details {
  border: 2px solid #0d6efd;      /* plavi naglasak */
  border-radius: 12px;
  background: #f8f9fa;
  padding: 12px 16px;
  transition: background 0.3s ease, box-shadow 0.3s ease;
}

details[open] {
  background: #ffffff;            /* svjetlija podloga kad je otvoreno */
  box-shadow: 0 4px 12px rgba(13, 110, 253, 0.20);
}