:root {
  --color-bg: #0b0c0f;
  --color-text: #e8eaed;
  --color-muted: #5f6368;
  --color-neutral: #3c4043;
  --color-active: #1a73e8;
  --color-connecting: #f9ab00;
  --color-error: #ea4335;
  --button-size: 144px;
  --wave-height: 24px;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.surface {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.audio-button {
  position: relative;
  width: var(--button-size);
  height: var(--button-size);
  border: none;
  border-radius: 50%;
  background: var(--color-neutral);
  color: var(--color-text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.15s ease, background 0.2s ease, box-shadow 0.2s ease;
  outline: none;
  -webkit-tap-highlight-color: transparent;
}

.audio-button:active {
  transform: scale(0.96);
}

.audio-button:disabled {
  cursor: wait;
}

.audio-icon {
  font-size: 56px;
  line-height: 1;
  z-index: 1;
}

.waveform {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  opacity: 0;
  transition: opacity 0.2s ease;
  z-index: 0;
}

.waveform span {
  width: 4px;
  height: 8px;
  background: rgba(255, 255, 255, 0.7);
  border-radius: 2px;
  animation: wave 1.2s ease-in-out infinite;
}

.waveform span:nth-child(1) { animation-delay: 0s; }
.waveform span:nth-child(2) { animation-delay: 0.15s; }
.waveform span:nth-child(3) { animation-delay: 0.3s; }
.waveform span:nth-child(4) { animation-delay: 0.45s; }
.waveform span:nth-child(5) { animation-delay: 0.6s; }

@keyframes wave {
  0%, 100% { height: 8px; }
  50% { height: var(--wave-height); }
}

.status-label {
  margin: 0;
  font-size: 16px;
  color: var(--color-muted);
  letter-spacing: 0.02em;
}

/* Connecting state */
body.connecting .audio-button,
.audio-button[data-state="connecting"] {
  background: var(--color-connecting);
  box-shadow: 0 0 0 0 rgba(249, 171, 0, 0.4);
  animation: pulse 1.2s infinite;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(249, 171, 0, 0.4); }
  70% { box-shadow: 0 0 0 24px rgba(249, 171, 0, 0); }
  100% { box-shadow: 0 0 0 0 rgba(249, 171, 0, 0); }
}

body.connecting .audio-icon {
  opacity: 0;
}

body.connecting .waveform {
  opacity: 1;
}

/* Connected state */
body.connected .audio-button,
.audio-button[data-state="connected"] {
  background: var(--color-active);
}

body.connected .audio-icon {
  opacity: 0;
}

body.connected .waveform {
  opacity: 1;
}

body.connected .waveform span {
  background: rgba(255, 255, 255, 0.9);
}

/* Error state */
.audio-button.error {
  background: var(--color-error) !important;
  animation: shake 0.4s ease-in-out;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-6px); }
  75% { transform: translateX(6px); }
}

#remote-audio {
  position: absolute;
  width: 0;
  height: 0;
  opacity: 0;
  pointer-events: none;
}