Bottom Border Gradient

HTML

<div>Content</div>

CSS

div {
  /* gradient shining border */
  border-top:0;
border-left:0;
border-right:0;
  border-bottom-style: solid;
  border-bottom-width: 10px;
  border-image: linear-gradient(to left, rgba(0, 0, 0, 0) 1%, rgba(2,49, 79, 7) 50%, rgba(0, 0, 0, 0) 100%) 
                10% 0 10% 0/1px 0 1px 0 stretch;
  border-image-width: 0 0 10px 0;
  border-image-repeat: stretch;
  
  /* other demo stuff */
  height: 50px;
  line-height: 50px;
  background-color: #fff;
  color: white;
  text-align: center;  
}