html {
  height: 100%;
  width: 100%;
}
body {
  background-color: #f5f5f5;
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  text-align: center;
  vertical-align: center;
}
table, th, td {column-width: 200px;border: 1px solid black;}
tr:nth-child(even) {background-color: #ddd;}