CSS3制作下拉菜单

导航菜单其实是没有什么可说的，制作方法到处可见，今天这个案例本来不只是一个导

航，还有一个搜索表单的，可是为了偷懒，把搜索表单部分去掉了，就变成了一个CSS3

制作的下拉菜单。在这个导航中主要两点，一个是渐变运用，另一个就是box-shodow

制作的立体效果。

HTML 结构：

<ul id="nav">
  <li><a href="#">Home</a></li>
  <li>
    <a href="#">Portfolio</a>
    <ul class="sub-menu">
      <li><a href="#">Identity</a></li>
      <li><a href="#">Print</a></li>
      <li><a href="#">Online</a></li>
    </ul>
  </li>
  <li><a href="#">About</a></li>
  <li><a href="#">Contact</a></li>
  <li><a href="#">W3cplus</a></li>
</ul>

　　CSS代码

*{
  margin: 0;
  padding: 0;
}
body {
  padding: 50px;
  background: url(data:image/j...);
  font-family: 'Jockey One', sans-serif;
  color: #fff;
}
a {
  color: rgb(1, 124, 185);
  text-decoration: none;
}
li {
  list-style: none outside none;
}
#nav:after,
#nav:before {
  content:"";
  display: table;
}
#nav:after {
  clear:both;
  overflow: hidden;
}
#nav {
  zoom: 1;
  margin: 50px auto;
  width: 530px;
}
#nav > li{
  float: left;
  display: inline;
  border-right: 1px solid #848d95;
  border-left: 1px solid #e3e8ec;
  box-shadow: 0 1px 0 rgba(84,95,109,0.75),0 2px 0 rgba(84,95,109,0.75),0 3px 0 rgba(84,95,109,0.75);
  position: relative;
  background-color: #c5cfd8; /* Old browsers */
  /* IE9 SVG, needs conditional override of 'filter' to 'none' */
  background-image: url(data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiA/Pgo8c3ZnIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgd2lkdGg9IjEwMCUiIGhlaWdodD0iMTAwJSIgdmlld0JveD0iMCAwIDEgMSIgcHJlc2VydmVBc3BlY3RSYXRpbz0ibm9uZSI+CiAgPGxpbmVhckdyYWRpZW50IGlkPSJncmFkLXVjZ2ctZ2VuZXJhdGVkIiBncmFkaWVudFVuaXRzPSJ1c2VyU3BhY2VPblVzZSIgeDE9IjAlIiB5MT0iMCUiIHgyPSIwJSIgeTI9IjEwMCUiPgogICAgPHN0b3Agb2Zmc2V0PSIwJSIgc3RvcC1jb2xvcj0iI2M1Y2ZkOCIgc3RvcC1vcGFjaXR5PSIxIi8+CiAgICA8c3RvcCBvZmZzZXQ9IjEwMCUiIHN0b3AtY29sb3I9IiM5Y2E4YjEiIHN0b3Atb3BhY2l0eT0iMSIvPgogIDwvbGluZWFyR3JhZGllbnQ+CiAgPHJlY3QgeD0iMCIgeT0iMCIgd2lkdGg9IjEiIGhlaWdodD0iMSIgZmlsbD0idXJsKCNncmFkLXVjZ2ctZ2VuZXJhdGVkKSIgLz4KPC9zdmc+);  background-image: -moz-linear-gradient(top,  #c5cfd8 0%, #9ca8b1 100%); /* FF3.6+ */
  background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#c5cfd8), color-stop(100%,#9ca8b1)); /* Chrome,Safari4+ */
  background-image: -webkit-linear-gradient(top,  #c5cfd8 0%,#9ca8b1 100%); /* Chrome10+,Safari5.1+ */
  background-image: -o-linear-gradient(top,  #c5cfd8 0%,#9ca8b1 100%); /* Opera 11.10+ */
  background-image: -ms-linear-gradient(top,  #c5cfd8 0%,#9ca8b1 100%); /* IE10+ */
  background-image: linear-gradient(to bottom,  #c5cfd8 0%,#9ca8b1 100%); /* W3C */
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#c5cfd8', endColorstr='#9ca8b1',GradientType=0 ); /* IE6-8 */
  -webkit-transition: all 0.25s ease-in .0038s;
  -moz-transition: all 0.25s ease-in .0038s;
  -o-transition: all 0.25s ease-in .0038s;
  transition: all 0.25s ease-in .0038s;
}
#nav li:first-child {
  border-left: none;
  border-radius:  5px 0 0 5px;
}
#nav li:last-child {
  border-radius: 0 5px 5px 0;
  border-right: none;
}
#nav li:last-child::after {
  display: none;
}
#nav .sub-menu {
  position: absolute;
  right: 0;
  left: -1px;
  top: 100%;
  border-radius: 0 0 5px 5px;
  box-shadow: 0 1px 0 rgba(84,95,109,0.75),0 2px 0 rgba(84,95,109,0.75),0 3px 0 rgba(84,95,109,0.75);
  background-color: #d9e0e5; /* Old browsers */
  /* IE9 SVG, needs conditional override of 'filter' to 'none' */
  background-image: url(data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiA/Pgo8c3ZnIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgd2lkdGg9IjEwMCUiIGhlaWdodD0iMTAwJSIgdmlld0JveD0iMCAwIDEgMSIgcHJlc2VydmVBc3BlY3RSYXRpbz0ibm9uZSI+CiAgPGxpbmVhckdyYWRpZW50IGlkPSJncmFkLXVjZ2ctZ2VuZXJhdGVkIiBncmFkaWVudFVuaXRzPSJ1c2VyU3BhY2VPblVzZSIgeDE9IjAlIiB5MT0iMCUiIHgyPSIwJSIgeTI9IjEwMCUiPgogICAgPHN0b3Agb2Zmc2V0PSIwJSIgc3RvcC1jb2xvcj0iI2Q5ZTBlNSIgc3RvcC1vcGFjaXR5PSIxIi8+CiAgICA8c3RvcCBvZmZzZXQ9IjEwMCUiIHN0b3AtY29sb3I9IiNjNWNkZDMiIHN0b3Atb3BhY2l0eT0iMSIvPgogIDwvbGluZWFyR3JhZGllbnQ+CiAgPHJlY3QgeD0iMCIgeT0iMCIgd2lkdGg9IjEiIGhlaWdodD0iMSIgZmlsbD0idXJsKCNncmFkLXVjZ2ctZ2VuZXJhdGVkKSIgLz4KPC9zdmc+);  background-image: -moz-linear-gradient(top,  #d9e0e5 0%, #c5cdd3 100%); /* FF3.6+ */
  background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#d9e0e5), color-stop(100%,#c5cdd3)); /* Chrome,Safari4+ */
  background-image: -webkit-linear-gradient(top,  #d9e0e5 0%,#c5cdd3 100%); /* Chrome10+,Safari5.1+ */
  background-image: -o-linear-gradient(top,  #d9e0e5 0%,#c5cdd3 100%); /* Opera 11.10+ */
  background-image: -ms-linear-gradient(top,  #d9e0e5 0%,#c5cdd3 100%); /* IE10+ */
  background-image: linear-gradient(to bottom,  #d9e0e5 0%,#c5cdd3 100%); /* W3C */
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#d9e0e5', endColorstr='#c5cdd3',GradientType=0 ); /* IE6-8 */
  display: none;
}
#nav > li:hover {
  background-color: #d8dfe4; /* Old browsers */
  /* IE9 SVG, needs conditional override of 'filter' to 'none' */
  background-image: url(data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiA/Pgo8c3ZnIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgd2lkdGg9IjEwMCUiIGhlaWdodD0iMTAwJSIgdmlld0JveD0iMCAwIDEgMSIgcHJlc2VydmVBc3BlY3RSYXRpbz0ibm9uZSI+CiAgPGxpbmVhckdyYWRpZW50IGlkPSJncmFkLXVjZ2ctZ2VuZXJhdGVkIiBncmFkaWVudFVuaXRzPSJ1c2VyU3BhY2VPblVzZSIgeDE9IjAlIiB5MT0iMCUiIHgyPSIwJSIgeTI9IjEwMCUiPgogICAgPHN0b3Agb2Zmc2V0PSIxJSIgc3RvcC1jb2xvcj0iI2Q4ZGZlNCIgc3RvcC1vcGFjaXR5PSIxIi8+CiAgICA8c3RvcCBvZmZzZXQ9IjEwMCUiIHN0b3AtY29sb3I9IiNkNWRlZTQiIHN0b3Atb3BhY2l0eT0iMSIvPgogIDwvbGluZWFyR3JhZGllbnQ+CiAgPHJlY3QgeD0iMCIgeT0iMCIgd2lkdGg9IjEiIGhlaWdodD0iMSIgZmlsbD0idXJsKCNncmFkLXVjZ2ctZ2VuZXJhdGVkKSIgLz4KPC9zdmc+);  background-image: -moz-linear-gradient(top,  #d8dfe4 1%, #d5dee4 100%); /* FF3.6+ */
  background-image: -webkit-gradient(linear, left top, left bottom, color-stop(1%,#d8dfe4), color-stop(100%,#d5dee4)); /* Chrome,Safari4+ */
  background-image: -webkit-linear-gradient(top,  #d8dfe4 1%,#d5dee4 100%); /* Chrome10+,Safari5.1+ */
  background-image: -o-linear-gradient(top,  #d8dfe4 1%,#d5dee4 100%); /* Opera 11.10+ */
  background-image: -ms-linear-gradient(top,  #d8dfe4 1%,#d5dee4 100%); /* IE10+ */
  background-image: linear-gradient(to bottom,  #d8dfe4 1%,#d5dee4 100%); /* W3C */
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#d8dfe4', endColorstr='#d5dee4',GradientType=0 ); /* IE6-8 */
  position: relative;
  top: 3px;
  border-right-color: #848d95;
  box-shadow: -1px 0 0 #848d95;
  color: #2281cd;
}
#nav li:hover > ul {
  display: block;
}
#nav a {
  display: block;
  float: left;
  padding: 15px 30px;
  font-size: 16px;
  color: #2d2f38;
  text-shadow: 0 1px 0 rgba(225,232,235,0.75);
  -webkit-transition: all 0.25s ease-in .0038s;
  -moz-transition: all 0.25s ease-in .0038s;
  -o-transition: all 0.25s ease-in .0038s;
  transition: all 0.25s ease-in .0038s;
}
#nav a:hover {
  color: #2281cd;
}
#nav .sub-menu a {
  color: #2d2f38;
  font-size: 14px;
  padding: 10px 30px;
  float: none;
}
#nav .sub-menu a:hover {
  background-color: #a4b0ba; /* Old browsers */
  /* IE9 SVG, needs conditional override of 'filter' to 'none' */
  background-image: url(data:image/svg+xml;base64,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);  background-image: -moz-linear-gradient(top,  #a4b0ba 0%, #d5dee4 4%, #b5c0c9 100%); /* FF3.6+ */
  background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#a4b0ba), color-stop(4%,#d5dee4), color-stop(100%,#b5c0c9)); /* Chrome,Safari4+ */
  background-image: -webkit-linear-gradient(top,  #a4b0ba 0%,#d5dee4 4%,#b5c0c9 100%); /* Chrome10+,Safari5.1+ */
  background-image: -o-linear-gradient(top,  #a4b0ba 0%,#d5dee4 4%,#b5c0c9 100%); /* Opera 11.10+ */
  background-image: -ms-linear-gradient(top,  #a4b0ba 0%,#d5dee4 4%,#b5c0c9 100%); /* IE10+ */
  background-image: linear-gradient(to bottom,  #a4b0ba 0%,#d5dee4 4%,#b5c0c9 100%); /* W3C */
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#a4b0ba', endColorstr='#b5c0c9',GradientType=0 ); /* IE6-8 */
  box-shadow: 0 1px 0 rgba(255,255,255,0.75),inset 0 2px 6px rgba(69,78,90,0.15);
}
#nav .sub-menu li:last-child a:hover {
  border-radius: 0 0 5px 5px;
}

　　

出处：

http://www.w3cplus.com/demo/create-nav-menu-with-css3.html