JSFiddle - React, Tailwind, and code Playground

HTML

<div class="line"></div>

CSS

.line {
    background: linear-gradient(to right, transparent, rgba(30,87,153,0.4) 20%, rgba(41,137,216,1) 50%, rgba(30,87,153,0.4) 80%, transparent);
    height: 2px;
}