layout.css

/**
 * @file
 * Stark layout method
 *
 * To avoid obscuring CSS added to the page by Backdrop or a contrib module, the
 * Stark theme itself has no styling, except just enough CSS to display the page
 * in a readable manner.
 */
body {
  margin: 0 10px;
}
body > .layout {
  max-width: 1200px;
  margin: 0 auto;
}

table {
  width: 100%;
}

/**
 * Responsive tables.
 */
@media screen and (max-width:450px) {
  th.priority-low,
  td.priority-low,
  th.priority-medium,
  td.priority-medium {
    display: none;
  }
}
@media screen and (max-width:720px) {
  th.priority-low,
  td.priority-low {
    display: none;
  }
}