body {margin:0;} .topnav { overflow: hidden; } .topnav a { float: left; display: block; color: white; width: 100px; text-align: center; font-weight: 550; padding: 14px 16px; text-decoration: none; font-size: 15px; letter-spacing: 1px; border-bottom: 3px solid transparent; } .topnav a:hover { border-bottom: 3px solid yellow; color: yellow; } .topnav a.active { border-bottom: 3px solid yell0w; color: yellow; }