Sidebar drops to bottom in Safari

This newbie would appreciate any help!

My sidebar drops to the bottom, below my posts, in Safari. The layout works great in Firefox and IE (for mac and pc). The code has been validated. I’m not sure where the problem lies– in the css?

Haven’t found the other forum comments to solve to this problem.

https://www.henzeldesign.com/wordpress/

https://www.henzeldesign.com/wordpress/wp-content/themes/henzeldesign%20white/style.css

Thanks!