body {
  margin: 0;
  background-image: linear-gradient(#ffbe79, #ffbe79 10%, #75bed6 40%, #75bed6);
  overflow: hidden;
  height: 100vh;
}

.bird {
  width: 25px;
  height: 5px;
  display: inline-block;
  position: absolute;
  transform: skew(20deg, 20deg);
  animation: wave 2.5s ease-in-out infinite;
}

.bird:before,
.bird:after {
  content: '';
  width: 100%;
  height: 100%;
  background-color: #000;
  position: absolute;
  border-radius: 20%;
}

.bird:before {
  right: 49%;
  transform-origin: right;
  transform: rotate(-40deg);
  animation: flap-left .75s ease-in-out infinite;
}

.bird:after {
  left: 49%;
  transform-origin: left;
  transform: rotate(40deg);
  animation: flap-right .75s linear infinite;
}

@keyframes wave {
  40% {
    transform: translateY(40px) skew(20deg, 20deg);
  }
  50% {
    transform: translateY(50px) skew(20deg, 20deg);
  }
  60% {
    transform: translateY(40px) skew(20deg, 20deg);
  }
  100% {
    transform: translateY(0) skew(20deg, 20deg);
  }
}

@keyframes flap-left {
  60% {
    transform: rotate(10deg);
  }
  75% {
    transform: rotate(20deg);
  }
  100% {
    transform: rotate(-40deg);
  }
}

@keyframes flap-right {
  60% {
    transform: rotate(-10deg);
  }
  75% {
    transform: rotate(-20deg);
  }
  100% {
    transform: rotate(40deg);
  }
}