JSFiddle - React, Tailwind, and code Playground

HTML

<form action="/login" method="post">
    <label for="username">Username:</label>
    <input type="text" name="username" id="username"><br />
    <label for="password">Password:</label>
    <input type="password" name="password" id="password"><br />
    <input type="submit" value="Log in">
</form>

CSS

form {
    background:#ccc;
    display: table;
    margin: 0 auto;
}