/*主選單按鈕*/
.main-menu{
    position: fixed;  /*固定在網頁上不隨卷軸移動，若要隨卷軸移動用absolute*/

	position:absolute;
	left:50%;
	bottom:0%;
	margin-left:-180px;
	margin-bottom:-90px;
}


iframe {
  position:absolute;
  top: 0px; /*where 0px is bootstrap default navbar height*/
  width: 100%;
  height: calc(100% - 0px);
}


.menu-picture {
width:100%
}