* { box-sizing: border-box; }

:root {
  --bg: #ece4d3;          /* warm parchment */
  --panel: #f5efe1;       /* soft cream panel */
  --border: #d6cdb8;
  --text: #3a3631;
  --muted: #7a7468;
  --accent: #c75b4a;      /* muted terracotta (root) */
  --note: #5d8aa8;        /* dusty blue (scale tones) */
  --flash: #d9b24c;       /* warm amber */
  --key-white: #f8f3e6;   /* off-white piano white-keys */
  --key-black: #3d3933;   /* warm charcoal piano black-keys */
  --fret-line: #b3a994;
  --fret-nut: #5a5147;
  --string: #6e6557;
  --inlay: #ddd2b8;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN", "Noto Sans JP", sans-serif;
  margin: 0;
  padding: 16px 18px 32px;
  background: var(--bg);
  color: var(--text);
}

header { margin-bottom: 16px; }

h1 {
  margin: 0 0 12px;
  font-size: 20px;
  letter-spacing: 0.02em;
}
h1 .sub {
  font-size: 12px;
  color: var(--muted);
  font-weight: normal;
  margin-left: 8px;
}
h2 {
  font-size: 13px;
  margin: 0 0 8px;
  color: var(--muted);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 16px;
  align-items: center;
  background: var(--panel);
  padding: 12px 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
}
.controls label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--muted);
}
.controls select,
.controls input[type="range"] {
  font: inherit;
  padding: 4px 8px;
  border-radius: 4px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
}
.controls select { min-width: 60px; }
.controls input[type="range"] { padding: 0; width: 120px; }
.controls #bpmVal {
  display: inline-block;
  min-width: 28px;
  text-align: right;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}
.controls button {
  font: inherit;
  cursor: pointer;
  background: var(--accent);
  color: #fff;
  border: 0;
  padding: 6px 14px;
  border-radius: 4px;
  font-weight: 600;
}
.controls button:hover { background: #a84838; }
.controls button.ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
}
.controls button.ghost:hover { background: var(--bg); color: var(--text); }

.legend {
  margin-top: 10px;
  font-size: 12px;
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  align-items: center;
}
.legend .swatch {
  display: inline-block;
  width: 10px; height: 10px;
  border-radius: 50%;
  margin-right: 4px;
  vertical-align: middle;
}
.legend .swatch.root { background: var(--accent); }
.legend .swatch.note { background: var(--note); }
.legend .deg-list { color: var(--text); font-weight: 600; }

.instrument {
  background: var(--panel);
  padding: 12px 14px 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
  margin-bottom: 14px;
}

.scroll-x {
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
}

#fretboard svg, #piano svg { display: block; }

.note { transition: opacity 0.18s; }
.note circle { transition: stroke 0.1s, stroke-width 0.1s; }
.note:hover circle { stroke: var(--flash); stroke-width: 3; }

.key { cursor: pointer; transition: fill 0.08s; }
.key.white:hover { fill: #efe6cf; }
.key.black:hover { fill: #5a5147; }
.key.flash { fill: var(--flash) !important; }

footer {
  margin-top: 12px;
  color: var(--muted);
  font-size: 11px;
  text-align: center;
}

@media (max-width: 700px) {
  body { padding: 12px; }
  h1 .sub { display: block; margin-left: 0; margin-top: 2px; }
  .controls { gap: 8px 12px; padding: 10px; }
  .controls label { font-size: 12px; }
  .controls input[type="range"] { width: 90px; }
}