Hi @sebash ,
You said you tried to edit in the liquid file but it didn’t work => It’s possible you didn’t edit the correct file or edited the code correctly. Please check again or send the store link and corrected code to check the details.
+) When editing code on Shopify, the css code should be added at the end of one of the files: theme.css; base.css; style.css;… (depending on the theme. Check your theme to see which file it is). Do not edit directly into the liquid file.
+) Code js: create a separate js file then embed that file into the liquid file. Refer to the post: https://www.askquesty.com/post/how-to-add-javascript-shopify-tutorial