title: how to stretch flexbox on full screen?
body: <p>how to make my flexbox stretched on fullscreen?
  this is my website and I want to remove free space from it >>
  <a href="https://i.stack.imgur.com/uAooe.png" rel="noreferrer"><img src="https://i.stack.imgur.com/uAooe.png" alt="enter image description here"></a></p>
  
  <p>please help me and tell me how to make my website fullscreen?
  I tried to make margin and padding zero but not working :/</p>
  
  <p>this is my website and please help me, this is very veri important. !important :)
  lumin.ge/html/wwwabc</p>