Good Morning Sam,
I just took a look and I’ve attached screenshots of what I’m seeing between Safari and Chrome on your site. You’ll notice the navigation menu item font looks a bit different between the two.
If you look closely at the text you’ll see that the letters have the same shapes, almost as if the ones in Safari were filled in, they would look like Chrome.
Browsers do render text differently from one another. So do operating systems. The same typeface in Firefox for Windows won’t look the same or even be the exact same size in Firefox for Mac.
They will even look slightly different from the customizer’s preview to the live view on the front end. I find the fonts render a bit lighter, weight wise, in the customizer than on the front page. If it’s a particularly delicate font, that can make a difference.
Let me know how things go.
Thanks,
Bill