I've attempted to create a design resembling the image below, but I'm not achieving the desired result. Can someone provide me with assistance? Any help would be greatly appreciated.
https://i.sstatic.net/J4LzC.png
<!DOCTYPE html>
<html>
<head>
<style>
#rcorners1 {
border-radius: 10px 90px 90px 10px / 8% 100% 100% 8%;
background: #18b1a0;
padding: 20px;
width: 200px;
height: 150px;
}
</style>
</head>
<body>
<p id="rcorners1">Rounded corners!</p>
</body>
</html>