.icon {
  display: inline-block;
  vertical-align: middle;
  line-height: 1;
}
.icon svg {
  display: inline-block;
  vertical-align: top;
  width: 1em;
  height: 1em;
  fill: currentColor;
  pointer-events: none;
}

.icon-burger {
  position: relative;
  display: inline-block;
  width: 19px;
  height: 18px;
  vertical-align: middle;
}
.icon-burger span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: currentColor;
  transition: width 0.3s;
}
.icon-burger span:nth-child(1) {
  top: 0;
}
.icon-burger span:nth-child(2) {
  top: 50%;
  transform: translateY(-50%);
  width: 70%;
}
.icon-burger span:nth-child(3) {
  bottom: 0;
}
*:hover > .icon-burger span:nth-child(2) {
  width: 100%;
  transition: width 0.2s;
}