Rounding corners on borders

This property can have from one to four values. Here are the rules:

Four values - border-radius: 15px 50px 30px 5px; (first value applies to top-left corner, second value applies to top-right corner, third value applies to bottom-right corner, and fourth value applies to bottom-left corner).

The higher the RADIUS value the more rounded the corners are.

When setting the border values you can...
  margin:2px solid red;

Which would set the
border WIDTH / STYLE / COLOUR

Then, to set the radius, you would use the command...eg...
  border-radius:5px;