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

:root {
  --bg-deep: #0d0b1a;
  --bg-mid: #151228;
  --bg-card: #1c1835;
  --bg-control: #231e40;
  --purple-dark: #2d1f5e;
  --purple-mid: #5b3ea5;
  --purple-light: #9b7ec8;
  --purple-glow: #c8a8e8;
  --accent-lavender: #b8a9d4;
  --accent-yellow: #f0d848;
  --accent-red: #e84050;
  --accent-blue: #5888e8;
  --accent-green: #48c878;
  --text-primary: #e8e0f0;
  --text-secondary: #9088a8;
  --text-dim: #584e78;
  --border: #3a3060;
  --pixel-font: 'Press Start 2P', monospace;
  --body-font: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

html {
  font-size: 16px;
}

body {
  font-family: var(--body-font);
  background: var(--bg-deep);
  color: var(--text-primary);
  min-height: 100vh;
  background-image:
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 2px,
      rgba(91, 62, 165, 0.03) 2px,
      rgba(91, 62, 165, 0.03) 4px
    );
  overflow-x: hidden;
}

/* Header */
#header {
  position: relative;
  background: linear-gradient(135deg, #1a0e3a 0%, #0d1a3a 50%, #1a0e3a 100%);
  padding: 2rem 1rem 1.5rem;
  text-align: center;
  border-bottom: 3px solid var(--purple-mid);
  overflow: hidden;
}

#header h1 {
  font-family: var(--pixel-font);
  font-size: clamp(0.7rem, 3vw, 1.4rem);
  color: var(--purple-glow);
  text-shadow: 0 0 20px rgba(200, 168, 232, 0.5), 0 2px 0 var(--purple-dark);
  letter-spacing: 2px;
  position: relative;
  z-index: 2;
}

.subtitle {
  font-family: var(--pixel-font);
  font-size: clamp(0.4rem, 1.5vw, 0.55rem);
  color: var(--text-secondary);
  margin-top: 0.75rem;
  position: relative;
  z-index: 2;
}

.scanline-overlay {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 1px,
    rgba(0, 0, 0, 0.15) 1px,
    rgba(0, 0, 0, 0.15) 2px
  );
  pointer-events: none;
  z-index: 1;
  animation: scanline-scroll 8s linear infinite;
}

@keyframes scanline-scroll {
  0% { transform: translateY(0); }
  100% { transform: translateY(20px); }
}

/* Main */
#main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1rem;
}

/* Upload Zone */
.upload-zone {
  border: 3px dashed var(--border);
  border-radius: 12px;
  padding: 3rem 2rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  background: var(--bg-card);
  position: relative;
}

.upload-zone:hover,
.upload-zone.drag-over {
  border-color: var(--purple-mid);
  background: var(--bg-control);
  box-shadow: 0 0 30px rgba(91, 62, 165, 0.3), inset 0 0 30px rgba(91, 62, 165, 0.05);
}

.upload-icon {
  margin-bottom: 1rem;
  opacity: 0.7;
}

.upload-text {
  font-family: var(--pixel-font);
  font-size: 0.65rem;
  color: var(--purple-light);
  margin-bottom: 0.5rem;
}

.upload-hint {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* Preview */
.preview-section {
  margin-bottom: 1.5rem;
}

.preview-mode-toggle {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
  justify-content: center;
}

.mode-btn {
  font-family: var(--pixel-font);
  font-size: 0.5rem;
  padding: 0.5rem 1rem;
  background: var(--bg-control);
  border: 2px solid var(--border);
  color: var(--text-secondary);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s;
}

.mode-btn:hover { border-color: var(--purple-mid); color: var(--text-primary); }
.mode-btn.active { background: var(--purple-dark); border-color: var(--purple-mid); color: var(--purple-glow); }

.canvas-container {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.canvas-wrap {
  flex: 1;
  min-width: 250px;
  max-width: 520px;
  text-align: center;
}

.canvas-label {
  font-family: var(--pixel-font);
  font-size: 0.5rem;
  color: var(--text-secondary);
  display: block;
  margin-bottom: 0.5rem;
  letter-spacing: 2px;
}

.canvas-wrap canvas,
.slider-container canvas {
  width: 100%;
  height: auto;
  border: 2px solid var(--border);
  border-radius: 4px;
  background: #000;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}

/* Slider Compare */
.slider-container {
  position: relative;
  max-width: 700px;
  margin: 0 auto;
  overflow: hidden;
  border-radius: 4px;
}

.slider-container canvas {
  display: block;
}

.slider-divider {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 4px;
  background: var(--purple-glow);
  cursor: ew-resize;
  z-index: 10;
  transform: translateX(-50%);
}

.slider-handle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 32px;
  height: 32px;
  background: var(--purple-mid);
  border: 2px solid var(--purple-glow);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.slider-handle::before {
  content: '◀▶';
  font-size: 8px;
  color: var(--purple-glow);
}

.slider-label-left, .slider-label-right {
  position: absolute;
  top: 8px;
  font-family: var(--pixel-font);
  font-size: 0.4rem;
  color: var(--purple-glow);
  background: rgba(0,0,0,0.6);
  padding: 4px 8px;
  border-radius: 3px;
  z-index: 5;
}
.slider-label-left { left: 8px; }
.slider-label-right { right: 8px; }

/* Controls */
.controls-section {
  background: var(--bg-card);
  border: 2px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.control-label {
  font-family: var(--pixel-font);
  font-size: 0.5rem;
  color: var(--accent-lavender);
  letter-spacing: 1px;
}

/* Algorithm Buttons */
.algo-buttons, .palette-options {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.algo-btn, .palette-btn {
  font-family: var(--pixel-font);
  font-size: 0.4rem;
  padding: 0.5rem 0.75rem;
  background: var(--bg-control);
  border: 2px solid var(--border);
  color: var(--text-secondary);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.algo-btn:hover, .palette-btn:hover {
  border-color: var(--purple-mid);
  color: var(--text-primary);
  transform: translateY(-1px);
}

.algo-btn.active, .palette-btn.active {
  background: var(--purple-dark);
  border-color: var(--purple-mid);
  color: var(--purple-glow);
  box-shadow: 0 0 10px rgba(91, 62, 165, 0.3);
}

.palette-swatch {
  display: inline-block;
  width: 40px;
  height: 10px;
  border-radius: 2px;
  border: 1px solid rgba(255,255,255,0.1);
}

/* Sliders */
.snes-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 8px;
  background: var(--bg-control);
  border: 1px solid var(--border);
  border-radius: 4px;
  outline: none;
}

.snes-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--purple-mid);
  border: 2px solid var(--purple-glow);
  border-radius: 50%;
  cursor: pointer;
  transition: transform 0.1s;
}

.snes-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.snes-slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  background: var(--purple-mid);
  border: 2px solid var(--purple-glow);
  border-radius: 50%;
  cursor: pointer;
}

.slider-labels {
  display: flex;
  justify-content: space-between;
  font-family: var(--pixel-font);
  font-size: 0.35rem;
  color: var(--text-dim);
}

/* Checkbox */
.checkbox-group {
  flex-direction: row;
  align-items: center;
}

.checkbox-label {
  font-family: var(--pixel-font);
  font-size: 0.5rem;
  color: var(--accent-lavender);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
  user-select: none;
}

.checkbox-label input { display: none; }

.checkbox-custom {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border);
  border-radius: 4px;
  background: var(--bg-control);
  position: relative;
  transition: all 0.2s;
  flex-shrink: 0;
}

.checkbox-label input:checked + .checkbox-custom {
  background: var(--purple-mid);
  border-color: var(--purple-glow);
}

.checkbox-label input:checked + .checkbox-custom::after {
  content: '✓';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 12px;
  color: var(--purple-glow);
}

/* Buttons */
.export-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.snes-btn {
  font-family: var(--pixel-font);
  font-size: 0.45rem;
  padding: 0.7rem 1.2rem;
  background: linear-gradient(180deg, var(--purple-mid) 0%, #4a2e8a 100%);
  border: none;
  border-bottom: 4px solid #3a1e6a;
  border-radius: 8px;
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.1s;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.snes-btn:hover {
  background: linear-gradient(180deg, #6b4ec0 0%, var(--purple-mid) 100%);
  transform: translateY(-1px);
}

.snes-btn:active {
  border-bottom-width: 2px;
  transform: translateY(2px);
}

.snes-btn.secondary {
  background: linear-gradient(180deg, var(--bg-control) 0%, #1a1530 100%);
  border-bottom-color: #0d0b1a;
}

.snes-btn.upload-new {
  align-self: center;
  margin-top: 0.5rem;
  background: linear-gradient(180deg, #3a6a3a 0%, #285828 100%);
  border-bottom-color: #1a3a1a;
}

/* Footer */
#footer {
  text-align: center;
  padding: 2rem 1rem;
  background: var(--bg-mid);
  border-top: 2px solid var(--border);
  margin-top: 2rem;
}

#footer p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
}

#footer .quip {
  font-family: var(--pixel-font);
  font-size: 0.35rem;
  color: var(--text-dim);
  margin-bottom: 0.75rem;
}

#footer a {
  font-family: var(--pixel-font);
  font-size: 0.45rem;
  color: var(--purple-light);
  text-decoration: none;
  border-bottom: 1px dashed var(--purple-light);
  transition: color 0.2s;
}

#footer a:hover { color: var(--purple-glow); }

/* Utility */
.hidden { display: none !important; }

/* Processing overlay */
.processing-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(13, 11, 26, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  font-family: var(--pixel-font);
  font-size: 0.6rem;
  color: var(--purple-glow);
}

.processing-overlay .dots::after {
  content: '';
  animation: dots 1.5s steps(3, end) infinite;
}

@keyframes dots {
  0% { content: '.'; }
  33% { content: '..'; }
  66% { content: '...'; }
}

/* Toast notification */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--purple-dark);
  border: 2px solid var(--purple-mid);
  color: var(--purple-glow);
  font-family: var(--pixel-font);
  font-size: 0.45rem;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  z-index: 200;
  transition: transform 0.3s ease;
  pointer-events: none;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
}

@media (max-width: 640px) {
  .canvas-container {
    flex-direction: column;
    align-items: center;
  }
  .canvas-wrap {
    max-width: 100%;
  }
  .algo-buttons, .palette-options, .export-buttons {
    justify-content: center;
  }
  #main {
    padding: 1rem 0.5rem;
  }
  .controls-section {
    padding: 1rem;
  }
}