CSS Checkbox :checked Not Working with Two Toggles

I am trying to create two different menus with two different checkbox toggles using :checked method. For some reason, I can't have two toggles even though each checkbox field has different ID's.

Here is what I'm working with: http://ift.tt/1pFTIHk

<input type="checkbox" id="menu-toggle-left">
<input type="checkbox" id="menu-toggle-right">

<div class="mobile-menu-wrap">

    <div class="mobile-menu-left">
        First Menu
    </div>

    <div class="mobile-menu-right">
        Second Menu
    </div>

</div>

The second checkbox toggle works fine, but the first only works if I remove the second. Any thoughts on what I'm doing wrong? Is this not possibe?