.tab-menu button {
  background: none;
  border: none;
  box-shadow: none;
  padding: 0.5rem 1rem;
  font-size: 1.2rem;
  color: red;   /* ปกติแดง */
  cursor: pointer;
  transition: color 0.2s ease;
}

.tab-menu button:hover {
  color: black; /* Hover ดำ */
}

.tab-menu button.active {
  color: green; /* Active เขียว */
  font-weight: bold;
}