form .field-validation-error {
    display: inline-block;
    position: relative;
    top: 2px;
    font-size: 12px;
    color: #fff;
    line-height: 1;
    padding: 5px;
    border-radius: 3px;
    background: #d9534f;
}
form .field-validation-error::before {
    content: "";
    display: block;
    border-top: 2px solid transparent;
    border-left: 6px solid transparent;
    border-right: 6px solid transparent;
    border-bottom: 6px solid #d9534f;
    position: absolute;
    left: 10px;
    top: -8px;
}