.parent2 .mask2 i{
  line-height: 100px;
}
.parent2 i{
  line-height: 60px;
}

.parent2 {
  top:15px;
  left:15px;
  position:fixed;
  display:block;
  width:100px;
  height:100px;
  background-color:transparent;
  border-radius:50%;
  z-index:20;
  -webkit-box-shadow: 0px 0px 5px 0px rgba(0,0,0,0.75);
-moz-box-shadow: 0px 0px 5px 0px rgba(0,0,0,0.75);
box-shadow: 0px 0px 5px 0px rgba(0,0,0,0.75);
}
.test1 {
  width:60%;
  height:60%;
  background-color:dimGray;
  border-radius:50%;
  position:absolute;
  color:white;
  text-align:center;
  line-height:70px;
  top:25%;
  left:25%;
  z-index:19;
  transition: all 500ms cubic-bezier(0.680, -0.550, 0.265, 1.550);
}
.test2 {
  width:60%;
  height:60%;
  background-color:dimGray;
  border-radius:50%;
  position:absolute;
  color:white;
  text-align:center;
  line-height:70px;
  top:25%;
  left:25%;
  z-index:19;
  transition: all 500ms cubic-bezier(0.680, -0.550, 0.265, 1.550) .2s;
}
.test3 {
  width:60%;
  height:60%;
  background-color:dimGray;
  border-radius:50%;
  position:absolute;
  color:white;
  text-align:center;
  line-height:70px;
    top:25%;
  left:25%;
  transition: all 500ms cubic-bezier(0.680, -0.550, 0.265, 1.550) .4s;  
}
  .test4 {
  width:60%;
  height:60%;
  background-color:dimGray;
  border-radius:50%;
  position:absolute;
  color:white;
  text-align:center;
  line-height:70px;
  top:25%;
  left:25%;
  transition: all 500ms cubic-bezier(0.680, -0.550, 0.265, 1.550) .6s;  
}
.mask2 {
  top:15px;
  left:15px;
  width:100px;
  height:100px;
  background:darkSlateGray;
  border-radius:50%;
  position:absolute;
  z-index:21;
  color:white;
  text-align:center;
  line-height:120px;
  cursor:pointer;
  position:fixed;
}