Here's a great page featuring a nice collection of animated hamburger menu buttons. The buttons are built in CSS/SCSS, and perform beautifully in modern browsers.

https://jonsuh.com/hamburgers/ Read more about Animated Hamburger Buttons

If you are using SASS/SCSS as a precompiler for CSS, here is a really useful cheatsheet to help remember all the wonderful functions.

https://sass-cheatsheet.brunoscopelliti.com/ Read more about SASS Cheatsheet