JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" class="menu" id="index"> some link</a><a href="#" class="menu" id="index"> link 2</a><a href="#" class="menu"> link3</a>

CSS

a.menu:link, a.menu:visited 
{ 
  width:160px; border-bottom:1px solid #CCC; float:left;
  font-family:Tahoma, Arial, Helvetica, sans-serif; 
  font-size:12px; background-color: #FFF; 
  height:21px; display:block; text-decoration:none; color:#999999;
  padding:5px 0px 0px 10px
}

a.menu:hover
{
     background-color:#f2f2f2;
     font-family:Tahoma, Arial, Helvetica, sans-serif;
     font-size:12px;color:#999999 
}

.on {
    background: #000 !important;
}

JavaScript

$('.menu').click(function() {
    $(".menu").not($(this)).removeClass("on");
    $(this).addClass("on");
    return false;
});