devdocs/assets/stylesheets/pages/_sphinx_simple.scss

._sphinx_simple {
  @extend %simple;

  .admonition { @extend %note; }
  .admonition.warning { @extend %note-orange; }
  .admonition.tip { @extend %note-green; }
  .admonition-title {
    margin: 0 0 .25rem;
    font-weight: $boldFontWeight;
  }

  code { @extend %label; }
}