devdocs/assets/stylesheets/pages/_rust.scss

._rust {
  @extend %simple;

  h4 { @extend %block-label; }
  .code-header { @extend %code; }
  .docblock { margin-left: 1em; }
  div.information, div.important-traits {
    @extend %note;

    > pre { margin: .5rem 0; }
  }

  div.stability { margin-bottom: 1em; }
  em.stab, span.stab { @extend %label; }
  em.stab.unstable, span.stab.unstable { @extend %label-orange; }
  .out-of-band { float: right; }
  .since, .srclink {
    float: right;
    margin-left: .5rem;
  }
}