JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
<ul>
    <li><a>Vocabulary Bowl.</a></li>    
    <li><a>Bowl.</a></li>       
    <li><a>Today's Leaders.</a></li>
    <li><a>Weekly LeadersToday's.</a></li>  
    <li><a>Bowl.</a></li>   
    <li><a>Monthly Leaders.</a></li>    
    <li><a>Bowl.</a></li>   
    <li><a>Vocabulary Bowl Today's Leaders.</a></li>    
    <li><a>Bowl Leaders.</a></li>       
    <li><a>Today's Leaders Today's Leaders Today's Leaders.</a></li>
    <li><a>Weekly Leaders.</a></li>
    <li><a>Monthly.</a></li>    
    <li><a>Vocabulary Bowl.</a></li>    
    <li><a>Bowl Leaders.</a></li>       
    <li><a>Today's Leaders.</a></li>
    <li><a>Weekly Leaders.</a></li>
    <li><a>Monthly Leaders.</a></li>    
    <li><a>Vocabulary Bowl.</a></li>    
    <li><a>Bowl Leaders.</a></li>       
    <li><a>Today's Leaders.</a></li>
    <li><a>Weekly Leaders.</a></li>
    <li><a>Monthly Leaders.</a></li>                        
</ul>

CSS

.wrapper{
        background: #eee none repeat scroll 0 0;
        border: 1px solid #ddd;
        height: 20px;
        overflow: hidden;
        padding: 5px;
        width: 600px;
        float: left;
    }   
    ul{
        float: left;
        margin: 0;
        padding: 0;
    }
    ul li{
        float: left;
        padding: 0 5px;
        list-style-type: none;
    }
    
    li.visible {
      color:#f00;
    }
    li.visible-whole {
      outline:1px solid #0f0;
    }

JavaScript

$(function(){

	var wrapper = document.querySelector('.wrapper'), 
  	wrapperBox = wrapper.getBoundingClientRect();
  var inBoxPartial = $("li").filter( function(idx, li){
  	var liBox = li.getBoundingClientRect();
  	return liBox.top < wrapperBox.bottom && liBox.left < wrapperBox.right;
  }).addClass('visible');
  
  var inBoxTotal = $("li").filter( function(idx, li){
  	var liBox = li.getBoundingClientRect();
  	return liBox.bottom < wrapperBox.bottom && liBox.right < wrapperBox.right;
  }).addClass('visible-whole');
  console.log( inBoxPartial, inBoxTotal );

});