Font Setup in shopify forms app.

Shopify Apps
2

Shopify Forms content lives inside Shadow DOM, so none of the CSS rules in your document apply to the form.

One way is to use Javascript code to push your rules into adoptedStylesheets inside this Shadow DOM.

Or you can piggy-back to the way App uses to pass styles into Form.

Create a “Custom liquid” section before your “Shopify Forms” app embed section and paste code like this:

You can see it working in my test store here https://sysftke9y30mzhvt-23104437.shopifypreview.com (at the bottom)