JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div class="page-header header" style="color:fff; font-size: large; font-family: Arial;">
        <h1 class="page-header-text">Review Networks</h1>
	</div>

CSS

html, body { 
    margin: 0; 
    padding: 0; 
    border: 0; 
}
				.header{
                    text-align:center;
					background-color: #61B329;
					color: #FFF;
					margin-top: 0px;
					margin-bottom:0 !important;
				}
				.page-header-text {
				color:fff;
				font-size: 36px;
				font-family: Arial;
				}
h1 {
    margin: 0 auto;
    padding-top: 0;
}