Responsive Navigationsbar

 <div class="topnav" id="myTopnav">  
            <a href="index.html"><img src="uploads/Logo.JPG" class="nav-image" alt="Bild" /></a>  
            <div class="nac-items">  
                <a class="item" href="index.html">Startseite</a>  
                <a class="item" href="wir.html">Wir &uuml;ber uns</a>  
                <a class="item" href="angebote.html">Angebote</a>  
                <a href="javascript:void(0);" style="font-size:15px;" class="icon" onclick="myFunction()">&#9776;</a>  
            </div>
            
            <script>
                function myFunction() {
                    var x = document.getElementById("myTopnav");  
                    if (x.className === "topnav") {  
                        x.className += " responsive";  
                    } else {
                        x.className = "topnav";  
                    }
                }
            </script>
        </div>

#index-table {
    border: none;
}

.nav-image {
    float: left;
    height: 50px;
    width: auto;
}

.topnav .item {
    float: right;
}

.topnav {
  overflow: hidden;
  background-color: #ffffff;
}

//.topnav a:first-child { display: none; background-color: white; }

.topnav a {
  float: left;
  display: block;
  color: red;
  text-align: center;
  padding: 14px 20px;
  text-decoration: none;
  font-size: 17px;

    margin-top: 10px;
    border: 1px solid white;
}

.nac-items {
    padding-left: 1%;
}

.topnav a:hover {
    border: 1px solid red;
    color: red;
}

a.active {
    background-color: red;
    color: white;
}

.topnav .icon {
    display: none;
}

.topnav a:not(:first-child) {display: none;}
        .topnav a:first-child {
            display: block; 
            background-color: white; 
            color: red; 
            border: none;
        }

        .nac-items(:first-child) { display: none; }

        .topnav a.icon {
            float: right;
            display: block;
        }

        .topnav.responsive {position: relative;}
        .topnav.responsive .icon {
            position: absolute;
            right: 0;
            top: 0;
        }
        .topnav.responsive a {
            float: none;
            display: block;
            text-align: left;

        }

        .nav-items {
            padding-top: 20px;
        }