.Card {
  /*background-color: var(--card-background-color); removed because of tables which take 100% height! when table's height is less then 100% white background is visible*/
  position: relative;
  border-radius: 2px;
  margin: 10px;
  padding: 0;
  box-sizing: border-box;
  min-width: 300px;
  flex: 1; /* take available space in flex container */
}

.Card.LessMargin {
  margin: 5px;
}