Happened to visit a part of the Safari prefs that I rarely see today. I had, frankly, forgot about this part of it! Some have complained about a sites fonts/text being either too small or too large and this section might be a solution.
We all know we can 'zoom' a page in most web browsers. But, Safari has a pref that lets you specify a particular domain/website to always display at a percentage that might be better for our needs.
Simply visit a site that you often use 'zoom' and then open Safari Prefs. Go to the "Websites tab and select the "Page Zoom" item in the left-hand, "General" column. To the right will be the domain of any currently open web sites. Select the domain/web site and the 'zoom' you'd like to always use for it. After you close this pref, Safari will remember your settings for that site.