body {
  font-family: 'Source Sans Pro',Helvetica Neue,Helvetica,Arial,sans-serif; 
  font-size: 16px;
  line-height: 1.75;
}

#timeline {
  display: flex;
  background-color: #FFF;

  &:hover {
    .tl-item {
      width: 23.3333%;
    }
  }
}

.tl-itemN {
  transform: translate3d(0, 0, 0);
  position: relative;
  width: 25%;
  height: 300px;
  min-height: 300px;
  color: #fff;
  overflow: hidden;
  transition: width 0.5s ease;
  
  &:before, &:after {
    transform: translate3d(0, 0, 0);
    content: '';
    position: absolute;
    left: 0; top: 0;
    width: 100%; height: 100%;
  }

  &:after {
    background: transparentize(#031625, 0.45);
    opacity: 1;
    transition: opacity 0.5s ease;
  }

  &:before {
    background: linear-gradient(to bottom, rgba(0,0,0,0) 0%,rgba(0,191,255,1) 75%);
    z-index: 1;
    opacity: 0;
    transform: translate3d(0, 0, 0) translateY(50%);
    transition: opacity 0.5s ease, transform 0.5s ease;
  }

  
  
  &:hover {
    width: 30% !important;
    
    &:after {
      opacity: 0;
    }

    &:before {
      opacity: 1;
      transform: translate3d(0, 0, 0) translateY(0);
      transition: opacity 1s ease, transform 1s ease 0.25s;
    }
    
    .tl-content {
      opacity: 1;
      transform: translateY(0);
      transition: all 0.75s ease 0.5s;
    }

    .tl-bg {
      filter: grayscale(0);
    }
  }
}

.tl-item {
  transform: translate3d(0, 0, 0);
  position: relative;
  width: 25%;
  height: 300px;
  min-height: 300px;
  color: #fff;
  overflow: hidden;
  transition: width 0.5s ease;
  
  &:before, &:after {
    transform: translate3d(0, 0, 0);
    content: '';
    position: absolute;
    left: 0; top: 0;
    width: 100%; height: 100%;
  }

  &:after {
    background: transparentize(#031625, 0.45);
    opacity: 1;
    transition: opacity 0.5s ease;
  }

  &:before {
    background: linear-gradient(to bottom, rgba(0,0,0,0) 0%,rgba(190,81,3,1) 75%);
    z-index: 1;
    opacity: 0;
    transform: translate3d(0, 0, 0) translateY(50%);
    transition: opacity 0.5s ease, transform 0.5s ease;
  }

  
  
  &:hover {
    width: 30% !important;
    
    &:after {
      opacity: 0;
    }

    &:before {
      opacity: 1;
      transform: translate3d(0, 0, 0) translateY(0);
      transition: opacity 1s ease, transform 1s ease 0.25s;
    }
    
    .tl-content {
      opacity: 1;
      transform: translateY(0);
      transition: all 0.75s ease 0.5s;
    }

    .tl-bg {
      filter: grayscale(0);
    }
  }
}



.tl-content {
  transform: translate3d(0, 0, 0) translateY(25px);
  position: relative;
  z-index: 1;
  text-align: center;
  margin: 0 1.618em;
  top: 65%;
  opacity: 0;
  
  h1 {
    font-family: 'Pathway Gothic One',Helvetica Neue,Helvetica,Arial,sans-serif;
    text-transform: uppercase;
    color: #fff;
    font-size: 1.44rem;
    font-weight: normal;
  }
}

.tl-year {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translateX(-50%) translateY(-50%);
  z-index: 1;
  border-top: 1px solid #fff;
  border-bottom: 1px solid #fff;
  
  p {
    font-family: 'Pathway Gothic One',Helvetica Neue,Helvetica,Arial,sans-serif;
    font-size: 1.728rem;
    line-height: 0;
    color: #fff;
  }
}

.tl-bg {
  transform: translate3d(0, 0, 0);
  position: absolute;
  width: 100%; height: 100%;
  top: 0; left: 0;
  background-size: cover;
  background-position: center center;
  transition: filter 0.5s ease;
  filter: grayscale(20%);
}