* {
  box-sizing: border-box;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
  min-height: 100vh;
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  background: #f4f6f8;
}

form {
  background: #ffffff;
  padding: 1.5rem;
  border-radius: 10px;
  width: 100%;
  max-width: 400px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

h1 {
  text-align: center;
}

label {
  display: block;
  margin-bottom: 0.25rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: #374151;
}

select,
input {
  width: 100%;
  padding: 0.6rem 0.8rem;
  margin-bottom: 1.2rem;
  border-radius: 6px;
  border: 1px solid #ccc;
  font-size: 0.95rem;
}

select:disabled {
  background-color: #f0f0f0;
  color: #888;
}

button {
  width: 100%;
  padding: 0.7rem;
  border: none;
  border-radius: 6px;
  background: #2563eb;
  color: #ffffff;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s ease;
}

button:hover {
  background: #1e4fd8;
}

#result {
  margin-top: 1rem;
  text-align: center;
  font-weight: 600;
  color: #111827;
}