.birds-container {
  z-index: 1;
  min-height: 15rem;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  top: 30px;
}

.bird {
  background-image: url(../img/parallax/animations/birds.svg);
  background-size: auto 100%;
  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;
  left: -10%;
  transform: scale(0) translateX(-10vw);
  will-change: transform;
  -webkit-animation-name: fly-right;
          animation-name: fly-right;
  -webkit-animation-timing-function: linear;
          animation-timing-function: linear;
  -webkit-animation-iteration-count: infinite;
          animation-iteration-count: infinite;
}
.bird-container--one {
  -webkit-animation-duration: 30s;
          animation-duration: 30s;
  -webkit-animation-delay: 0;
          animation-delay: 0;
}
.bird-container--two {
  -webkit-animation-duration: 32s;
          animation-duration: 32s;
  -webkit-animation-delay: 2s;
          animation-delay: 2s;
}
.bird-container--three {
  -webkit-animation-duration: 29.2s;
          animation-duration: 29.2s;
  -webkit-animation-delay: 19s;
          animation-delay: 19s;
}
.bird-container--four {
  -webkit-animation-duration: 32s;
          animation-duration: 32s;
  -webkit-animation-delay: 20.5s;
          animation-delay: 20.5s;
}

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

@keyframes fly-cycle {
  100% {
    background-position: -900px 0;
  }
}
@-webkit-keyframes fly-right {
  0% {
    transform: scale(0.3) translateX(-10vw);
  }
  10% {
    transform: translateY(2vh) translateX(50vw) scale(0.4);
  }
  20% {
    transform: translateY(0vh) translateX(100vw) scale(0.5);
  }
  30% {
    transform: translateY(4vh) translateX(150vw) scale(0.6);
  }
  40% {
    transform: translateY(2vh) translateX(200vw) scale(0.6);
  }
  50% {
    transform: translateY(0vh) translateX(250vw) scale(0.6);
  }
  60% {
    transform: translateY(0vh) translateX(300vw) scale(0.6);
  }
  70% {
    transform: translateY(0vh) translateX(350vw) scale(0.6);
  }
  80% {
    transform: translateY(0vh) translateX(400vw) scale(0.6);
  }
  90% {
    transform: translateY(0vh) translateX(450vw) scale(0.5);
  }
  100% {
    transform: translateY(0vh) translateX(500vw) scale(0.4);
  }
}
@keyframes fly-right {
  0% {
    transform: scale(0.3) translateX(-10vw);
  }
  10% {
    transform: translateY(2vh) translateX(50vw) scale(0.4);
  }
  20% {
    transform: translateY(0vh) translateX(100vw) scale(0.5);
  }
  30% {
    transform: translateY(4vh) translateX(150vw) scale(0.6);
  }
  40% {
    transform: translateY(2vh) translateX(200vw) scale(0.6);
  }
  50% {
    transform: translateY(0vh) translateX(250vw) scale(0.6);
  }
  60% {
    transform: translateY(0vh) translateX(300vw) scale(0.6);
  }
  70% {
    transform: translateY(0vh) translateX(350vw) scale(0.6);
  }
  80% {
    transform: translateY(0vh) translateX(400vw) scale(0.6);
  }
  90% {
    transform: translateY(0vh) translateX(450vw) scale(0.5);
  }
  100% {
    transform: translateY(0vh) translateX(500vw) scale(0.4);
  }
}