To change the look and feel of your JS implementation, there is a built-in way to change the styling.
In the Tweakwise app, go to Plugin Studio and hit "Edit stylesheet" on the bottom of the page:
A page will open with a code editor:
Use the editor to change the appearance of suggestions, facets, product tiles or any other element that is on the page.
When ready, hit "Save" on the bottom of the page. The status sidebar will state "Changes detected". For the changes to be visible on your front-end, a deploy is required.
Hit "Deploy latest version". This will generate a fresh bundle with all plugins and customizations. If the bundle is ready a notificaton will be displayed. Your changes will be visible on your front-end.
Best Practise
Apply changes to your TEST instance first, so changes can be validated before elevating to production.