round border in css code example

Example 1: how to make borders rounded in css

#rcorners {
  border-radius: 25px;
}

Example 2: how to round the corners of a div outline in css

div {
  outline: auto;
  outline-style: round;
}

Example 3: How to make a round corner in CSS

#roundCornerID {
    border-radius: 30%;
    width: 200px;
    height: 150px;   
}