body {
  font-family: "Times", serif;
  font-size: 18px;
  padding: 20px;
}
.container {
  display: grid;
  grid-row-gap: 20px;
}
@media only screen and (min-width: 468px) {
  .container {
    grid-column-gap: 20px;
    grid-template-columns: 300px 300px 300px;
  }
}

article {
  border-bottom: 1px #ccc dashed;
  margin-bottom: 20px;
  padding-bottom: 20px;
}
ul, p, li {
  margin-bottom: 20px;
}

article:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}