<!doctype html>
<html><head>
<title>Border-radius inheritance</title>
<style>
.div1 { width: 100px; height: 100px;
      border: 10px solid black; 
      border-radius: 10px;
      left: 50px;
      top: 50px;
}

div > div {
  width: 40px; height: 40px;
  border: 10px solid black;
  position: absolute;
  border-radius: 0px;
  left: 40px;
  top: 40px;
}

</style>
</head>
<body>
  <div class="div1"><div></div></div>
</body></html>