Heartbeat of Steam is a Golden Age Policy Card from the Dramatic Ages game mode in Civilization VI. It is available from the Industrial Era to the Information Era (Atomic Era in Gathering Storm) and uses a Wildcard slot.
Available from the Industrial Era, Heartbeat of Steam is one of the best overall Golden Age policy cards, as it gives you a Production bonus for every Campus based on its adjacency bonus. It works especially well with civilizations who can easily earn high adjacency bonus for their Campuses: Korea, the Maya, and Australia. If there is a wonder crucial to your strategy, it may be worth running this card even if the adjacency bonuses of your Campuses are less than optimal; otherwise, you may be better off dedicating your precious Wildcard slot to something else.
The industrial revolution forever altered relationships between labor, technology and industry. Clocks marked off workhours, steam mills did the labor of hundreds of animals and people, and workers increasingly performed simple, repetitive, almost machine-like tasks. More so than ever before, technology existed as an end in and for itself.