JSFiddle - React, Tailwind, and code Playground

HTML

<div class="colcontainer">
    <div class="col-left">
    {% block news %}{% endblock %}
        <br/>
        <b>Hover on me to increase my height </b>
    </div>  
    <div id="main_content">
        <div class="col-right">
            {% block rightcol %}{% endblock %}
        </div> 
    </div>
    <div id="content">
        <div class="contentwrap">
            <div class="itemwrap">
                {% block content %}{% endblock %}
            </div>
        </div>


    <div class="content-bottom"><div class="content-bottom-left"></div></div>
    </div>
</div>

CSS

.colcontainer{
    width: auto;
}

.col-left {
    background: none repeat scroll 0 0 silver;
    float:left;
    padding:0;
    margin:0;
    width: 300px;
    min-height:198px;
}

.col-left:hover{    
    height: 300px;
}

.col-right {
    background: none repeat scroll 0 0 steelblue;
    text-align:left;
    padding:0;
    margin:0 0 0 200px;
    height:198px;
}

#content {
    background: none repeat scroll 0 0 yellowgreen;    
    margin: 10px auto;
    padding: 10px;

}