 6px;
  font-size: 12px;
  cursor: pointer;
  margin-bottom: 4px;
}

.select:focus {
  outline: 2px solid var(--accent);
}

.toggle-label {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
}

.toggle-label input[type="checkbox"] {
  width: 14px;
  height: 14px;
  accent-color: var(--accent);
}

.layers-section {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.layer-item {
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 6px 8px;
  font-size: 12px;
}

.layer-item.active {
  border-color: var(--accent);
  background: var(--bg-hover);
}

.shortcuts-section {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.shortcuts-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.shortcut {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  color: var(--text-muted);
}

kbd {
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 1px 4px;
  font-family: monospace;
  font-size: 10px;
  color: var(--text);
  min-width: 18px;
  text-align: center;
}

/* ─── Status bar ─────────────────────────────────────────────────── */
.status-bar {
  height: var(--status-h);
  background: var(--bg-panel);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 12px;
  gap: 8px;
  font-size: 12px;
  color: var(--text-muted);
  flex-shrink: 0;
}

#status {
  color: var(--text);
}

.coords-label {
  margin-left: auto;
}

#coords {
  font-family: monospace;
  min-width: 48px;
}

/* ─── Buttons ────────────────────────────────────────────────────── */
.btn {
  background: var(--btn-bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 5px 10px;
  font-size: 12px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

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

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent-hover);
  color: #fff;
  font-weight: 600;
}

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

.btn-small {
  padding: 3px 8px;
  font-size: 11px;
}

.icon-btn {
  width: 30px;
  height: 30px;
  padding: 0;
  font-size: 16px;
}

/* ─── Scrollbar ──────────────────────────────────────────────────── */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: var(--bg);
}
::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* ─── Responsive: hide right panel on narrow screens ─────────────── */
@media (max-width: 700px) {
  :root {
    --panel-w: 120px;
  }
  .right-panel {
    display: none;
  }
}