Regularity and Reusability - Builders can make certain regularity throughout the full website, by defining models in the central CSS file. Models could be reused across many pages, cutting down redundancy and making updates easier. There's no way to call a CSS rule, which might permit (by way of example) https://www.presta-addons-modules.com/en/front-office/prestashop-social-media-side-bar-links-buttons-on-all-pages.html