* 
{
  box-sizing: border-box;
  font-family: arial;
}

img, .column
{
  display: block;
  margin-left: auto;
  margin-right: auto;
  width: 90%;
  text-align: center;
}

/* Create four equal columns that floats next to each other */
.column {
  float: left;
  width: 25%;
  padding: 20px;
}

/* On screens that are 992px wide or less, go from four columns to two columns */
@media screen and (max-width: 992px) {
  .column {
    width: 50%;
  }
}

/* On screens that are 600px wide or less, make the columns stack on top of each other instead of next to each other */
@media screen and (max-width: 600px) {
  .column {
    width: 100%;
  }
}