header.css

header {
  background: url('https://getwallpapers.com/wallpaper/full/4/6/6/1132666-ark-survival-evolved-wallpapers-1920x1080-for-samsung-galaxy.jpg');
  text-align: center;
  width: 100vw;
  height: 100vh;
  background-size: cover;
  position: relative;
  overflow: hidden;
}

header .overlay{
  position: absolute;
  top: 0;
  width: 100%;
  height: 100%;
  color: #FFF;
  text-shadow: 1px 1px 1px #333;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

#titre{
  font-size: 5vw;
  font-weight: bold;
  transition: margin-top 1.5s, margin-bottom 1.5s, 0.5s ease;
}

#titre:hover {
  letter-spacing: 10px;
  transform: scale(1.3);
}

#descSite{
  font-size: 2vw;
  margin-top: -40px;
  font-weight: bold;
}

#seeMore {
  border: none;
  outline: none;
  padding: 10px 20px;
  border-radius: 50px;
  color: #333;
  background: #fff;
  box-shadow: 0 3px 20px 0 #0000003b;
  font-size: large;
  width: 150px;
  height: auto;
  margin-top: -20px;
}
#seeMore:hover{
  cursor: pointer;
  opacity: 0.8;
  transform: scale(1.01);
}
/**SEARCH BAR**/

#searchBar {
  position: fixed;
  top: 30px;
  right: 0;
  z-index: 9999;
  margin-right: 1vw;
}

#searchBar input {
  height: 3vh;
  border-radius: 50px;
  border: none;
  padding: 0 20px;
  font-size: 1em;
  outline: none;
  box-shadow: 0 3px 20px 0 #0000003b;
}

.material-icons {
  position: absolute;
  top: 50%;
  right: 10px;
  transform: translateY(-50%);
}

.material-icons:hover {
  cursor: pointer;
}



/**HAMBURGER MENU*/

#menu-bar {
  width: 45px;
  height: 40px;
  margin: 30px 0 20px 20px;
  cursor: pointer;
  z-index: 1000;
}

.bar {
  height: 5px;
  width: 100%;
  background-color: #ffffff;
  display: block;
  border-radius: 5px;
  transition: 0.3s ease;
  z-index: 1000;
}

#bar1 {
  transform: translateY(-4px);
  z-index: 1000;
}

#bar3 {
  transform: translateY(4px);
  z-index: 1000;
}

.nav {
  transition: 0.3s ease;
  display: none;
  z-index: 1000;
}

.nav ul {
  padding: 0 22px;
  z-index: 1000;
}

.nav li {
  list-style: none;
  padding: 12px 0;
  z-index: 1000;
}

.nav li a {
  color: white;
  font-size: 20px;
  text-decoration: none;
  font-weight: bold;
  text-shadow: 2px 2px 2px rgb(0, 0, 0), -2px -2px 2px rgb(0, 0, 0), 2px -2px 2px rgb(0, 0, 0), -2px 2px 2px rgb(0, 0, 0);
  z-index: 1000;
}

.nav li a:hover {
  display: block;
  font-weight: bold;
  z-index: 1000;
  transform: scale(1.03);
}

#menu {
  z-index: 1000;
  position: fixed;
  top: 0;
  left: 0;
}

.menu-bg {
  width: 0;
  height: 0;
  background: url("https://w0.peakpx.com/wallpaper/178/906/HD-wallpaper-ark-2-game-2021.jpg");
  background-position: left 400%;
  border-radius: 50%;
  transition: 0.3s ease;
  z-index: 999;
  position: fixed;
  top: 0;
  left: 0;
}

.change {
  display: block;
}

.change .bar {
  background-color: white;
}

.change #bar1 {
  transform: translateY(4px) rotateZ(-45deg);
}

.change #bar2 {
  opacity: 0;
}

.change #bar3 {
  transform: translateY(-6px) rotateZ(45deg);
}

.change-bg {
  width: 520px;
  height: 610px;
  transform: translate(-60%,-30%);
}