Unfortunately, it’s still the case that most staking, whether directly under a pure proof-of-stake model or indirectly using a delegated proof-of-stake consensus, is online. This usually means handing control of your cryptocurrency to a third party or delegating to a random service.
Tezos (XTZ) would be the most similar model to offline staking, since its coins stay liquid and users can set up their own “baker,” or validator, but “bakers” are required to hold at least 10,000 to become a delegate, which costs close to $40,000 at current prices.