TL;DR: I branded Ghost's Solo theme using only Admin settings and Code Injection CSS. No theme fork, no custom templates, no maintenance overhead. The whole project — palette, typography, icon design, 600 lines of CSS, an implementation guide — was built with Claude Opus. I directed. Opus built. Complete source files on GitHub.

The starting point

I had a Ghost blog running on Coolify with Cloudflare in front and Google Fiber underneath. Stock Casper theme. One post published. It worked, but it looked like a default install — because it was.

I wanted it to look intentional. But I also didn't want to fork a theme and own the merge conflicts forever. Ghost publications like 404 Media and Platformer look polished and distinctive, but the platform underneath is the same one I'm running. The differentiator isn't the technology. It's the brand work on top of it.

So the constraint was: Ghost Admin settings + Code Injection only. No theme files edited. Anything I build survives Ghost updates and theme updates without rework.

Why Solo

I asked Opus to research Ghost themes — both free and premium. It looked at options from Aspire and Bright Themes, evaluated the official free themes, and came back with a recommendation: Solo. Built for individual writers, maintained in the TryGhost/Themes monorepo alongside Ghost's other official themes, gets updates automatically. Free, official, and since we had AI doing the heavy lifting on CSS, the shortcomings of a free theme didn't matter much. We could override whatever we needed to.

The tradeoff with Solo is that its defaults are designed to look impressive on a demo page. Everything is oversized — the hero title, the card titles, the spacing, the footer. Great for a first impression in a theme showcase. Not great for a site people would actually sit down and read.

Craftsman Modern

I landed on a palette and type system I'm calling Craftsman Modern. Warm parchment background, copper accent, DM Sans for body and headings, DM Mono for code and dates. The vibe is warm workshop, not cold SaaS.

For the icon, I wanted something subtle. infer.blog isn't in-your-face about AI — "infer" is a word that works whether you're in the AI world or not. Inference is a core concept in machine learning, but it's also just a word people use. I wanted the logo to work the same way. If you take a second to think about it, the connection is there. If you don't, it still feels right with the name.

Opus designed a grid of four squares — three filled, one empty with a copper stroke. I'm calling it the Missing Piece. It reads like a matrix, which is another quiet nod to ML. And the missing piece itself ties into the blog's premise: there's always something left to figure out. But none of that is loud. You'd have to be paying attention.

Opus built the logo PNGs, SVGs, and favicon at multiple sizes. It also generated an HTML file that renders the wordmark in real DM Sans from Google Fonts so I could screenshot pixel-perfect versions. The PNGs that actually shipped use Liberation Sans as a proxy because Google Fonts wasn't reachable from the build environment. At nav bar scale, nobody can tell.

Before writing any CSS, I had Opus build a full HTML mockup of what the branded site should look like. Homepage, article view, mobile viewport. This became the reference we worked toward for the rest of the project.

Making it real

The first round of CSS Opus wrote was surface-level — font overrides, accent colors, border tweaks. On the live site, Solo's defaults were still showing through everywhere. We'd styled the surface but hadn't touched the structure. I told Opus to go deeper. It cloned the Solo repo, read through every stylesheet in the theme and its shared CSS library, and figured out that Solo uses responsive sizing for nearly every value. Once it understood the actual structure, the overrides started working. The card grid, the article layout, the homepage hero — all converted through CSS alone, no template changes.

Mobile had a problem that took a few rounds. Solo's header was rendering way too tall because the hamburger menu hides nav elements in a way that makes them invisible without removing them from the layout. The space was still allocated. Opus kept looking in the wrong place until I pulled up dev tools and sent screenshots of the actual computed layout. Once it had that, the fix came together quickly. There was also a Ghost version issue where a setting Opus referenced in the implementation guide didn't exist in the Admin panel — a recent Ghost update had collided with Solo's typography config. Opus tracked it down and we worked around it.

How we worked

Opus wrote every line of CSS, generated the logo assets, built the mockups, and produced a full implementation guide. I made the brand decisions — palette, typography, icon concept, layout direction. When Opus produced CSS, I deployed it to the live site and checked the result. When I needed to, I reviewed the code in dev tools and sent screenshots back so Opus could iterate. The whole project happened across a few sessions.

The interesting part wasn't the CSS. It was watching how fast the whole thing came together once the direction was clear. Brand identity, icon design, full-page mockups, 600 lines of production CSS, a step-by-step implementation guide, all the logo assets at every size Ghost needs. That's a project that used to take weeks with a designer and a developer. We did it in a few conversations.

The result

The complete Code Injection CSS, implementation guide, logo assets, and mockup files are on GitHub. If you're running Ghost and want to brand a stock theme without forking it, the approach and all the source files are there. The Nemotron post is the best example of the styling in action.

Built with Opus. Directed by me.

Daniel Soteldo is COO and Co-Founder of Revelus Dermatology in Austin, TX. He writes about the things he finds interesting — including the problems he solves along the way — at infer.blog.