JSFiddle - React, Tailwind, and code Playground

by Luca Detomi

HTML

<div class="progressbar" style="width:75%"></div>

CSS

*,:before,:after {box-sizing:border-box;}

.progressbar {
    height: 15px;
    border-radius: 1em;
    overflow: hidden;
    position:relative;
    transition:width 1s ease-in-out;
}

.progressbar:before,
.progressbar:after {
  content:"";
  display:block;
  height: 100%;
  position:absolute;
  top:0;
  left:0;
}

.progressbar:before {
  width: 100vw;
  background: linear-gradient(to right, red 0%, yellow 50%, green 100%);
  box-shadow:inset 0px -2px 5px rgba(0, 0, 0, 0.5);            
}

.progressbar:not([style]):before,
.progressbar[style='']:before{
   background: lightgray;
}

.progressbar:after {
    z-index:1;
    width: 100%;
    border-radius: 1em;
    animation: progress 1s linear infinite;
    background-repeat: repeat-x;
    background-size: 30px 30px;
    background-image: linear-gradient(-45deg, 
                                      rgba(255, 255, 255, 0.15) 25%, 
                                      transparent 25%, 
                                      transparent 50%, 
                                      rgba(255, 255, 255, 0.15) 50%, 
                                      rgba(255, 255, 255, 0.15) 75%, 
                                      transparent 75%, transparent);
}

@keyframes progress
{
  to {background-position: 30px 0;}
}