Souke/producer/web/sass/credit/_add.scss

.credit-add {
    .form {
        width: 300px ;
        margin-top: 30px;
        text-align: center ;

        .form-group.field-creditform-amount {
            //text-align: center ;
            margin-bottom: 30px;

            label {
                margin-bottom: 25px ;
                color: black ;
                font-size: 20px ;
            }

            .input-group {
                width: 150px;
                margin: 0px auto;

                input#creditform-amount {
                    text-align: center;
                }
            }

            .hint-block {
                margin-top: 8px;
            }
        }
    }
}