:root,
[data-theme="dark"] {
  --bg: #0f1417;
  --panel: #1a2126;
  --accent: #3ddc84;
  --accent-dim: #235c3f;
  --accent-text: #06210f;
  --flat: #ff6b6b;
  --flat-text: #2a0a0a;
  --sharp: #ffb347;
  --text: #eef2f4;
  --text-dim: #9aa7ad;
  --input-bg: #10161a;
  --border-color: #2c363c;
}

[data-theme="light"] {
  --bg: #f4f6f7;
  --panel: #ffffff;
  --accent: #1f9d55;
  --accent-dim: #d3f3e0;
  --accent-text: #ffffff;
  --flat: #e0453c;
  --flat-text: #ffffff;
  --sharp: #c97a12;
  --text: #1a2126;
  --text-dim: #5b6770;
  --input-bg: #f1f3f4;
  --border-color: #d7dde0;
}

[data-theme="sunset"] {
  --bg: #1f1310;
  --panel: #2c1c17;
  --accent: #ff8a3d;
  --accent-dim: #6b3a1a;
  --accent-text: #2c1300;
  --flat: #ff4d6d;
  --flat-text: #2a0410;
  --sharp: #ffd23d;
  --text: #fff3ea;
  --text-dim: #cfa48c;
  --input-bg: #241611;
  --border-color: #4a2c1f;
}

[data-theme="ocean"] {
  --bg: #0b1a24;
  --panel: #142a38;
  --accent: #38c6d9;
  --accent-dim: #1c5560;
  --accent-text: #06232a;
  --flat: #ff6b6b;
  --flat-text: #2a0a0a;
  --sharp: #ffb347;
  --text: #eaf6f9;
  --text-dim: #8fb4c0;
  --input-bg: #0f2530;
  --border-color: #22475a;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  padding: 24px;
  transition: background 0.2s ease-out, color 0.2s ease-out;
}

.app {
  width: 100%;
  max-width: 480px;
  background: var(--panel);
  border-radius: 16px;
  padding: 28px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
  text-align: center;
  transition: background 0.2s ease-out;
}

h1 {
  margin: 0 0 4px;
  font-size: 1.6rem;
}

.subtitle {
  margin: 0 0 24px;
  color: var(--text-dim);
  font-size: 0.9rem;
}

.controls {
  margin-bottom: 20px;
  text-align: left;
}

.controls label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-bottom: 6px;
}

#instrument,
#theme {
  width: 100%;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--input-bg);
  color: var(--text);
  font-size: 1rem;
  margin-bottom: 14px;
}

.strings {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}

.string-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1 1 auto;
  min-width: 56px;
}

.string-btn {
  width: 100%;
  padding: 10px 8px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--input-bg);
  color: var(--text);
  font-size: 0.95rem;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}

.string-btn:hover {
  border-color: var(--accent);
}

.string-btn.active {
  background: var(--accent-dim);
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}

.string-play {
  width: 100%;
  padding: 4px 8px;
  border-radius: 6px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text-dim);
  font-size: 0.9rem;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}

.string-play:hover {
  color: var(--accent);
  border-color: var(--border-color);
}

.string-play.playing {
  color: var(--accent);
}

.checkbox-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 14px;
  color: var(--text-dim);
  font-size: 0.85rem;
  cursor: pointer;
}

.checkbox-row input {
  accent-color: var(--accent);
  width: 15px;
  height: 15px;
  cursor: pointer;
}

.meter-section {
  margin-bottom: 20px;
}

.meter {
  position: relative;
}

.gauge {
  width: 100%;
  height: auto;
}

.gauge-track {
  fill: none;
  stroke: var(--border-color);
  stroke-width: 14;
  stroke-linecap: round;
}

.gauge-track-green {
  fill: none;
  stroke: var(--accent-dim);
  stroke-width: 14;
  stroke-linecap: round;
  stroke-dasharray: 12 88;
  stroke-dashoffset: -44;
}

.tick {
  stroke: var(--text-dim);
  stroke-width: 2;
  stroke-linecap: round;
}

.tick.major {
  stroke: var(--text);
  stroke-width: 3;
}

.needle {
  stroke: var(--text);
  stroke-width: 3;
  stroke-linecap: round;
  transform-origin: 150px 160px;
  transition: transform 0.1s ease-out, stroke 0.1s ease-out;
}

.needle-hub {
  fill: var(--text);
}

.meter-labels {
  display: flex;
  justify-content: space-between;
  padding: 0 10px;
  color: var(--text-dim);
  font-size: 0.75rem;
  margin-top: -8px;
}

.readout {
  margin-top: 8px;
}

.note {
  font-size: 3.2rem;
  font-weight: 700;
  line-height: 1;
}

.target-note {
  color: var(--text-dim);
  font-size: 0.9rem;
  min-height: 1.2em;
}

.frequency {
  color: var(--text-dim);
  font-size: 1rem;
  margin-top: 6px;
}

.frequency.hidden {
  display: none;
}

.cents {
  font-size: 1rem;
  font-weight: 600;
  margin-top: 4px;
}

.cents.in-tune {
  color: var(--accent);
}

.cents.flat {
  color: var(--flat);
}

.cents.sharp {
  color: var(--sharp);
}

.action {
  margin-top: 8px;
}

#mic-toggle {
  padding: 12px 28px;
  border-radius: 999px;
  border: none;
  background: var(--accent);
  color: var(--accent-text);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
}

#mic-toggle.listening {
  background: var(--flat);
  color: var(--flat-text);
}

.status {
  color: var(--text-dim);
  font-size: 0.85rem;
  min-height: 1.2em;
  margin: 12px 0 0;
}