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

html, body {
  width: 100%; height: 100%;
  overflow: hidden;
  background: #000;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  -webkit-font-smoothing: antialiased;
  color: #fff;
  user-select: none;
  -webkit-user-select: none;
}

#app {
  position: relative;
  width: 100%; height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

#heart-bg {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  pointer-events: none;
  z-index: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}
#heart-bg svg {
  width: min(60vw, 60vh);
  height: min(60vw, 60vh);
  opacity: 0.20;
  fill: #FF6B9D;
  transform: scale(0.85);
}

#image-bg {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  z-index: 0;
  pointer-events: none;
  opacity: 0;
}
#image-display {
  width: 100%; height: 100%;
  object-fit: contain;
  background: #000;
}

#lyrics {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1;
}

.verse-slot {
  width: 100%;
  padding: 0 6vw;
  text-align: center;
  pointer-events: none;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.5;
  font-size: calc(clamp(18px, 5.5vmin, 48px) * var(--s, 1));
}

.verse-line {
  margin-bottom: clamp(2px, 0.6vmin, 8px);
}

.word {
  display: inline;
  transition: color 0.15s ease;
}
.word.active {
  color: #FFD700;
  text-shadow: 0 0 16px rgba(255, 215, 0, 0.4);
}
.word.done {
  color: rgba(255, 255, 255, 0.35);
}

#waiting {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  display: flex; align-items: center; justify-content: center;
  z-index: 10;
  font-size: clamp(16px, 3vmin, 24px);
  color: #555;
  pointer-events: none;
}

#master-controls {
  position: fixed;
  bottom: clamp(20px, 4vmin, 40px);
  left: 50%;
  transform: translateX(-50%);
  z-index: 10;
  display: none;
  gap: clamp(12px, 3vmin, 24px);
}
#master-controls button {
  width: clamp(56px, 10vmin, 80px);
  height: clamp(56px, 10vmin, 80px);
  border-radius: 50%;
  border: 2px solid rgba(255,255,255,0.25);
  background: rgba(255,255,255,0.08);
  color: #fff;
  font-size: clamp(22px, 4vmin, 32px);
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: background 0.2s, border-color 0.2s;
}
#master-controls button:active {
  background: rgba(255,255,255,0.18);
  border-color: rgba(255,255,255,0.5);
}
#btn-restart {
  font-size: clamp(18px, 3.5vmin, 26px) !important;
}