Page font size and background colour widgets mobile

Hi Catch Themes, I have two questions: 1. Can I change the font size and density of the page titles: example: https://voorbeeld.ovh/contact/ I would like to have the size of the word "Contact" smaller and not bold. Same for other pages on website. 2. I found the css for the background colour of the widgets. This code .widget {background-color: #3291B4;color: #000000;} only works for non mobile. Is there a css code that same widget colour also shows on mobile devices? Thank you so much, Dirk