body {
    min-width: 1000px;
    background-attachment: fixed;
    background-image:url('background-repeat.jpg')
}



*{
    margin: 0px;
    padding: 0px;
    font-family: Avenir, sans-serif;
}

nav {
    width: 100%;
    margin: 0 auto;
    background-color: yellow;
    position: sticky;
    top: 0px;
}

nav ul{
    list-style-type: none;
}

nav ul li{
    float: left;
    width: 25%;
    text-align: center;
    position: relative;
}

nav ul::after{
    content: "";
    display: table;
    clear: both;
}

nav a{
    display: block;
    text-decoration: none;
    color: black;
    border-bottom: 2px solid transparent;
    padding: 10px 0px;
}

nav a:hover{
    color: violet;
    border-bottom: 2px solid violet;
}

.sous{
    display: none;
    box-shadow: 0px 1px 2px #CCC;
    background-color: yellow;
    position: absolute;
    width: 100%;
    z-index: 1000;
}
nav > ul li:hover .sous{
    display: block;
}
.sous li{
    float: none;
    width: 100%;
    text-align: left;
}
.sous a{
    padding: 10px;
    border-bottom: none;
}
.sous a:hover{
    border-bottom: none;
    background-color: RGBa(200,200,200,0.1);
}
.deroulant > a::after{
    content:" ▼";
    font-size: 12px;
}





.bloc {
  width: 600px;
  padding: 50px;
  border: 5px solid #9932CC;
  background-color: black;
  margin: auto;
  color : white;
  border-radius: 25px;

}


h1, h2 {
	text-align: center;
	color :#9932CC;
	background-color: yellow;
	padding 15px;
	border-radius: 15px;
	outline-style: double;
}

p {
  text-indent: 1.5em;
  margin-bottom: 0;
  text-align: justify; 
}