How to reduce the size of 'Contact' header text?

https://byanymeans.net.au/pages/contact

@Anonymous - add this css to the very end of your base.css file and check, adjust number as per the need. This will change header size on all pages

.main-page-title{font-size: 30px;}

Thanks so much! Following on from that, do you know how I can reduce the gap between ‘Contact’ and the ‘Name’ box?

@Anonymous - add this css, this too will be applied on all pages

@media screen and (min-width: 750px){
.main-page-title {margin-bottom: 2rem !important;}
}