Defines the radius of the element's corners.

默认属性 border-radius: 0;

Removes any border radius.

border-radius: 20px;

You can use pixel values.

border-radius: 50%;

You can use percentage values. In this example, the radius starts halfway through each border.

border-radius: 20px 50%;

If you set two values, the first one is for the top and bottom borders, the second one for the left and right borders.