JSFiddle - React, Tailwind, and code Playground

HTML

<div id="secondaryTopBarContainer">
            <div id="secondaryTopMenuContainer">
                <ul id="secondaryTopMenu">
                    <li>
                        <a>Mercados</a>
                        <ul>
                            <li><a href="#">Portugal</a></li>
                            <li><a href="#">Angola</a></li>
                            <li><a href="#">Moçambique</a></li>
                            <li><a href="#">Cabo Verde</a></li>
                            <li><a href="#">São Tomé e Príncipe</a></li>
                            <li><a href="#">Timor Leste</a></li>
                            <li><a href="#">Malta</a></li>
                        </ul>
                    </li>
                    <li><a>Industrias</a></li>
                    <li><a>Serviços Profissionais</a></li>
                    <li>
                        <a>Software</a>
                        <ul>
                            <li><a href="#">Promosoft Financial Suite</a></li>
                            <li>
                                <a href="#" class="drop">Channels</a>
                                <ul>
                                    <li><a href="#">aBanka</a></li>
                                    <li><a href="#">bBanka</a></li>
                                    <li><a href="#">cBanka</a></li>
                                    <li><a href="#">dBanka</a></li>
                                </ul>
                            </li>
                        </ul>
                    </li>
                    <li><a>Alianças</a></li>
                </ul>
            </div>
            <div id="customerLogin"><a href="#">[Login Utilizador]</a></div>
        </div>

CSS

body {
    font-family: Calibri;
    font-size: 12px;
}

#secondaryTopBarContainer
{
    height: 30px;
    line-height: 30px;
    background-color:#ffffff;
}

#secondaryTopBarContainer a
{
    text-transform: uppercase;
}

#secondaryTopMenuContainer
{
    cursor: pointer;
}

#secondaryTopMenuContainer li
{
    position: relative;
}

#secondaryTopMenu li a
{
    display: block;
    color: #333;
    height: 30px;
    padding: 0 16px;
    line-height: 30px;
}

#secondaryTopMenuContainer > ul > li > a {
    margin: -5px 0 5px;
}

#secondaryTopMenuContainer ul ul a.drop
{
    background: #A7C9CA url(../images/exictosLayout/seta.gif) no-repeat 160px center;
}

#secondaryTopMenuContainer ul ul a.drop:hover
{
    background: #769494 url(../images/exictosLayout/seta_activa.gif) no-repeat 160px center;
}

#secondaryTopMenuContainer ul ul :hover > a.drop
{
    background: #769494 url(../images/exictosLayout/seta_activa.gif) no-repeat 160px center;
}

#secondaryTopMenuContainer ul ul ul a
{
    background: #A7C9CA;
}

#secondaryTopMenuContainer ul ul ul a:hover
{
    background: #769494;
}

#secondaryTopMenuContainer ul ul
{
    visibility: hidden;
    position: absolute;
    top: 30px;
    left: 0;
    width: 170px;
    padding: 1px 0 0 0;
}

#secondaryTopMenuContainer ul ul ul
{
    left: 181px;
    top: -1px;
    width: 170px;
}

#secondaryTopMenuContainer ul ul a
{
    background: #A7C9CA;
    padding: 0px 16px;
    width: 148px;
    margin: 0 0 1px 0;
}

#secondaryTopMenuContainer :hover > a, 
#secondaryTopMenuContainer ul ul :hover > a
{
    color: #FFF;
    background: #A7C9CA;
}

#secondaryTopMenuContainer ul ul a:hover
{
    color: #FFF;
    background: #769494;
}

#secondaryTopMenuContainer ul li:hover ul, 
#secondaryTopMenuContainer ul a:hover ul
{
    visibility: visible;
}

#secondaryTopMenuContainer ul :hover ul ul
{
    visibility: hidden;
}

#secondaryTopMenuContainer ul :hover ul :hover ul
{
    visibility: visible;
}

#secondaryTopMenuContainer > ul > li
{
...

JavaScript

dojo.require("dojo.NodeList-traverse");

dojo.query("#secondaryTopMenuContainer > ul > li").connect("onmouseenter", function(evt) {
   dojo.style(evt.currentTarget, "borderLeft", "1px solid #ffffff");
}).connect("onmouseleave", function(evt) {
    dojo.style(evt.currentTarget, "borderLeft", "1px solid #999999"); 
});