100% height front page

Hi,

I am struggling to find a way to make my front page 100% height. I would like the header, body, and footer all to display on one page (without scroll). Here is my current site: https://www.christinelellis.com. I am using the Fashionista theme.

On recommendation from another thread, I already tried this with no luck:
‘html {
height: 100%
}
body {
height: 100%
margin: 0:
}’

Thank you!