.container {
  max-width: 500px;
  margin: auto;
  padding: 20px;
  background: #1e1e1e;
  color: #fff;
  font-family: sans-serif;
  border-radius: 12px;
  box-shadow: 0 0 10px rgba(255,255,255,0.1);
  text-align: center;
}

.container h2 {
  margin-bottom: 15px;
}

.subject {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 10px;
}

.subject input,
.subject select {
  flex: 1;
  padding: 10px;
  background: #2c2c2c;
  color: #fff;
  border: none;
  border-radius: 6px;
  min-width: 0;
}

button {
  margin: 10px 5px;
  padding: 10px 15px;
  border: none;
  background: #4caf50;
  color: white;
  border-radius: 6px;
  cursor: pointer;
  font-size: 16px;
}

button:hover {
  background: #43a047;
}

#result {
  margin-top: 15px;
  font-weight: bold;
  font-size: 18px;
}

@media (max-width: 500px) {
  .subject {
    flex-direction: column;
  }
}
