How can I edit text on a one-page website without accessing the HTML?

What about Adobe Dreamweaver? It's a solid choice for making edits without diving too deep into HTML.

It sounds like you're worried about your HTML getting messed up during edits. For that reason, some people prefer using static site generators. You can keep your content in a markdown file while the HTML is handled through a template, making it a cleaner setup for updates.

Have you tried using your browser's DevTools with the 'contenteditable' attribute? By adding `contenteditable="true"` to your text elements, you can make visual edits directly in the browser and then copy the updated HTML. It's not perfect but helps keep your design intact. Another tool you could look into is Pinegrow; it allows visual editing of HTML and CSS while preserving your existing code structure. It's a paid option but could be worth it for your needs.

You're definitely after a customized WYSIWYG editor. Look for options that let you apply your own CSS styles easily; there are quite a few that can cater to that.

I’m a bit puzzled by what you mean by 'ruining your design with old code.' If changes are affecting the layout, it might not necessarily be the tool's fault but rather how your current styling is set up. Editing it directly in a good code editor might work better for you. Also, maybe try using Claude with a detailed prompt or ask a friend who could help!