<script>
          
    $('.t405__showmore').append('<div class="flash lighting" style="height: 60px;width: 40px;top: 0px;left: -140px;"></div>');
</script>

<style>

    .t405__showmore{
        position: relative;
        overflow: hidden;
    }

    .flash{
       content: "";
    background-color: rgba(255, 255, 255, 0.5);
    height: 100%;
    width: 3em;
    display: block;
    position: absolute;
    top: 0;
    left: -4.5em;
    -webkit-transform: skewX(-45deg) translateX(0);
    transform: skewX(-45deg) translateX(0);
    -webkit-transition: none;
    transition: none;
    }
    
    .lighting {
    webkit-animation: moving 2s ease-in-out infinite;
    -moz-animation: moving 2s ease-in-out infinite;
    -ms-animation: moving 2s ease-in-out infinite;
    -o-animation: moving 2s ease-in-out infinite;
    animation: moving 2s ease-in-out infinite;
   
    }
    
  @keyframes moving {  
     30% {  webkit-transform: skewX(-45deg) translateX(13.5em);
        transform: skewX(-45deg) translateX(22.5em);   
        
        }
   
    100% {  webkit-transform: skewX(-45deg) translateX(13.5em);
        transform: skewX(-45deg) translateX(22.5em);   
        
        }
     }
      
</style>
Made on
Tilda