JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>

    <head>
        <title>Login</title>
        <meta charset="UTF-8">
        <link rel="stylesheet" type="text/css" href="main.css">
        <link href="https://fonts.googleapis.com/css?family=Raleway:100" rel="stylesheet">
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
        <link href="https://fonts.googleapis.com/css?family=Open+Sans:300" rel="stylesheet">
        <link href="https://fonts.googleapis.com/css?family=Roboto+Condensed" rel="stylesheet">
    </head>

    <body>

        <div class="LoginBox" style="">
            <div class="element_wrapper">
                <a class="Login">Login</a>


                <input type="text" name="" class="username" placeholder="Username">
                <input type="password" name="" class="password" placeholder="Password">


                <class>
                    <center>
                        <button class="btn" onclick="myFunction()">Login</button>
                        <a href="https://www.beastfox.com">
                            <input type="submit" value="Create" class="btn2" />
                        </a>




                    </center>
                </class>
            </div>
        </div>

    </body>

</html>

CSS

*{box-sizing:border-box;}
body,
html {
    background: linear-gradient(27deg, #151515 5px, transparent 5px) 0 5px, linear-gradient(207deg, #151515 5px, transparent 5px) 10px 0px, linear-gradient(27deg, #222 5px, transparent 5px) 0px 10px, linear-gradient(207deg, #222 5px, transparent 5px) 10px 5px, linear-gradient(90deg, #1b1b1b 10px, transparent 10px), linear-gradient(#1d1d1d 25%, #1a1a1a 25%, #1a1a1a 50%, transparent 50%, transparent 75%, #242424 75%, #242424);
    background-color: #131313;
    background-size: 20px 20px;
    overflow-x: hidden;
    overflow-y: hidden;
}

.username {
    display: block;
    margin: 0 auto;
    background: #333;
    color: #ccc;
    width: 150px;
    padding: 6px 15px 6px 5px;
    transition: 500ms all ease;
    border: 1px solid #333;
    margin-bottom: 10px;
    text-align: center;
    vertical-align: middle;
}

.username:hover {
    box-shadow: 0px 0px 4px #000;
}

.password {
    padding-top: 3;
    text-align: center;
    display: block;
    margin: 0 auto;
    background: #333;
    color: #ccc;
    width: 150px;
    padding: 6px 15px 6px 5px;
    transition: 500ms all ease;
    border: 1px solid #333;
}

.password:hover {
    box-shadow: 0px 0px 4px #000;
}

.LoginBox {
    top: 50%;
    left: 50%;
    margin: -150px 0 0 -150px;
    position: fixed;
    padding-top: 50 auto;
    width: 300px;
    height: 300px;
    padding: 25px;
    background-color: firebrick;
    z-index: -3;
    box-shadow: 0px 0px 9px #000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.Login {
    display: block;
    width: 100%;
    text-align: center;
    font-size: 30px;
    font-family: 'Roboto Condensed', sans-serif;
    color: #FFF;
    margin-bottom: 1em;
    border-bottom: 2px solid #ccc;
}

.btn {
    margin-top: 3em;
    top 70%;
    width: 70px;
    height: 30px;
    background-color: #333;
    border: none;
    color: #ccc;
    cursor: pointer;
    margin-right: 2em;
}

.btn:hover {
    box-shadow: 0px 0px...