:root {
  color-scheme: light;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #eef1f5;
}

* { box-sizing: border-box; }

html, body, #viewer {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
}

#viewer {
  position: relative;
  background: radial-gradient(circle at 50% 42%, #ffffff 0%, #f2f5f8 56%, #e5e9ef 100%);
}

.model-picker {
  position: absolute;
  top: 1rem;
  left: 50%;
  z-index: 2;
  display: flex;
  gap: 0.25rem;
  transform: translateX(-50%);
  padding: 0.25rem;
  border: 1px solid rgb(30 40 55 / 12%);
  border-radius: 999px;
  background: rgb(255 255 255 / 82%);
  box-shadow: 0 5px 18px rgb(30 40 55 / 10%);
  backdrop-filter: blur(8px);
}

.model-button {
  border: 0;
  border-radius: 999px;
  padding: 0.45rem 0.9rem;
  background: transparent;
  color: #4c5868;
  cursor: pointer;
  font: inherit;
  font-size: 0.8rem;
  transition: background 0.15s ease, color 0.15s ease;
}

.model-button:hover { background: rgb(89 107 131 / 10%); }

.model-button.active {
  background: #536981;
  color: #fff;
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
  outline: none;
}

.status {
  position: absolute;
  top: 50%;
  left: 50%;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 0.65rem;
  transform: translate(-50%, -50%);
  padding: 0.8rem 1rem;
  border: 1px solid rgb(255 255 255 / 12%);
  border-radius: 0.65rem;
  background: rgb(255 255 255 / 92%);
  color: #20242b;
  font-size: 0.9rem;
  box-shadow: 0 10px 30px rgb(0 0 0 / 20%);
}

.status[hidden] { display: none; }

.spinner {
  width: 1rem;
  height: 1rem;
  border: 2px solid rgb(30 40 55 / 18%);
  border-top-color: #596b83;
  border-radius: 50%;
  animation: spin 0.75s linear infinite;
}

.error {
  max-width: min(90vw, 30rem);
  color: #9f2828;
  text-align: center;
}

.hint {
  position: absolute;
  right: 1rem;
  bottom: 1rem;
  margin: 0;
  color: rgb(30 40 55 / 62%);
  font-size: 0.75rem;
  pointer-events: none;
  user-select: none;
}

@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 600px) {
  .model-picker { top: 0.75rem; }

  .hint {
    right: 0.75rem;
    bottom: 0.75rem;
    font-size: 0.67rem;
  }
}