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(-14px, 69px, -48px) rotateY(90deg);
}
#sky .bird .wind:nth-child(1)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 70, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1956ms 2776ms linear infinite;
          animation: wind 1956ms 2776ms linear infinite;
}
#sky .bird .wind:nth-child(2) {
  transform: translate3d(86px, 123px, -49px) rotateY(90deg);
}
#sky .bird .wind:nth-child(2)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 203, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1819ms 1772ms linear infinite;
          animation: wind 1819ms 1772ms linear infinite;
}
#sky .bird .wind:nth-child(3) {
  transform: translate3d(-17px, -125px, -93px) rotateY(90deg);
}
#sky .bird .wind:nth-child(3)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 240, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1098ms 2213ms linear infinite;
          animation: wind 1098ms 2213ms linear infinite;
}
#sky .bird .wind:nth-child(4) {
  transform: translate3d(92px, 31px, -90px) rotateY(90deg);
}
#sky .bird .wind:nth-child(4)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 43, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2953ms 2433ms linear infinite;
          animation: wind 2953ms 2433ms linear infinite;
}
#sky .bird .wind:nth-child(5) {
  transform: translate3d(-48px, -149px, 94px) rotateY(90deg);
}
#sky .bird .wind:nth-child(5)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 17, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1199ms 1506ms linear infinite;
          animation: wind 1199ms 1506ms linear infinite;
}
#sky .bird .wind:nth-child(6) {
  transform: translate3d(-6px, 137px, -48px) rotateY(90deg);
}
#sky .bird .wind:nth-child(6)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 116, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2225ms 3471ms linear infinite;
          animation: wind 2225ms 3471ms linear infinite;
}
#sky .bird .wind:nth-child(7) {
  transform: translate3d(111px, 136px, -69px) rotateY(90deg);
}
#sky .bird .wind:nth-child(7)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 34, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1862ms 3158ms linear infinite;
          animation: wind 1862ms 3158ms linear infinite;
}
#sky .bird .wind:nth-child(8) {
  transform: translate3d(166px, -73px, -82px) rotateY(90deg);
}
#sky .bird .wind:nth-child(8)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 183, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2956ms 1301ms linear infinite;
          animation: wind 2956ms 1301ms linear infinite;
}
#sky .bird .wind:nth-child(9) {
  transform: translate3d(-55px, -70px, 57px) rotateY(90deg);
}
#sky .bird .wind:nth-child(9)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 67, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1678ms 4470ms linear infinite;
          animation: wind 1678ms 4470ms linear infinite;
}
#sky .bird .wind:nth-child(10) {
  transform: translate3d(-94px, -77px, -14px) rotateY(90deg);
}
#sky .bird .wind:nth-child(10)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 103, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 2123ms 1929ms linear infinite;
          animation: wind 2123ms 1929ms linear infinite;
}
#sky .bird .wind:nth-child(11) {
  transform: translate3d(-88px, -43px, -60px) rotateY(90deg);
}
#sky .bird .wind:nth-child(11)::before {
  content: "";
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 87, 0.3);
  border-radius: 999px;
  transform: translateY(-300px);
  -webkit-animation: wind 1011ms 3255ms linear infinite;
          animation: wind 1011ms 3255ms linear infinite;
}
#sky .bird_body {
  position: relative;
  width: 30px;
  height: 40px;
  background: #c06fd0;
}
#sky .bird_head {
  position: absolute;
  top: -30px;
  border-right: 15px solid transparent;
  border-bottom: 30px solid #719bd7;
  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 #819bc9;
  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 #8297ff;
  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 #a285f6;
  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 #8367f2;
  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 #aba3ce;
  transform-origin: 50% 0;
  transform: rotateX(-20deg);
}
#sky .bird_tail_right {
  position: absolute;
  top: 40px;
  border-left: 30px solid transparent;
  border-top: 40px solid #a591d0;
  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);
  }
}