Andreas Theme (tweaked) WP falls apart in Safari

Hello all,

I have, with the great help of Vicki (thanks V) got our site WP online: https://www.shadowsandlight.ca

Unfortunately it seems that it falls apart pretty much in Safari. I do have quite a few Mac users who visit the site (musicians like to use Mac around us), so this could be quite important. I have uploaded a couple of screenshots of the problems, and would appreciate it if anyone has any solutions to this.
https://www.iistudio.com/kennard.jpg
https://www.iistudio.com/kennard2.jpg

I appreciate that not many use Safari here, but many Mac users have it as the default browser.

Thanks in advance

Ellie