.content-2fa{max-width:400px;margin:auto;background:#008eff99;padding:20px;border-radius:20px;margin-top:10%}
h1{ color: #ffffff;
    display: block;
    text-align: center;
    font-weight: 700;
    padding: 20px;
    font-size: 29px;
    border-radius: 15px;
}
h2{color:#373333}
#output, #input{
    font-size: 80px;
    font-weight: 700;
    color: #e51b1b;
    border: 0;
    background: white;
    width: 400px;
    overflow: hidden;
    margin: 0;
    text-align: center;
    border-radius: 10px;
    margin-bottom: 10px;}
    button{color:#fff;background:green;padding:10px 20px;border-radius:8px;border:0;margin:auto;display:block;cursor:pointer;}
    .red{background: red; margin-top: 10px;}


    #input {
        color: orange;
        font-size: 20px;
        height: 40px;
    }


    input:invalid {
  border: 2px dashed red;
}