main {
  flex: 1 0 auto;
}

footer {
  text-align: center;
  position: fixed;
  bottom: 0;
}

.row {
  margin-top: 20px;
  display: flex;
  justify-content: space-between;
}

.col-md-6 {
  flex: 0 0 50%;
  max-width: 50%;
}

.col-md-12 {
  flex: 0 0 100%;
  max-width: 100%;
}