On the site I'm working on for my high school basketball team, certain elements don't work in Internet Explorer. The site is hermantownbasketball.com. The boys basketball sidebar should have nested drop down menus, one when you mouse over the team, such as "High School" and then another when you mouse over the grade under the team, such as 9th grade. This works perfectly fine in chrome, however, I can't get it to work in any version of Internet Explorer. Below is the part of the html and the corresponding css I am using.

Unfortunately, I don't know enough css to know which part of my code IE doesn't like or how to fix it.

Any help is greatly appreciated!

HTML

    <span class = "boyItem">
    <h3>High School</h3>

    <li class="group">
    <h4>9th Grade</h4>
    <div class = "nested">Schedule</div>
    <div class = "nested">Events</div>
    <div class ="nested">Forms</div>
    <div class ="nested">Calendar</div>
    </li>
    <li class="group">
    <h4>JV/Varsity</h4>
    <div class = "nested">Schedule</div>
    <div class = "nested">Events</div>
    <div class = "nested">Forms</div>
    <div class = "nested">Calendar</div>
    </li>

    </span>


    /* Creates the box around the title for each boy section. */
    .boyItem h3 { background:#1C23E8; 
    color:#EFFA20; 
    padding-right:2px; padding:10px; 
    font-size:18px; 
    margin-left:-30px; 
    margin-top:-10px;
    }

###CSS

    .boyItem h3:hover { background:#2A8FF5; }

    /* Prevents the boy sub-sections from being visable */
    .boyItem li h4 { position: absolute; left:-9999px; font-size:15px; list-style-type:none;} 

    /* Shows the boy sub-sections when user mouses over the section title. */
    .boyItem:hover li h4 { 
    position:relative; 
    left:10px; 
    background:#1C23E8; 
    color:#EFFA20;  
    padding-left:20px; 
    padding:5px;
    }

    .boyItem:hover li h4:hover { background:#2A8FF5;}


    .nested { position:absolute; 
    left:-9999px; 
    background:#352EFF; 
    color:#EFFA20; 
    padding-right:2px; 
    padding:4px; 
    font-size:14px; 
    margin:2px; 
    margin-left:30px; 
    margin-top:0px; 
    margin-right:0px; 
    margin-bottom:-2px;} 

    .group:hover .nested {position:relative; left:0px; } 
    .group:hover .nested:hover { background:#2A8FF5}