JSFiddle - React, Tailwind, and code Playground

by Kabir Hossain

HTML

<div id='cssmenu'>
<ul>
   <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 class='has-sub'><a href='#'><span>Many Sub Product</span></a>
                            <ul>
               <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub Product</span></a></li>
                <li><a href='#'><span>Sub...

CSS

#cssmenu ul,
#cssmenu li,
#cssmenu span,
#cssmenu a {
  margin: 0;
  padding: 0;
  position: relative;
}
#cssmenu {
  line-height: 1;
  border-radius: 5px 5px 0 0;
  -moz-border-radius: 5px 5px 0 0;
  -webkit-border-radius: 5px 5px 0 0;
  
  width: auto;
}
#cssmenu:after,
#cssmenu ul:after {
  content: '';
  display: block;
  clear: both;
}
#cssmenu a {
  background: #141414;
  background: -moz-linear-gradient(top, #333333 0%, #141414 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #333333), color-stop(100%, #141414));
  background: -webkit-linear-gradient(top, #333333 0%, #141414 100%);
  background: -o-linear-gradient(top, #333333 0%, #141414 100%);
  background: -ms-linear-gradient(top, #333333 0%, #141414 100%);
  background: linear-gradient(to bottom, #333333 0%, #141414 100%);
  color: #ffffff;
  display: block;
  font-family: Helvetica, Arial, Verdana, sans-serif;
  padding: 19px 20px;
  text-decoration: none;
}
#cssmenu ul {
  list-style: none;
}
#cssmenu > ul > li {
  display: inline-block;
  float: left;
  margin: 0;
}
#cssmenu.align-center {
  text-align: center;
}
#cssmenu.align-center > ul > li {
  float: none;
}
#cssmenu.align-center ul ul {
  text-align: left;
}
#cssmenu.align-right > ul {
  float: right;
}
#cssmenu.align-right ul ul {
  text-align: right;
}
#cssmenu > ul > li > a {
  color: #ffffff;
  font-size: 12px;
}
#cssmenu > ul > li:hover:after {
  content: '';
  display: block;
  width: 0;
  height: 0;
  position: absolute;
  left: 50%;
  bottom: 0;
  border-left: 10px solid transparent;
  border-right: 10px solid transparent;
  border-bottom: 10px solid #0fa1e0;
  margin-left: -10px;
}
#cssmenu > ul > li:first-child > a {
  border-radius: 5px 0 0 0;
  -moz-border-radius: 5px 0 0 0;
  -webkit-border-radius: 5px 0 0 0;
}
#cssmenu.align-right > ul > li:first-child > a,
#cssmenu.align-center > ul > li:first-child > a {
  border-radius: 0;
  -moz-border-radius: 0;
  -webkit-border-radius:...

JavaScript

var maxHeight = 400;

$(function(){

    $("#cssmenu > li").hover(function() {
    
         var $container = $(this),
             $list = $container.find("ul"),
             $anchor = $container.find("a"),
             height = $list.height() * 1.1,       // make sure there is enough room at the bottom
             multiplier = height / maxHeight;     // needs to move faster if list is taller
        
        // need to save height here so it can revert on mouseout            
        $container.data("origHeight", $container.height());
        
        // so it can retain it's rollover color all the while the dropdown is open
        $anchor.addClass("hover");
        
        // make sure dropdown appears directly below parent list item    
        $list
            .show()
            .css({
                paddingTop: $container.data("origHeight")
            });
        
        // don't do any animation if list shorter than max
        if (multiplier > 1) {
            $container
                .css({
                    height: maxHeight,
                    overflow: "hidden"
                })
                .mousemove(function(e) {
                    var offset = $container.offset();
                    var relativeY = ((e.pageY - offset.top) * multiplier) - ($container.data("origHeight") * multiplier);
                    if (relativeY > $container.data("origHeight")) {
                        $list.css("top", -relativeY + $container.data("origHeight"));
                    };
                });
        }
        
    }, function() {
    
        var $el = $(this);
        
        // put things back to normal
        $el
            .height($(this).data("origHeight"))
            .find("ul")
            .css({ top: 0 })
            .hide()
            .end()
            .find("a")
            .removeClass("hover");
    
    });
    
    // Add down arrow only to menu items with submenus
    $("#cssmenu > li:has('ul')").each(function() {
       ...