Demo: rounded corners (border-radius)

Four values Example - border-radius: 15px 50px 30px 5px:

Three values Example - border-radius: 15px 50px 30px:

Two values Example - border-radius: 15px 50px:

One value Example - border-radius: 15px:

Elliptical border Example - border-radius: 50px / 15px:

Elliptical border Example - border-radius: 15px / 50px:

Ellipse border Example - border-radius: 50%:

Circle Example - border-radius: 50%: