IE and Safari layout FAIL

Hey party people.
I did a website for a client:
It looks as intended in Chrome, Edge, and Firefox.
But in IE and Safari, the layout has some pretty significant problems.
I don’t have an Apple device so it is kinda hard for me to tackle that one.
If anyone could look at the code and let me know what the problem is. I know it is a big ask. I am a self-taught developer and never worked out the tricks to get layouts working properly in IE and Safari.
Thanks for any and all tips / advice / responses!

If you can, it’s a good idea to get minimum supported versions for all browsers from your customer (if you’re freelancing and your customer wants older versions of browsers - or IE at all- you’ll want to build that into your price). Some browser devtools (or developer extensions) will allow you to view your site in an older version. There are also a few documentation sites, like MDN, that are pretty good at providing information about browser support:

There are also tools of varying cost and quality for testing browser compatibility. If you are going to be facing this problem often, it is probably worth investing time (and maybe money) into finding one that works well for you.

Thanks Ariel. Guess I need to do finally really dig into this browser compatibility issue.

The bane of web developers everywhere. I feel your pain.