@media screen and (max-width:900px) and (min-width:750px){
    body{
        width:100%;
        overflow-x:hidden;
        display:flex;
        justify-content: center;
        align-items:center;
        flex-direction:column;
        background-color:red;
    }
    .case{
        width:60%;
    }

    b{
        left:20%;
    }
    
    .resultado{
        width:70%;
    }
}

@media screen and (max-width:749px){
    body{
        width:100%;
        overflow-x:hidden;
        display:flex;
        justify-content: center;
        align-items:center;
        flex-direction:column;
        background-color:rgb(0, 0, 0);
    }
    .case{
        width:80%;
        height:670px;
        
    }

    .resultado{
        width:70%;
    }

    .erase{
        font-size:15px;
    }

    b{
        left:20%;
    }

}