Nobody can say whether browsers, IP networking, DNS, HTTP will exist in 500 years from now, so aiming for very long-term "hosting" isn't feasible, with browsers

Nobody can say whether browsers, IP networking, DNS, HTTP will exist in 500 years from now, so aiming for very long-term "hosting" isn't feasible, with browsers the most complex and fragile part. Your best bet to preserve digital text and other data would be to use standards specifically designed for preservation/reuse that made it during that time when we still had multilateral standards development, and that have stood the test of time, such as SGML and XML. Or use plain text/markdown/other Wiki syntax and render to the viewer app of the day and century, the idea being that capturing your text at the intentional authoring stage would be free of delivery concerns and artifacts as best as it can (possible with SGML out of the box). And/or, author/render to a conservative HTML subset without JS and progressive/optional CSS. Or, print it out on acid-free paper with mineral colors.