Header Icons are minimizing when I open up the store preview

[willpollard96]

Hoping someone can help me out here, my header icons seem to be really small.

To me it looks like they're SUPER small when I head to the store preview, maybe they're not and it's my eyes

I've tried a few methods to make the icons larger that are already on the forums, but I can't seem to crack it!

Any help is much appreciated

 

[willpollard96]

Inspecting the icons shows me that their size is dependent on the body font size and the size changes when I increase the font size. 
 

I edited the settings_schema.json to increase the threshold of the font size, however when I up it past Shopify's recommended 130% and make it a suitable size, this sends the mobile view completely haywire and ruins the alignment of text in my product cards etc.

I am not yet clever enough to figure this out!

I am bamboozled