JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
    <header>
        <div id="header-top">
            <p>I am fixed at the top</p>
        </div>
        <div id="header-middle">
            <p>I am vertically centered</p>
        </div>
        <div id="header-bottom">
            <p>I am stuck at the bottom but not fixed</p>
        </div>
    </header>
</div>

CSS

* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
    min-height: 100%;
}

#wrapper {
    height: 100%;
    min-height: 100%;
    position: relative;
    background-color: red;
}

header {
    height: 100%;
    min-height: 100vh;
    position: relative;
    background-color: green;
    text-align: center;
}

#header-top {
    position: fixed;
    left: 0;
    right: 0;
    top: 0;
    width: 100%;
    outline: 1px dotted red;
    background-color: blue;
}

#header-middle {
    position: relative;
    top: 50%;
    transform: translateY(-50%);
    background-color: yellow;
    outline: 1px dotted red;
}

#header-bottom {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    width: 100%;
    background-color: grey;
    outline: 1px dotted red;
}