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

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #0a0a0f;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  color: #ffffff;
  cursor: default;
  user-select: none;
  -webkit-user-select: none;
}

canvas#particles {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

canvas#circle {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1;
  pointer-events: none;
}

#title {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 13px;
  font-weight: 300;
  letter-spacing: 6px;
  text-transform: lowercase;
  color: rgba(255, 255, 255, 0.08);
  z-index: 10;
  pointer-events: none;
}

#controls {
  position: fixed;
  bottom: 60px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  opacity: 0;
  transition: opacity 0.8s ease;
  pointer-events: none;
}

#controls.visible {
  opacity: 1;
  pointer-events: auto;
}

#master-volume {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 220px;
}

#master-volume input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 1px;
  background: rgba(255, 255, 255, 0.15);
  outline: none;
  border-radius: 1px;
}

#master-volume input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 200, 140, 0.5);
  cursor: pointer;
}

#master-volume input[type="range"]::-moz-range-thumb {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 200, 140, 0.5);
  border: none;
  cursor: pointer;
}

#layer-toggles {
  display: flex;
  gap: 20px;
}

.layer-btn {
  background: none;
  border: none;
  color: rgba(255, 255, 255, 0.2);
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 11px;
  font-weight: 300;
  letter-spacing: 2px;
  text-transform: lowercase;
  cursor: pointer;
  padding: 4px 0;
  transition: color 0.4s ease;
  position: relative;
}

.layer-btn.active {
  color: rgba(255, 255, 255, 0.55);
}

.layer-btn::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 1px;
  background: rgba(255, 200, 140, 0.3);
  transition: width 0.4s ease;
}

.layer-btn.active::after {
  width: 100%;
}

.layer-btn:hover {
  color: rgba(255, 255, 255, 0.4);
}

#start-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #0a0a0f;
  cursor: pointer;
  transition: opacity 1.2s ease;
}

#start-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

#start-text {
  font-size: 14px;
  font-weight: 300;
  letter-spacing: 4px;
  text-transform: lowercase;
  color: rgba(255, 255, 255, 0.15);
  animation: breathe 3s ease-in-out infinite;
}

@keyframes breathe {
  0%, 100% { opacity: 0.15; }
  50% { opacity: 0.35; }
}

/* Mobile */
@media (max-width: 600px) {
  #layer-toggles {
    gap: 14px;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .layer-btn {
    font-size: 10px;
    letter-spacing: 1.5px;
  }
  
  #master-volume {
    width: 180px;
  }
}