JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div id="handler">
        <div id="content">I want to 100% height of browser</div>
        <div id="content2">I want 10% of height browser</div>
    </div>
</body>

CSS

html, body {
                margin: 0;
                padding:0;
            }
            div#handler {
                width: 100%;
                height: 110%;
                display:block;
            }
            div#content {
                width: 100%;
                height:100%;
                background: red;
            }
            div#content2 {
                width: 100%;
                height: 10%;
                background: blue;
            }