uneven border

<style>
#scrollbox {
width: 300px;
height: 300px;
border: 2px solid #737373;
border-radius: 255px 15px 225px 15px/15px 225px 15px 255px;
border: 3px solid #737373;
overflow: auto;
}
</style>
<div id="scrollbox">
text
</div>