切换响应式菜单

Question

我在网站上有以下代码（由codepen提供）。

然而，在320px它覆盖整个窗口，而我需要它在触发时切换。目前它隐藏了页面内容。这个代码有可能吗？感谢

#menuwrap {
    width: 700px;
    margin: -50px auto 0 auto;
float: right;
    text-align: center;
height: 40px;
}

nav {
    display: block;
    position: relative;
z-index: 100;
    min-height: 40px;
    margin: 0 auto;
}
nav, nav a {
    color: #fff;
    text-decoration: none;
    font-family: Verdana, sans-serif;
font-size: 90%;
}
nav a {
    display: block;
    padding: 10px;
}
nav a:hover {
    background: gray;
}
nav li {
    margin: 0 auto;
}
nav ul {
    padding:0;
    margin: 0;
}
nav ul li {
    float:left;
    display:inline;
    position:relative;
    width: 100px;
}
nav ul li ul {
    left:0;
    top:100%;
}
nav ul ul {
    display:none;
}
nav li:hover > ul {
    display:block;
    position:absolute;
    z-index:1000;
    width: 150px;
}
nav ul ul li:hover > ul {
    right: -150px;
    top: 0;
    left: auto;
}

/*Hide checkbox and label by default*/
nav > input,
nav > label {
  display: none;
}

nav > label {
  width: 100%;
  float: left;
  padding: 10px;
  padding-right: 0;
  cursor: pointer;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

/*Media query*/
@media (max-width: 400px) {
    nav > label, nav ul li ul {
        display: block;

    }
    nav > ul {
        display: none;
        clear: both;
    }
    nav > input:checked + ul {
        display: block;
    }
    nav ul ul li a:before {
        /*content:'↪ ';*/
        display: inline;
    }
    nav ul li {
        display: block;
        border-right: none;
        padding-left: 10px;
float:right:
margin-top: -50px;
    }
    nav li:hover ul {
        position: relative;
        width: auto;
    }
    nav ul ul li:hover > ul {
        right:auto;
        top: auto;
        left: auto;
    }
}