%btn {
  color: black;
  background: white;
  border: 1px solid gray;
  padding: 5px 7px;
}


.blue-custom-button {
  @extend %btn;
  background: blue;
}

.yellow-custom-button {
  @extend %btn;
  background: yellow;
}


.default-custom-button {
  @extend %btn;
  color: gray;
}