body {
  background: url(/images/niva.jpg) no-repeat center center;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
  font-family: sans-serif;
}

.img-fluid {
  width: 100%;
}

.card-columns {
  column-gap: 0;
}

@media all and (min-width: 576px) {
  .card-columns {
    column-count: 2;
  }
}

@media all and (min-width: 992px) {
  .card-columns {
    column-count: 3;
  }
}

@media all and (min-width: 1200px) {
  .card-columns {
    column-count: 4;
  }
}