Social Link Page with HTML5 , CSS3 and JavaScript

What are you most proud of, and what would you do differently next time?

I believe I'm finally understanding how css3 works, the use of variables and mixins are really useful during development.

What challenges did you encounter, and how did you overcome them?

This time I dared to create a javascript function instead of the conventional tag, I would like to discover new javascript methods and better understand how the DOM works

What specific areas of your project would you like help with?

I have no doubts regarding the code, as I believe it was as good as possible, but if you have a tip, see something I could have done better or did wrong, please let me know.