11.2 update of prettier/PostCSS/stylelint dropped use of @nest and rgba()

PostCSS and its plugins has been updated to the latest version, removing the need for the @nest keyword and removing the use of rgba(). Drupal maintains the 2021 nesting behavior to avoid adding :is() selectors throughout the CSS. For details, see the PostCSS Nesting plugin documentation.

Removal of @nest

Before

@nest .touchevents & .draggable td {
    padding: 0 10px;
  }

After

.touchevents & .draggable td {
    padding: 0 10px;
  }

Stylelint and stylelint-config-standard have also been updated to the latest version. Most notably the CSS rgb() function is preferred over the equivalent rgba() function. Drupal core stylesheets have been updated to account for these changed standards.

Using rgb() instead of rgba()

Before

#drupal-off-canvas-wrapper {
  --off-canvas-wrapper-box-shadow: 0 0 0.25rem 2px rgba(0, 0, 0, 0.3);
  --off-canvas-wrapper-border-color: #2d2d2d;
  --off-canvas-wrapper-border-width: 1px;

After

#drupal-off-canvas-wrapper {
  --off-canvas-wrapper-box-shadow: 0 0 0.25rem 2px rgb(0, 0, 0, 0.3);
  --off-canvas-wrapper-border-color: #2d2d2d;
  --off-canvas-wrapper-border-width: 1px;