.menu-burger
{
  position: relative
}

.menu-burger span
{
  display: block;
  width: 26px;
  height: 4px;
  margin-bottom: 5px;
  position: relative;
  
  background: white;
  border-radius: 3px;
  
  z-index: 1;
  
  transform-origin: 4px 0px;
  
  transition: transform 0.5s cubic-bezier(0.77,0.2,0.05,1.0),
              background 0.5s cubic-bezier(0.77,0.2,0.05,1.0),
              opacity 0.55s ease;
}

.menu-burger span:first-child
{
  transform-origin: 0% 0%;
}

.menu-burger span:nth-last-child(1)
{
  transform-origin: 0% 100%;
  margin-bottom: 0;
}

.menu-burger.open span
{
  opacity: 1;
  transform: rotate(45deg) translate(0px, -10px);
}

/*
 * But let's hide the middle one.
 */
.menu-burger.open span:nth-last-child(3)
{
  opacity: 0;
  transform: rotate(0deg) scale(0.2, 0.2);
}

/*
 * Ohyeah and the last one should go the other direction
 */
.menu-burger.open span:nth-last-child(1)
{
  transform: rotate(-45deg) translate(5px, 6px);
}