JSFiddle - React, Tailwind, and code Playground

HTML

<div id="pagewrap">
    <header id="header">
      <hgroup>
        <h1 id="site-logo">Demo</h1>
        <h2 id="site-description">Site Description</h2>
      </hgroup>
      <nav id="main-nav">
        <a href="#" class="main-nav-li">Home</a>
        <a href="#" class="main-nav-li">About</a>
        <a href="#" class="main-nav-li">Blog</a>
        <a href="#" class="main-nav-li">Contacts</a>
      </nav>
    </header>
    <div id="content">
      <article class="post">
        <h2>Can User Experience Be Beautiful?<br>An Analysis Of Navigation In<br>Portfolio Websites</h2>
        <p>This is a different take on Responsive Web design. elephant in the room; that is, how we can rely on media queries and <a href="#">breakpoints</a> without any concern for devices.</p>
        <p>Let’s start our journey by looking at the online tools such as Responsive Design Testing, Responsive.is, Responsinator and BriCSS. This article discusses how we can better.</p>
      </article>
      <aside>
        <iframe id="video" src="http://player.vimeo.com/video/50856814?title=0&amp;byline=0&amp;portrait=1&amp;color=ffffff" frameborder="0" webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe>
      </aside>
    </div>
    <footer id="footer">
      footer
    </footer>
  </div>

CSS

/* Reset default styles */

html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed,
figure, figcaption, footer, header, hgroup,
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
  margin: 0;
  padding: 0;
  border: 0;
  font-size: 100%;
  font: inherit;
  vertical-align: baseline;
}
/* HTML5 display-role reset for older browsers */
article, aside, details, figcaption, figure,
footer, header, hgroup, menu, nav, section {
  display: block;
}
body {
  line-height: 1;
}
ol, ul {
  list-style: none;
}
blockquote, q {
  quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
  content: '';
  content: none;
}
table {
  border-collapse: collapse;
  border-spacing: 0;
}
a {
outline: none;
}

/* User styles */

.clear {
  clear: both;
}

body {
  font-family: arial, sans-serif;
  line-height: 110%;
}

h2, a {
  color: #5a9e61;
}

#pagewrap {
  width: 980px;
  margin: 0 auto;
}

#header {
  overflow: hidden;
  width: 100%;
}

#header hgroup {
  float: left;
  margin: 10px 0;
}

#site-logo {
  font-size: 24px;
}

#site-description {
  font-size: 16px;
}

#main-nav {
clear: both;
margin: 0 auto;
}

.main-nav-li {
  float: left;
  margin: 20px 10px;
}

#content {
  width: 100%;
  overflow: auto;
}

.post {
  width: 370px;
  float: left;
}

.post p {
  margin: 15px 0;
}

aside {
  float: right;
  width: 460px;
}

#video {
  width: 460px;
  height: 280px;
}

#footer {
  height: 40px;
  clear: both;
}