In the last lesson, you learned how to modify the dimensions of boxes. In this lesson, you'll learn how to manipulate another box property: borders.
In a previous exercise, you typed the following unexplained snippet of code into your stylesheet:
border: 1px solid rgba(0, 0, 0, 0.3);
In this lesson, you'll learn exactly what this code means and how it can be used to help support your learning of the box model.