body {
  font-family: Arial;
  text-align: center;
  background: #121212;
  color: white;
}

.container {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-top: 50px;
}

.card {
  display: flex;
  flex-direction: column;
  align-items: center;
}

button {
  padding: 15px 30px;
  font-size: 16px;
  margin-bottom: 15px;
  cursor: pointer;
}

.led {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: gray;
}

/* States */
.loading { background: orange; }
.success { background: limegreen; }
.error { background: red; }