/*css source*/
h1 {
  text-align: center;
  color: red;
  text-decoration: underline;
}

body {
  background-size: cover;
  background-repeat: no-repeat;
  background-attachment: fixed;
  color: white;
  font-family: Arial, sans-serif;
  padding: 20px;
}

nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: #15A102;
  z-index: 1000;
  padding: 10px 0;
  opacity: 0.8; 
}

nav ul {
  margin: 0;
  padding: 0;
  display: flex;
  width: 100%;
}

nav li {
  flex: 1;
  text-transform: uppercase;
  text-align: center;
  list-style-type: none;
}

nav a {
  text-decoration: none;
  color: black;
  display: block;
  padding: 10px;
}

nav a:hover {
  background-color: #4EE051;
  color: white;
}

#titre1 {
  position: relative;
  overflow: auto;
  margin: auto;
  margin-top: 150px
}