body {
	background-color: #0500cc;
	font-family: Verdana, sans-serif;
}

.menu {
    background-color: #050080;
    width: 100%;
    font-size: 5px;
    position: absolute;
    margin: none;
    top: 0px;
    right: -5px;
    padding-bottom: 120px;
    left: 0px;
    padding: none;
    text-decoration: none;
}
.menu > .button{
    float:left;
    font-size: 5px;
    top: 5vh;
    position: relative;
}
.menu > .button > a {
    color:white;
    text-decoration: none;
    
    left: 2%;
    font-size: 30px;
    position: relative;
    margin-right: 4vw;
}
.menu > .button > a:hover {
	border-bottom: 3px solid white;
}
.menu > .text-menu{
    float:right;
}
.menu > .text-menu > p {
    color:white;
    font-weight: bold;
    font-size:60px;
    position: relative;
    right: 3vw;
}

h1 {
    position: relative;
    color: white;
    top: 225px;
    left: 70px;
}

#x {
    border-bottom: 3px solid white;
}

p {
    position: fixed;
    top: 330px;
    left: 70px;
    color: white;
    font-size: 40px;
}

#ps {
    position: fixed;
    top: 430px;
    left: 70px;
    color: white;
    font-size: 40px;
}

h1 {
    font-size: 50px;
    position: fixed;
}

#logo{
    position: fixed;
    bottom: 20px;
    right: 20px;
    border-radius: 15px;
    z-index: 5;
}

#phone {
    position: fixed;
    top: 250px;
    left: 50px;
    display: inline;
    z-index: 1;
    border: 5px solid #050080;
    border-radius: 50px;
    width: 500px;
}

#phone2 {
    position: fixed;
    top: 250px;
    left: 600px;
    display: inline;
    z-index: 1;
    border: 5px solid #050080;
    border-radius: 50px;
    width: 500px;
}

#avant {
    position: fixed;
    top: 425px;
    left: 250px;
    z-index: 4;
    color: white;
}

#apres {
    position: fixed;
    top: 425px;
    left: 800px;
    z-index: 4;
    color: white;
}

 #descmontage {
    padding:150px;
    background-color: #050080;
    position: fixed;
    top: 610px;
    width: 400px; 
    left: 50px;
 }

 #montage {
    position: fixed;
    top: 610px;
    left: 100px;
 }
 
  #jeus {
    position: fixed;
    top: 600px;
    left: 100px;
 }

 #imp {
    position: relative;
    top: 250px;
    left: 25px;
    display: inline;
    z-index: 1;
    border: 5px solid #050080;
    border-radius: 50px;
 }

  #impp {
    padding:150px;
    background-color: #050080;
    position: fixed;
    top: 610px;
    padding-bottom: 200px;
    padding-right: 170px;
    width: 400px; 
    left: 50px;
 }

#ch {
	position: fixed;
	top: 300px;
	left: 50px;
	display: inline;
    z-index: 1;
    border: 5px solid #050080;
    border-radius: 50px;
}

#chh {
	position: fixed;
	top: 300px;
	left: 500px;
	display: inline;
    z-index: 1;
    border: 5px solid #050080;
    border-radius: 50px;
}

#chhh {
	position: fixed;
	top: 300px;
	left: 950px;
	display: inline;
    z-index: 1;
    border: 5px solid #050080;
    border-radius: 50px;
}

 #descchateau {
    padding:200px;
    background-color: #050080;
    position: fixed;
    padding-top:120px;		
    top: 610px;
    width: 400px; 
    left: 80px;
 }
 
  iframe {
	position:fixed;
	top:200px;
	left: 900px;
	width:400px;
	height: 400px;
 }
 
/* Style the navigation menu */
.topnav {
  overflow: hidden;
  background-color: blue;
  position: relative;
  top: -717px;
  left: 1200px;
}

/* Hide the links inside the navigation menu (except for logo/home) */
.topnav #myLinks {
  display: none;
}

/* Style navigation menu links */
.topnav a {
  color: white;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
  text-align: center;
  display: block;
}

/* Style the hamburger menu */
.topnav a.icon {
  background: #0500cc;
  display: block;
  text-align: center;
  position: absolute;
  right: 0;
  top: 0;
}

/* Add a grey background color on mouse-over */
.topnav a:hover {
  background-color: #;
  text-align: center;
  color:  gray;
}

/* Style the active link (or home/logo) */
.active {
  background-color:  #0500cc;
  color: white;
}

Step 3) Add JavaScript:
Example
/* Toggle between showing and hiding the navigation menu links when the user clicks on the hamburger menu / bar icon */
function myFunction() {
  var x = document.getElementById("myLinks");
  if (x.style.display === "block") {
    x.style.display = "none";
  } else {
    x.style.display = "block";
  }
}