Result jQuery$('a','nav').mouseover(function(){ $('span','nav').animate({ 'width': $(this).width(), 'left': $(this).position().left} ,'fast'); });cssnav a{ text-decoration:none; color:#333; } nav li{ display:inline-block; margin-left:2px; padding:3px; background:#eee; } nav span{ background:#666; height:2px; display:block; position:relative; width:50px; left:0; }html<nav><ul> <li><a href="#">menu0
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