Hello, that is completely normal. If you zoom a mobile page is like zooming in a page in a browser in your computer.
It is normal that the logo looks blurry if you zoom the page . I have tried some other webpages and the outcoume is the same.
However I found a hack that maybe works. If you open the header.php file in a HTML Editor you will see on top something like this:
<meta name="viewport" content="width=device-width, initial-scale=1">
I have read here https://stackoverflow.com/questions/4472891/how-can-i-disable-zoom-on-a-mobile-web-page
that if you chaneg the above tag to
<meta
name='viewport'
content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0'
/>
then the user could not zoom the mobile page :).
You can try it.
PS: If you want to make change to our theme and in a theme in general consider creating a child theme to apply these changes because when the parent theme is updated you won’t lose any changes at all.