Removes at-rules that do not have any bearing on the CSS file. This is unsafe if you have other stylesheets which pair up to these rules.

@keyframes fadeOut {
    from {
        opacity: 1;
    to {
        opacity: 0;
/* (removed) */

⚠ Risk of breakage

This transform may be unsafe in certain situations, because of the following condition(s):

  • Assumes concatenation
  • Changes semantics

For more information, see our advanced transforms guide.