JSFiddle - React, Tailwind, and code Playground

by Hashem Qolami

HTML

<div class="timeline-unit"> imeline 1 </div>
<div class="timeline-unit"> Timeline 2 </div>
<div class="timeline-unit"> Timeline 3 </div>

CSS

body {
    background: red;
    
  -webkit-animation: bgcolor 4s linear 0s infinite alternate;
     -moz-animation: bgcolor 4s linear 0s infinite alternate;
       -o-animation: bgcolor 4s linear 0s infinite alternate;
          animation: bgcolor 4s linear 0s infinite alternate;
}

@-webkit-keyframes bgcolor { from { background: red; } to { background: green; }  }
   @-moz-keyframes bgcolor { from { background: red; } to { background: green; }  }
     @-o-keyframes bgcolor { from { background: red; } to { background: green; }  }
        @keyframes bgcolor { from { background: red; } to { background: green; }  }

.timeline-unit:before, .timeline-unit:after {
    top: 0;
    border: solid transparent;
    border-width: 1.65em;
    height: 0;
    width: 0;
    position: absolute;
    pointer-events: none;
}

.timeline-unit:after {
    content: " ";
    left: 100%;
    border-left-color: rgba(51, 51, 51, 0.8);
}

.timeline-unit {
    position: relative;
    display: inline-block;
    background: rgba(51,51,51,.8);
    padding: 1em;
    line-height: 1.25em;
    color: #FFF;
    
    -webkit-filter: drop-shadow(0 0 2px black);
            filter: drop-shadow(0 0 0 2px black);
}

.timeline-unit:before { content: none; }

.timeline-unit + .timeline-unit:before {
    content: " ";
    border-color: rgba(51, 51, 51, 0.8);
    border-left-color: transparent;
    border-right: 0;
    right: 100%;
}

.timeline-unit + .timeline-unit {
    margin-left: 2em;
}