title: CSS flex box with vertical content equal full screen distribution
body: <p>I am try to apply flex box to my layout, but i am bit lost on how to achieve the following. How would i achieve this so the 3 panel always take the full screen with 5% 90% and 5%.</p>
  
  <p>Note: at the moment i have top and bottom position fixed, and javascript calculate the height with the middle panel but it's not ideal.</p>
  
  <p><a href="https://i.stack.imgur.com/Shd4l.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Shd4l.jpg" alt="enter image description here"></a></p>