.test-formula pre {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
}
.test-formula .slot-content {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
}
.test-formula .slot-content .sib-form {
  width: 4rem;
  margin: auto 0;
  padding: 0 0.5rem;
}