My code is up here : https://jsfiddle.net/krbomcj5/
It's small and self explanatory for a CSS pro. 
What's the issue is, I'm expecting a space between the .main-content and .head-content.
I'm able to achieve it by adding a padding to .main-content. 
What is the alternate best practice if I want to get a space between .main-content and .head-content
 
    