Dawn Theme - Checkout css file or liquid file

I am a developer.

Using Dawn 9.0

I would like to make the element “abbr” in the checkout to disappear by “display: block” ( Attached image

I would like to know where is the CSS file that related to the checkout?

and the liquid file of the cart?

I know that if there isn’t a possibility to have them - I can add a script to the checkout and write a JS script to catch the element and change “display” styling property to “none”.

You can’t modify checkout liquid file. Right now we have only branding Api which has limited to basic styles. We can’t add custom css.

So can I inject a CSS code though the script input on the cart section on the admin panel?