JSFiddle - React, Tailwind, and code Playground

HTML

<div class="banner" id="bannera"></div>

<div class="l-content" style="height: 700px;"> </div>

CSS

html, body{ 
width: 100%;
height: 100%;
margin:0px; }

body{
      background: rgba(0, 0, 0, 0) url('http://wallpoper.com/images/00/31/33/51/black-background_00313351.jpg') 0 0 no-repeat fixed;

}

.banner {
  text-align: center;
  background-size: cover;
  height: 350px;
  width: 100%;
  margin-bottom: 3em;
  display: table;
  height: 100%;
}