.line {
  position: absolute;
  left: 0px;
  top: -20px;
  height: 4px;
  width: 40px;
  background: #000;
  border-radius: 2px;
  display: block;
  transition: 0.5s;
  transform-origin: center;
}

.line:nth-child(1) {
  top: 12px;
}

.line:nth-child(2) {
  top: 24px;
}

.line:nth-child(3) {
  top: 36px;
}

#burger:checked+.burger .line:nth-child(1) {
  transform: translateY(12px) rotate(-45deg);
}

#burger:checked+.burger .line:nth-child(2) {
  opacity: 0;
}

#burger:checked+.burger .line:nth-child(3) {
  transform: translateY(-12px) rotate(45deg);
}

label.burger {
  display: block;
  top: -11px;
  width: 75px;
  height: 50px;
  position: relative;
  margin-left: auto;
  margin-right: auto;
}

input#burger {
  display: none
}