.button {
  display: block;
  position: relative;
  width: 50px;
  height: 50px;
  background-color: lightgreen;
  border: 0;
  border-radius: 5px;
  cursor: pointer;
}

.button__line {
  position: absolute;
  display: inline-block;
  background-color: #fff;
  width: 45%;
  height: 2px;
  left: 14px;
  border-radius: 5px;
}

.button__line-1 {
  top: 15px;
}

.button__line-2 {
  top: 23px;
}

.button__text::before {
  content: "MENU";
  position: absolute;
  bottom: 8px;
  right: 0;
  left: 0;
  color: #fff;
  font-size: 0.6rem;
}

.button.active .button__line-1 {
  top: 14px;
  left: 18px;
  width: 30%;
  transform: translateY(6px) rotate(-45deg);
}

.button.active .button__line-2 {
  top: 26px;
  left: 18px;
  width: 30%;
  transform: translateY(-6px) rotate(45deg);
}

.button.active .button__text::before {
  content: "CLOSE";
}