Curved background

.container {
                        /* Background color */
                        background-color: rgba(0, 0, 0, 0.3);

                        /* You can use gradient background color such as
    background: 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%;
                    }