The whole argument of a pour-over is that it is repeatable. Same water, same grind, same three pours at the same seconds, and you will get the same cup in a different kitchen.
50 g of water, poured in 5 seconds, then wait. The coffee degasses and the bed swells.
150 g, poured slowly from the centre, in a spiral, staying off the paper.
Another 150 g. The bed should be flat and the level should be dropping steadily.
The last 50 g. If the bed is still swimming at 2:30, the grind was too fine.
Almost every brewing guide is written in ranges — "around 30 seconds", "wait until it drops halfway". Ranges are kind and useless. A pour-over is a sequence of events that happen at particular seconds, and the only way to hit them twice is to stop guessing.
So this page is a stopwatch with the recipe built into it. Press start and the phases advance on their own; the stream stops and starts, the step list ticks over, and the ring fills. If the water in your kitchen behaves like the water in the ring, you have made the same cup twice.