用CSS和Javascript创建一个选项卡系统

如果您没有使用ie8或更早版本，这是一个简单的解决方案。正如Diego所说，你不能在一个页面中重复id值。

<script>
		$(function () {
			var links = $('.sidebar-links > div');
			links.on('click', function () {
				links.removeClass('selected');
				$(this).addClass('selected');
			});
		});
		
		function openCity(evt, cityName) {
		    // Declare all variables
		    var i, tabcontent, tablinks;
		    // Get all elements with class="tabcontent" and hide them
		    tabcontent = document.getElementsByClassName("tabcontent");
		    for (i = 0; i < tabcontent.length; i++) {
		        tabcontent[i].style.display = "none";
		    }
		    // Get all elements with class="tablinks" and remove the class "active"
		    tablinks = document.getElementsByClassName("tablinks");
		    for (i = 0; i < tabcontent.length; i++) {
		        tablinks[i].className = tablinks[i].className.replace(" active", "");
		    }
		    // Show the current tab, and add an "active" class to the link that opened the tab
		    document.getElementById(cityName).style.display = "block";
		    evt.currentTarget.className += " active";
		}
	</script>

/* The main content */
.main-content {
	font-family: Arial, Helvetica, sans-serif;
	max-width: 600px;
	padding-top: 40px;
	margin: 0 0 40px 260px;
}
.tabcontent {
    display: none;
}
.tabcontent:target
{
  display:block;
}
/* The left-collapsing sidebar */
.sidebar-left-collapse {
	font-family: Arial, Helvetica, sans-serif;
	position: fixed;
	top: 0;
	left: 0;
	background-color: #292c2f;
	width: 180px;
	height: 100%;
	padding: 20px 0;
}
.sidebar-left-collapse > a {
	display: block;
	text-decoration: none;
	font-family: Cookie, cursive;
	width: 122px;
	height: 122px;
	margin: 0 auto;
	text-align: center;
	color:  #ffffff;
	font-size: 44px;
	font-weight: normal;
	line-height: 2.6;
	border-radius: 50%;
	background-color:  #181a1b;
}
.sidebar-left-collapse .sidebar-links {
	margin: 30px auto;
}
.sidebar-links div > a {
	display: block;
	text-decoration: none;
	margin: 0 auto 5px auto;
	padding: 10px 0 10px 5px;
	background-color: #35393e;
	text-align: left;
	color:  #b3bcc5;
	font-size: 12px;
	font-weight: bold;
	line-height: 2;
	border-left-width: 2px;
	border-left-style: solid;
}
.sidebar-links div.selected > a{
	background-color: #ffffff;
	color: #565d63;
	line-height: 2.3;
	margin: 0;
}
.sidebar-links div > a i.fa {
	position: relative;
	font-size: 20px;
	top: 3px;
	width: 40px;
	text-align: center;
}
.sidebar-links div ul.sub-links {
	max-height: 0;
	overflow: hidden;
	list-style: none;
	padding: 0 0 0 30px;
	color:  #b3bcc5;
	font-size: 12px;
	font-weight: bold;
	line-height: 24px;
	margin: 0;
	transition: 0.4s;
}
.sidebar-links div.selected ul.sub-links {
	max-height: 150px;
	padding: 12px 0 12px 30px;
}
.sidebar-links div .sub-links a {
	text-decoration: none;
	color: #b3bcc5;
	display: block;
	text-align: left;
}
/* Link Colors */
.sidebar-links div.link-blue > a {
	border-color: #487db2;
}
.sidebar-links div.link-blue > a i.fa {
	color: #487db2;
}
.sidebar-links div.link-red > a {
	border-color: #da4545;
}
.sidebar-links div.link-red > a i.fa {
	color: #da4545;
}
.sidebar-links div.link-yellow > a {
	border-color: #d0d237;
}
.sidebar-links div.link-yellow > a i.fa {
	color: #d0d237;
}
.sidebar-links div.link-green > a {
	border-color: #86be2e;
}
.sidebar-links div.link-green > a i.fa {
	color: #86be2e;
}
/* Making the sidebar responsive */
@media (max-width: 900px) {
	.main-content{
		max-width: none;
		padding: 70px 20px;
		margin: 0 0 40px;
	}
	.sidebar-left-collapse {
		width: auto;
		height: auto;
		position: static;
		padding: 20px 0 0;
	}
	.sidebar-left-collapse .sidebar-links {
		text-align: center;
		margin: 20px auto 0;
	}
	.sidebar-links div {
		display: inline-block;
		width: 100px;
	}
	.sidebar-links div > a {
		text-align: center;
		margin: 0;
		padding: 10px 0;
		border-left: none;
		border-top-width: 2px;
		border-top-style: solid;
	}
	.sidebar-links div > a i.fa {
		display: block;
		margin: 0 auto 5px;
	}
	.sidebar-links div ul.sub-links {
		display: none;
	}
	.sidebar-links div.selected .sub-links {
		display: block;
		position: absolute;
		text-align: center;
		width: auto;
		left: 0;
		right: 0;
	}
	.sidebar-links div.selected .sub-links li {
		display: inline-block;
	}
	.sidebar-links div.selected .sub-links a {
		display: inline-block;
		margin-right: 20px;
		font-size: 13px;
		color: #748290;
	}
}
/* Smartphone version */
@media (max-width: 450px) {
	.main-content{
		padding: 90px 20px;
	}
	.sidebar-left-collapse {
		padding: 20px 0;
	}
	.sidebar-left-collapse .sidebar-links {
		text-align: center;
		margin: 20px auto 0;
		position: relative;
	}
	.sidebar-links div {
		display: block;
		width: 240px;
		margin: 0 auto 5px;
	}
	.sidebar-links div > a {
		text-align: left;
		padding: 10px 25px;
		vertical-align: middle;
		border-top: none;
		border-left-width: 2px;
		border-left-style: solid;
	}
	.sidebar-links div > a i.fa {
		display: inline-block;
		font-size: 20px;
		width: 20px;
		margin: 0 20px 0 0;
	}
	.sidebar-links div.selected .sub-links {
		bottom: -90px;
	}
}
/*	Removing margins and paddings from the body, so that
    the sidebar takes the full height of the page */
body {
	margin: 0;
	padding: 0;
}

<aside class="sidebar-left-collapse">
		<a href="#" class="company-logo">Logo</a>
		<div class="sidebar-links">
			<div class="link-blue selected">
				<a href="#">
					<i class="fa fa-picture-o"></i>Photography
				</a>
				<ul class="sub-links">
					<li><a href="#portraits"  class="tablinks">Portraits</a></li>
					<li><a href="#landscape"  class="tablinks">Landscape</a></li>
					<li><a href="#studioshots"  class="tablinks">Studio shots</a></li>
					<li><a href="#macros"  class="tablinks">Macros</a></li>
				</ul>
			</div>
			
		</div>
	</aside>
	<div class="main-content">
		
		<div id="portraits" class="tabcontent"> Portraits ...</div>
		
		<div id="landscape" class="tabcontent"> Landscape ...</div>
		
		<div id="studioshots" class="tabcontent"> Studioshots ...</div>
		<div id="macros" class="tabcontent"> Macros ...</div>
	</div>
<script> window.location = "#portraits"; </script>

所以，我稍微改变了你的逻辑和行为：

现在"根"菜单通过点击切换子链接，子链接显示其内容并隐藏子链接：

$(function() {
    $(".root-link").click(function() {
    $(this).parent().toggleClass("selected");
  });
  $(".tablinks").click(function() {
    $(".tabcontent").hide();
    var idtab = $(this).data("tab");
    $("#" + idtab + "-tab").show();
    $(".link-blue").removeClass("selected");
  });  
});

PS：不同的元素不能有相同的id，所以我在内容元素id上添加了sufix-tab。

Fiddle：https://jsfiddle.net/diegopolido/sar6spzb/