r-width-properties" />
        <meta name="flags" content="ahem" />
        <meta name="assert" content="The 'border-right-width' property supports a nominal length value in 'ex' units that sets the width of the right border." />
        <style type="text/css">* { margin: 0; padding: 0 }
            div
            {
                font: 20px Ahem;
                height: 1in;
            }
            #reference
            {
                background-color: black;
                width: 1in;