HTML5 Knockout TriState Tree Control

.UncheckedCheckBox {
    background: url('../Images/chk-1.jpg') no-repeat center;
    width: 16px;
    height: 16px;
    border: none;
    display: inline-block;
    overflow: hidden;
    margin: 0px;
    padding: 0px;
    vertical-align: central;
    text-align: center;
}

.CheckedCheckBox {
    background: url('../Images/chk-2.jpg') no-repeat center;
    width: 16px;
    height: 16px;
    border: none;
    display: inline-block;
    overflow: hidden;
    margin: 0px;
    padding: 0px;
    vertical-align: central;
    text-align: center;
}

.IndeterminateCheckBox {
    background: url('../Images/chk-3.jpg') no-repeat center;
    width: 16px;
    height: 16px;
    border: none;
    display: inline-block;
    overflow: hidden;
    margin: 0px;
    padding: 0px;
    vertical-align: central;
    text-align: center;
}

.CheckBoxOuterDiv {
    display: inline;
    cursor: pointer;
    margin: 0px;
    padding: 0px;
    vertical-align: central;
    text-align: center;
}

.CheckBoxDisplayText {
    margin: 0px;
    padding: 0px;
    vertical-align: central;
    text-align: center;
}

.ExpandCheckBoxTree {
    background: url('../Images/ex-1.jpg') no-repeat center;
    width: 16px;
    height: 16px;
    border: none;
    display: inline-block;
    overflow: hidden;
    margin: 0px;
    padding: 0px;
    vertical-align: central;
    text-align: center;
    cursor: pointer;
}

.CollapseCheckBoxTree {
    background: url('../Images/ex-2.jpg') no-repeat center;
    width: 16px;
    height: 16px;
    border: none;
    display: inline-block;
    overflow: hidden;
    margin: 0px;
    padding: 0px;
    vertical-align: central;
    text-align: center;
    cursor: pointer;
}