JSFiddle - React, Tailwind, and code Playground

HTML

<meta name="viewport" content="user-scalable=0, initial-scale=1.0, maxiumum-scale=1.0, width=device-width" />

<div class="wrapper">
    <h1>HOW TO OPERATE A MIG WELDER</h1>
     
    <section>
        <h2>turn on the oxygen knob</h2>
        <div class="content">
        <p>this is a critical step</p>
            <blockquote>
                The oxygen makes the weld penentrate and illuminates spatter
            </blockquote> 
            <img src=http://pubx.annexmedia.ca/metalworking/wp-content/uploads/sites/30/2013/04/LeakTest.jpg/>
        </div>
    </section>
    
    <section>
        <h2>Connect the ground clamp to your work</h2>
        <div class="content">
            <img src=http://www.gowelding.org/wp-content/uploads/Ground_Clamp.jpg />
           
        </div>
    </section>
    
    <section>
        <h2>turn on welder</h2>
        <div class="content">
            <p>
            you should then hear a humming noise
           
            </p>
        
        
         
        </div>
    </section>
    
    <section>
        <h2>start welding</h2>
        <div class="content">
       <iframe width="640" height="360" src="https://www.youtube.com/embed/nPxqErIVQ9I" frameborder="0" allowfullscreen></iframe>     
    <section>
    
    <section>
        <h2>take it slow</h2>
        <div class="content">
            <p>
            go super slow
            
            </p>
        </div>
    </section>
    
    <section>
        <h2>be careful</h2>
        <div class="content">
           
        </div>
    </section>
    
    <section>
        <h2>have fun</h2>
        <div class="content">
            <img src="http://public.harmonicnw.com/tft_2013-02-20/binocs.gif" />
        </div>
    </section>
    
    <footer>Coded by Gage Choat on Dec 10, 2015</footer>


<script src="http://public.harmonicnw.com/tft_2013-02-20/jquery.fitvids.js"></script>

CSS

body {
   background: #ddd;
   font-family: "lucida grande", tahoma, sans-serif; 
   font-size: 20px;
   height: 100%;
}
html {
    height: 100%;
}
footer {
    color: gray;
    font-size: 0.8em;
    font-style: italic;
    margin: 1em 0;
    text-align: center;
}
blockquote {
  font-style: italic;
  padding: 0 20px;
  font-size: 16px;
}
h1 {
    border-top: 2px dashed rgb(200,200,200);
    border-bottom: 2px dashed rgb(200,200,200);
    font-family: "georgia", serif;
    font-size: 1.6em;
    margin: 1em 0;
    padding: 0.5em;
    text-align: center;
}
h2 {
    background-position: left center;
    background-repeat: no-repeat;
    cursor: pointer;
    font-family: "georgia", serif;
    font-size: 1.2em;
    margin: 0.5em 0;
    opacity: 0.5;
    padding-left: 20px;
    transition: all 500ms ease;
}
h2:hover {
    /*color: rgb(100,100,100);*/
    opacity: 1;
    margin-left: 20px;
}
h2.open {
    background-image: url('http://public.harmonicnw.com/tft_2013-02-20/ddarrow-down.png');
    opacity: 1;
}
h2.closed {
    background-image: url('http://public.harmonicnw.com/tft_2013-02-20/ddarrow-right.png');
}
img {
    height: auto;
    margin-bottom: 1em;
    width: 100%;
}
p {
    margin: 1em 0;
}
section {
    background: rgb(240,240,240);
    border-left: 3px solid rgb(150,50,50);
    margin: 5px 0;
    padding: 5px 3%;
    width: 94%;
}
ul {
    list-style: circle;
    margin: 1em 2em;
}

.wrapper {
    background: white;
    height: 100%;
    margin: 0 auto;
    overflow-y: auto;
    padding: 0 3%;
    width: 90%;
}

JavaScript

$(document).ready( function() {
   
    $(".wrapper").fitVids();
    
    $("section").each( function(i) {
        var content = $(this).children(".content");
        var hdr =  $(this).children("h2");
        hdr.text(i+1 + ". " + hdr.text());
        hdr.click( function(e) {
            if (content.is(":visible")) {
                content.slideUp();
                hdr.removeClass("open").addClass("closed");
            } else {
                $("section").children(".content:visible").slideUp();
                $("section").children("h2").removeClass("open").addClass("closed");
                content.slideDown();
                hdr.removeClass("closed").addClass("open");
            }
            e.preventDefault();
            $(this).blur();
        });
        content.hide();
        hdr.addClass("closed");
    });
    
});