Video is not confined to the div block - appears on the landing page

I tried to add video to a div block and which is at the bottom of the page. But when published it comes at he top of the landing page. I tried background video as well as video block.

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

Really good concept. I am interested to know how can I do this for playing video for wilbur soot.

I am also know how can I do this for georgenotfound merch project.