GOOD! Thanks, I needed that!
For the Web pages for my startup, I just started with what I wanted the pages to look like. Then I calculated where everything should be. I looked at this as a special case of layout in word processing, e.g., D. Knuth's TeX.
Then I turned to HTML and saw tables. Okay, the HTML table constructs are nice, sorry D., nicer than in TeX. So, I decided to use tables.
I heard about CSS, but I saw only a little need for that. Eventually I wrote a few lines of CSS. So, sure, I discovered that I could have separate CSS files, but that seemed like a way to slow the upload to the users. So, I just copied the CSS into the HTML code of the relevant Web pages.
For the rest, I saw how to use the Microsoft .NET ASP.NET to create and send the pages with the appropriate dynamic content, e.g., the results for the user.
I heard about JavaScript but saw no big need for it and so far have written not even a single line of it. Eventually I discovered that somehow ASP.NET writes a little JavaScript for me, maybe having something to do with cursor positioning -- maybe convenient and nice but not really necessary.
For the page designs, they are simple -- high contrast, large fonts, simple parts and pieces easy to understand right away, each page exactly 800 pixels wide, no icons, pull-downs, pop-ups, roll-overs, or overlays. There are some links, but each one is just a word in English.
The pages all have both horizontal and vertical scroll bars and should still be usable in a window only 300 pixels wide. So, the pages, without change, should look good on everything from a smartphone to a high end desktop. The user just needs a Web browser up to date as of maybe 10 years ago -- so, there should be no compatiblity problems. And, there are no user IDs, passwords, logins, or use of cookies! JavaScript is optional!
There really are some really simple, really successful Web pages on the Internet. So, sometimes simple can be good enough!!!