.btn {
  background: white;
  color: black;
  border: 0px solid black;
  height: 20px;
  padding: 10px;
}
.btn__primary {
  background-color: blue;
  color: white;
  font-size: 1.3em;
  transition: font-weight 0.2s ease;
}
.btn__primary--current {
  color: gray;
}
.btn__primary--current.btn--active {
  font-weight: 700;
}