Overleaf/services/web/frontend/stylesheets/app/recurly.less

.recurly-hosted-field {
  &:extend(.form-control);
}

.recurly-element-card {
  &:extend(.form-control);
  padding: 4px 4px;
  border: 1px #cccccc solid;
  border-radius: 20px;
  height: 50px;
}

.recurly-element-card-invalid {
  &:extend(.has-error);
  border-color: @red;
}

.recurly-element-number {
  &:extend(.form-control);
}