$foreground: #FFFFFF;
$background: #000000;

$animation-length: 5s;
$animation-delay: $animation-length - 1.7;
$slide-count: 6;

* {
  box-sizing: border-box;
}

body {
  justify-content: center;
  align-items: center;
  background: $background;
  color: $foreground;
  font-family: Sans-Serif;
  margin:0;
  padding:0;
  overflow:hidden;
  animation: colorchange 30s linear alternate infinite;
}

h1 {
  margin:0;
}

.container {
  height:100vh;
  width: 100vw;

  @for $child from 0 to $slide-count - 2 {
    >:nth-child(#{$child+1}) {
      animation-delay: $animation-delay*$child;
      animation-duration: $animation-length;
      animation-name: slide-in-out;
      animation-fill-mode: both;
    }
  }

  >:nth-child(#{$slide-count - 1}) {
    animation-delay: $animation-delay* ($slide-count - 2);
    animation-duration: $animation-length;
    animation-name: slide-in-and-move-up;
    animation-fill-mode: both;
  }

  >:nth-child(#{$slide-count}) {
    animation-delay: $animation-delay* ($slide-count - 1);
    animation-duration: $animation-length;
    animation-name: slide-in;
    animation-fill-mode: both;

    h2 {
      margin-bottom: 120px;
    }
  }

  >:nth-child(#{$slide-count + 1}) {
    animation-delay: $animation-delay* ($slide-count + 1);
    animation-duration: $animation-length;
    animation-name: slide-in-last;
    animation-fill-mode: both;

    h1 {
      margin: 120px;
    }
  }
}

.slide {
  position: absolute;
  height:100vh;
  width: 100vw;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  text-align: center;

  img {
    max-height: 80vh;
  }
}

@keyframes slide-in-out {
  0% {
    transform: translateY(50px);
    opacity: 0;
  }
  30%, 60% {
    transform: translateY(0);
    opacity: 1;
  }

  100% {
    transform: translateY(-50px);
    opacity: 0;
  }
}

@keyframes slide-in-and-move-up {
  0% {
    transform: translateY(50px);
    opacity: 0;
  }
  30%, 60% {
    transform: translateY(0);
    opacity: 1;
  }

  100% {
    transform: translateY(50px);
    opacity: 1;
  }
}

@keyframes slide-in {
  0% {
    transform: translateY(100px);
    opacity: 0;
  }
  30%, 100% {
    transform: translateY(0);
    opacity: 1;
  }
}

@keyframes slide-in-last {
  0% {
    transform: translateY(300px);
    opacity: 0;
  }
  30%, 100% {
    transform: translateY(200px);
    opacity: 1;
  }
}

@keyframes colorchange {
  0%  {background: #01004b;}
  33%  {background: #002b4a;}
  66%  {background: #01004b;}
  100% {background: #30004b;}
}