Border Image on just one of the borders while others are solid
===

I use border image to create a gradient on the left border of a TH but right border must be solid. But border image applies to all borders and there is no border-image-right to prevent it. How can I fix this? 

    <style>
    TH {
        border-left:1px solid;
        -webkit-border-image:-webkit-linear-gradient(bottom, #BBB, rgba(255, 255, 255, 0)) 0 100%
        border-right:1px solid #CCC;
    }
    </style>