label {
    display: block;
    margin: 1px;
    padding: 1px;
}

.field {
    margin: 1px;
    padding: 1px;
}

input:invalid {
    background-color: #ffdddd;
}

form:invalid {
    border: 5px solid #ffdddd;
}

input:valid {
    background-color: #ddffdd;
}

form:valid {
    border: 5px solid #ddffdd;
}

input:required {
    border-color: #800000;
    border-width: 3px;
}

input:required:invalid {
    border-color: #c00000;
}