JSFiddle - React, Tailwind, and code Playground

HTML

<div id="login_box">
<form name="login_page" id="login_page" method="post">
<input type="text" name="username" placeholder="Username" autofocus required="required" /><br />
<input type="password" name="password" placeholder="Password" required="required" /><br />
<div id="login_page_checkbox">
<label class="checkbox">
          <input type="checkbox" name="rememberme" value="1"> Remember me
        </label></div><br />
<input type="submit" name="login_submit" value="Log In" />
</form>
</div>

CSS

html, body {
	width: 100%;
    margin: 0;
    padding:0;
}

#login_page {
	top: 0;
	margin-top: 50px;
	margin-left: 0;
	position: static;
}

#login_box {
	width: 100%;
    position:relative;
}

input[type="text"], input[type="password"] {
	position:absolute;
    left:5px;
    right: 5px
}

#login_page input[type="submit"] {
	width: 97% !important;
	margin: 5px;
}