:root {
  color-scheme: dark;
  --page: #0d0d0d;
  --surface: #1a1a19;
  --canvas: #070807;
  --text: #fff;
  --secondary: #c3c2b7;
  --muted: #898781;
  --border: rgba(255, 255, 255, 0.12);
  --blue: #3987e5;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

body {
  max-width: 1600px;
  margin: 0 auto;
  padding: 16px 18px 48px;
  background: var(--page);
  color: var(--text);
  font-size: 14px;
}

header,
.drop-zone,
.status-row,
.panel-head,
.spectrum-head,
footer {
  display: flex;
  align-items: center;
}

header {
  min-height: 46px;
  justify-content: space-between;
  gap: 20px;
}

h1 {
  display: inline;
  margin: 0 9px 0 0;
  font: 700 21px/1 ui-monospace, SFMono-Regular, Menlo, monospace;
}

header p { display: inline; margin: 0; color: var(--secondary); }
a { color: var(--secondary); }
a:hover { color: var(--text); }
code, select, button { font: inherit; }

.drop-zone {
  min-height: 58px;
  margin-top: 10px;
  padding: 10px 12px;
  gap: 12px;
  flex-wrap: wrap;
  border: 1px dashed rgba(255, 255, 255, 0.25);
  border-radius: 10px;
  background: var(--surface);
  color: var(--muted);
  transition: border-color 120ms, background 120ms;
}

.drop-zone.dragging {
  border-color: var(--blue);
  background: rgba(57, 135, 229, 0.12);
}

.target-note {
  margin-left: auto;
  font-size: 12px;
}

button,
select {
  min-height: 32px;
  padding: 5px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: #262624;
  color: var(--text);
}

button { cursor: pointer; }
button:hover:not(:disabled) { border-color: rgba(255, 255, 255, 0.3); background: #30302e; }
button.primary { border-color: rgba(57, 135, 229, 0.7); background: var(--blue); }
button:disabled { cursor: default; opacity: 0.42; }

.status-row {
  min-height: 38px;
  justify-content: space-between;
  gap: 16px;
  color: var(--secondary);
  font-size: 12.5px;
  font-variant-numeric: tabular-nums;
}

#summary { color: var(--muted); text-align: right; }

#progress {
  display: block;
  width: 100%;
  height: 4px;
  margin: -4px 0 10px;
  border: 0;
  accent-color: var(--blue);
}

#progress[hidden] { display: none; }

.panels {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.panel,
.spectrum-panel {
  min-width: 0;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
}

.panel-head {
  min-height: 28px;
  justify-content: space-between;
  gap: 12px;
  padding: 0 2px 6px;
}

.panel-head strong,
.spectrum-head strong { font-size: 13px; }

.panel-head span {
  color: var(--muted);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}

.canvas-wrap { position: relative; }
canvas { display: block; width: 100%; }

canvas[id$="-cloud"] {
  height: min(64vh, 720px);
  min-height: 430px;
  border-radius: 7px;
  background: var(--canvas);
  cursor: grab;
  touch-action: none;
}

canvas[id$="-cloud"]:active { cursor: grabbing; }

.empty-label {
  position: absolute;
  inset: 50% auto auto 50%;
  transform: translate(-50%, -50%);
  color: var(--muted);
  pointer-events: none;
}

.spectrum-panel { margin-top: 12px; }

.spectrum-head {
  min-height: 28px;
  gap: 15px;
  flex-wrap: wrap;
  padding: 0 2px 6px;
  color: var(--secondary);
  font-size: 12px;
}

.key {
  display: inline-block;
  width: 14px;
  height: 3px;
  margin-right: 5px;
  border-radius: 2px;
  vertical-align: 3px;
}

.key.original { background: var(--muted); }
.key.retained { background: var(--blue); }
.hint { margin-left: auto; color: var(--muted); }

#spectrum {
  height: 170px;
  border-radius: 7px;
  background: #111110;
}

footer {
  justify-content: space-between;
  gap: 20px;
  padding-top: 14px;
  color: var(--muted);
  font-size: 11.5px;
}

body.busy { cursor: progress; }
body.busy button,
body.busy select { pointer-events: none; }

@media (max-width: 850px) {
  .panels { grid-template-columns: 1fr; }
  canvas[id$="-cloud"] { height: 52vh; min-height: 340px; }
  .target-note { width: 100%; margin-left: 0; }
  .hint { width: 100%; margin-left: 0; }
  footer { align-items: flex-start; flex-direction: column; }
}