CSS menü boşluğu nasıl giderilir?

<style>
 body{
 background: #fff;
 }

 ul.mobmen {
 list-style-type: none;
 margin: 0;
 padding: 0;
 overflow: hidden;
 background-color: #333;
 }
 ul.mobmen li {float: left;}
 ul.mobmen li a {
 display: inline-block;
 color: #f2f2f2;
 text-align: center;
 padding: 14px 16px;
 text-decoration: none;
 transition: 0.3s;
 font-size: 17px;
 }
 ul.mobmen li a:hover {background-color: #555;}
 ul.mobmen li.icon {display: none;}

 @media screen and (max-width:680px) {
 ul.mobmen li:notfirst-child) {display: none;}
 ul.mobmen li.icon {
 float: right;
 display: inline-block;
 }
 }

 @media screen and (max-width:680px) {
 ul.mobmen.responsive {position: relative;}
 ul.mobmen.responsive li.icon {
 position: absolute;
 right: 0;
 top: 0;
 }
 ul.mobmen.responsive li {
 float: none;
 display: inline;
 }
 ul.mobmen.responsive li a {
 display: block;
 text-align: left;
 }
 }

 </style>

body {
  background: #fff;
  padding: 0;
  margin: 0;
  height: 100vh;
  width: 100vw;
}