When you create a pseudo element, you have access to the parent HTML attributes. They can be used inside the content attribute of a pseudo element.

 

[data-length]:hover:after {
     content: attr(data-length)  " / "  attr(data-weight);  color: orange;  position: absolute;  right: 1em;}

 

     
      
      
Tyrannosaurus
      
      
Carnotaurus
      
      
Stegosaurus
      
      
Triceratops