body {
  background: #E6F0F2;
}
h1 {
  font-weight: bold;
  margin-top: 100px;
}
.card,
.card-header:first-child {
  border-radius: 0;
}
.card-header {
  border-radius: 0;
  background: #999;
  color: #fff;
}
.card-header h4 {
  margin: 10px 0;
}
.card-block {
  padding: 15px;
}
.message {
  flex: 0 100%;
  text-align: center;
  color: red;
  margin-top: 15px;
}