Probleme CSS ne s'applique pas

<!DOCTYPE html>
<html>
<head>
 <link rel="stylesheet" type="text/css" href="style.css">
 <title>
  Find Ur Own Way
 </title>
</head>
<body>

 <p>bonjour</p>


<header>
 <div class="wrap">
  <h1>FUOW <span class="orange">.</span></h1>
  <h5>Find Ur Own Way</h5>
  <nav>
  <ul>
   <li>
    <a href="Projet.html">Notre Projet</a>
   
   </li>

   <li>
    <a href="Voie.html">Trouve ta voie</a>
    
   </li>

   <li>
    <a href="Metier.html">Les metiers</a>
   
   </li>

   <li>
    <a href="Contact.html">Contact</a>
  
   </li>
  </ul>

  </nav>
 </div>
</header>

  <section id="image-principal">
   <div class="wrap">
  
 </div>
  </section>


  <section id="steps">
   <div class="wrap">
  
 </div>
  </section>


  <section id="possibilité">
   <div class="wrap">
  
 </div>
  </section>


  <section id="contact">
   <div class="wrap">
  
 </div>
  </section>




<footer>
</footer>

</body>
</html>