JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <header>
        <div id="site-title"><a href="#">Site Title</a></div>
        <div id="search">
            <form>
                <input type="search" placeholder="Search..." />
            </form>
        </div>
    </header>
</body>

CSS

body {
    font-family: Arial, sans-serif;
}

header {
    overflow: hidden;
    background-color: black;
}

a {
    text-decoration: none;
    color: white;
}

#site-title, #search {
    float: left;
}

#site-title {
    margin-right: 50px;
    background-color: green;
    font-size: 28px;
}

#search {
    background-color: red;
    margin-top: 5px
}