body
{
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: #1b141a;
}
ul
{
  margin: 0;
  padding: 0;
  display: flex;
}
ul li
{
  position: relative;
  list-style: none;
  width: 85px;
  height: 85px;
  margin: 0 10px;
  border-radius: 50%;
  box-sizing: border-box;
}
ul li:before,
ul li:after
{
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: #000;
  border-radius: 50%;
  filter: blur(20px);
  opacity: 0;
  transition: 1s;
  z-index: -1;
}
ul li:after
{
  filter: blur(40px);
}
ul li:hover:before,
ul li:hover:before
{
  opacity: 1;
}
ul li a
{
  position: absolute;
  top: 5px;
  left: 5px;
  right: 5px;
  bottom: 5px;
  text-align: center;
  line-height: 80px;
  color: #fff;
  background: #000;
  font-size: 36px;
  border-radius: 50%;
}
ul li a .fa
{
  text-shadow: 0 2px 5px rgba(0,0,0,.2);
  transition: 0.5s;
  transform: rotateY(0deg) scale(0.8);
  opacity: 0.2;
}
ul li a:hover .fa
{
  opacity: 1;
  transform: scale(1.2);
}
ul li:nth-child(1) a,
ul li:nth-child(1):before,
ul li:nth-child(1):after
{
  background: linear-gradient(45deg , #ff0057 , #e64a19);
}
ul li:nth-child(2) a,
ul li:nth-child(2):before,
ul li:nth-child(2):after
{
  background: linear-gradient(45deg , #89ff00 , #00bcd4);
}
ul li:nth-child(3) a,
ul li:nth-child(3):before,
ul li:nth-child(3):after
{
  background: linear-gradient(45deg , #e91e63 , #5d02ff);
}
ul li:nth-child(4) a,
ul li:nth-child(4):before,
ul li:nth-child(4):after
{
  background: linear-gradient(45deg , #ff0000 , #ffc107);
}