Notice how the blue header box stays floating at the top of your browser screen, casting a shadow over this text as you scroll down. This is achieved with position: sticky;.
Because this is a pure HTML/CSS page, you can write as much content as you want here. Unlike a typical presentation slide deck, this "slide" stretches infinitely vertically. As you scroll, the content goes underneath the header and stops right before the fixed footer at the bottom.
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
Scroll down a bit more to see how far the page can go...
And here is even more text to fully demonstrate the infinite scrolling nature of this single-slide website format.