.bird {
  background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/174479/bird-cells-new.svg);
  background-size: auto 100%;
  color:#36e3d9;
  width: 88px;
  height: 125px;
  will-change: background-position;
  -webkit-animation-name: fly-cycle;
          animation-name: fly-cycle;
  -webkit-animation-timing-function: steps(10);
          animation-timing-function: steps(10);
  -webkit-animation-iteration-count: infinite;
          animation-iteration-count: infinite;
}
.bird--one {
  -webkit-animation-duration: 1s;
          animation-duration: 1s;
  -webkit-animation-delay: -0.5s;
          animation-delay: -0.5s;
}
.bird--two {
  -webkit-animation-duration: 0.9s;
          animation-duration: 0.9s;
  -webkit-animation-delay: -0.75s;
          animation-delay: -0.75s;
}
.bird--three {
  -webkit-animation-duration: 1.25s;
          animation-duration: 1.25s;
  -webkit-animation-delay: -0.25s;
          animation-delay: -0.25s;
}
.bird--four {
  -webkit-animation-duration: 1.1s;
          animation-duration: 1.1s;
  -webkit-animation-delay: -0.5s;
          animation-delay: -0.5s;
}

.bird-container {
  position: absolute;
  top: 20%;
  left: -10%;
  -webkit-transform: scale(0) translateX(-10vw);
          transform: scale(0) translateX(-10vw);
  will-change: transform;
  -webkit-animation-name: fly-right-one;
          animation-name: fly-right-one;
  -webkit-animation-timing-function: linear;
          animation-timing-function: linear;
  -webkit-animation-iteration-count: infinite;
          animation-iteration-count: infinite;
}
.bird-container--one {
  -webkit-animation-duration: 15s;
          animation-duration: 15s;
  -webkit-animation-delay: 0;
          animation-delay: 0;
}
.bird-container--two {
  -webkit-animation-duration: 16s;
          animation-duration: 16s;
  -webkit-animation-delay: 1s;
          animation-delay: 1s;
}
.bird-container--three {
  -webkit-animation-duration: 14.6s;
          animation-duration: 14.6s;
  -webkit-animation-delay: 9.5s;
          animation-delay: 9.5s;
}
.bird-container--four {
  -webkit-animation-duration: 16s;
          animation-duration: 16s;
  -webkit-animation-delay: 10.25s;
          animation-delay: 10.25s;
}

@-webkit-keyframes fly-cycle {
  100% {
    background-position: -900px 0;
  }
}

@keyframes fly-cycle {
  100% {
    background-position: -900px 0;
  }
}
@-webkit-keyframes fly-right-one {
  0% {
    -webkit-transform: scale(0.3) translateX(-10vw);
            transform: scale(0.3) translateX(-10vw);
  }
  10% {
    -webkit-transform: translateY(2vh) translateX(10vw) scale(0.4);
            transform: translateY(2vh) translateX(10vw) scale(0.4);
  }
  20% {
    -webkit-transform: translateY(0vh) translateX(30vw) scale(0.5);
            transform: translateY(0vh) translateX(30vw) scale(0.5);
  }
  30% {
    -webkit-transform: translateY(4vh) translateX(50vw) scale(0.6);
            transform: translateY(4vh) translateX(50vw) scale(0.6);
  }
  40% {
    -webkit-transform: translateY(2vh) translateX(70vw) scale(0.6);
            transform: translateY(2vh) translateX(70vw) scale(0.6);
  }
  50% {
    -webkit-transform: translateY(0vh) translateX(90vw) scale(0.6);
            transform: translateY(0vh) translateX(90vw) scale(0.6);
  }
  60% {
    -webkit-transform: translateY(0vh) translateX(110vw) scale(0.6);
            transform: translateY(0vh) translateX(110vw) scale(0.6);
  }
  100% {
    -webkit-transform: translateY(0vh) translateX(110vw) scale(0.6);
            transform: translateY(0vh) translateX(110vw) scale(0.6);
  }
}
@keyframes fly-right-one {
  0% {
    -webkit-transform: scale(0.3) translateX(-10vw);
            transform: scale(0.3) translateX(-10vw);
  }
  10% {
    -webkit-transform: translateY(2vh) translateX(10vw) scale(0.4);
            transform: translateY(2vh) translateX(10vw) scale(0.4);
  }
  20% {
    -webkit-transform: translateY(0vh) translateX(30vw) scale(0.5);
            transform: translateY(0vh) translateX(30vw) scale(0.5);
  }
  30% {
    -webkit-transform: translateY(4vh) translateX(50vw) scale(0.6);
            transform: translateY(4vh) translateX(50vw) scale(0.6);
  }
  40% {
    -webkit-transform: translateY(2vh) translateX(70vw) scale(0.6);
            transform: translateY(2vh) translateX(70vw) scale(0.6);
  }
  50% {
    -webkit-transform: translateY(0vh) translateX(90vw) scale(0.6);
            transform: translateY(0vh) translateX(90vw) scale(0.6);
  }
  60% {
    -webkit-transform: translateY(0vh) translateX(110vw) scale(0.6);
            transform: translateY(0vh) translateX(110vw) scale(0.6);
  }
  100% {
    -webkit-transform: translateY(0vh) translateX(110vw) scale(0.6);
            transform: translateY(0vh) translateX(110vw) scale(0.6);
  }
}
@-webkit-keyframes fly-right-two {
  0% {
    -webkit-transform: translateY(-2vh) translateX(-10vw) scale(0.5);
            transform: translateY(-2vh) translateX(-10vw) scale(0.5);
  }
  10% {
    -webkit-transform: translateY(0vh) translateX(10vw) scale(0.4);
            transform: translateY(0vh) translateX(10vw) scale(0.4);
  }
  20% {
    -webkit-transform: translateY(-4vh) translateX(30vw) scale(0.6);
            transform: translateY(-4vh) translateX(30vw) scale(0.6);
  }
  30% {
    -webkit-transform: translateY(1vh) translateX(50vw) scale(0.45);
            transform: translateY(1vh) translateX(50vw) scale(0.45);
  }
  40% {
    -webkit-transform: translateY(-2.5vh) translateX(70vw) scale(0.5);
            transform: translateY(-2.5vh) translateX(70vw) scale(0.5);
  }
  50% {
    -webkit-transform: translateY(0vh) translateX(90vw) scale(0.45);
            transform: translateY(0vh) translateX(90vw) scale(0.45);
  }
  51% {
    -webkit-transform: translateY(0vh) translateX(110vw) scale(0.45);
            transform: translateY(0vh) translateX(110vw) scale(0.45);
  }
  100% {
    -webkit-transform: translateY(0vh) translateX(110vw) scale(0.45);
            transform: translateY(0vh) translateX(110vw) scale(0.45);
  }
}
@keyframes fly-right-two {
  0% {
    -webkit-transform: translateY(-2vh) translateX(-10vw) scale(0.5);
            transform: translateY(-2vh) translateX(-10vw) scale(0.5);
  }
  10% {
    -webkit-transform: translateY(0vh) translateX(10vw) scale(0.4);
            transform: translateY(0vh) translateX(10vw) scale(0.4);
  }
  20% {
    -webkit-transform: translateY(-4vh) translateX(30vw) scale(0.6);
            transform: translateY(-4vh) translateX(30vw) scale(0.6);
  }
  30% {
    -webkit-transform: translateY(1vh) translateX(50vw) scale(0.45);
            transform: translateY(1vh) translateX(50vw) scale(0.45);
  }
  40% {
    -webkit-transform: translateY(-2.5vh) translateX(70vw) scale(0.5);
            transform: translateY(-2.5vh) translateX(70vw) scale(0.5);
  }
  50% {
    -webkit-transform: translateY(0vh) translateX(90vw) scale(0.45);
            transform: translateY(0vh) translateX(90vw) scale(0.45);
  }
  51% {
    -webkit-transform: translateY(0vh) translateX(110vw) scale(0.45);
            transform: translateY(0vh) translateX(110vw) scale(0.45);
  }
  100% {
    -webkit-transform: translateY(0vh) translateX(110vw) scale(0.45);
            transform: translateY(0vh) translateX(110vw) scale(0.45);
  }	
}