.counter {
  border: 1px solid lightgray;
  margin: 36px 24px;
  padding: 24px;
  width: 240px;
}

.header {
  font-size: 24px;
  font-weight: normal;
  margin: 0 0 12px;
  text-align: center;
}

.button {
  background: lightseagreen;
  border: none;
  border-radius: 5px;
  color: white;
  cursor: pointer;
  display: block;
  font-size: 16px;
  margin: 0 auto 24px;
  padding: 12px 24px;
  text-shadow: 1px 1px 1px rgb(0 0 0 / 50%);
}

.button:disabled {
  background: lightgray;
  cursor: not-allowed;
}

.button:active:not(:disabled) {
  left: 1px;
  position: relative;
  top: 1px;
}