how to round the corners of a div outline in css

1/* Set rounded corners with border-radius property */
2
3.class {
4  border-radius: 4px;
5}
6
7.circle {
8  border-radius: 50%;
9}

1div {
2  outline: auto;
3  outline-style: round;
4}

1/* Use border-radius property */
2
3.class {
4  border-radius: 5px;
5}
6
7.circle {
8  border-radius: 50%;
9}