body {
  font-family: times;
  font-size: 16px;
  margin: 1em 1em 1em 1em;

}

table.prettytable {
  /* margin: 1em 1em 1em 2em; */
  background: whitesmoke;
  border-collapse: collapse;
}
table.prettytable th, table.prettytable td {
  border: 1px silver solid;
  padding: 0.2em;
}
table.prettytable th {
  background: gainsboro;
  text-align: left;
}
table.prettytable caption {
  margin-left: inherit;
  margin-right: inherit;
}