body {
  background-color: #DCDCDC;
  padding: 1rem;
  margin: 0;
}

.card {
  border: 1px solid black;
  margin-bottom: 1rem;
  background-color: white;
}

.card:last-child {
  margin-bottom: 0;
}

.card-header {
  display: flex;
  justify-content: space-between;
  border-bottom: 1px solid black;
  padding: .5rem;
  font-size: 2rem;
  align-items: center;
  margin-bottom: -1px;
}

.card-body {
  padding: 0 .5rem;
  height: 0;
  overflow: hidden;
  transition: height 150ms;
}

.card-body.show {
  height: auto;
  padding: .5rem;
}

button {
  cursor: pointer;
}