body {
  margin: 0;
  font-family: sans-serif;
  background-color: #1e1e2f;
  color: white;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem;
}

h1 {
  margin-bottom: 2rem;
  border-bottom: 1px solid #666;
  padding-bottom: 0.5rem;
  width: 100%;
  max-width: 600px;
  text-align: center;
}

.card {
  background-color: #2e2e3e;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
  max-width: 300px;
  width: 100%;
  margin-bottom: 2rem;
  text-align: center;
}

.card label {
  margin-top: 1rem;
  display: block;
  text-align: left;
}

.card input, .card select {
  width: 100%;
  padding: 0.5rem;
  margin-top: 0.3rem;
  border: none;
  border-radius: 4px;
  margin-bottom: 1rem;
}

.card button {
  background-color: #00aaff;
  color: white;
  padding: 0.6rem;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  width: 100%;
}

.card button:hover {
  background-color: #0088cc;
}

#result {
  margin-top: 1rem;
  font-weight: bold;
  color: #aefbaf;
}

#error {
  color: #ff6b6b;
  font-size: 0.9rem;
}

.chart-container {
  max-width: 600px;
  width: 100%;
}