nav {
    float: left;
} 

nav ul {
    text-align: left;
    display: inline;
    margin: 0;
    padding: 15px 4px 17px 0;
    list-style: none;
    -webkit-box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
    -moz-box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
    z-index:2;
}

nav ul li {
  font: bold 12px/18px sans-serif;
  display: inline-block;
  margin-right: -4px;
  position: relative;
  /*padding: 15px 20px;*/
  background: #dadada;
  cursor: pointer;
  -webkit-transition: all 0.2s;
  -moz-transition: all 0.2s;
  -ms-transition: all 0.2s;
  -o-transition: all 0.2s;
  transition: all 0.2s;
}

nav ul li:hover {
  background: #555;
  color: #fff;
}

nav ul li:hover a {
  background: #555;
  color: #fff !important;
}

    nav ul li span {
        padding: 15px 20px;
        background-color: #dadada;
        display: block;
        color:black;
    }

    nav ul li span:hover {
        background: #555;
        color: #fff !important;
    }

    nav ul li:hover span {
        background: #555;
        color: #fff !important;
    }



nav ul li ul {
  padding: 0;
  position: absolute;
  top: 48px;
  left: 0;
  width: 150px;
  -webkit-box-shadow: none;
  -moz-box-shadow: none;
  box-shadow: none;
  display: none;
  opacity: 0;
  visibility: hidden;
  -webkit-transiton: opacity 0.2s;
  -moz-transition: opacity 0.2s;
  -ms-transition: opacity 0.2s;
  -o-transition: opacity 0.2s;
  -transition: opacity 0.2s;
}

nav ul li ul li { 
  background: #555; 
  display: block; 
  color: #fff;
  /*text-shadow: 0 -1px 0 #000;*/
}

nav ul li ul li:hover { background: #666; }

nav ul li:hover ul {
  display: block;
  opacity: 1;
  visibility: visible;
}