CSS Grid - Huddle landing page

Not sure how to get the social media icons to stay at the bottom of the page.

Also not sure if the "Register" button should be of a fixed width that varies by resolution or if it should be relative and take up f.ex 1/2 of the screen in mobile resolution.

Had the most difficult time making the illustration mockup image responsive. Settled on setting it to "max-width:100%" although it shrinks way too much right before it hits the media query limit.