/TR/CSS21/box.html#border-width-properties" />
        <meta name="flags" content="invalid" />
        <meta name="assert" content="The 'border-top-width' property does not support a negative length value in centimeters and resets to the initial value." />
        <style type="text/css">* { margin: 0; padding: 0 }
            span
            {
                border-top-style: solid;
            }
            #span1
            {
                border-top-width: -1cm;
            }
           