h1 { margin:0px auto 10px auto; text-align:center; color: #76737A;font-family:Century Gothic;}
nav {
  margin: 0px auto;
  width: 100%;
  font-family: 'Century Gothic';
  
}
  
  
  <title>Menu déroulant</title>
    <style>
        /* Style pour la liste */
        ul {
            list-style-type: none;
            padding: 0;
        }

        /* Style pour les éléments de la liste */
        li {
            display: inline-block;
            position: relative;
        }

        /* Style pour les liens */
        li a {
            display: block;
            padding: 10px;
            text-decoration: none;
            background-color: #fff;
            color: #fff;
        }

        /* Style pour les sous-menus */
        li ul {
            display: none; /* Masquer les sous-menus par défaut */
            position: absolute;
            top: 100%;
            left: 0;
            min-width: 200px;
        }

        /* Afficher les sous-menus au survol */
        li:hover ul {
            display: block;
			
        }

        /* Style pour les éléments des sous-menus */
        li ul li {
            display: block;
        }

        /* Style pour les liens des sous-menus */
        li ul li a {
            background-color: #444;
        }

        /* Changer la couleur au survol des liens */
        li a:hover, li ul li a:hover {
            background-color: #ccc;
            
		 }
		
body{
     max-width: 710px;
    min-width: 250px;
	background: #fff;
	text-align: center;
	margin: 0 auto; 
	 height:3200px;
	}

#contener{
    background-color:#fff;
	margin-top:5px;	
    height:3400px;
    box-shadow: 7px 7px 5px rgb(190, 190, 190);
    max-width: 710px;
    min-width: 250px;
	border: 1px #ccc solid;
	margin: 0 auto;
}

#checkbox1,
.toggle {
  display: none;
  
}

 
        .image-row {
           
            justify-content: center;
            flex-wrap: wrap;
        }
        .image-row img {
            width: 20%;
            height: auto;
            margin: 10px;
			
			cursor: pointer;
            transition: transform 0.3s;
        }
		        .image-row img:hover {
            transform: scale(1.1);
        }
        .modal {
            display: none;
            position: fixed;
            z-index: 1;
            left: 0;
            top: 50px;
            width: 100%;
            height: 100%;
            overflow: auto;
             background-color: rgba(0, 0, 0, 0.5); /* Fond semi-transparent */
			
        }
        .modal-content {
            margin: auto;
            display: block;
            width: 80%;
            max-width: 700px;
			
			
        }
        .modal-content img {
            width: 100%;
            height: auto;
			 
        }
        .close {
            position: absolute;
            top: 15px;
            right: 35px;
            color: #fff;
            font-size: 40px;
            font-weight: bold;
            transition: 0.3s;
        }
        .close:hover,
        .close:focus {
            color: #bbb;
            text-decoration: none;
            cursor: pointer;
			
        }
		
	
	
	@media screen and (max-width: 550px) {
   .toggle {
    clear: both;
    display: block;
    text-align: center;
    font-size: 10px;
    line-height: 40px;
    cursor: pointer;
    width: 100%;
    height: 40px;
    font-size: 15px;
    color: #595959;
    background: #dbdbdb;
    border-bottom-left-radius: 5px;
    border-bottom-right-radius: 5px;
    transition: all .1s linear;
	
	
	
  }
   .toggle:hover {
    background: #cecece;
  }
  #checkbox1:checked + label .demo li {
    opacity: 1;
    visibility: visible;
    transition: all .7s linear;
	
  }

  #checkbox1:checked + label .demo {
    height: 200px;
  }
  .menu {
    text-align:center;
    border-radius: 0px;
    border-top-left-radius: 5px;
    border-top-right-radius: 5px;
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    align-items: center;
    height: 0px;
    transition: height .3s linear;
	
  }
  .menu li {
    display: flex;
    /* magic */
    align-self: center;
    width: 95%;
    opacity: 0;
    visibility: hidden;
	max-width: 710px;
    min-width: 250px;
  }
  .menu li a {
    width: 95%;
    text-align: center;
    align-self: center;
    align-content: center;
	max-width: 710px;
    min-width: 250px;
  }
}

.demo {
  background: #transparent;
  max-width: 710px;
  min-width: 250px;
  margin-top:30px;
}

.demo li a {
  color:#ADC795;
}
.demo li a:hover {
   color:#fff;
    

}
.images0{
	align-items: center;
    max-width: 710px;
    min-width: 250px;
	margin-top:50px;
   
    text-align: center; /* Aligne le texte horizontalement */
}
.images01{
	align-items: center;
    max-width: 710px;
    min-width: 250px;
	margin-top:50px;
   
    text-align: center; /* Aligne le texte horizontalement */
}

.images{
	align-items: center;
    max-width: 710px;
    min-width: 250px;
	margin-top:50px;
   
    text-align: center; /* Aligne le texte horizontalement */
}	

.images1{
	align-items: center;
    max-width: 710px;
    min-width: 250px;
	margin-top:50px;
    
	
    text-align: center; /* Aligne le texte horizontalement */
}



.images2{
	align-items: center;
    max-width: 710px;
    min-width: 250px;
	margin-top:50px;
   
    text-align: center; /* Aligne le texte horizontalement */
}

.images3{
	align-items: center;
    max-width: 710px;
    min-width: 250px;
	margin-top:40px;
    
    text-align: center; /* Aligne le texte horizontalement */
}

.images4{
	align-items: center;
    max-width: 710px;
    min-width: 250px;
	margin-top:50px;
    
    text-align: center; /* Aligne le texte horizontalement */
}

.images4 img:hover{
	
	 box-shadow: 0px 0px 150px #000000;
    z-index: 2;
    -webkit-transition: all 200ms ease-in;
    -webkit-transform: scale(1.5);
    -ms-transition: all 200ms ease-in;
    -ms-transform: scale(1.5);   
    -moz-transition: all 200ms ease-in;
    -moz-transform: scale(1.5);
    transition: all 500ms ease-in;
    transform: scale(2.5);
	
}





.images5{
	align-items: center;
    max-width: 710px;
    min-width: 250px;
	margin-top:50px;
    
    text-align: center; /* Aligne le texte horizontalement */
}


.ligne{
  
  width: 100%;
  height: 4px;
  background-color: orange;
  margin-top: 50px;
}	
.ligne2{
  
  width: 100%;
  height: 4px;
  background-color: orange;
  margin-top: 50px;
}	
.top4{
	
   
} 


#scrollToTopg a{ 
     display:block;
     font-family:"Optima";
	 color:#3E4745;
	 font-size:20px;
	 text-decoration:none;
}
 
#scrollToTopd a{
	display:block;
    font-size:25px;
    text-decoration:none;
    margin-top: 50px;
  
  
	
           }		   
#scrollToTopm a{ 
     display:block;
     font-family:"Optima";
	 color:#3E4745;
	 font-size:20px;
	 text-decoration:none;
	 
}