<div class="container">...</div>
.container {/* Background color */background-color: rgba(0, 0, 0, 0.3);/* You can use gradient background color such asbackground: linear-gradient(rgba(0, 0, 0, 0.2) 0%, rgba(0, 0, 0, 0.1) 100%); *//* Curved corners */border-bottom-left-radius: 50% 40%;border-bottom-right-radius: 50% 40%;}