.cng-box {
  max-width: 500px;
  margin: 30px auto;
  padding: 25px;
  border-radius: 16px;
  background: #ffffff;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  text-align: center;
}

.cng-box select,
.cng-box button {
  width: 100%;
  padding: 10px;
  margin-top: 10px;
  border-radius: 8px;
}

.cng-box button {
  background: black;
  color: white;
  cursor: pointer;
}

#cng-result {
  margin-top: 20px;
  font-size: 18px;
  padding: 12px;
  background: #f7f7f7;
  border-radius: 10px;
}