JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8"/>
		<link rel="stylesheet" href="css/site2_contact.css"/>
		<link rel="stylesheet" href="http://fonts.googleapis.com/css?family=Lobster" />
		<title>Mook mookeen</title>
	</head>
	
	<body>
		<header>
			<h1>Mook<span id="decalage">mookeen</span></h1>
		</header>
		
		<nav>
			<ul>
				<li><a href="#">l'entreprise</a></li>
				<li><a href="#">nos activités</a></li>
				<li><a href="#">blog</a></li>
				<li><a href="#">tutoriaux</a></li>
				<li><a href="#">contact</a></li>
				<li><form method="post" action="traitement.php">
				<p><input type="text" name="recherche" placeholder="recherche"/>
				<input type="submit" value="Go"/></p></li>
				</form>
			</ul>
		</nav>
		
		<section>
			<section id="grande_section">
					<h2>Nous contacter</h2>
					<form method="post" action="#">
						<label for="nom">Votre nom</label>
						<input type="text" name="nom" id="nom" />
						
						<label for="nom">Votre email</label>
						<input type="email" name="email" id="email" />
						
						<label for="nom">Votre message</label>
						<textarea rows="5"></textarea>

						<input type="submit" value="Envoyer" />
					</form>
			</section>
		</section>

CSS

@font-face {
    font-family: 'capture_itregular';
    src: url('../fonts/captureit_regular_macroman/Capture_it-webfont.eot');
    src: url('../fonts/captureit_regular_macroman/Capture_it-webfont.eot?#iefix') format('embedded-opentype'),
         url('../fonts/captureit_regular_macroman/Capture_it-webfont.woff') format('woff'),
         url('../fonts/captureit_regular_macroman/Capture_it-webfont.ttf') format('truetype'),
         url('../fonts/captureit_regular_macroman/Capture_it-webfont.svg#capture_itregular') format('svg');
    font-weight: normal;
    font-style: normal;
}

/*body*/

body
{
	background: url('../images/bg_head.jpg') top center repeat-x, url('../images/bg_tile.jpg');
}

body
{
	margin: 0px;
	padding: 0px;
}

/*input*/

input
{
	margin: 0px;
	padding: 0px;
}

/*header*/

header h1
{
	width: 550px;
	font-family: 'capture_itregular';
	margin-left: 145px;
	margin-top: 80px;
	padding: 0px 25px 5px 10px;
	color: white;
	font-weight: normal;
	font-style: italic;
	font-size: 3.3em;
	text-shadow: 5px 3px 5px grey;
}

#decalage
{
	position: relative;
	top: 20px;
	left: 10px;
}

/*navigation*/

nav
{
	box-shadow: 0px 0px 10px grey;
	margin-top: 105px;
	background-color: #222222;
}

nav ul
{
	list-style-type: none;
	padding-left: 150px;
}

nav li
{
	display: inline-block;
	margin-right: 20px;
}

nav a
{
	font-size: 1em;
	color: white;
	text-transform: uppercase;
	padding: 18px 8px 19px 8px;
	text-decoration: none;
}

nav p
{
	position: relative;
	left: 160px;
}

nav a:hover
{
	background-color: rgba(0,0,0,0.8);
}

input[type="text"]
{
	border-radius: 5px;
	width: 200px;
	height: 20px;
}

input[placeholder="recherche"]
{
	font-weight: bold;
	padding-left: 8px;
}

input[type="submit"]
{
	background-color: #222222;
	color: white;
	box-shadow: 0px 0px 7px grey;
	border-radius: 5px;
	font-weight: bold;
	padding-left: 10px;
	padding-right: 10px;
	padding-top: 2px;
	padding-bottom: 2px;
	margin-left: 3px;
}

/*corps*/

section
{
	background-color:...