body #step-4-form .gform_wrapper .gform_button {
  background-color: transparent;
  border-width: 0;
  color: #000;
  position: relative;
border-bottom:2px solid #000;
box-shadow:none;
}

body #step-4-form .gform_wrapper .gform_button:after {
  content: '+';
  position: absolute;
  top: 50%;
  right: 0;
  color: #172554; /* blue-950 */
  transition: transform 0.3s;
}

body #step-4-form .gform_wrapper .gform_button:hover::after {
  transform: rotate(180deg);
}