How I Create My Capsule Wardrobe

By default, blocks provide their styles to enable basic support for blocks in themes without any change. Themes can add/override these styles, or they can provide no styles at all, and rely fully on what the blocks provide.

Some advanced block features require opt-in support in the theme itself as it’s difficult for the block to provide these styles, they may require some architecting of the theme itself, in order to work well.

To opt-in for one of these features, call add_theme_support in the functions.php file of the theme.