.jumbotron {
  padding: 2rem 1rem;
  margin-bottom: 2rem;
  background-color: #e9ecef;
  border-radius: .3rem;
}
.navbar {
  padding: .5rem 1rem
}
.mr-auto, .mx-auto {
  margin-right: auto !important;
}
.card-deck .card {
  margin-bottom: 15px
}
.main-image {
  width: 100%;
  max-width: 500px;
}
.main-image-lg {
  width: 100%;
  max-width: 700px;
}
@media (min-width: 576px) {
  .card-deck {
    display:-ms-flexbox;
    display: flex;
    -ms-flex-flow: row wrap;
    flex-flow: row wrap;
  }

  .card-deck .card:not(:first-child) {
    margin-left: 15px
  }

  .card-deck .card {
    -ms-flex: 1 0 0%;
    flex: 1 0 0%;
    margin-bottom: 0;
  }
}