JSFiddle - React, Tailwind, and code Playground

HTML

<header>
  <div class="bar-menu">
    <a href="index.html"><img src="DT.png" alt="Logo"/></a>
    <nav>
      <ul>
        <li><a href="index.html"><i class="fas fa-home"></i>Accueil</a></li>
        <li class="active">
          <a href="page1.html"><i class="fas fa-clone"></i>Services</a>
          <div class="sous-menu1">
            <ul>
              <li><a href="#">aaa</a></li>
              <li><a href="#">aaa</a></li>
              <li><a href="#">aaa</a></li>
            </ul>
          </div>
        </li>
        <li>
          <a href="page2.html"><i class="fas fa-user"></i>A propos</a>
        </li>
      </ul>
    </nav>
  </div>
</header>

CSS

html {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

body{
  background-image: url(backgroud.jpg);
  background-size: cover;
  background-position: center;
  font-family: sans-serif;
  padding: 0;
  margin: 0;
}

.bar-menu{
  background: rgb(0, 100, 0);
  text-align: center;
  padding: 0;
  margin: 0;
}

.bar-menu ul{
  display: inline-flex;
  list-style: none;
  color: #fff;
}

.bar-menu ul li{
  width: 120px;
  margin: 15px;
  padding: 15px;
}

.bar-menu ul li a{
 text-decoration: none;
 color: #fff;
}

.active, .bar-menu ul li:hover{
  background: #12ab0d;
  border-radius: 3px;
}

.bar-menu .fas{
  margin-right: 5px;
}

.sous-menu1{
  display: none;
}

.bar-menu ul li:hover .sous-menu1{
  display: block;
  position: absolute;
  background: rgb(0,100,0);
  margin-top: 15px;
  margin-left: -15px;
}
 .bar-menu ul li:hover .sous-menu1 ul{
   display: block;
   margin: 10px;
 }

.bar-menu ul li:hover .sous-menu1 ul li{
  width: 150px;
  padding: 10px;
  border-bottom: 1px dotted #fff;
  background: transparent;
  border-radius: 0;
  text-align: left;
}

.bar-menu ul li:hover .sous-menu1 ul li:last-child{
  border-bottom: none;
}

.bar-menu ul li:hover .sous-menu1 ul li a:hover{
  color: #b2ff00;
}

.fa-angle-right{
  float: right;
}

.sous-menu2{
  display: none;
}

.hover-me:hover .sous-menu2{
  position: absolute;
  display: block;
  margin-top: -40px;
  margin-left: 140px;
  background: rgb(0, 100, 0);
}