body{
        height: 800px;
        display: flex;
        justify-content: center;
        align-items: center;
    }
    #parent{
        height: 600px;
        width: 300px;
        border: 1px solid;
        background-color: gray;
    }
    .bulb{
        height: 150px;
        width: 150px;
        border: 1px solid;
        background-color: white;
        margin-left: 70px;
        margin-top: 30px;
        border-radius: 50%;
    }