#mainframeset {
	display: flex;
	flex-direction: column;
	margin: 0;
	padding: 0; 
}
#top {
	height: auto;
	width: 100%;
	border: 0;
}
#bottom {
	flex: 1;
	width: 100%;
	border: 0;
}
#myTopnav { 
	display: none;
}



@media screen and (max-width: 600px) {
	#top {
		display: none;
	}
	#myTopnav { 
		display: block;
	}
}


/* Add a black background color to the top navigation */
.topnav {
    background-color: #333;
    overflow: hidden;
}
/* Style the links inside the navigation bar */
.topnav a {
    float: left;
    display: block;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 17px;
}

/* Change the color of links on hover */
.topnav a:hover {
    background-color: #ddd;
    color: black;
}

/* Add an active class to highlight the current page */
.active {
    background-color: #4CAF50;
    color: white;
}

.topnav a:not(:first-child) {display: none;}
.topnav a.icon {
	float: right;
	display: block;
}

.topnav.responsive {position: relative;}
.topnav.responsive a.icon {
	position: absolute;
	right: 0;
	top: 0;
}
.topnav.responsive a {
	float: none;
	display: block;
	text-align: left;
}