body {
  background: white;
  height: 100vh;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
}

#sky {
  margin-top: -60px;
  perspective: 400px;
  filter: drop-shadow(0px 150px 10px rgba(0, 0, 0, 0.2));
}
@-moz-document url-prefix() {
  #sky {
    filter: none;
  }
}
#sky div {
  transform-style: preserve-3d;
}
#sky .bird {
  -webkit-animation: fly 10000ms linear infinite;
  animation: fly 10000ms linear infinite;
}
#sky .bird .wind {
  position: absolute;
  left: 50%;
  width: 4px;
  height: 200px;
  margin-left: -2px;
  border-radius: 999px;
  overflow: hidden;
}
#sky .bird .wind:nth-child(1) {
  transform: translate3d(-45px, -14px, -31px) rotateY(90deg);
}
#sky .bird .wind:nth-child(1)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1975ms 4319ms linear infinite;
  animation: wind 1975ms 4319ms linear infinite;
}
#sky .bird .wind:nth-child(2) {
  transform: translate3d(-77px, -79px, -28px) rotateY(90deg);
}
#sky .bird .wind:nth-child(2)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2608ms 4602ms linear infinite;
  animation: wind 2608ms 4602ms linear infinite;
}
#sky .bird .wind:nth-child(3) {
  transform: translate3d(133px, 45px, -69px) rotateY(90deg);
}
#sky .bird .wind:nth-child(3)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1072ms 2077ms linear infinite;
  animation: wind 1072ms 2077ms linear infinite;
}
#sky .bird .wind:nth-child(4) {
  transform: translate3d(-194px, -30px, 15px) rotateY(90deg);
}
#sky .bird .wind:nth-child(4)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1706ms 1499ms linear infinite;
  animation: wind 1706ms 1499ms linear infinite;
}
#sky .bird .wind:nth-child(5) {
  transform: translate3d(56px, -32px, -45px) rotateY(90deg);
}
#sky .bird .wind:nth-child(5)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1123ms 2447ms linear infinite;
  animation: wind 1123ms 2447ms linear infinite;
}
#sky .bird .wind:nth-child(6) {
  transform: translate3d(103px, 63px, -49px) rotateY(90deg);
}
#sky .bird .wind:nth-child(6)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1981ms 3831ms linear infinite;
  animation: wind 1981ms 3831ms linear infinite;
}
#sky .bird .wind:nth-child(7) {
  transform: translate3d(-81px, -33px, -37px) rotateY(90deg);
}
#sky .bird .wind:nth-child(7)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2506ms 2422ms linear infinite;
  animation: wind 2506ms 2422ms linear infinite;
}
#sky .bird .wind:nth-child(8) {
  transform: translate3d(19px, -59px, -86px) rotateY(90deg);
}
#sky .bird .wind:nth-child(8)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2379ms 4537ms linear infinite;
  animation: wind 2379ms 4537ms linear infinite;
}
#sky .bird .wind:nth-child(9) {
  transform: translate3d(-148px, 86px, -95px) rotateY(90deg);
}
#sky .bird .wind:nth-child(9)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2255ms 2079ms linear infinite;
  animation: wind 2255ms 2079ms linear infinite;
}
#sky .bird .wind:nth-child(10) {
  transform: translate3d(133px, 39px, -62px) rotateY(90deg);
}
#sky .bird .wind:nth-child(10)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2616ms 1437ms linear infinite;
  animation: wind 2616ms 1437ms linear infinite;
}
#sky .bird .wind:nth-child(11) {
  transform: translate3d(-74px, 51px, -9px) rotateY(90deg);
}
#sky .bird .wind:nth-child(11)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgb(0, 188, 238, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1086ms 4524ms linear infinite;
  animation: wind 1086ms 4524ms linear infinite;
}
#sky .bird_body {
  position: relative;
  width: 30px;
  height: 40px;
  background: rgb(0, 188, 238);
}
#sky .bird_head {
  position: absolute;
  top: -30px;
  border-right: 15px solid transparent;
  border-bottom: 30px solid rgb(0, 188, 238);
  border-left: 15px solid transparent;
  transform-origin: 50% 100%;
  transform: rotateX(-20deg);
}
#sky .bird_wing_left {
  position: absolute;
  left: -30px;
  height: 30px;
  border-right: 30px solid rgb(0, 188, 238);
  border-bottom: 10px solid transparent;
  transform-origin: 100% 0;
  -webkit-animation: wingLeft 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
  animation: wingLeft 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
}
#sky .bird_wing_left_top {
  position: absolute;
  left: -30px;
  border-right: 30px solid rgb(0, 188, 238);
  border-bottom: 30px solid transparent;
  transform-origin: 100% 0;
  -webkit-animation: wingLeft 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
  animation: wingLeft 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
}
#sky .bird_wing_right {
  position: absolute;
  left: 30px;
  height: 30px;
  border-left: 30px solid rgb(0, 188, 238);
  border-bottom: 10px solid transparent;
  transform-origin: 0 0;
  -webkit-animation: wingRight 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
  animation: wingRight 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
}
#sky .bird_wing_right_top {
  position: absolute;
  border-left: 30px solid rgb(0, 188, 238);
  border-bottom: 30px solid transparent;
  transform-origin: 0 0;
  -webkit-animation: wingRight 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
  animation: wingRight 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
}
#sky .bird_tail_left {
  position: absolute;
  top: 40px;
  border-right: 30px solid transparent;
  border-top: 40px solid rgb(0, 188, 238);
  transform-origin: 50% 0;
  transform: rotateX(-20deg);
}
#sky .bird_tail_right {
  position: absolute;
  top: 40px;
  border-left: 30px solid transparent;
  border-top: 40px solid rgb(0, 188, 238);
  transform-origin: 50% 0;
  transform: rotateX(-20deg);
}

@-webkit-keyframes fly {
  0% {
    transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
  }
  100% {
    transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
  }
}

@keyframes fly {
  0% {
    transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
  }
  100% {
    transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
  }
}
@-webkit-keyframes wingLeft {
  0% {
    transform: rotateY(-40deg);
  }
  100% {
    transform: rotateY(40deg);
  }
}
@keyframes wingLeft {
  0% {
    transform: rotateY(-40deg);
  }
  100% {
    transform: rotateY(40deg);
  }
}
@-webkit-keyframes wingRight {
  0% {
    transform: rotateY(40deg);
  }
  100% {
    transform: rotateY(-40deg);
  }
}
@keyframes wingRight {
  0% {
    transform: rotateY(40deg);
  }
  100% {
    transform: rotateY(-40deg);
  }
}
@-webkit-keyframes wind {
  0% {
    transform: translateY(-300px);
  }
  100% {
    transform: translateY(200px);
  }
}
@keyframes wind {
  0% {
    transform: translateY(-300px);
  }
  100% {
    transform: translateY(200px);
  }
}