html,
body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  background: #1d2426;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: #e8eef0;
}

#scene {
  display: block;
  width: 100vw;
  height: 100vh;
  cursor: crosshair;
}

#panel {
  position: fixed;
  top: 16px;
  right: 16px;
  width: 230px;
  padding: 14px 16px;
  background: rgba(20, 28, 32, 0.78);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 10px;
  backdrop-filter: blur(6px);
  font-size: 13px;
  user-select: none;
}

#panel h1 {
  margin: 0 0 4px;
  font-size: 16px;
  font-weight: 600;
}

#panel .hint {
  margin: 0 0 12px;
  color: #a9bac0;
}

#panel label {
  display: block;
  margin-bottom: 10px;
}

#panel label span {
  display: flex;
  justify-content: space-between;
  margin-bottom: 3px;
}

#panel output {
  color: #8fd3ea;
  font-variant-numeric: tabular-nums;
}

#panel input[type="range"] {
  width: 100%;
  accent-color: #4fb3d9;
}

#panel label.checkbox {
  display: flex;
  align-items: center;
  gap: 8px;
}

#panel label.checkbox span {
  margin: 0;
}

#panel button {
  width: 100%;
  padding: 7px 0;
  border: 0;
  border-radius: 6px;
  background: #2f7fa3;
  color: #fff;
  font: inherit;
  cursor: pointer;
}

#panel button:hover {
  background: #3a93bb;
}

#error {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: #1d2426;
  font-size: 16px;
  text-align: center;
}

#error[hidden] {
  display: none;
}