JSFiddle - React, Tailwind, and code Playground

HTML

<div class="firstnav">
    <div id="second">
        <p>second
            <p>
    </div>
    <div id="third">
        <div id="registration-form">
            <div class='fieldset'>
                <legend>Todays news</legend>
                <form action="#" method="post" data-validate="parsley"></form>
            </div>
        </div>
    </div>

CSS

* {
    margin: 0;
    padding: 0;
}
body {
    width: 100%;
    font-family:'Cabin', sans-serif;
    background-color: #333;
}
.firstnav {
    margin:auto;
    background: #0f0;
    height: 1500px;
    display: block;
    width: 70%;
    -webkit-flex: 3 1 60%;
    flex: 3 1 60%;
    -webkit-order: 2;
    order: 2;
}
#third {
    background: #f00;
    position:relative;
    display:inline-block;
    width: 30%;
    margin-left:auto;
    margin-right:auto;
    height: 500px;
    -webkit-flex: 1 6 20%;
    flex: 1 6 20%;
    -webkit-order: 3;
    order: 3;
}
#second {
    background: #fff;
    position:relative;
    display:inline-block;
    margin-left:auto;
    margin-right:auto;
    float: left;
    width: 67%;
    height: 1500px;
    -webkit-flex: 1 6 20%;
    flex: 1 6 20%;
    -webkit-order: 3;
    order: 3;
}
#registration-form {
    font-family:'Open Sans Condensed', sans-serif;
    width: 100%;
    margin: 20px auto;
    position: relative;
    display:block;
    position:absolute;
}
#registration-form .fieldset {
    background-color:#d5d5d5;
    border-radius: 3px;
}
#registration-form legend {
    text-align: center;
    background: #364351;
    width: 100%;
    padding: 30px 0;
    border-radius: 3px 3px 0 0;
    color: white;
    font-size:2em;
}
.fieldset form {
    border:1px solid #2f2f2f;
    margin:0 auto;
    display:block;
    width:100%;
    padding:30px 20px;
    box-sizing:border-box;
    border-radius:0 0 3px 3px;
}