/* ── Custom Properties ────────────────────────────────────────────── */
:root {
  --bg-primary:    #0d0d0f;
  --bg-surface:    #1a1a1f;
  --bg-elevated:   #25252d;
  --accent:        #7c6af7;
  --accent-dim:    #7c6af744;
  --accent-glow:   #7c6af733;
  --text-primary:  #f0f0f5;
  --text-muted:    #6b6b80;
  --beat-inactive: #2a2a35;
  --beat-active:   #7c6af7;
  --danger:        #ff5c5c;
  --border:        rgba(255,255,255,0.06);
  --safe-bottom:   env(safe-area-inset-bottom, 0px);
  --safe-top:      env(safe-area-inset-top, 0px);
}

/* ── Reset & Base ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { height: 100%; }

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  display: flex;
  flex-direction: column;
  min-height: 100%;
  height: 100dvh;      /* dynamic viewport height — handles mobile browser chrome */
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  padding-top: var(--safe-top);
}

/* ── Header / Controls Bar ────────────────────────────────────────── */
#controls-bar {
  flex: 0 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
  padding: 10px 16px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
}

.app-title {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  white-space: nowrap;
  flex: 1;
}

.control-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.control-group label {
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  white-space: nowrap;
}

/* BPM Range Slider */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 90px;
  height: 4px;
  background: var(--bg-elevated);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  box-shadow: 0 0 8px var(--accent-dim);
  transition: transform 0.1s, box-shadow 0.1s;
}
input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 0 14px var(--accent);
}
input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  border: none;
  cursor: pointer;
}

/* BPM Number Input */
input[type="number"] {
  width: 54px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-primary);
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  font-weight: 500;
  padding: 6px 8px;
  text-align: center;
  outline: none;
  -moz-appearance: textfield;
}
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button { -webkit-appearance: none; }
input[type="number"]:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent-dim);
}

/* Time Signature Buttons */
.time-btn-group {
  display: flex;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
}
.time-btn {
  padding: 6px 12px;
  background: var(--bg-elevated);
  border: none;
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  min-height: 36px;
}
.time-btn + .time-btn {
  border-left: 1px solid var(--border);
}
.time-btn.active {
  background: var(--accent);
  color: #fff;
}
.time-btn:not(.active):hover {
  background: var(--bg-primary);
  color: var(--text-primary);
}

/* Notes / Click / Piano Toggle Buttons — shared style */
#chords-toggle-btn,
#click-toggle-btn,
#piano-toggle-btn {
  padding: 6px 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s, box-shadow 0.15s;
  min-height: 36px;
  white-space: nowrap;
  touch-action: manipulation;
}
#chords-toggle-btn:hover,
#click-toggle-btn:hover,
#piano-toggle-btn:hover {
  color: var(--text-primary);
}
#chords-toggle-btn.active,
#click-toggle-btn.active,
#piano-toggle-btn.active {
  background: var(--bg-elevated);
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: 0 0 8px var(--accent-dim);
}

/* Start / Stop Button */
#start-stop-btn {
  padding: 8px 22px;
  border-radius: 8px;
  border: none;
  background: var(--accent);
  color: #fff;
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s, box-shadow 0.2s;
  box-shadow: 0 0 16px var(--accent-dim);
  min-height: 38px;
  white-space: nowrap;
}
#start-stop-btn:hover {
  box-shadow: 0 0 24px var(--accent-dim);
}
#start-stop-btn:active {
  transform: scale(0.96);
}
#start-stop-btn.running {
  background: var(--danger);
  box-shadow: 0 0 16px rgba(255,92,92,0.3);
}

/* On wider screens: single-row header */
@media (min-width: 600px) {
  #controls-bar {
    flex-wrap: nowrap;
    height: 64px;
    padding: 0 28px;
    gap: 24px;
  }
  #start-stop-btn {
    margin-left: auto;
  }
  input[type="range"] {
    width: 110px;
  }
}

/* ── Main Stage ───────────────────────────────────────────────────── */
#stage {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 16px;
  min-height: 0;
}

/* Beat Indicator Dots */
#beat-indicator {
  display: flex;
  gap: 12px;
  height: 20px;
  align-items: center;
}

.beat-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--beat-inactive);
  transition: background 0.06s, transform 0.06s, box-shadow 0.06s;
}

.beat-dot.active {
  background: var(--beat-active);
  box-shadow: 0 0 10px var(--beat-active);
}

.beat-dot.active.downbeat {
  width: 16px;
  height: 16px;
  background: #fff;
  box-shadow: 0 0 20px var(--accent), 0 0 40px var(--accent-dim);
}

/* Chord Display */
#chord-display {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 1em;
}

#chord-name {
  display: block;
  font-family: 'Bebas Neue', sans-serif;
  font-size: clamp(72px, 20vw, 260px);
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--text-primary);
  text-shadow: 0 0 80px var(--accent-glow), 0 0 160px var(--accent-glow);
  user-select: none;
}

/* Roman numeral mode — accent colour signals "quiz mode" */
#chord-name.roman {
  color: var(--accent);
  text-shadow: 0 0 80px var(--accent-dim), 0 0 160px var(--accent-glow);
}

/* Chord Transition Animations */
#chord-display.exiting #chord-name {
  animation: chordExit 0.22s ease-in forwards;
}
#chord-display.entering #chord-name {
  animation: chordEnter 0.22s ease-out forwards;
}

@keyframes chordExit {
  from { opacity: 1; transform: translateY(0) scale(1); }
  to   { opacity: 0; transform: translateY(-24px) scale(0.96); }
}
@keyframes chordEnter {
  from { opacity: 0; transform: translateY(28px) scale(0.96); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

/* ── Progression Info (below chord name) ──────────────────────────── */
#progression-info {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  min-height: 32px;
}

#progression-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.06em;
}

#progression-dots {
  display: flex;
  gap: 7px;
}

.prog-dot {
  width: 7px;
  height: 7px;
  border-radius: 2px;
  background: var(--beat-inactive);
  transition: background 0.15s, box-shadow 0.15s;
}

.prog-dot.active {
  background: var(--accent);
  box-shadow: 0 0 6px var(--accent);
}

/* ── Chord Selector ───────────────────────────────────────────────── */
#chord-selector {
  flex: 0 0 auto;
  padding: 12px 16px calc(12px + var(--safe-bottom));
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  overflow-y: auto;
  max-height: 42vh;
}

@media (min-width: 600px) {
  #chord-selector {
    padding: 14px 28px 18px;
    max-height: none;
  }
}

.selector-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}

.selector-header h2 {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

/* Selector Rows */
.selector-row {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 8px;
}
.selector-row:last-child { margin-bottom: 0; }

.selector-row-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  width: 28px;
  flex-shrink: 0;
  padding-top: 7px;
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* Shared button style */
.sel-btn {
  padding: 6px 12px;
  border-radius: 7px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s, box-shadow 0.15s;
  user-select: none;
  min-height: 34px;
  touch-action: manipulation;
}
.sel-btn:hover {
  color: var(--text-primary);
  border-color: rgba(124,106,247,0.3);
}
.sel-btn.active-selection {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  box-shadow: 0 0 10px var(--accent-dim);
}

/* Key buttons — uniform width */
.key-btn {
  padding: 6px 0;
  min-width: 40px;
  text-align: center;
}

/* Random button */
#random-btn {
  margin-left: auto;
  padding: 5px 12px;
  border-radius: 5px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
  font-size: 11px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  min-height: 30px;
  touch-action: manipulation;
}
#random-btn:hover {
  background: var(--bg-primary);
  color: var(--text-primary);
}