How to properly float two columns side by side with css

Question

This is one of those things I learned a long time ago and never thought much about if I was actually doing it the right way.

Let\'s say we have a structure

Answer 1

using float left or right is not important. you have wrapper with the width of 600px. when you using float for both sidebar and contain inside the wrapper, you must make sure that the width of sidebar and contain (including margin and padding) equal or less than 600px. If not, the second element will be below the first one. Hope this helps ^^