Styled checkboxes provide consistency across the site. Just add .checkbox-styled to the .checkbox.
<form role="form">
<div class="checkbox checkbox-styled">
<input type="checkbox" name="sample" id="checkbox1" checked="checked">
<label for="checkbox1">Checkbox - Checked</label>
</div>
<div class="checkbox checkbox-styled">
<input type="checkbox" name="sample" id="checkbox2">
<label for="checkbox2">Checkbox</label>
</div>
</form><form role="form">
<div class="checkbox checkbox-styled">
<input type="checkbox" name="sample" id="checkbox1" checked="checked">
<label for="checkbox1">Checkbox Disabled</label>
</div>
<div class="checkbox checkbox-styled">
<input type="checkbox" name="sample" id="checkbox2">
<label for="checkbox2">Checkbox Disabled & Checked</label>
</div>
</form>