:root {
  --bone-small-height: 20px;
  --bone-large-height: 35px;
  --bone-opacity: 0.6;
}

@media (max-width: 600px) {
  :root {
    --bone-small-height: 12px;
    --bone-large-height: 20px;
  }
}

.bone-small {
  position: absolute;
  height: var(--bone-small-height);
}

.bone-large {
  position: absolute;
  height: var(--bone-large-height);
}

.bone {
    opacity: var(--bone-opacity);
}