I love the attention to small details they're giving here. It's the kind that I absolutely admire but so rarely see. For example, in the section "Less code. Fewer edge cases." - a) the code "image" scrolls in the direction you scroll, and b) the code is actual code, made to look that way through use of a font (Flow-Circular). They could have went with a nonsense PNG with horizontal lines, but instead, they put actual code. They even went as far to leave this in the HTML just above that place:

<!-- This is a trimmed down real Stripe.js v2 basic integration. The full version would be much longer. -->

Hats off to them.