Letter-spacing issue on mobile (Fulton)

Site URL: http://dustlight.co

Have posted this question before but still can't resolve. I've added several typefaces to my site and defined all styles in my custom CSS. Per page, I'm either using the default squarespace text box to add copy, or I'm adding a code box and just adding a little bit of CSS to my html text to change color or alignment. Using the Fulton template.

I'm not having trouble anywhere except my <h1> is showing up weirdly on mobile—for some reason seems like letter-spacing is being added. It doesn't show up when I manually resize the window on desktop, just on mobile (see attached). I don't have any manual letter-spacing added anywhere on the site via CSS, and I also don't have any letter-spacing added to any of my text in the squarespace site styles dialogue. 

It works fine on both of my devices, but I am going to guess that some browsers aren't supporting letter-spacing: 0;

Try letter-spacing: 0px; or letter-spacing: normal;

3 hours ago, rwp said:

It works fine on both of my devices, but I am going to guess that some browsers aren't supporting letter-spacing: 0;

Try letter-spacing: 0px; or letter-spacing: normal;

I guess problem on iPhone/Safari.

happens to me too and I can't figure it out!!!!! SOS