same height on other pages as the frontpage

Hi,

I am strugling already for an hour to fix the site
height of de text area of my site. I want the withe page on the pages “Portfolio”and “Contact” have the same height als the home page (Anja jordens). Now the white area’ are different wenn i switch pages

link to the site https://www.jordenskunst.nl

I have a childtheme, i only need the right code ??
Thanks i advanced. I i can help you with something? let me now/