You can set custom CSS for blog page styles in Wix.
What is CSS?
CSS, or Cascading Style Sheets, is a styling language used to control how HTML elements of websites are displayed selectively. CSS defines how the site looks to the end user.
Here’s a short guide:
Go to your Wix Dashboard.
Click Settings -> Custom Code.
Click Add Custom Code button at the top.
Paste your CSS in the text box:
<style type="text/css">
YOUR_CSS_HERE
</style>Under Add Code to Pages select Choose specific pages, and pick your blog page in the Wix Blog section.
Set Place Code in to the Body - end.
Click Apply, then publish your site to see the changes.