Force sidebar height 100% using CSS (with a sticky bottom image)?

Question

I\'ve been banging my head against the wall for hours trying to figure out this issue and think it must be something small I\'m missing. I\'ve searched online, but nothing

Answer 1

Further to @montrealmike 's answer, can I just add my adaptation?

I did this:

.container { 
  overflow: hidden; 
  .... 
} 

#sidebar { 
  margin-bottom: -101%;
  padding-bottom: 101%; 
  .... 
} 

I did the "101%" thing to cater for the (ultra rare) possibility that somebody may be viewing the site on a huge screen with a height more than 5000px!

Great answer though, montrealmike. It worked perfectly for me.