JSFiddle - React, Tailwind, and code Playground

HTML

<div id="main_menu">
                <div class="menu-left-container"><ul id="menu-left" class="menu"><li id="menu-item-266" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home menu-item-266"><a href="http://localhost/">Главная</a></li>
<li id="menu-item-267" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-267"><a href="http://localhost/o-nas.html">О нас</a></li>
<li id="menu-item-271" class="menu-item menu-item-type-taxonomy menu-item-object-category menu-item-271"><a href="http://localhost/category/nashi-raboty">Наши работы</a>
<ul class="sub-menu">
    <li id="menu-item-276" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-276"><a href="http://localhost/nashi-raboty/vanna.html">ванна</a></li>
    <li id="menu-item-277" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-277"><a href="http://localhost/nashi-raboty/prixozhaya.html">прихожая</a></li>
    <li id="menu-item-278" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-278"><a href="http://localhost/nashi-raboty/garderobnaya.html">гардеробная</a></li>
    <li id="menu-item-279" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-279"><a href="http://localhost/nashi-raboty/gostinaya.html">гостиная</a></li>
    <li id="menu-item-280" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-280"><a href="http://localhost/nashi-raboty/detskaya.html">детская</a></li>
    <li id="menu-item-281" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-281"><a href="http://localhost/nashi-raboty/kuxnya.html">кухня</a></li>
</ul>
</li>
<li id="menu-item-268" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-268"><a href="http://localhost/galereya.html">Галерея</a></li>
<li id="menu-item-269" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-269"><a...

CSS

a{
    padding:0;
    margin:0;
    color:#000;
    text-decoration:none;
}

#main_menu {
  width: 180px; 
  margin: 8px 0 0 33px; 
  padding: 0;  
  float: left;
  border:0;
}
.menu-item{
width: 150px;
padding: 3px 5px 3px 15px;
margin: 2px;
float:left;
border: 3px solid #FF6600;
}
.menu-item-object-category{
    width: 170px;
    margin-top: -3px;
    margin-bottom: -3px;
    border:0;
    line-height:1.6
}

.menu-item-object-category a{
    border:3px solid #FF6600;
    margin-left:-15px;
    padding: 3px 64px 4px 15px;
    line-height: 2.2;
}
.menu-item-object-category .menu-item{
    padding: 0 5px 1px 0;
    margin-left:0;
}

.menu-item-object-category .menu-item a{
    border:0;
    margin-left:0;
    line-height:0;
}