Mettre une barre de progression dans son parent

 <style type="text/css">



                .progress {
                    height: 20px;
                    position: relative;
                    background-color: #555;
                    border-radius: 25px;
                    padding: 10px;
                     box-shadow: inset 0 -1px 1px rgba(255, 255, 255, 0.3);
  
                }

                .progress > span{
                    display: block;
                    height: 20px;

                    border-top-right-radius: 8px;

                    border-bottom-right-radius: 8px;

                    border-top-left-radius: 20px;

                     border-bottom-left-radius: 20px;

                     background-color: rgb(43,194,83);


                    background-image: linear-gradient(
                   center bottom,
                   rgb(43,194,83) 37%,
                   rgb(84,240,84) 69%
                         );

                    box-shadow: 
                     inset 0 2px 9px  rgba(255,255,255,0.3),
                      inset 0 -2px 6px rgba(0,0,0,0.4);
                 
                     overflow: hidden;
                      position: relative;
                }

                .progress > span::after {
                    content:"";
                    position: absolute;
                    
                    top: 0; left: 0; bottom: 0; right: 0;
                    background-image: linear-gradient(
                   -45deg, 
                    rgba(255, 255, 255, .2) 25%, 
                    transparent 25%, 
                    transparent 50%, 
                   rgba(255, 255, 255, .2) 50%, 
                   rgba(255, 255, 255, .2) 75%, 
                    transparent 75%, 
                    transparent
                    );
                    z-index: 1;
                    background-size: 50px 50px;
                    animation: move 2s linear infinite;
                    border-top-right-radius: 8px;
                    border-bottom-right-radius: 8px;
                    border-top-left-radius: 20px;
                    border-bottom-left-radius: 20px;
                    overflow: hidden;
                   }


                   @keyframes move {
                    0% {
                    background-position: 0 0;
                    }
                    100% {
                     background-position: 50px 50px;
                         }
                   }

                   .progress > span::after, .bar > span > span {
  animation: move 2s linear infinite;
}

<div class="progress bar">
  <span style="width: 80%"><span></span></span>
</div>