A more programmatic way of creating colors
A neat way to control anchor tags
Make your HTML more semantic with better tags
Getting things to stay at the bottom of your page.
A reminder on css variables and how they work
Unique ways to select your elements ;)
Make use of the ::before element for border effects
Will infinite animations trigger animationend ?
For all those times you've wondered why an element does not apply your CSS.
Placing things on the right spot of the page is hard!