*{
    margin: 0;
    padding: 0;
    background-color: #345;
    box-sizing: border-box;
}
html,body{
    width: 100%;
    height: 100vh;
}
body{
    overflow: hidden;
}
.color{
    border-radius: 50%;
    width: 300px;
    height: 300px;
    background-color: rebeccapurple;
    position: absolute;
    transition:all  cubic-bezier(0.19, 1, 0.22, 1) 1s; 
}