body {
    color: white;
    background-color: black;
    height: 5000px;
}

.block_1 {
    min-height: 100px;
    background-color: white;
    border-radius: 5px;
    position: fixed;
    left: 50%;
    bottom: 100px;
    right: 50px;
}

.block_2 {
    background-color: red;
    height: 100px;
    width: 100px;
    border-radius: 50px;
    position: absolute;
    bottom: 50%;
    left: 10%;
}