The Guidance provided have been a little bit outdated (due to improvements made to google and payapl sites), but support for this module is excellent. CSS would be the acronym for "Cascading Design and style Sheet". It's a design and style sheet language useful for describing the presentation of the https://www.presta-addons-modules.com/en/front-office/prestashop-twitter-feeds-widget-for-selected-categories-and-languages.html