#timeline {
    display: flex;
    background-color: #031625;
  
    &:hover {
      .tl-item {
        width: 23.3333%;
      }
    }
  }
  
  .tl-item {
    transform: translate3d(0, 0, 0);
    position: relative;
    width: 25%;
    height: 100vh;
    min-height: 600px;
    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, 0.15);
      opacity: 1;
      transition: opacity 0.5s ease;
    }
  
    &:before {
      background: linear-gradient(to bottom, rgba(0,0,0,0) 0%,rgba(0,0,0,1) 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: 55%;
    opacity: 0;
    
    h1 {
      text-transform: uppercase;
      font-size: 25px;
      font-weight: 600;
      color: #fff;
    }
  }
  
  .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;
    background-color: rgba(0,0,0,0.6);
    
    p {
        font-size: 30px;
        line-height: 60px;
        margin-bottom: 0;
        font-weight: 600;
        text-align: center;
    }
  }
  
  .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(100%);
  }