JSFiddle - React, Tailwind, and code Playground

HTML

<div id="menu1">
    <ul class="menu">
        <li><a class="haschild" title="" href="">Home</a>
            <ul class="sub-menu">
                <li><a class="haschild" title="" href="">Sub Link 1</a>
                    <ul>
                        <li><a title="" href="">Sub Sub Link 1</a></li>
                        <li><a title="" href="">Sub Sub Link 2</a></li>
                        <li><a title="" href="">Sub Sub Link 3</a></li>
                    </ul>
                </li>
                <li><a title="" href="">Sub Link 2</a></li>
                <li><a class="haschild" title="" href="">Sub Link 3</a>
                    <ul>
                        <li><a title="" href="">Sub Sub Link 1</a></li>
                        <li><a title="" href="">Sub Sub Link 2</a></li>
                        <li><a title="" href="">Sub Sub Link 3</a></li>
                    </ul>
                </li>
            </ul>
        </li>
        <li><a class="haschild" title="" href="">About Us</a>
            <ul class="sub-menu">
                <li><a title="" href="">Sub Link 1</a></li>
                <li><a title="" href="">Sub Link 2</a></li>
                <li><a class="haschild" title="" href="">Sub Link 3</a>
                    <ul>
                        <li><a title="" href="">Sub Sub Link 1</a></li>
                        <li><a title="" href="">Sub Sub Link 2</a></li>
                        <li><a title="" href="">Sub Sub Link 3</a></li>
                    </ul>
                </li>
            </ul>
        </li>
        <li><a class="haschild" title="" href="">Our Services Etc Etc Etc</a>
            <ul class="sub-menu">
                <li><a title="" href="">Sub Link 1</a></li>
                <li><a class="haschild" title="" href="">Sub Link 2</a>
                    <ul>
                        <li><a title="" href="">Sub Sub Link 1</a></li>
                        <li><a title="" href="">Sub Sub Link 2</a></li>
                        <li><a...

CSS

#menu1 *
{
    margin: 0;
    padding: 0;
}

#menu1 ul.menu
{
    float: left;
    font-family: "Arial", sans-serif;
    font-size: 14px;
    font-weight: bold;
    text-transform: uppercase;
}

#menu1 ul.menu li
{
    position: relative;
    float: left;
    list-style-type: none;
}

#menu1 ul.menu li a
{
    position: relative;
    display: block;
    line-height: 21px;
    font-size: 14px;
    padding: 14px 21px;
    text-decoration: none;
    z-index: 100;
}

#menu1 ul.menu > li:first-child > a
{
    border-left: 0;
}

#menu1 ul.menu > li:last-child > a
{
    border-right: 0;
}

/** Sub Menu - Tier 2 **/

#menu1 ul.menu li ul.sub-menu
{
    position: relative;
    display: none;
    margin: 0;
    padding: 0;
}

#menu1 ul.menu li:hover ul.sub-menu
{
    display: block;
    float: left;
    position: absolute;
    z-index: 200;
}

#menu1 ul.menu li ul.sub-menu > li:first-child
{
    margin: 5px 0 0 0;
}

#menu1 ul.menu li ul.sub-menu li a
{
    width: 140px;
    display: block;
}

#menu1 ul.menu li ul.sub-menu li:first-child > a
{
    border-top: 0;
}

#menu1 ul.menu li ul.sub-menu li:last-child > a
{
    border-bottom: 0;
}

/** Sub Menu - Tier 3 **/

#menu1 ul.menu li ul.sub-menu li ul
{
    position: relative;
    display: none;
    left: 100%;
}

#menu1 ul.menu li ul.sub-menu li ul li
{
    margin: 0 0 0 5px;
}

#menu1 ul.menu li ul.sub-menu li:hover ul
{
    display: block;
    float: left;
    position: absolute;
    top: 0;
}

#menu1 ul.menu li ul.sub-menu li ul li a
{
    width: 140px;
    display: block;
}


/** Colour Styles **/

#menu1 ul.menu li a
{
    background: #09F;
    color: #FFF;
}

#menu1 ul.menu > li > a
{
    border-left: 1px solid #26A8FF;
    border-right: 1px solid #0082D9;
}

#menu1 ul.menu li:hover > a, #menu1 ul.menu li a:hover
{
    color: #09F;
    background: #ddd;
}

#menu1 ul.menu li ul.sub-menu li a
{
    border-top: 1px solid #26A8FF;
    border-bottom: 1px solid #0082D9;
}