You’re a bit late in recognizing that the parties have switched as well Though if you’re from the UK that would be an excuse, especially given how much Republicans like to promote themselves as the “party of Lincoln”, and continue to refer to Democrats as the party of the KKK even though the latter moved over to the Rs decades ago.
Foundationally, Republicans are the part of big capital and industry, and Democrats are the party of agriculture and workers. That hasn’t changed much; what has changed is how those interest groups regard actual policies as being in their interest or not. Social issues have always been used as a tool by both parties to get votes from people who wouldn’t otherwise vote for them, or at least to drive enthusiasm among those who don’t care much for more abstract and boring issues like budgets.