:root {
  --bg: #12141a;
  --panel: #1b1f29;
  --line: #2c3344;
  --text: #e8ecf4;
  --muted: #8b93a7;
  --accent: #3dff9a;
  --accent-dim: #1f3d2e;
  --danger: #ff5d6c;
  --channel: #232836;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background:
    radial-gradient(1200px 500px at 10% -10%, #1e2a22 0%, transparent 55%),
    var(--bg);
  color: var(--text);
  font-family: "Segoe UI", system-ui, sans-serif;
}

.app {
  max-width: 1100px;
  margin: 0 auto;
  padding: 32px 20px 48px;
}

.header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 28px;
}

.brand {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.brand-mark {
  width: 14px;
  height: 14px;
  margin-top: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 18px #3dff9a;
}

h1 {
  margin: 0 0 6px;
  font-size: 28px;
  letter-spacing: 0.02em;
}

.subtitle {
  margin: 0;
  color: var(--muted);
  max-width: 520px;
}

.folder-btn {
  display: inline-flex;
  align-items: center;
  height: 42px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--panel);
  cursor: pointer;
  user-select: none;
}

.folder-btn:hover {
  border-color: var(--accent);
}

.transport {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--panel);
  margin-bottom: 24px;
}

.transport-controls {
  display: flex;
  align-items: center;
  gap: 12px;
}

.seek {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 12px;
}

.seek-time {
  min-width: 3.2em;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
  font-size: 13px;
}

.seek-slider,
.volume-slider {
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
  margin: 0;
}

.seek-slider {
  width: 100%;
  height: 18px;
  cursor: pointer;
}

.seek-slider::-webkit-slider-runnable-track,
.volume-slider::-webkit-slider-runnable-track {
  border-radius: 999px;
}

.seek-slider::-webkit-slider-runnable-track {
  height: 6px;
  background: linear-gradient(
    to right,
    var(--accent) 0 var(--fill, 0%),
    #2a3142 var(--fill, 0%) 100%
  );
}

.seek-slider::-webkit-slider-thumb,
.volume-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px;
  height: 14px;
  border: 0;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 10px rgba(61, 255, 154, 0.45);
}

.seek-slider::-webkit-slider-thumb {
  margin-top: -4px;
}

.seek-slider::-moz-range-track,
.volume-slider::-moz-range-track {
  border: 0;
  border-radius: 999px;
  background: #2a3142;
}

.seek-slider::-moz-range-thumb,
.volume-slider::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border: 0;
  border-radius: 50%;
  background: var(--accent);
}

.play-btn,
.stop-btn {
  height: 48px;
  min-width: 110px;
  border: 0;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.08em;
  cursor: pointer;
}

.play-btn {
  background: var(--accent);
  color: #082014;
}

.play-btn.playing {
  animation: pulse 1.4s ease-in-out infinite;
}

.stop-btn {
  background: #2a3142;
  color: var(--text);
}

button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.status {
  margin: 0 0 0 8px;
  color: var(--muted);
}

.mixer {
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(27, 31, 41, 0.85);
  padding: 16px;
  min-height: 180px;
}

.empty-hint {
  margin: 28px 8px;
  color: var(--muted);
}

.channels {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 12px;
}

.channel {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 14px 12px 12px;
  border-radius: 14px;
  background: var(--channel);
  border: 1px solid transparent;
}

.volume {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 8px 0 4px;
}

.volume-value,
.volume-label {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.volume-slider {
  width: 18px;
  height: 128px;
  writing-mode: vertical-lr;
  direction: rtl;
  cursor: pointer;
}

.volume-slider::-webkit-slider-runnable-track {
  width: 6px;
  height: 128px;
  background: linear-gradient(
    to top,
    var(--accent) 0 var(--fill, 100%),
    #2a3142 var(--fill, 100%) 100%
  );
}

.volume-slider::-webkit-slider-thumb {
  margin-left: -4px;
}

.channel-index {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.08em;
}

.channel-name {
  min-height: 40px;
  font-size: 14px;
  line-height: 1.3;
  word-break: break-word;
}

.mute-btn {
  height: 42px;
  border: 0;
  border-radius: 10px;
  background: var(--accent-dim);
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 0.06em;
  cursor: pointer;
}

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

.channel.muted .mute-btn {
  background: var(--danger);
  color: #fff;
}

@keyframes pulse {
  0%,
  100% {
    box-shadow: 0 0 0 0 rgba(61, 255, 154, 0.45);
  }
  50% {
    box-shadow: 0 0 0 8px rgba(61, 255, 154, 0);
  }
}

@media (max-width: 640px) {
  .header,
  .transport-controls {
    flex-direction: column;
    align-items: stretch;
  }

  .status {
    margin: 4px 0 0;
  }
}