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

:root {
  --bg: #0d0f14;
  --surface: #161a23;
  --border: #252b3b;
  --text: #c8d0e0;
  --text-dim: #5a6580;
  --accent: #2a9d3f;
  --accent-dim: #1a5c28;
  --danger: #e05252;
  --canvas-bg: #0a0c10;
  --canvas-line: #1e2530;
  --panel-radius: 8px;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #f0f3f8;
    --surface: #ffffff;
    --border: #ccd4e0;
    --text: #1a2035;
    --text-dim: #7a8aa0;
    --canvas-bg: #e8ecf4;
    --canvas-line: #c8d4e8;
  }
}

[data-theme="light"] {
  --bg: #f0f3f8;
  --surface: #ffffff;
  --border: #ccd4e0;
  --text: #1a2035;
  --text-dim: #7a8aa0;
  --canvas-bg: #e8ecf4;
  --canvas-line: #c8d4e8;
}

[data-theme="dark"] {
  --bg: #0d0f14;
  --surface: #161a23;
  --border: #252b3b;
  --text: #c8d0e0;
  --text-dim: #5a6580;
  --canvas-bg: #0a0c10;
  --canvas-line: #1e2530;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Courier New', Courier, monospace;
  font-size: 13px;
  min-height: 100vh;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

h1 {
  font-size: 16px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text);
}

#enable-audio-btn {
  background: var(--accent);
  border: none;
  color: #fff;
  padding: 6px 16px;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 13px;
  font-weight: bold;
  letter-spacing: 0.05em;
  animation: pulse 1.5s ease-in-out infinite;
}

#enable-audio-btn:hover {
  background: #34b84d;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.7; }
}

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
}

#status-bar {
  display: flex;
  align-items: center;
  gap: 8px;
}

.dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  display: inline-block;
}

.dot--connecting { background: #e0a030; }
.dot--connected  { background: var(--accent); }
.dot--failed     { background: var(--danger); }

.channel-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(2, auto);
  gap: 12px;
  padding: 16px;
}

@media (max-width: 900px) {
  .channel-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  .channel-grid { grid-template-columns: 1fr; }
}

.channel-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--panel-radius);
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.channel-header {
  display: flex;
  align-items: center;
  gap: 8px;
}

.channel-label {
  font-weight: bold;
  letter-spacing: 0.06em;
  color: var(--accent);
}

.channel-freq {
  flex: 1;
  color: var(--text-dim);
  font-size: 11px;
}

.signal-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #333;
  transition: background 0.15s ease;
}

.signal-dot.active {
  background: var(--accent);
  box-shadow: 0 0 6px var(--accent-dim);
}

.channel-canvas {
  width: 100%;
  height: 100px;
  display: block;
  background: var(--canvas-bg);
  border-radius: 4px;
  border: 1px solid var(--border);
}

.timeline-canvas {
  width: 100%;
  height: 20px;
  display: block;
  background: var(--canvas-bg);
  border-radius: 4px;
  border: 1px solid var(--border);
}

.channel-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.mute-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 3px 10px;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 12px;
  transition: border-color 0.15s, color 0.15s;
  white-space: nowrap;
}

.mute-btn:hover {
  border-color: var(--text-dim);
  color: var(--text);
}

.mute-btn.muted {
  border-color: var(--danger);
  color: var(--danger);
}

.vol-slider {
  flex: 1;
  accent-color: var(--accent);
  cursor: pointer;
  height: 4px;
}

.theme-switcher {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
}

.theme-btn {
  background: transparent;
  border: none;
  border-left: 1px solid var(--border);
  color: var(--text-dim);
  padding: 4px 10px;
  cursor: pointer;
  font-family: inherit;
  font-size: 12px;
  transition: background 0.15s, color 0.15s;
}

.theme-btn:first-child {
  border-left: none;
}

.theme-btn:hover {
  color: var(--text);
}

.theme-btn.active {
  background: var(--accent);
  color: #fff;
}