title: CSS pilling up block to the left using one class
body: <p>This is probably a very basic question but I can't get this to work.
  I want all the divs to pill up to the left until the main div's height is reached and go to the next row.</p>
  
  <p>Using float:left, I get the result on the left (in the picture below)</p>
  
  <p>How can I achieve the result on the right using one general css class that will be applied on each div element?
  <img src="https://i.stack.imgur.com/PQeDl.png" alt="enter image description here"></p>