<html>
<head>
<link rel="help" href="https://developer.mozilla.org/en-US/docs/Web/CSS/border-top-right-radius">
<style>
.class4 {
  /* bug happens when width < border-bottom-left-radius + border-bottom-right-radius (horizontal) with vertical axis of the elipse values set to 0 */
  border-bottom: solid;
  width: 200px;
  height: 200px;
  background-color: darkgoldenrod;
  border-right: 100px solid red;
  border-bottom-width: 43px;

  /* 130 + 130 = 260 > width */
  border-bottom-left-radius: 130px 0px;
  border-bottom-right-radius: 130px 0px;
}
</style>
</head>
<body>
<div class="class4"></div>
</body>
</html>
