Default explainer A calm, premium product demo, the kind a well-funded startup puts on its homepage. Its whole trick is restraint: a bright, airy canvas, one short line of text at a time, and the product's own interface rebuilt cleanly and filmed up close while it is being used. The camera does the storytelling: it pushes into a line of text, rides along with typing, pulls back to reveal the result, and glides to the next feature. You write it as one HTML page that renders any frame from a time value, then render it to MP4 with motion blur and a soundtrack. Step 1: Get the brief (one message,…