如何将下拉显示从悬停更改为单击

试试这个

$(function() {
  $('.animenu li').click(function(e) {
    $(this).find('> ul').addClass('show');
    $(this).addClass('selected');
    e.stopImmediatePropogation();
  });
  $(document).click(function(e) {
    if ($(e.target).closest('.animenu').length == 0) {
      $('.animenu .show').parents('li').removeClass('selected');
      $('.animenu ul').removeClass('show');
    }
  })
});

.animenu > ul:after {
  content: "";
  display: table;
  clear: both;
}
body {
  -webkit-animation: bugfix infinite 1s;
}
@-webkit-keyframes bugfix {
  from {
    padding: 0;
  }
  to {
    padding: 0;
  }
}
.animenu {
  font: 13px Arial, Helvetica;
}
.animenu * {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
.animenu ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.animenu li {
  position: relative;
}
.animenu li > ul.show {
  opacity: 1;
  visibility: visible;
  margin: 0;
}
li {
  outline: none;
}
.animenu li.selected > a {
  color: white;
  background: #ff0000;
}
.animenu input[type=checkbox] {
  position: absolute;
  top: -9999px;
  left: -9999px;
}
.animenu label {
  display: none;
  cursor: pointer;
  user-select: none;
}
.animenu > ul {
  background: #f1f1f1;
}
.animenu > ul > li {
  float: left;
}
.animenu > ul > li > a {
  float: left;
  padding: 1em 3em;
  text-transform: uppercase;
}
.animenu > ul a {
  color: #333;
  text-decoration: none;
}
.animenu > ul ul {
  position: absolute;
  top: 100%;
  left: 0;
  z-index: 1;
  opacity: 0;
  visibility: hidden;
  margin: 2em 0 0 0;
  background-color: #f1f1f1;
  background-image: none;
  -webkit-transition-property: margin, opacity;
  -moz-transition-property: margin, opacity;
  -o-transition-property: margin, opacity;
  transition-property: margin, opacity;
  -webkit-transition-duration: .15s;
  -moz-transition-duration: .15s;
  -o-transition-duration: .15s;
  transition-duration: .15s;
  -webkit-transition-timing-function: ease-in-out;
  -moz-transition-timing-function: ease-in-out;
  -o-transition-timing-function: ease-in-out;
  transition-timing-function: ease-in-out;
}
.animenu > ul ul li {
  display: block;
}
.animenu > ul ul li:first-child > a {} .animenu > ul ul li:first-child > a:after {
  content: '';
  position: absolute;
  left: 4em;
  top: -12px;
  border: 6px solid transparent;
  border-bottom-color: inherit;
}
.animenu > ul ul li:last-child {
  -webkit-box-shadow: none;
  -moz-box-shadow: none;
  box-shadow: none;
}
.animenu > ul ul li:last-child > a {} .animenu > ul ul a {
  padding: 1em;
  width: 175px;
  display: block;
  border-color: #373737;
}
.animenu > ul ul a {
  /*background-color: #ff0000;
  border-color: #fff;*/
  color: #ff0000;
  background-color: #f1f1f1;
}
@media screen and (max-width: 480px) {
  .animenu > ul,
  .animenu > ul ul {
    visibility: visible;
    opacity: 1;
    display: none;
  }
  .animenu input[type=checkbox]:checked ~ label,
  .animenu input[type=checkbox] ~ label:hover {
    color: white;
  }
  .animenu label {
    background-color: #f1f1f1;
    color: #333;
    text-transform: uppercase;
    position: relative;
    display: block;
    padding: 1em 3em;
  }
  .animenu label:before {
    position: absolute;
    left: 0.5em;
    top: 0.2em;
    content: "'2261";
    font-size: 2em;
  }
  .animenu > ul {
    position: relative;
    margin: 0.5em 0 !important;
    padding: 0.25em;
    background-color: #f1f1f1;
    background-image: none;
  }
  .animenu > ul:after {
    content: '';
    position: absolute;
    left: 2em;
    top: -12px;
    border: 6px solid transparent;
    border-bottom-color: inherit;
  }
  .animenu > ul li {
    display: block;
  }
  .animenu > ul > li {
    float: none;
    border: 0;
    background-color: #f1f1f1;
    background-image: none;
  }
  .animenu > ul > li > a {
    float: none;
    display: block;
    padding: 1em;
  }
  .animenu > ul ul {
    position: static;
    background-color: #f1f1f1;
    background-image: none;
    margin: 0;
    -webkit-transition-property: none;
    -moz-transition-property: none;
    -o-transition-property: none;
    transition-property: none;
  }
  .animenu > ul ul li:first-child > a {} .animenu > ul ul li:first-child > a:after {
    content: none;
  }
  .animenu > ul ul li:last-child > a {} .animenu > ul ul a {
    padding-left: 2em;
    display: block;
    width: auto;
  }
  .animenu input[type=checkbox]:checked ~ ul {
    display: block;
  }
  .animenu input[type=checkbox]:checked ~ ul ul {
    display: block;
  }
}
@media screen and (max-width: 600px) {
  .animenu > ul > li > a {
    padding: 1em 2em;
  }
}
.animenu-third-level {
  left: 100% !important;
  top: 0 !important;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<nav class="animenu">
  <input type="checkbox" id="button">
  <label for="button" onclick="">Menu</label>
  <ul>
    <li class="first selected bc"><a href="http://localhost/2/en-us/">Home</a>
    </li>
    <li tabindex="0"><a href="javascript:void(0);">About Us</a>
      <ul>
        <li class="first"><a href="http://localhost2/en-us/About-Us/StyleGuide">Style Guide</a>
        </li>
        <li class="last" tabindex="0"><a href="javascript:void(0);">Test</a>
          <ul class="animenu-third-level">
            <li class="first"><a href="http://localhost2/en-us/About-Us/Test/3rd-level">3rd level</a>
            </li>
            <li><a href="http://localhost2/en-us/About-Us/Test/First-Page">First Page</a>
            </li>
            <li><a href="http://localhos2/en-us/About-Us/Test/Second-Page">Second Page</a>
            </li>
            <li><a href="http://localhos2/en-us/About-Us/Test/Third-Page">Third Page</a>
            </li>
            <li><a href="http://localhost2/en-us/About-Us/Test/Fourth-Page">Fourth Page</a>
            </li>
            <li class="last"><a href="http://localhos2/en-us/About-Us/Test/Fifth-Page">Fifth Page</a>
            </li>
          </ul>
        </li>
      </ul>
    </li>
  </ul>
</nav>

我想这就是您想要的：

下拉菜单仅HTML&CSS
http://koen.kivits.com/articles/pure-css-menu/