* { box-sizing: border-box; }

#btn {
  position: fixed;
  z-index: 5;
  top: 15px;
  left: 15px;
  cursor: pointer;
  -webkit-transition: left 500ms cubic-bezier(0.6, 0.05, 0.28, 0.91);
  transition: left 500ms cubic-bezier(0.6, 0.05, 0.28, 0.91);
}

#btn div {
  width: 35px;
  height: 2px;
  margin-bottom: 8px;
  background-color: #ffffff;
  -webkit-transition: -webkit-transform 500ms cubic-bezier(0.6, 0.05, 0.28, 0.91), opacity 500ms, box-shadow 250ms, background-color 500ms;
  transition: transform 500ms cubic-bezier(0.6, 0.05, 0.28, 0.91), opacity 500ms, box-shadow 250ms, background-color 500ms;
}

#btn:hover > div { box-shadow: 0 0 1px #00DFFC; }

#btn.active { left: 230px; }

#btn.active div { background-color: #343838; }

#btn.active:hover > div { box-shadow: 0 0 1px #343838; }

#btn.active #top {
  -webkit-transform: translateY(10px) rotate(-135deg);
  -ms-transform: translateY(10px) rotate(-135deg);
  transform: translateY(10px) rotate(-135deg);
}

#btn.active #middle {
  -webkit-transform: scale(0);
  -ms-transform: scale(0);
  transform: scale(0);
}

#btn.active #bottom {
  -webkit-transform: translateY(-10px) rotate(-45deg);
  -ms-transform: translateY(-10px) rotate(-45deg);
  transform: translateY(-10px) rotate(-45deg);
}

#box {
  position: fixed;
  z-index: 4;
  overflow: auto;
  top: 0px;
  left: -275px;
  width: 275px;
  opacity: 0;
  padding: 20px 0px;
  height: 100%;
  background-color: #f6f6f6;
  color: #343838;
  -webkit-transition: all 350ms cubic-bezier(0.6, 0.05, 0.28, 0.91);
  transition: all 350ms cubic-bezier(0.6, 0.05, 0.28, 0.91);
}

#box.active {
  left: 0px;
  opacity: 1;
}

#items {
  position: relative;
  top: 50%;
  -webkit-transform: translateY(-50%);
  -ms-transform: translateY(-50%);
  transform: translateY(-50%);
}

#items .item {
  position: relative;
  cursor: pointer;
  font-size: 1em;
  padding: 5px 20px;
  -webkit-transition: all 250ms;
  transition: all 250ms;
}

#items .item:hover {
  background-color: rgba(104, 212, 255, 0.2);
}