ircle span:nth-child(4) {
  background-color: #50C878;
  border-bottom-right-radius: 100%;
}

/* glider animation */
.card:before {
  content: '';
  position: absolute;
  height: 130%;
  width: 1em;
  background-color: aliceblue;
  opacity: 0.14;
  animation: glider 1.8s infinite linear;
  animation-delay: 0.05s;
}

.card:after {
  content: '';
  position: absolute;
  height: 120%;
  width: 0.8em;
  background-color: aliceblue;
  opacity: 0.1;
  animation: glider 1.8s infinite linear;
}

@keyframes glider {