* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft JhengHei', sans-serif;
  background-color: #f5f5f5;
  color: #333;
  line-height: 1.6;
}

header {
  background-color: #4a90e2;
  color: white;
  padding: 2rem;
  text-align: center;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

header {
  position: relative;
}

header h1 {
  font-size: 2rem;
}

.logout-btn {
  position: absolute;
  top: 50%;
  right: 2rem;
  transform: translateY(-50%);
  padding: 0.5rem 1rem;
  background-color: rgba(255, 255, 255, 0.2);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 4px;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background-color 0.3s;
}

.logout-btn:hover {
  background-color: rgba(255, 255, 255, 0.3);
}

main {
  max-width: 600px;
  margin: 2rem auto;
  padding: 0 1rem;
}

.form-section {
  background-color: white;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.form-section h2 {
  margin-bottom: 1.5rem;
  color: #333;
  font-size: 1.5rem;
}

.product-form {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-group label {
  font-weight: 600;
  color: #555;
  font-size: 0.95rem;
}

.form-group input {
  padding: 0.75rem;
  border: 2px solid #ddd;
  border-radius: 4px;
  font-size: 1rem;
  transition: border-color 0.3s;
}

.form-group input:focus {
  outline: none;
  border-color: #4a90e2;
}

.submit-btn {
  padding: 0.875rem 2rem;
  background-color: #4a90e2;
  color: white;
  border: none;
  border-radius: 4px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.3s;
}

.submit-btn:hover {
  background-color: #357abd;
}

.submit-btn:active {
  transform: scale(0.98);
}

.message {
  margin-top: 1rem;
  padding: 0.75rem;
  border-radius: 4px;
  font-size: 0.95rem;
  display: none;
}

.message.success {
  display: block;
  background-color: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
}

.message.error {
  display: block;
  background-color: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
}

.hidden {
  display: none !important;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}