JSFiddle - React, Tailwind, and code Playground

HTML

<body>
<div id="navi">
     <ul id="menu">
          <li ><a class="drop">navi</a>
               <div class="dropdown_columns">
                    <div class="col">
                          <a href="">sample 1<span class="mask"></span></a>
                          <a href="">sample 2<span class="mask"></span></a>
                          <a href="">sample 3<span class="mask"></span></a> 
                    </div>
               </div>
          </li>
     </ul>
</div>
</body>

CSS

#navi {
  width:1120px;
  height:30px;
  text-align:center;
}
#menu {
    list-style:none;
    background-repeat:repeat-x;
    width:791px;
	height:30px;
	padding:0 165px 0 164px;
	font-family:MyCustomFont;
	text-align:center;
	float:left;
}
menu a{
  opacity:0;
  -webkit-transition: all .2s ease-in-out;
  -moz-transition: all .2s ease-in-out;
  -o-transition: all .2s ease-in-out;
  transition: all .2s ease-in-out;
}
#menu li {
  width:113px;
  height:30px;
  padding-top:7px;
  display:inline-block;
  text-align:center;
  position:relative;
  float:left;
  -webkit-transition: background 0.2s ease-in-out;
  -moz-transition: background 0.2s ease-in-out;
  -o-transition: background 0.2s ease-in-out;
  transition: background 0.2s ease-in-out;	
  top:-1px;
}
ul#menu li a span {
  display:block;
  position:absolute;
  top:0;
  left:0;
  height:100%;
  width:100%;
  z-index:0;
}
#menu li:hover {
  width:113px;
  height:30px;
}
#menu li a {
  font-size:16px; 
  color: #cbcbcb;
  display:block;
  outline:0;
  text-decoration:none;
  text-transform:uppercase;
}
#menu li:hover a {
  color:#000;
  -webkit-transition: all .2s ease-in-out;
  -moz-transition: all .2s ease-in-out;
  -o-transition: all .2s ease-in-out;
  transition: all .2s ease-in-out;
}
.dropdown_columns {
	width:150px;
	margin-left:10px;
	/*margin-top:12px;*/
	float:left;
	position:absolute;
	left:-999em; /* Hides the drop down */
	text-align:left;
	padding:1px 0 1px 0;
	font-weight:normal;
	color:#5f5f5f;
	-webkit-border-radius: 2px;
    -moz-border-radius: 2px;
    border-radius: 2px;
	background-image:url('http://cms.team-pheenix.de/templates/stars/images/navi/col_bg.png');	
	box-shadow: 1px 3px 3px 0 #000;
    -webkit-box-shadow: 1px 3px 3px 0 #000;
    box-shadow: 1px 3px 3px 0 #000;
}
#menu li:hover .dropdown_columns {
	left:0;
	top:auto;
	z-index:99;		
}
.col {
	display:inline;
	float: left;
	position: relative;
	padding:0 3px 0 3px;
	opacity:0.8;
}	
a:hover .mask {
  	opacity: 1;
    zoom: 1;
   ...