Border radius 1

HTML

border-top-left-radius:     3em 2em;<br>
border-top-right-radius:    1em 3em;<br>
border-bottom-right-radius: 4em 1em;<br>
border-bottom-left-radius:  1em 3em;
<div></div>

CSS

div {
    margin: 10px;
    border: 2px solid blue;
    padding: 10px; 
    background: blue;
    width: 120px;
    height: 120px;
    border-top-left-radius:     3em 2em;
    border-top-right-radius:    1em 3em;
    border-bottom-right-radius: 4em 1em;
    border-bottom-left-radius:  1em 3em;
}