:root {
  --bg-dark: #2D3436;
  --bg-panel: #1e2426;
  --bg-panel-light: #3a4548;
  --accent-primary: #FF6B9D;
  --accent-cyan: #C7ECEE;
  --text-main: #F5F6FA;
  --text-muted: #8395A7;
  --border: #4A5568;
  --checker-light: #526063;
  --checker-dark: #3e494b;
}

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

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

h1, h2, h3, .brand { font-family: 'Inter', sans-serif; }

/* Buttons & Inputs */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: var(--bg-panel-light);
  color: var(--text-main);
  border: 1px solid var(--border);
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  transition: all 0.2s;
}
.btn:hover { background: #4b5a5e; }
.btn-primary { background: var(--accent-primary); border-color: var(--accent-primary); color: #fff; }
.btn-primary:hover { background: #e05b8a; }
.btn-danger { background: transparent; border-color: #ff4757; color: #ff4757; }
.btn-danger:hover { background: rgba(255, 71, 87, 0.1); }
.btn-icon { padding: 0.5rem; aspect-ratio: 1; }
.btn-icon i { width: 1.2rem; height: 1.2rem; }
.btn-small { padding: 0.2rem; }
.btn-small i { width: 1rem; height: 1rem; }
.btn-sm { padding: 0.3rem 0.6rem; font-size: 0.8rem; }

select:focus, input:focus { outline: 1px solid var(--accent-primary); }

/* Layout Structure */
.app-header {
  height: 50px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1rem;
  flex-shrink: 0;
}
.brand { display: flex; align-items: center; gap: 0.5rem; color: var(--accent-primary); font-weight: bold; letter-spacing: 1px; }
.brand h1 { font-family: 'Press Start 2P', monospace; font-size: 0.8rem; margin-top: 4px; }
.brand-icon { width: 1.5rem; height: 1.5rem; }

.toolbar-center, .toolbar-right { display: flex; align-items: center; gap: 0.75rem; }
.divider { width: 1px; height: 24px; background: var(--border); margin: 0 0.5rem; }
.select-input { background: var(--bg-dark); color: white; border: 1px solid var(--border); padding: 0.3rem 0.5rem; border-radius: 4px; font-size: 0.85rem;}

.app-workspace {
  display: flex;
  flex: 1;
  overflow: hidden;
}

.sidebar {
  width: 260px;
  background: var(--bg-panel);
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border);
  flex-shrink: 0;
  overflow-y: auto;
}
.sidebar::-webkit-scrollbar { width: 6px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border); }
.right-sidebar { border-right: none; border-left: 1px solid var(--border); }

.panel { padding: 1rem; border-bottom: 1px solid var(--border); }
.panel:last-child { border-bottom: none; }
.panel-title { font-size: 0.75rem; text-transform: uppercase; color: var(--text-muted); margin-bottom: 0.75rem; font-weight: bold; letter-spacing: 0.5px; display: flex; justify-content: space-between; align-items: center;}
.flex-fill { flex: 1; display: flex; flex-direction: column; }

/* Tools */
.tools-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0.4rem; }
.tool-btn { 
  aspect-ratio: 1; background: var(--bg-dark); border: 1px solid var(--border); border-radius: 4px; 
  color: var(--text-main); cursor: pointer; display: flex; justify-content: center; align-items: center; 
  transition: all 0.15s;
}
.tool-btn i { width: 1.2rem; height: 1.2rem; }
.tool-btn:hover { background: var(--bg-panel-light); border-color: var(--text-muted); }
.tool-btn.active { background: var(--accent-primary); border-color: var(--accent-primary); color: white; }

/* Options */
.option-row { margin-bottom: 0.5rem; }
.checkbox-label { display: flex; align-items: center; gap: 0.5rem; font-size: 0.85rem; cursor: pointer; user-select: none; }
.checkbox-label input { accent-color: var(--accent-primary); width: 1.1rem; height: 1.1rem;}

/* Colors */
.color-picker-main { width: 100%; height: 40px; border: none; border-radius: 4px; margin-bottom: 0.75rem; cursor: pointer; background: transparent; padding: 0; }
.color-picker-main::-webkit-color-swatch-wrapper { padding: 0; }
.color-picker-main::-webkit-color-swatch { border: 1px solid var(--border); border-radius: 4px; }
.palette-grid { display: grid; grid-template-columns: repeat(8, 1fr); gap: 4px; }
.swatch { aspect-ratio: 1; border-radius: 2px; border: 1px solid rgba(255,255,255,0.2); cursor: pointer; }
.swatch:hover { transform: scale(1.1); box-shadow: 0 0 0 1px white; z-index: 10; }
.swatch.selected { border: 2px solid white; box-shadow: 0 0 4px black; }

/* Main Editor Area */
.editor-area {
  flex: 1;
  background: var(--bg-dark);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden; /* Handle zooming internally */
}

/* Canvas Wrapper sets up the checkerboard and handles zooming */
.canvas-wrapper {
  position: relative;
  background-image: conic-gradient(var(--checker-dark) 90deg, var(--checker-light) 90deg 180deg, var(--checker-dark) 180deg 270deg, var(--checker-light) 270deg);
  background-size: 20px 20px; /* Size of the checkerboard */
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
  transform-origin: center center;
  /* Make sure dragging doesn't select text */
  user-select: none;
}

#main-canvas, #overlay-canvas {
  /* Crisp rendering for pixel art */
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  cursor: crosshair;
}

#main-canvas { z-index: 1; }
#overlay-canvas { z-index: 2; pointer-events: none; }

.zoom-controls {
  position: absolute;
  bottom: 1.5rem;
  right: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--bg-panel);
  padding: 0.5rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}
#zoom-level { font-size: 0.85rem; font-weight: 600; min-width: 3rem; text-align: center; }

/* Preview */
.preview-container {
  width: 100%;
  aspect-ratio: 1;
  background-image: conic-gradient(var(--checker-dark) 90deg, var(--checker-light) 90deg 180deg, var(--checker-dark) 180deg 270deg, var(--checker-light) 270deg);
  background-size: 10px 10px;
  border-radius: 4px;
  border: 1px solid var(--border);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
#preview-canvas { image-rendering: pixelated; max-width: 100%; max-height: 100%; }
.preview-controls { display: flex; align-items: center; justify-content: space-between; }
.fps-label { font-size: 0.8rem; display: flex; align-items: center; gap: 0.5rem; }
.fps-label input { width: 50px; background: var(--bg-dark); color: white; border: 1px solid var(--border); border-radius: 4px; padding: 0.2rem; text-align: center;}

/* Layers */
.layer-list { list-style: none; flex: 1; overflow-y: auto; margin-top: 0.5rem; }
.layer-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem;
  background: var(--bg-dark);
  border: 1px solid var(--border);
  border-radius: 4px;
  margin-bottom: 0.4rem;
  cursor: pointer;
  transition: background 0.1s;
}
.layer-item:hover { background: #353f42; }
.layer-item.active { background: rgba(255, 107, 157, 0.15); border-color: var(--accent-primary); }
.layer-name { flex: 1; font-size: 0.85rem; }
.layer-vis-btn { background: transparent; border: none; color: var(--text-muted); cursor: pointer; }
.layer-vis-btn:hover { color: white; }
.layer-vis-btn i { width: 1.1rem; height: 1.1rem; }

/* Timeline Footer */
.app-footer {
  height: 100px;
  background: var(--bg-panel);
  border-top: 1px solid var(--border);
  display: flex;
  flex-shrink: 0;
}
.timeline-header {
  width: 260px;
  padding: 1rem;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.timeline-header h3 { font-size: 0.75rem; text-transform: uppercase; color: var(--text-muted); margin-bottom: 0.5rem; }
.timeline-actions { display: flex; flex-wrap: wrap; gap: 0.25rem; }
.frames-container {
  flex: 1;
  display: flex;
  align-items: center;
  padding: 1rem;
  gap: 0.5rem;
  overflow-x: auto;
}
.frames-container::-webkit-scrollbar { height: 8px; }
.frames-container::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
.frame-box {
  height: 100%;
  aspect-ratio: 1;
  background-image: conic-gradient(var(--checker-dark) 90deg, var(--checker-light) 90deg 180deg, var(--checker-dark) 180deg 270deg, var(--checker-light) 270deg);
  background-size: 6px 6px;
  border-radius: 4px;
  border: 2px solid var(--border);
  position: relative;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}
.frame-box canvas { width: 100%; height: 100%; image-rendering: pixelated; }
.frame-box:hover { border-color: #8395A7; }
.frame-box.active { border-color: var(--accent-cyan); box-shadow: 0 0 10px rgba(199, 236, 238, 0.3); }
.frame-number { position: absolute; bottom: -20px; font-size: 0.75rem; color: var(--text-muted); }

/* Modal */
.modal {
  position: fixed; top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(0,0,0,0.8);
  display: flex; justify-content: center; align-items: center;
  z-index: 1000;
  opacity: 1;
  transition: opacity 0.2s;
}
.modal.hidden { opacity: 0; pointer-events: none; }
.modal-content {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2rem;
  width: 400px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.5);
}
.modal-content h2 { margin-bottom: 1.5rem; color: white; display:flex; align-items:center; gap: 0.5rem; }
.export-options { display: flex; flex-direction: column; gap: 1rem; margin-bottom: 2rem; }
.export-options label { display: flex; flex-direction: column; gap: 0.5rem; font-size: 0.9rem; color: var(--text-muted); }
.export-options select { width: 100%; }
.modal-actions { display: flex; justify-content: flex-end; gap: 1rem; }