:root {
  --bg: #fafafa;
  --bg-secondary: #f4f4f5;
  --bg-tertiary: #e4e4e7;
  --border: #d4d4d8;
  --text: #18181b;
  --text-secondary: #52525b;
  --text-muted: #a1a1aa;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;

  --dmg-0: #e0f8d0;
  --dmg-1: #88c070;
  --dmg-2: #346856;
  --dmg-3: #081820;

  --code-bg: #f8f8f8;
  --code-line-bg: #f0f0f0;
  --code-highlight: #fff3cd;
  --code-font: 'Cascadia Code', 'Fira Code', ui-monospace, SFMono-Regular, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #09090b;
    --bg-secondary: #18181b;
    --bg-tertiary: #27272a;
    --border: #3f3f46;
    --text: #fafafa;
    --text-secondary: #a1a1aa;
    --text-muted: #71717a;
    --accent: #60a5fa;
    --accent-hover: #93bbfd;

    --code-bg: #111113;
    --code-line-bg: #1a1a1e;
    --code-highlight: #3b3500;
  }
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100dvh;
}

/* ---- Drop Zone ---- */

.drop-zone {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100dvh;
  padding: 2rem;
}

.drop-zone.compact {
  min-height: 0;
  padding: 0;
}

.drop-inner {
  text-align: center;
  padding: 3rem 4rem;
  border: 2px dashed var(--border);
  border-radius: 1rem;
  transition: border-color 0.15s, background 0.15s;

  & p {
    margin-top: 0.75rem;
    color: var(--text-secondary);
  }

  & .hint {
    font-size: 0.85rem;
    color: var(--text-muted);
  }
}

.drop-zone.compact .drop-inner {
  padding: 0.5rem 1rem;
  border-radius: 0;
  border: none;
  border-bottom: 2px dashed var(--border);
  width: 100%;
  display: flex;
  align-items: center;
  gap: 0.75rem;

  & .drop-icon {
    width: 1.25rem;
    height: 1.25rem;
  }

  & p {
    margin-top: 0;
    font-size: 0.8rem;
  }

  & .hint { display: none; }
}

.drop-zone.drag-over .drop-inner {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 8%, transparent);
}

.drop-icon {
  width: 3rem;
  height: 3rem;
  color: var(--text-muted);
}

.file-label {
  color: var(--accent);
  cursor: pointer;
  text-decoration: underline;
}

/* ---- Buttons ---- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.4rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  background: var(--bg-secondary);
  color: var(--text);
  font-size: 0.8rem;
  cursor: pointer;
  transition: background 0.1s, border-color 0.1s;
  white-space: nowrap;

  &:hover {
    background: var(--bg-tertiary);
    border-color: var(--text-muted);
  }
}

.btn-ghost {
  background: transparent;
  border-color: transparent;

  &:hover {
    background: var(--bg-secondary);
    border-color: var(--border);
  }
}

.btn-sm {
  padding: 0.3rem 0.6rem;
  font-size: 0.75rem;
}

/* ---- Toolbar ---- */

.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border-bottom: 1px solid var(--border);
  background: var(--bg-secondary);
  position: sticky;
  top: 0;
  z-index: 20;
  flex-wrap: wrap;
}

.file-name {
  font-family: var(--code-font);
  font-size: 0.85rem;
  color: var(--text-secondary);
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.toolbar-actions {
  display: flex;
  gap: 0.375rem;
  flex-shrink: 0;
}

/* ---- Two-panel layout ---- */

.panels {
  display: flex;
  min-height: calc(100dvh - 3rem);
}

.source-panel {
  flex: 1;
  min-width: 0;
  overflow-x: auto;
}

.editor-panel {
  width: 21rem;
  flex-shrink: 0;
  border-left: 1px solid var(--border);
  background: var(--bg-secondary);
}

.editor-sticky {
  position: sticky;
  top: 3rem;
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  max-height: calc(100dvh - 3rem);
  overflow-y: auto;
}

/* ---- Source Code ---- */

.source-wrap {
  display: flex;
  font-family: var(--code-font);
  font-size: 0.8rem;
  line-height: 1.6;
  min-height: 100%;
}

.line-numbers {
  flex-shrink: 0;
  padding: 0.75rem 0.5rem 0.75rem 0.75rem;
  text-align: right;
  color: var(--text-muted);
  background: var(--code-line-bg);
  user-select: none;
  border-right: 1px solid var(--border);
  min-width: 3rem;
  white-space: pre;
  font-family: var(--code-font);
  font-size: 0.8rem;
  line-height: 1.6;
}

.source-code {
  flex: 1;
  padding: 0.75rem 1rem;
  margin: 0;
  background: var(--code-bg);
  white-space: pre;
  overflow-x: auto;
  tab-size: 4;
  min-width: 0;
}

/* Hex byte highlighting */
.hex-byte {
  border-radius: 2px;
  padding: 0 1px;
}

.hex-byte[data-array-idx] {
  background: color-mix(in srgb, var(--accent) 15%, transparent);
  cursor: pointer;

  &:hover {
    background: color-mix(in srgb, var(--accent) 30%, transparent);
  }
}

.hex-byte.active-tile {
  background: var(--code-highlight);
}

/* Inline tile previews */
.tile-preview-row {
  display: inline-flex;
  gap: 2px;
  vertical-align: middle;
  margin: 2px 0 2px 0.5rem;
}

.tile-preview-row canvas {
  cursor: pointer;
  border: 1px solid var(--border);
  border-radius: 2px;
  image-rendering: pixelated;
  transition: border-color 0.1s;

  &:hover {
    border-color: var(--accent);
  }

  &.selected {
    border-color: var(--accent);
    box-shadow: 0 0 0 1px var(--accent);
  }
}

/* ---- Tile Editor ---- */

.editor-info {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-family: var(--code-font);
  text-align: center;
  padding: 0.25rem;
}

.tile-grid-controls {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.cluster-toggle {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
  cursor: pointer;
  user-select: none;
}

.tile-grid-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  background: var(--bg-tertiary);
  padding: 4px;

  & canvas {
    display: block;
    image-rendering: pixelated;
    cursor: pointer;
  }
}

#tileZoomCanvas {
  display: block;
  width: 100%;
  aspect-ratio: 1;
  max-width: 320px;
  margin-inline: auto;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  image-rendering: pixelated;
  cursor: crosshair;
  background: var(--dmg-0);
}

/* ---- Palette ---- */

.palette {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
}

.palette-btn {
  width: 2.5rem;
  height: 2.5rem;
  border: 2px solid var(--border);
  border-radius: 0.375rem;
  cursor: pointer;
  padding: 3px;
  background: var(--bg);
  transition: border-color 0.1s, box-shadow 0.1s;

  & span {
    display: block;
    width: 100%;
    height: 100%;
    border-radius: 2px;
  }

  &[data-color="0"] span { background: var(--dmg-0); }
  &[data-color="1"] span { background: var(--dmg-1); }
  &[data-color="2"] span { background: var(--dmg-2); }
  &[data-color="3"] span { background: var(--dmg-3); }

  &.active {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 40%, transparent);
  }
}

/* ---- Editor Nav ---- */

.editor-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
}

.tile-counter {
  font-family: var(--code-font);
  font-size: 0.8rem;
  color: var(--text-secondary);
  min-width: 4rem;
  text-align: center;
}

/* ---- Mobile ---- */

@media (max-width: 768px) {
  .panels {
    flex-direction: column;
  }

  .editor-panel {
    width: 100%;
    border-left: none;
    border-top: 1px solid var(--border);
  }

  .editor-sticky {
    position: static;
    max-height: none;
  }

  .toolbar {
    padding: 0.5rem;
  }
}