:root {
  --bg: #0a0a0a;
  --fg: #fafafa;
  --muted: #525252;
  --border: #262626;
  --accent: #22d3ee;
  --good: #4ade80;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, system-ui, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
  overscroll-behavior: none;
  user-select: none;
  -webkit-user-select: none;
}

main {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;       /* fallback */
  min-height: 100dvh;      /* tracks the dynamic viewport on mobile */
  padding:
    max(1rem, env(safe-area-inset-top))
    1.25rem
    max(1rem, env(safe-area-inset-bottom));
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.tabs {
  display: flex;
  gap: 1.6rem;
  align-self: center;
  flex-shrink: 0;
  flex-wrap: wrap;
  justify-content: center;
}

.tab {
  background: none;
  border: 0;
  padding: 0.5rem 0;
  color: var(--muted);
  border-bottom: 1px solid transparent;
  font: inherit;
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.tab.active {
  color: var(--fg);
  border-bottom-color: var(--fg);
}

.view {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2rem;
  width: 100%;
}

#view-chord {
  position: relative;  /* anchor for .harmonic-indicators */
  gap: 2.25rem;
}

.view.hidden { display: none; }

/* --- chord view --- */

.keys {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  flex-wrap: wrap;
  flex-shrink: 0;
}

.key-btn {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.4rem 0.95rem;
  font: inherit;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.key-btn.active {
  color: var(--fg);
  border-color: var(--fg);
}

.chord-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem 0.4rem;
  max-width: 340px;
  width: 100%;
  justify-items: center;
  align-items: center;
}

.chip {
  font-size: 1.55rem;
  font-weight: 400;
  color: var(--fg);
  opacity: 0.15;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
  text-align: center;
  line-height: 1.1;
}

.harmonic-indicators {
  position: absolute;
  top: 0;
  right: 0;
  display: flex;
  gap: 0.5rem;
  pointer-events: none;
}

.harm-ind {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--good);
  opacity: 0.15;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

/* --- clips view --- */

#view-clips {
  justify-content: flex-start;
  padding-top: 1rem;
  gap: 0;
}

.clip-list {
  width: 100%;
  max-width: 380px;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  overflow-y: auto;
  min-height: 0;
}

.clip {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--fg);
  font-variant-numeric: tabular-nums;
}

.clip-time {
  flex: 1;
  text-align: left;
  color: var(--fg);
  font-size: 0.95rem;
  letter-spacing: 0.01em;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.clip-duration {
  color: var(--muted);
  font-size: 0.8rem;
  min-width: 3em;
  text-align: right;
}

.clip-btn {
  background: none;
  border: 0;
  color: var(--muted);
  font: inherit;
  font-size: 1.15rem;
  line-height: 1;
  padding: 0.45rem 0.55rem;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  flex-shrink: 0;
}

.clip-btn.primary {
  color: var(--fg);
  font-size: 1.3rem;
}

.clip-btn.primary.playing {
  color: var(--good);
}

.clip-btn.delete:active {
  color: var(--rec);
}

.clip-empty {
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
  padding: 2rem 0;
  letter-spacing: 0.02em;
}

#clip-audio {
  display: none;
}

/* --- metronome view --- */

.bpm-line {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.75rem;
  width: 100%;
}

.bpm-btn {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 999px;
  width: 3rem;
  height: 3rem;
  color: var(--fg);
  font: inherit;
  font-size: 1.5rem;
  line-height: 1;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  flex-shrink: 0;
}

.bpm-btn:active {
  border-color: var(--fg);
  color: var(--fg);
}

.bpm-readout {
  font-size: clamp(4rem, 16vw, 6rem);
  font-weight: 300;
  line-height: 1;
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
  color: var(--fg);
  min-width: 3ch;
  text-align: center;
}

.bpm-label {
  color: var(--muted);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-align: center;
  margin-top: -1rem;
}

.note-line {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.8em;
  width: 100%;
}

.readout {
  font-size: clamp(3.5rem, 14vw, 5.5rem);
  font-weight: 300;
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--fg);
  font-variant-numeric: tabular-nums;
  text-align: center;
}

#view-chord .readout {
  font-size: clamp(4.5rem, 18vw, 7rem);
}

.readout.silent { color: var(--muted); }

.readout sub {
  font-size: 0.3em;
  font-weight: 400;
  color: var(--muted);
  vertical-align: sub;
  margin-left: 0.05em;
}

.cents {
  font-size: 1.15rem;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
  letter-spacing: 0.03em;
  min-width: 3.5em;
  text-align: left;
}

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

.meter {
  position: relative;
  width: 100%;
  max-width: 360px;
  height: 72px;
}

.meter-band {
  position: absolute;
  top: calc(50% - 24px);
  height: 48px;
  left: 45%;        /* ±5 cents at ±50-cent full scale = 10% centered */
  right: 45%;
  background: var(--good);
  opacity: 0.12;
  border-radius: 3px;
}

.meter-track {
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--border);
  transform: translateY(-50%);
}

.meter-center {
  position: absolute;
  top: 12%;
  bottom: 12%;
  left: 50%;
  width: 1px;
  background: var(--muted);
  transform: translateX(-50%);
}

.meter-needle {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 3px;
  background: var(--fg);
  border-radius: 2px;
  transform: translateX(-50%);
  visibility: hidden;
}

.meter-needle.active { visibility: visible; }
.meter-needle.good { background: var(--good); }

.btn {
  align-self: center;
  background: transparent;
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.85rem 2.25rem;
  font: inherit;
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  flex-shrink: 0;
}

.btn.listening { border-color: var(--fg); }

@media (max-height: 640px) {
  main { gap: 0.75rem; }
  .view { gap: 1.5rem; }
}