.square, .circle{
    width: 200px;
    height: 200px;
    display: block;
    float: left;
}
.circle{
    border-radius:50%
}

#blockGreen {background-color: green;}
#blockBlue {background-color: blue;}

#container{
    background-color: aqua;
    margin: 0 auto;
    width: 400px;
}

#blockGreen{
    background-color: green;
    position: fixed;
}

#blockBlue{
    background-color: blue;
    position: relative;
}
#texture{
    background-image: url('images/pexels-aleksandr-slobodianyk-989941.jpg');
}

.texture{
    width: 1000px;
    height: 1000px;
}