Center CSS / HTML menu

#cssmenu > ul,
#cssmenu > ul li,
#cssmenu > ul ul {
      list-style: none;
      margin: 0;
      padding: 0;
}
#cssmenu > ul {
      position: relative;
      z-index: 597;
      float: left;
}
#cssmenu > ul li {
      float: left;
      min-height: 1px;
      line-height: 1.3em;
      vertical-align: middle;
      padding: 10px;
}
#cssmenu > ul li.hover,
#cssmenu > ul li:hover {
      z-index: 599;
      cursor: default;
}
#cssmenu > ul ul {
      visibility: hidden;
      position: absolute;
      top: 100%;
      left: 0;
      z-index: 598;
}
#cssmenu > ul ul li {
      float: none;
}
#cssmenu > ul li:hover > ul {
      visibility: visible;
}
/* Align last drop down RTL */
/* Theme Styles */
#cssmenu > ul a:link {
      text-decoration: none;
}
#cssmenu > ul a:active {
      color: #ffa500;
}
#cssmenu li {
      padding: 0;
      color: #000;
}
#cssmenu {
      font-family: 'Lato', sans-serif;
      width: auto;
      -webkit-border-radius: 3px;
      -moz-border-radius: 3px;
      -ms-border-radius: 3px;
      -o-border-radius: 3px;
      border-radius: 3px;
      background: #1b9bff;
      font-size: 13px;
      -moz-box-shadow: inset 0 2px 2px rgba(255, 255, 255, 0.3);
      -webkit-box-shadow: inset 0 2px 2px rgba(255, 255, 255, 0.3);
      box-shadow: inset 0 2px 2px rgba(255, 255, 255, 0.3);
}
#cssmenu > ul {
      padding: 0 5px;
      -moz-box-shadow: inset 0 -2px 2px rgba(0, 0, 0, 0.3);
      -webkit-box-shadow: inset 0 -2px 2px rgba(0, 0, 0, 0.3);
      box-shadow: inset 0 -2px 2px rgba(0, 0, 0, 0.3);
      -webkit-border-radius: 3px;
      -moz-border-radius: 3px;
      -ms-border-radius: 3px;
      -o-border-radius: 3px;
      border-radius: 3px;
      display: block;
      float: none;
      zoom: 1;
 }
 #cssmenu > ul:before {
      content: '';
      display: block;
 }
 #cssmenu > ul:after {
      content: '';
      display: table;
      clear: both;
 }
 #cssmenu > ul > li {
      padding: 8px 5px;
 }
 #cssmenu > ul > li > a,
 #cssmenu > ul > li > a:link,
 #cssmenu > ul > li > a:visited {
      text-shadow: 0 -1px 1px #004881;
      color: #fff;
      padding: 7px 20px;
      display: block;
      -webkit-border-radius: 3px;
      -moz-border-radius: 3px;
      -ms-border-radius: 3px;
      -o-border-radius: 3px;
      border-radius: 3px;
 }
 #cssmenu > ul > li > a:hover,
 #cssmenu > ul > li:hover > a {
      background-color: #0082e7;
 }
 #cssmenu li li a {
      color: #8b8b8b;
      font-size: 13px;
 }
 #cssmenu li li a:hover {
      color: #5c5c5c;
      border-color: #5c5c5c;
 }
 #cssmenu ul ul {
      margin: 0 10px;
      padding: 0 10px;
      float: none;
      background: #efefef;
      border: 2px solid #1b9bff;
      border-top: none;
      right: 0;
      left: 0;
      -webkit-border-radius: 0 0 3px 3px;
      -moz-border-radius: 0 0 3px 3px;
      -ms-border-radius: 0 0 3px 3px;
      -o-border-radius: 0 0 3px 3px;
      border-radius: 0 0 3px 3px;
      -moz-box-shadow: 0 2px 3px rgba(0, 0, 0, 0.2);
      -webkit-box-shadow: 0 2px 3px rgba(0, 0, 0, 0.2);
      box-shadow: 0 2px 3px rgba(0, 0, 0, 0.2);
}
#cssmenu ul > li > ul > li {
      margin: 0 10px 0 0;
      position: relative;
      padding: 0;
      float: left;
}
#cssmenu ul > li > ul > li > a {
      padding: 10px 20px 10px 10px;
      display: block;
}
#cssmenu ul > li > ul > li.has-sub > a:before {
      content: '';
      position: absolute;
      top: 18px;
      right: 6px;
      border: 5px solid transparent;
      border-top: 5px solid #8b8b8b;
}
#cssmenu ul > li > ul > li.has-sub > a:hover:before {
      border-top: 5px solid #5c5c5c;
}
#cssmenu ul ul ul {
      width: 200px;
      top: 100%;
      border: 2px solid #1b9bff;
}
#cssmenu ul ul ul li {
      float: none;
}

<div id='cssmenu'>
    <ul>
       <li><a href='#'><span>Home</span></a></li>
       <li class='active has-sub'><a href='#'><span>Products</span></a>
          <ul>
             <li class='has-sub'><a href='#'><span>Product 1</span></a>
                <ul>
                   <li><a href='#'><span>Sub Product</span></a></li>
                   <li class='last'><a href='#'><span>Sub Product</span></a></li>
                </ul>
             </li>
             <li class='has-sub'><a href='#'><span>Product 2</span></a>
                <ul>
                   <li><a href='#'><span>Sub Product</span></a></li>
                   <li class='last'><a href='#'><span>Sub Product</span></a></li>
                </ul>
             </li>
          </ul>
       </li>
       <li><a href='#'><span>About</span></a></li>
       <li class='last'><a href='#'><span>Contact</span></a></li>
    </ul>
</div>