html {
    color: #fff;
    background-color: #000;
    font-size: 40px;
}

.block {
    position: fixed;
    left: 50%;
    right: 50px;
    bottom: 100px;
    min-height: 100px;
    background-color: #fff;
    border-radius: 32px;
}

.square {
    position: absolute;
    top: -45px;
    left: 90px;
    width: 100px;
    height: 100px;
    background-color: red;
    border-radius: 90%;
}