Super basic tabs with JavaScript: click/touch adds a class to the clicked element and to the element with the id of the clicked elements href.

body.js

(function(w,d) {
	var q = 'querySelectorAll',
		navs = d[q]('nav a'), // Tabs
		pages = d[q]('section'), // Contents
		a = 'active', // ClassName
		cn="className",
		aC=function(c,b){if(c.classList){c.classList.add(b)}else{var d=" ";var a=(d)?(d+c[cn]+d).indexOf(d+b+d)>-1:String(this).indexOf(b)>-1;if(!a){c[cn]=(c[cn]+" "+b)}}},
		rC=function(b,a){if(b.classList){b.classList.remove(a)}else{b[cn]=b[cn].replace(new RegExp("(^|\\s)"+a+"(?:\\s|$)"),"$1")}};
	for (var i=0; i < navs.length; i++) {
		navs[i].savedPage = d[q](navs[i].href.match(/#.*$/)[0])[0];
		navs[i].addEventListener(('ontouchstart' in w)?'touchstart':'click', function(event) {
			event.preventDefault();
			for (var i=0; i < navs.length; i++) {
				rC(navs[i],a);
				rC(pages[i],a);
			}
			aC(this,a);
			aC(this.savedPage,a);
		});
	};
}(window,document));

example.css

nav a{ color: #000 }
nav a.active{ color: #f00; }

section{ display: none; }
section.active{ display: block; }