body {
  background: #eef;
  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(147px, -26px, 64px) rotateY(90deg);
}
#sky .bird .wind:nth-child(1)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 18, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1384ms 2377ms linear infinite;
          animation: wind 1384ms 2377ms linear infinite;
}
#sky .bird .wind:nth-child(2) {
  transform: translate3d(-88px, 67px, 11px) rotateY(90deg);
}
#sky .bird .wind:nth-child(2)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 230, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1990ms 1284ms linear infinite;
          animation: wind 1990ms 1284ms linear infinite;
}
#sky .bird .wind:nth-child(3) {
  transform: translate3d(-114px, -54px, -85px) rotateY(90deg);
}
#sky .bird .wind:nth-child(3)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 55, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2159ms 2007ms linear infinite;
          animation: wind 2159ms 2007ms linear infinite;
}
#sky .bird .wind:nth-child(4) {
  transform: translate3d(-169px, 107px, -14px) rotateY(90deg);
}
#sky .bird .wind:nth-child(4)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 134, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1367ms 1825ms linear infinite;
          animation: wind 1367ms 1825ms linear infinite;
}
#sky .bird .wind:nth-child(5) {
  transform: translate3d(126px, -94px, 75px) rotateY(90deg);
}
#sky .bird .wind:nth-child(5)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 120, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2401ms 4116ms linear infinite;
          animation: wind 2401ms 4116ms linear infinite;
}
#sky .bird .wind:nth-child(6) {
  transform: translate3d(195px, -33px, 20px) rotateY(90deg);
}
#sky .bird .wind:nth-child(6)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 50, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1272ms 4492ms linear infinite;
          animation: wind 1272ms 4492ms linear infinite;
}
#sky .bird .wind:nth-child(7) {
  transform: translate3d(131px, 32px, 10px) rotateY(90deg);
}
#sky .bird .wind:nth-child(7)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 131, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2803ms 3607ms linear infinite;
          animation: wind 2803ms 3607ms linear infinite;
}
#sky .bird .wind:nth-child(8) {
  transform: translate3d(-125px, -61px, -42px) rotateY(90deg);
}
#sky .bird .wind:nth-child(8)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 171, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2916ms 3421ms linear infinite;
          animation: wind 2916ms 3421ms linear infinite;
}
#sky .bird .wind:nth-child(9) {
  transform: translate3d(99px, 69px, 87px) rotateY(90deg);
}
#sky .bird .wind:nth-child(9)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 144, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1319ms 1683ms linear infinite;
          animation: wind 1319ms 1683ms linear infinite;
}
#sky .bird .wind:nth-child(10) {
  transform: translate3d(-132px, -76px, -69px) rotateY(90deg);
}
#sky .bird .wind:nth-child(10)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 108, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1308ms 3393ms linear infinite;
          animation: wind 1308ms 3393ms linear infinite;
}
#sky .bird .wind:nth-child(11) {
  transform: translate3d(112px, -74px, 64px) rotateY(90deg);
}
#sky .bird .wind:nth-child(11)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 45, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1791ms 1860ms linear infinite;
          animation: wind 1791ms 1860ms linear infinite;
}
#sky .bird_body {
  position: relative;
  width: 30px;
  height: 40px;
  background: #c391e9;
}
#sky .bird_head {
  position: absolute;
  top: -30px;
  border-right: 15px solid transparent;
  border-bottom: 30px solid #8774da;
  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 #b68cd5;
  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 #9daffd;
  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 #a485df;
  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 #7ebef6;
  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 #ba94de;
  transform-origin: 50% 0;
  transform: rotateX(-20deg);
}
#sky .bird_tail_right {
  position: absolute;
  top: 40px;
  border-left: 30px solid transparent;
  border-top: 40px solid #b591e4;
  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);
  }
}