响应式导航栏失败

Question

我有一个导航栏，我希望它只有第一个元素Wakanda Team和一个汉堡图标，当屏幕小于900px。但我不断得到其他元素如图所示。有人可以帮忙吗？

 <ul class="topnav" id="myTopnav">
    <li style="float:left"><a href="#home" class="home">Wakanda Team</a></li>
    <li><a><i class="material-icons">subdirectory_arrow_left</i> Sign out</a></li>
    <li><a><i class="material-icons">exit_to_app</i> Sign in</a></li>
    <li><a><i class="material-icons">person_add</i> Register</a></li>
    <li><a href="javascript:void(0);" style="font-size:15px;" class="icon" onclick="myFunction()">&#9776;</a></li>
  </ul>
      <p>Welcome to <%= title %></p>
  <script>
      function myFunction() {
          var x = document.getElementById("myTopnav");
          if (x.className === "topnav") {
              x.className += " responsive";
          } else {
              x.className = "topnav";
          }
      }
  </script>

CSS：

 ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #FFFFFF;
    position: fixed;
    top: 0;
    width: 100%;
}

li {
    float: right;
}

li a {
    display: block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
}

li a:hover:not(.home){
    background-color: #111;
    text-decoration: none;
    color: white;
}

li a .home:hover{
    text-decoration: none;
}

.material-icons {
    vertical-align: middle;
}

.topnav .icon {
    display: none;
}

@media screen and (max-width: 900px) {
    .topnav a:not(:first-child) {display: none;}
    .topnav a.icon {
        float: right;
        display: block;
    }
}

@media screen and (max-width: 900px) {
    .topnav.responsive {position: relative;}
    .topnav.responsive .icon {
        position: absolute;
        right: 0;
        top: 0;
    }
    .topnav.responsive a {
        float: none;
        display: block;
        text-align: left;
    }
}