style.css

@media (max-width: 700px) {
  article {
    width: 95%;
  }
}

.choice-grid {
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
}
.choice-grid div {
  padding: 10px 10px 10px 10px;
  margin: 10px 0 10px 0;
  border: #dcdcdc 1px solid;
  width: calc(32.5% - 22px);
}
@media (max-width: 500px) {
  .choice-grid div {
    padding: 10px 10px 10px 10px;
    margin: 10px 0 10px 0;
    border: #dcdcdc 1px solid;
    width: calc(49% - 22px);
  }
  header div {
    display: none;
  }
}
.choice-grid div img {
  width: 100%
}
.choice-grid div .checkbox {
  width: 20px;
}
.unanswered {
  background-color: #f4f4f4;
}
.highlighted{
  background-color: #cfe3ff;
}
.unhighlighted {
  opacity: 0.6;
}
#resultSection {
  padding: 20px 20px 20px 20px;
  margin: 40px 0px 20px 0px;
}
#restartButton{
  height: 50px;
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #cecece;
}
#restartButton:hover{
  background-color: #e0e0e0;
}
.resultElement{
  margin: 18px 0px 18px 0px;
}