header {
  font-size: 36px;
  background-color: #477B7F;
  padding: 5%;
}

.background {
  background-image: url("../pictures/languagesmedium.jpg");
  background-position: center;
  background-size: cover;
  background-repeat: repeat;
  height: 3em;
}

.image_grid {
  list-style: none;
  width: auto;
}

.image_grid li {
  display: inline-block;
  padding: 5px;
  border: 1px solid #DDD;
  vertical-align: bottom;
  max-width: 45%;

}

.image_grid img {
  margin: 5px;
  max-width: 75%;
  height: auto;
}

.question_order {
  font-size: 22px;
  text-decoration: underline;
}
.question
{
  font-size: 28px;
}

.correct_answer {
color: blue;
}

.status {
font-size: 26px;
text-align: center;
}

#correct  {
  color: #19BF19;
}

#incorrect {
  color: #E52622;
}

#submit {
  width: 10em;
  height: 2em;
  font-size: 18px;
}

footer {
  bottom: 0;
  padding: 5%;
  background-color: #477B7F;
}
header {
  font-size: 36px;
  background-color: #477B7F;
  padding: 5%;
}

.background {
  background-image: url("../pictures/languagesmedium.jpg");
  background-position: center;
  background-size: cover;
  background-repeat: repeat;
  height: 3em;
}

.image_grid {
  list-style: none;
  width: auto;
}

.image_grid li {
  display: inline-block;
  padding: 5px;
  border: 1px solid #DDD;
  vertical-align: bottom;
  width: 45%;
  height: 45%;

}

.image_grid img {
  margin: 5px;
  max-width: 75%;
  height: auto;
}

.question_order {
  font-size: 22px;
  text-decoration: underline;
}
.question
{
  font-size: 28px;
}

.correct_answer {
color: blue;
}

.status {
font-size: 26px;
text-align: center;
}

#correct  {
  color: #19BF19;
}

#incorrect {
  color: #E52622;
}

#submit {
  width: 10em;
  height: 2em;
  font-size: 18px;
}

footer {
  bottom: 0;
  padding: 5%;
  background-color: #477B7F;
}
Fix image height and width in grid
Fix image height and width in grid
