form.main-form{
    margin: 0 1%;
}

form.main-form > div{
    margin: 1em;
}

form.main-form fieldset{
    border:1px solid #ccc;
    max-width:350px;
}

form.main-form legend{
    margin-left:0.5em;
    padding: 0.2em 0.5em;
    border-left:1px solid #ccc;
    border-right:1px solid #ccc;
}

form.main-form input:required{
    border:1.25px solid red;
}

form.main-form input[type="submit"]{
    border-radius:4px;
    border:1px solid #ccc;
    padding:0.3em 0.5em;
}