Hello,

You would need to use your own custom CSS to override the default styles of the theme.

You can use the inspector of Safari or Developer Tools on Chrome to check the elements and CSS rules of the current ones (screenshot: https://share.getcloudapp.com/4guX5b28 )

For example, this is a sample custom CSS about your case:

.post-content-container, 
.list-wrapper.col1 .post-content-container {
    padding: 4% 0;
}
.post-content, 
.list-wrapper.col1 .post-content {
    margin-bottom: 4%;
}
.content-width {
    width: 400px;
}

You can put the custom CSS in the "Appearance > Customize > Custom CSS"

Keep in mind that when you customize any styles on a page, it might also affect the other pages and the responsive styles as well.

Regards,
Paul