height - how to make sidebar NOT equal to content in wordpress -

I want the WordPress sidebar to get a specific height, not equal to the content on the post / page. Just 400px, for example, I'm working with atahualpa in which code I got PHP? Thank you

If I understand you correctly, then you want to edit a relevant CSS file. - Nothing more.

Keep in mind that which selector wants to limit you and add properties, is appropriate:

  height: 400px; Hidden flurry;  

or overflow: auto; If you want to show the scrollbar.