I'm creating an HTML nav bar for the first time and I'm having white space issue, I fixed it only sideways(left, right) but there is still space on the top of the nav bar. Pls help to fill it.
Image of the problem - Image
This is my CSS and HTML. Run the code and open in full mode.
li.na-li {
  float: left;
  text-align: center;
  font-size: 20px;
    }
    
li.na-li a.na-a {
        display:block;
        text-decoration: none;
        color:white;
        padding: 15px;
        
    
    }
li a:hover{background-color: #00F003}   
    
ul.na-ul {
        background-color:#000000;
        position: fixed;
        top: 0;
        width: 100%;
        list-style-type: none;
        
    }   
.navbar {
        background-color: #073A00;
        width: 0%;
    }       
    
body {
width: 100%;
height: 100%;
padding: 0px;
margin: 0px;
overflow-x: hidden;
}
    
    
   
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Untitled Document</title>
</head>
    
<body>
    <div class="navbar">
<ul class="na-ul">
    <li class="na-li"><a class="na-a" href="#home">Home</a></li>
    <li class="na-li"><a class="na-a" href="Services"> Services</a></li>
    <li class="na-li"><a class="na-a" href="Contact">Contact</a></li>
    <li class="na-li"><a class="na-a" href="Help">Help</a></li>
    </ul>   
</div>  
    
    
</body>
</html>