Test. That kind of blind targetting is never what you need in CSS for anything at all but the most common styles. Modules will inform you about available updates. Study the changelog and conduct a 1-click on module update instantly from your retail store. Step one: Add the module zip https://www.presta-addons-modules.com/en/free-modules/prestashop-popup-on-exit-page-on-browser-tab-close-event.html