.hamburger {
  width: 1.5rem;
  height: 1.5rem;
  position: relative;
  cursor: pointer;
  display: none;
}
.hamburger > span {
  position: absolute;
  border-radius: 1rem;
  width: 100%;
  height: 2px;
  background-color: var(--white);
  opacity: 0.8;
  transform: rotate(0);
  transition: 250ms ease-in-out;
}
.hamburger > span:nth-child(1) {
  top: 10%;
}
.hamburger > span:nth-child(2) {
  width: 80%;
  top: 50%;
}
.hamburger > span:nth-child(3) {
  top: 90%;
}
.hamburger.open span:nth-child(1) {
  top: 50%;
  transform: rotate(45deg);
}
.hamburger.open span:nth-child(2) {
  transform: translateX(-100%);
  opacity: 0;
}
.hamburger.open span:nth-child(3) {
  top: 50%;
  transform: rotate(-45deg);
}

@media only screen and (min-width: 0px) and (max-width: 900px) {
  .hamburger {
    display: block;
  }
}