.ej1 {
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #f0f0f0;
    margin: 0;
}

#simulation {
    position: relative;
    width: 350px;
    height: 300px;
    border: 1px solid #000;
    background-color: #fff;
}

#ball {
    position: absolute;
    width: 50px;
    height: 50px;
    background-color: red;
    border-radius: 50%;
    top: 0;
    left: 50%; /* Centra horizontalmente */
    transform: translateX(-50%); /* Ajusta el centro del círculo */
}

body{
    /*background-color: #43b9fe4f;*/
    /*background: linear-gradient(to right, rgb(56, 189, 248), rgb(30, 64, 175))*/
    background: linear-gradient(to right, rgb(243, 244, 246), rgb(209, 213, 219));
    
}