.box {
  border-radius: 2px;
  position: absolute;
  top: 35px;
  left: 35px;
  width: 30px;
  height: 30px;
}

.btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.5);
  width: 80px;
  cursor: pointer;
  cursor: hand;
}

.box span {
  display: block;
  width: 100%;
  box-shadow: 0 2px 10px 0 rgba(0,0,0,0.3);
  border-radius: 3px;
  height: 8px;
  background: #f09234;
  transition: all .3s;
  position: relative;
}

.box span + span {
  margin-top: 14px;
}

.activemenu span:nth-child(1) {
  animation: ease .7s top forwards;
}

.not-active span:nth-child(1) {
  animation: ease .7s top-2 forwards;
}

.activemenu span:nth-child(2) {
  animation: ease .7s scaled forwards;
}

.not-active span:nth-child(2) {
  animation: ease .7s scaled-2 forwards;
}

.activemenu span:nth-child(3) {
  animation: ease .7s bottom forwards;
}

.not-active span:nth-child(3) {
  animation: ease .7s bottom-2 forwards;
}

@keyframes top {
  0% {
    top: 0;
    transform: rotate(0);
  }
  50% {
    top: 22px;
    transform: rotate(0);
  }
  100% {
    top: 22px;
    transform: rotate(45deg);
  }
}

@keyframes top-2 {
  0% {
    top: 22px;
    transform: rotate(45deg);
  }
  50% {
    top: 22px;
    transform: rotate(0deg);
  }
  100% {
    top: 0;
    transform: rotate(0deg);
  }
}

@keyframes bottom {
  0% {
    bottom: 0;
    transform: rotate(0);
  }
  50% {
    bottom: 22px;
    transform: rotate(0);
  }
  100% {
    bottom: 22px;
    transform: rotate(135deg);
  }
}

@keyframes bottom-2 {
  0% {
    bottom: 22px;
    transform: rotate(135deg);
  }
  50% {
    bottom: 22px;
    transform: rotate(0);
  }
  100% {
    bottom: 0;
    transform: rotate(0);
  }
}

@keyframes scaled {
  50% {
    transform: scale(0);
  }
  100% {
    transform: scale(0);
  }
}

@keyframes scaled-2 {
  0% {
    transform: scale(0);
  }
  50% {
    transform: scale(0);
  }
  100% {
    transform: scale(1);
  }
}