body {
    margin: 0;
    height: 2000px;
    background-color: rgb(58, 57, 57);
    color: white;
}
.fixed-rectangle {
    position: fixed;
    left: 50vw;
    right: 50px;
    bottom: 100px;
    min-height: 100px;
    background-color: white;
    display: flex;
    border-radius: 5px;
    }

.red-circle {
    transform: translate(-50%, -50%);
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background-color: red;
    position: relative;
    right: -20%
}