title: How to use grid system without bootstrap
body: <p>I'm trying to handle my homework, where I got asked to create a responsive grid (using media queries) which contains UP to 4 columns (column minimal width is 300 pixels)
  and I'm not allowed to use any library. </p>
  
  <p>I have tried to look at bootstrap grid system and to apply it on my code but it did not go so well for me.
  I have issues with the part of the minimum width of each column and the fact that it needs to contain up to 4 columns...</p>
  
  <p>maybe I did not understand the requirements of the question so well...</p>