JSFiddle - React, Tailwind, and code Playground

HTML

<div id='cssmenu'>
<ul>
   <li class='has-sub '><a href='#'><span>a</span></a>
      <ul>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
      </ul>
   </li>
   <li class='has-sub '><a href='#'><span>a</span></a>
      <ul>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
      </ul>
   </li>
   <li class='has-sub '><a href='#'><span>a</span></a>
      <ul>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
      </ul>
   </li>
   <li class='has-sub '><a href='#'><span>a</span></a>
      <ul>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
      </ul>
   </li>
   <li class='has-sub '><a href='#'><span>a</span></a>
      <ul>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
      </ul>
   </li>
   <li class='has-sub '><a href='#'><span>a</span></a>
      <ul>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a href=a.php'><span>a</span></a>
         <li class='has-sub '><a...

CSS

#cssmenu ul,
#cssmenu li,
#cssmenu span,
#cssmenu a {
  margin: 0;
  padding: 0;
  position: relative;
}
#cssmenu {
  height: 49px;
  border-radius: 0px 0px 0 0;
  -moz-border-radius: 0px 0px 0 0;
  -webkit-border-radius: 0px 0px 0 0;
  background: #2F612F;
  background: -moz-linear-gradient(top, #32323a 0%, #2F612F 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #32323a), color-stop(100%, #2F612F));
  background: -webkit-linear-gradient(top, #32323a 0%, #2F612F 100%);
  background: -o-linear-gradient(top, #32323a 0%, #2F612F 100%);
  background: -ms-linear-gradient(top, #32323a 0%, #2F612F 100%);
  background: linear-gradient(to bottom, #32323a 0%, #2F612F 100%);
  filter: progid:DXImageTransform.Microsoft.Gradient(StartColorStr='#32323a', EndColorStr='#2F612F', GradientType=0);
}
#cssmenu:after,
#cssmenu ul:after {
  content: '';
  display: block;
  clear: both;
}
#cssmenu a {
  background: #2F612F;
  background: -moz-linear-gradient(top, #32323a 0%, #2F612F 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #32323a), color-stop(100%, #2F612F));
  background: -webkit-linear-gradient(top, #32323a 0%, #2F612F 100%);
  background: -o-linear-gradient(top, #32323a 0%, #2F612F 100%);
  background: -ms-linear-gradient(top, #32323a 0%, #2F612F 100%);
  background: linear-gradient(to bottom, #32323a 0%, #2F612F 100%);
  filter: progid:DXImageTransform.Microsoft.Gradient(StartColorStr='#32323a', EndColorStr='#2F612F', GradientType=0);
  color: #ffffff;
  display: inline-block;
  font-family: Helvetica, Arial, Verdana, sans-serif;
  font-size: 12px;
  line-height: 49px;
  padding: 0 10px;
  text-decoration: none;
}
#cssmenu ul {
  list-style: none;
}
#cssmenu > ul {
  float: left;
}
#cssmenu > ul > li {
  float: left;
}
#cssmenu > ul > li:hover > a {
  background: #070707;
  background: -moz-linear-gradient(top, #26262c 0%, #070707 100%);
  background: -webkit-gradient(linear, left top, left bottom,...