* {
  border: 1px solid #66ff66cc;
}

body {
  display: flex;
  flex-wrap: wrap;
  flex-direction: row;
  justify-content: space-around;
  align-items: stretch;
  align-content: stretch;
}

body div {
  display: inline-block;
  padding: .5em;
  margin: .1em;
  border: 1px solid #9933cccc;
  max-width: 250px;
}