JSFiddle - React, Tailwind, and code Playground

HTML

<div id="navcontainer">
<ul id="navlist">
<li><a href="obs-geostrategique-sport1.php?cat=2">ACTUALITÉS</a></li>
<li><a href="obs-geostrategique-sport1.php?cat=5">ANALYSE</a></li>
<li><a href="obs-geostrategique-sport1.php?cat=1">PROGRAMME EUROPÉEN DE LUTTE <br>CONTRE LE TRUCAGE DE MATCHS</a></li>
<li><a href="obs-geostrategique-sport1.php?cat=3">COMMUNIQUÉ</a></li>

<li><a href="#">THEMATIQUES</a> 
<ul id="subnavlist">
	<li id="subactive"> <a href="obs-geostrategique-sport1.php?cat=4&id=1">Lutte contre la corruption</a></li>
	<li><a href="obs-geostrategique-sport1.php?cat=4&id=2">Evènements sportifs </a></li>
	<li><a href="obs-geostrategique-sport1.php?cat=4&id=3">Bonne gouvernance du sport</a></li>
	<li><a href="obs-geostrategique-sport1.php?cat=4&id=4">Economie du sport</a></li>
	<li><a href="obs-geostrategique-sport1.php?cat=4&id=5">Lutte contre le dopage</a></li>
	<li><a href="obs-geostrategique-sport1.php?cat=4&id=7">Lutte pour l'intégrité dans le sport</a></li>
</ul>
</li>
</ul>
</div>

CSS

<style type="text/css">

html, body {
  margin: 0;
  padding: 0;
}

#navcontainer { padding: 0 5 20px 10px; }


ul#navlist {
  font-family: sans-serif;
  margin-left: 0;
  padding: 0;
}

ul#navlist li
{
  padding: 10px 5px 10px 5px;
  background-color: #EF634A;
}
ul#navlist > li
{
  height:38px; 
  line-height:38px;
}
ul#navlist li:hover
{
  color: #ffff00;
  background-color: #3E748A;
}
ul#navlist a
{
  font-weight: bold;
  text-decoration: none;
  display: inline-block;
  line-height:1.1;
  vertical-align: middle;
}


ul#navlist ul, ul#navlist li
{
  padding: 0 8px;
  margin: 0 8px;
  list-style-type: none;
  box-shadow: 8px 8px 12px #aaa;
}

ul#navlist > li:first-child {
  margin-left: 0;
}

ul#navlist li { float: left; 
}

ul#navlist li a
{
  color: #ffffff;
  
  //padding:10px;
  
  /*border: 1px #ffffff outset;
  height: 40px;*/ 
}


ul#navlist li:active
{
  color: #cccccc;
  background-color: #3E748A;
  border: 1px #ffffff inset;
  box-shadow: none;
}

ul#subnavlist { display: none; }
ul#subnavlist li { float: none;line-height:normal; }

ul#subnavlist li a
{
  padding: 0px;
  margin: 0px;
  height: 14px;
}

ul#navlist li:hover ul#subnavlist
{
  display: block;
  //display: inline-block;
  //display: table-cell;
  
  position: absolute;
  font-size: 8pt;
  padding-top: 5px;
  box-shadow: none;
}

ul#navlist li:hover ul#subnavlist li a
{
  display: block;
  width : 360;
  height : 100;
  border: none;
  padding: 2px;
}

ul#navlist li:hover ul#subnavlist li a:before { content: " >> "; }

a.white:link {color: #fff;}
a.white:active {color: #fff;}
a.white:visited {color: #fff;}
a.white:hover {color: #fff;}

</style>