* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  height: 100%;
  background: #0a0a0f;
  color: #f5f5f5;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", sans-serif;
  overscroll-behavior: none;
  user-select: none;
  -webkit-user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.screen {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  text-align: center;
  background: radial-gradient(circle at 30% 20%, #1a0f2e 0%, #0a0a0f 60%);
}

.screen.hidden { display: none; }

.stack {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  max-width: 360px;
  width: 100%;
}

h1 { font-size: 2rem; letter-spacing: 0.04em; font-weight: 300; }
h2 { font-size: 1.3rem; margin-bottom: 1.5rem; opacity: 0.85; font-weight: 400; }
p { opacity: 0.7; line-height: 1.5; font-size: 1rem; }
.hint { opacity: 0.45; font-size: 0.85rem; margin-top: 0.6rem; }
.lab {
  margin-top: 2rem;
  font-size: 0.75rem;
  opacity: 0.4;
  letter-spacing: 0.25em;
  text-transform: uppercase;
}

.primary {
  margin-top: 1rem;
  padding: 1rem 2.5rem;
  font-size: 1.05rem;
  background: linear-gradient(135deg, #6c4ee0, #d04ee0);
  color: white;
  border: none;
  border-radius: 999px;
  font-weight: 500;
  cursor: pointer;
  letter-spacing: 0.02em;
}
.primary:active { transform: scale(0.97); }

.modes {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  width: 100%;
  max-width: 380px;
}
.mode-btn {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  color: white;
  padding: 1.15rem 1.25rem;
  border-radius: 16px;
  text-align: left;
  font: inherit;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.mode-btn strong { font-size: 1.05rem; font-weight: 600; }
.mode-btn span { opacity: 0.55; font-size: 0.85rem; line-height: 1.4; }
.mode-btn.disabled { opacity: 0.3; cursor: not-allowed; }
.mode-btn:not(.disabled):active {
  transform: scale(0.98);
  background: rgba(255,255,255,0.09);
}

.back {
  position: absolute;
  top: max(1rem, env(safe-area-inset-top));
  left: 1rem;
  background: rgba(255,255,255,0.08);
  color: white;
  border: none;
  width: 44px; height: 44px;
  border-radius: 50%;
  font-size: 1.4rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

#hud { gap: 2rem; }

.big-note {
  font-size: 5rem;
  font-weight: 200;
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
  min-height: 5rem;
}

.meters {
  display: flex;
  gap: 1.5rem;
  width: 100%;
  max-width: 320px;
}
.meter { flex: 1; display: flex; flex-direction: column; gap: 0.4rem; }
.meter span {
  font-size: 0.7rem;
  opacity: 0.5;
  text-transform: uppercase;
  letter-spacing: 0.2em;
}
.bar {
  height: 6px;
  background: rgba(255,255,255,0.08);
  border-radius: 3px;
  overflow: hidden;
}
.bar > div {
  height: 100%;
  background: linear-gradient(90deg, #6c4ee0, #d04ee0);
  width: 0%;
  transition: width 0.05s linear;
}

.status {
  font-size: 0.8rem;
  opacity: 0.45;
  text-transform: uppercase;
  letter-spacing: 0.25em;
}
.status.playing {
  color: #6cf078;
  opacity: 1;
}