body {
  background: linear-gradient(rgba(0,0,0,0.45), rgba(0,0,0,0.45)),
              url('/background.jpg') no-repeat center center fixed;
  background-size: cover;
  min-height: 100vh;
}

.card,
.card-body,
.card-footer {
  background-color: rgba(255,255,255,0.9);
}