Fix small font sizes
Why does this matter?
Font sizes smaller than 12px are often difficult to read on mobile devices, and may require users to pinch-to-zoom in order to display the text at a comfortable reading size. Mobile-friendly pages is a ranking factor for many search engines because users should be able to navigate your site on their mobile devices.
Lighthouse displays the following failed audit if your content is too small #for mobile devices: "Document doesn't use legible font sizes"
Fix small font
Check font sizes in your CSS. Aim for font sizes of 12px or more for at least 60% of the text on your pages.
Run the Lighthouse SEO Audit (Lighthouse > Options > SEO) and look for the results of the audit "Document doesn't use legible font sizes".