form#wpforms-form-7439 .wpforms-page.last .wpforms-field-pagebreak {
  float: none;
  display: inline-block;
  width: auto;
  padding: 0;
  text-align: center;
}

form#wpforms-form-7439 .wpforms-page.last .wpforms-page-prev {
  display: inline-block;
  width: auto;
  margin-right: 10px; /* spacing between prev and submit */
}

form#wpforms-form-7439 .wpforms-submit-container {
  float: none;
  width: auto;
  text-align: center;
  margin: 0 auto;
  padding: 0;
  clear: both;
}

form#wpforms-form-7439 .wpforms-submit-container button {
  display: inline-block;
  width: 25%; /* Adjust to taste */
}