:root {
  --bg: #000;
  --fg: #fff;
  --dim: #555;
  --dimmer: #2a2a2a;
  --accent: #ff3860;
  --ok: #1fd16b;
  --panel: #0b0b0b;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  margin: 0; padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  overscroll-behavior: none;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
}

#app {
  position: fixed;
  inset: 0;
  overflow: hidden;
}

/* Beat-synced flash overlay. JS sets opacity briefly on each beat;
   CSS transitions it back to 0 for a smooth fade. */
.flash {
  position: absolute;
  inset: 0;
  z-index: 0;
  background: var(--accent);
  opacity: 0;
  transition: opacity 280ms ease-out;
  pointer-events: none;
}
.flash.locked {
  background: var(--ok);
}

/* Full-screen invisible tap target */
.taplayer {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  background: transparent;
  border: 0;
  padding: 0;
  margin: 0;
  z-index: 1;
  /* gets disabled (pointer-events: none) when tap input is off */
}
.taplayer:active {
  background: rgba(255, 56, 96, 0.06);
}
.taplayer.off { pointer-events: none; }

/* HUD bars sit above the tap layer */
.hud {
  position: absolute;
  left: 0; right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 14px;
  z-index: 3;
  pointer-events: none; /* children re-enable */
}
.hud > * { pointer-events: auto; }
.hud-top    { top:    max(env(safe-area-inset-top), 8px); }
.hud-bottom { bottom: max(env(safe-area-inset-bottom), 8px); justify-content: center; }

.seg {
  display: inline-flex;
  background: #111;
  border: 1px solid #1f1f1f;
  border-radius: 999px;
  overflow: hidden;
}
.seg-btn {
  background: transparent;
  color: #888;
  border: 0;
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  font-family: inherit;
}
.seg-btn.active { background: var(--accent); color: #fff; }

.icon-btn {
  background: #111;
  border: 1px solid #1f1f1f;
  color: #aaa;
  border-radius: 999px;
  width: 40px; height: 40px;
  font-size: 18px;
  font-family: inherit;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.icon-btn:active { background: #1a1a1a; }

.bpm-wrap {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 2;
  pointer-events: none;
  padding: 64px 16px;
}

.bpm {
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: 45vh;
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--fg);
  transition: color 200ms linear, transform 80ms ease-out, opacity 200ms linear, text-shadow 200ms linear;
  will-change: transform;
}
.bpm.idle { color: var(--dim); }
.bpm.pulse { transform: scale(1.04); }
.bpm.locked {
  color: var(--ok);
  text-shadow: 0 0 24px rgba(31, 209, 107, 0.35);
}

.lock-badge {
  position: absolute;
  top: 18%;
  left: 50%;
  transform: translateX(-50%);
  font-size: 13px;
  letter-spacing: 0.3em;
  font-weight: 700;
  color: var(--ok);
  padding: 4px 10px;
  border: 1px solid var(--ok);
  border-radius: 999px;
  background: rgba(31, 209, 107, 0.08);
  pointer-events: none;
}

.stability {
  margin-top: 18px;
  width: min(60vw, 280px);
  height: 4px;
  background: #181818;
  border-radius: 2px;
  overflow: hidden;
}
.stability > span {
  display: block;
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 180ms ease-out, background-color 200ms;
}

.status {
  position: absolute;
  bottom: calc(max(env(safe-area-inset-bottom), 8px) + 56px);
  left: 0; right: 0;
  text-align: center;
  font-size: 13px;
  color: var(--dim);
  letter-spacing: 0.04em;
  pointer-events: none;
  z-index: 2;
  padding: 0 20px;
}

.hidden { display: none !important; }

/* Drawer */
.drawer {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.75);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 10;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 16px;
}
.drawer-inner {
  width: 100%;
  max-width: 480px;
  background: var(--panel);
  border: 1px solid #1f1f1f;
  border-radius: 18px;
  padding: 18px;
  margin-top: max(env(safe-area-inset-top), 12px);
}
.drawer-row {
  display: grid;
  grid-template-columns: 1fr 2fr auto;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid #181818;
  font-size: 14px;
}
.drawer-row:last-of-type { border-bottom: 0; }
.drawer-row label { color: #bbb; }
.drawer-row .val  { color: #888; font-variant-numeric: tabular-nums; min-width: 36px; text-align: right; }
.drawer-row input[type=range] { accent-color: var(--accent); width: 100%; }
.drawer-actions {
  display: flex; justify-content: space-between; gap: 12px; padding-top: 14px;
}
.drawer-actions button {
  flex: 1;
  font-family: inherit; font-size: 15px; font-weight: 600;
  border: 1px solid #222;
  background: #111; color: var(--fg);
  padding: 12px 18px; border-radius: 999px;
}
.drawer-actions .primary { background: var(--accent); border-color: var(--accent); }
.drawer-actions .ghost   { background: transparent; color: #aaa; }

@media (max-width: 380px) {
  .bpm { font-size: 38vh; }
}