Power users can go beyond the visual editor by overriding templates and adding CSS.
Custom CSS
Boxes render with stable class names. Add rules in Appearance → Customize → Additional CSS to fine-tune anything the editor doesn’t expose. Inspect a box in your browser to find the class to target.
Template overrides
ProductReview loads its box markup from template files. Copy the relevant template into your theme (in a productreview subfolder) and edit the copy — your version is used instead of the plugin’s, and survives plugin updates.
Keep overrides minimal. The smaller your change, the easier it is to keep working across plugin updates. Prefer CSS for styling and only override templates for structural changes.