admin-reset-styles.css

/**
 * @file
 * Reset styles from parent theme.
 * https://developer.mozilla.org/en-US/docs/Web/CSS/all
 */

:is(#extra-specificity-hack, [data-drupal-admin-styles]) {
  box-sizing: border-box;

  *:focus {
    outline: var(--admin-toolbar-size-focus) solid var(--admin-toolbar-color-focus);
  }

  *:not(:where(svg, svg *)) {
    all: revert;
    box-sizing: border-box;

    button {
      font-family: inherit;
    }

    &::after,
    &::before {
      all: revert;
      box-sizing: border-box;
    }
  }

  .visually-hidden {
    position: absolute !important;
    overflow: hidden;
    clip: rect(1px, 1px, 1px, 1px);
    width: 1px;
    height: 1px;
    word-wrap: normal;
  }
}