.topnav {
  			overflow: hidden;
  			background-color: white;
		}
		.topnav a {
  			float: left;
  			display: block;
  			color: #7F7F7F;
  			text-align: center;
  			padding: 14px 16px;
  			text-decoration: none;
  			font-size: 17px;
		}
		.active {
  			background-color: #FFFFFF;	/* Boton de Inicio*/
  			color: #BFBFBF;
		}
		.topnav .icon {
  			display: none;
		}
		.dropdown {
    		float: left;
    		overflow: hidden;
		}
		.dropdown .dropbtn {
    		font-size: 12px;    
    		border: none;
    		outline: none;
    		/*color: #7F7F7F;
    		padding: 14px 16px;
    		background-color: inherit;
    		font-family: inherit;*/
    		margin: 0;
		}
		.dropdown-content {
    		display: none;
    		position: absolute;
    		background-color: #f9f9f9;
    		min-width: 160px;
    		box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    		z-index: 1;
		}
		.dropdown-content a {
    		float: none;
    		color: black;
    		padding: 12px 16px;
    		text-decoration: none;
    		display: block;
    		text-align: left;
		}
		.topnav a:hover, .dropdown:hover .dropbtn {
  		/*	background-color: #555;*/
  			color: white;
		}
		.dropdown-content a:hover {
    	/*	background-color: #ddd;*/
    		color: black;
		}

		.dropdown:hover .dropdown-content {
    		display: block;
		}
		@media screen and (max-width: 600px) {
  			.topnav a:not(:first-child), .dropdown .dropbtn {
    			display: none;
  			}
  			.topnav a.icon {
    			float: right;
    			display: block;
  			}
		}
		@media screen and (max-width: 600px) {
  			.topnav.responsive {position: relative;}
  			.topnav.responsive .icon {
    			position: absolute;
    			right: 0;
    			top: 0;
  			}
  			.topnav.responsive a {
    			float: none;
    			display: block;
    			text-align: left;
  			}
  			.topnav.responsive .dropdown {float: none;}
  			.topnav.responsive .dropdown-content {position: relative;}
  			.topnav.responsive .dropdown .dropbtn {
    			display: block;
    			width: 100%;
    			text-align: left;
  			}
		}
		#izquierda {
			float: left;
		}
		#centro {
			float: none;
		}
		#derecha {
			float: right;
			<!-- background: #fc0; -->
			background: pink;
		}

		#bloque{	width: 100%;}
		#bloque .A, #bloque .B, #bloque .C, #bloque .D { display: inline-block;}
		.A{
			background: none;
		}
		.B{
			background: none;
		}
		.C{
			background: none;
		}
		.D{
			background: none;
		}