.protein-calculator {
  font-family: Arial, sans-serif;
  max-width: 600px;
  margin: 0 auto;
  padding: 20px;
  border: 1px solid #ddd;
  border-radius: 8px;
  background: white;
}
.input-group {
  margin-bottom: 15px;
}
.input-group label {
  display: inline-block;
  width: 120px;
  font-weight: bold;
}
input, select {
  padding: 8px;
  border: 1px solid #ddd;
  border-radius: 4px;
}
button {
  background-color: #4CAF50;
  color: white;
  padding: 10px 15px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-size: 16px;
}
button:hover {
  background-color: #45a049;
}