The Volstead Act was partially repealed by the 74th Congress: "Titles I and II of the National Prohibition Act...are hereby repealed". You can see the relevant law passed in 1935 via these links. Title III of the Volstead Act pertains to industrial alcohol, and was not repealed.
Section 2 of the 21st Amendment states:
The transportation or importation into any State, Territory, or
possession of the United States for delivery or use therein of
intoxicating liquors, in violation of the laws thereof, is hereby
prohibited.
This grants states (territories, possessions) the power to prohibit or otherwise regulate importation of alcohol, despite the Commerce Clause (only Congress may regulate interstate commerce). But this is okay: Craig v. Boren 429 U.S. 190 "resolves" the seeming contradiction, saying
The wording of §2 of the Twenty-first Amendment closely follows the
Webb-Kenyon and Wilson Acts, expressing the framers' clear intention
of constitutionalizing the Commerce Clause framework established under
those statutes. This Court's decisions since have confirmed that the
Amendment primarily created an exception to the normal operation of
the Commerce Clause.
The federal government can impose all sorts of limits, and there are 200 pages of federal regulations on alcohol which instantiate the power via the Commerce Clause to control alcohol. An outright ban on production / consumption / sale would probably fail, not passing strict scrutiny, but it's hard to know what might be seen as a fundamental right calling for strict scrutiny, some time in the future. See Wickard v. Filburn, 317 U.S. 111 for an example of how the power to regulate interstate commerce doesn't actually have to involve interstate commerce.
