.problem {
  background-color: #FFF9E8; /*complementary to E9EFFF*/
  border: 1px solid dimgray;
  line-height: calc(1em * 1.5); /*baseline*/
  margin-left: 1em;
  margin-right: 1em;
  /*top, right, bottom, left*/
  padding: 0.5em 0.75em 0.5em 0.75em;
  text-align: justify;
}