.form-box{
    padding-top:1%;
    padding-bottom: 1%;
    overflow: hidden;
    clear:both;
}

h1{
    padding:1em;
    background: rgba(0,0,0,0.1);
    text-align: center;
}

.caja{
    clear:both;
    margin:5% 2% 2% 2%;
}

@media(max-width:768px){
    .form-box label, .form-box input, .form-box textarea{
        display: block;
        width:98%;
        margin:1%;
    }
}

@media(min-width:768px){
    form{
        max-width:80%;
        margin:0 10% 0 10%;
    }

    .form-box label, .form-box-check label{
        float:left;
        width:48%;
        margin:0 2% 0 0;
        text-align:right;
    }

    .form-box input, .form-box textarea{
        float:left;
        width:48%;
        text-align:left;
        margin:0;
    }
}