a {font-family: helvetica; font-size: 1em}
body {background-image: url('bck_dugrau.jpg');
height: 90%; max-width: 160vh;}
table {margin: 0px auto}
header {background-color: lightgray;  margin: 0px auto; width: 105vh;}
table { margin:0px auto }
strong.bckgr { background-color: lightgray; margin:0px auto}