Hello @adrienpiron,
Which text do you want to change the font size?
Can you please share a screenshot? You can upload your screenshot here: https://postimages.org.
If you want to change the font size on the notification bar, Since you are using the third-party plugin, please check the plugin settings. Perhaps they’ve provided some options for this.
Also, you can put the CSS below in Customizing > Custom CSS/JS > CSS Code:
@media(max-width: 480px) {
.edn-notify-bar p {
font-size: 17px !important;
}
.edn-notify-bar span {
font-size: 17px !important;
}
}
For more information about the CSS/JS code on the customizer, please read this link:
https://docs.oceanwp.org/article/354-add-custom-css-and-js-to-your-website.
You can learn how to use Chrome Developer Tools or Firefox Developer Tools to help you see and test changes to your CSS:
https://developers.google.com/web/tools/chrome-devtools/
https://developer.mozilla.org/en-US/docs/Tools
CSS Tutorial: https://www.w3schools.com/css/
Best Regards
