<ul id="menu">
  <li><a href="#">Menu</a>
    <ul>
      <li><a href="#">Child Menu</a></li>
      <li><a href="#">Child Menu</a></li>
      <li><a href="#">Child Menu</a></li>
      <li><a href="#">Child Menu</a></li>
    </ul>
  </li>
  <li><a href="#">Menu</a>
    <ul>
      <li><a href="#">Child Menu</a></li>
      <li><a href="#">Child Menu</a></li>
      <li><a href="#">Child Menu</a></li>
    </ul>
  </li>
  <li><a href="#">Menu</a>
    <ul>
      <li><a href="#">Child Menu</a></li>
      <li><a href="#">Child Menu</a></li>
    </ul>
  </li>
  <li><a href="#">Menu</a>
    <ul>
      <li><a href="#">Child Menu</a></li>
      <li><a href="#">Child Menu</a></li>
      <li><a href="#">Child Menu</a></li>
    </ul>
  </li>
</ul>
#menu{
  list-style-type: none;
  width: 500px;
  height: 40px;
  margin: 0 auto;
  padding: 0;
  background: #276baa;
}
#menu li{
  position: relative;
  width: 25%;
  float: left;
  margin: 0;
  padding: 0;
  text-align: center;
}
#menu li a{
  display: block;
  margin: 0;
  padding: 13px 0;
  color: #fff;
  font-size: 14px;
  font-weight: bold;
  line-height: 1;
  text-decoration: none;
}
#menu li ul{
  list-style: none;
  position: absolute;
  top: 100%;
  left: 0;
  margin: 0;
	padding: 0;
}
#menu li:last-child ul{
  left: -100%;
  width: 100%
}
#menu li ul li{
  overflow: hidden;
  width: 200%;
  height: 0;
  color: #fff;
  -moz-transition: .2s;
  -webkit-transition: .2s;
  -o-transition: .2s;
  -ms-transition: .2s;
  transition: .2s;
}
#menu li ul li a{
  padding: 13px 15px;
  background: #1a5293;
  text-align: left;
  font-size: 12px;
  font-weight: normal;
}
#menu li:hover > a{
  background: #1a5293;
  color: #e0dc62;
}
#menu li:hover ul li{
  overflow: visible;
  height: 38px;
  border-bottom: 1px solid #fff;
}
#menu li:hover ul li:first-child{
  border-top: 0;
}
#menu li:hover ul li:last-child{
  border-bottom: 0;
}

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