#rules {
background-color: #edeff2;
border: 1px solid #b3bcc9;
overflow: auto;
max-height: 400px;
}

@media only screen and (min-width : 640px) {
  .row {
    display: flex;
  }

  .inputs, #rules {
    float: left;
  }

  #rules {
    align-items: stretch;
  }
}