xml/css table display

[summertimefl]

my problem is that the table cells don't line up .i attached the xml file

here is the css code:
<?xmlns:html="http://www.w3.org/1999/xhtml">
@namespace html url(http://www.w3.org/1999/xhtml">

reservation {margin:15px}
html\:h1 {font-width: 32pt;font-family: arial, helvetica;color:rgb(0,128,0) ;
margin:0px}
date {display:block}
hour {display:table-cell;text-align: center;font-size:8pt; font-family:arial, helvetica; background-color:yellow; width:50px; border-width:1px;border- style:solid;border-color:black;border-bottom-width: 2px; padding:2px}
rooms {display:block}
times {display:block}
usage {display:table-cell;font-size:8pt; border-width:1px;borderstyle:solid;border-color:black; padding:2px}

.roomname {width:100px}
usage.yes {width:50px;background-color:red;color:white;text-align:center}
usage.no {width:0px;background-color:white; text-align: center;color:green}

thanks

[drhowarddrfine]

I believe that property still needs width/height assigned to it and does not display exactly the same as a table would in HTML. HTML <table> comes with those properties built in while table-cell does not.