Sidebar Dropping in IE7

I think it’s because of the huge margin-left and padding on #sidebar.

IE treats margins different from other browsers. Try to solve it with a float left, a smaller width, and without the left margin/padding.

Peter

Peter`s right. IE renders margins differently.

in your future projects, try to incorporate Eric Meyer`s CSS Reset:
https://meyerweb.com/eric/thoughts/2007/05/01/reset-reloaded/

why css reset?
https://www.webresourcesdepot.com/do-you-use-resetcss/

IE7 is borked! It inherited a faulty CSS box model from IE6. Hacks are definitely not a good way of dealing with this as they will bite back one day (witness the initial release of IE7). A better way way of approaching the problem is to use conditional comments to target CSS at specific versions of IE:

https://quirm.net/2009/06/29/wordpress-conditional-comment-css/

Meyer’s reset sheet isn’t bad. At least his sheet suggests he put some real thought into it. Beware of other reset sheets, though. Some simply use * to reset padding and margins from every element whilst others do the same thing using a humongous list of almost every element you can think of – including the p tag which promptly wrecks most designs.