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

body {
  overflow: hidden;
  background: #050510;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: #fff;
}

#spectrogram {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  image-rendering: auto;
}

#overlay {
  position: fixed;
  inset: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(5, 5, 16, 0.95);
  transition: opacity 0.6s ease;
}

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

#overlay-content {
  text-align: center;
}

#overlay-content h1 {
  font-size: 3rem;
  font-weight: 300;
  letter-spacing: 0.3em;
  margin-bottom: 0.5rem;
}

#overlay-content p {
  font-size: 1rem;
  opacity: 0.5;
  margin-bottom: 2rem;
}

#start-btn {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: #fff;
  padding: 0.8rem 2.5rem;
  font-size: 1rem;
  cursor: pointer;
  border-radius: 4px;
  transition: border-color 0.3s, background 0.3s;
}

#start-btn:hover {
  border-color: rgba(255, 255, 255, 0.7);
  background: rgba(255, 255, 255, 0.05);
}

#spectrogram-labels {
  position: fixed;
  top: 0;
  left: 0;
  width: 60px;
  height: 100vh;
  z-index: 2;
  pointer-events: none;
}

.spec-label {
  position: absolute;
  left: 4px;
  transform: translateY(-50%);
  font-size: 9px;
  line-height: 1;
  color: rgba(255, 255, 255, 0.6);
  text-shadow: 0 0 3px rgba(0, 0, 0, 0.9);
  white-space: nowrap;
}

.feat-label {
  color: rgba(255, 255, 255, 0.5);
  font-size: 8px;
}

#gain-controls {
  position: fixed;
  bottom: 12px;
  right: 12px;
  z-index: 5;
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 11px;
  opacity: 0.6;
}

#gain-controls:hover {
  opacity: 1;
}

#gain-controls label {
  display: flex;
  align-items: center;
  gap: 6px;
}

#gain-controls input[type="range"] {
  width: 100px;
  accent-color: #888;
}

#gain-controls span {
  width: 28px;
  text-align: right;
}