body {background-color: #f7f7f7;padding: 2rem;}.diagnosis-tool {max-width: 40rem;margin: 0 auto;background: #ffffff;padding: 2rem;border-radius: 8px;box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);}.progress-bar {height: 8px;background: #e0e0e0;border-radius: 4px;margin-bottom: 30px;overflow: hidden;}.progress {height: 100%;background-color: #3b82f6;width: 0%;transition: width 0.3s ease;}.step {display: none;opacity: 0;transition: opacity 0.5s ease-in-out;}.step.active {display: block;opacity: 1;}select, input[type=text] {width: 100%;padding: 10px;margin-top: 8px;margin-bottom: 20px;border-radius: 4px;border: 1px solid #ccc;font-size: 1rem;}button {padding: 10px 20px;background-color: #3b82f6;color: #fff;border-radius: 4px;cursor: pointer;font-size: 1rem;}button:hover {background-color: #2563eb;}h2, h3 {margin: 1rem 0;}p {margin-bottom: 1rem;}#watchTypeError, #symptomError {color: red;font-size: 0.9rem;margin-top: -10px;}