The document that outlines the fundamental rights of citizens in a democracy is the Bill of Rights in the United States, which encompasses the first ten amendments to the Constitution. These amendments guarantee essential civil liberties and protections such as freedom of speech, religion, assembly, and the press, as well as the right to a fair trial and protection against unreasonable searches and seizures. The Bill of Rights serves as a crucial safeguard against government overreach, ensuring that individual rights are preserved and respected within the democratic framework of governance.