body {
  padding: 50px;
  font: 14px "Lucida Grande", Helvetica, Arial, sans-serif;
}

a {
  color: #00B7FF;
}

#posts_box{
  display: flex;
  flex-wrap: wrap;
}

.post{
  width:300px;
  margin:5px;
  border: solid 1px;
}