docs: revert global theme to restore dev-notes CSS

[lbliii]

📋 Summary

Hotfix that reverts the global-theme migration (#713) to restore the NeMo Data Designer Dev Notes layouts. Under global-theme: nvidia, Fern treats css as a theme-owned field and replaces the child repo's css: list at publish, so DataDesigner's product stylesheets (blog-card, authors, notebook-viewer, metrics-table, trajectory-viewer, main) stopped loading and the Dev Notes pages collapsed to unstyled HTML.

🔗 Related Issue

🔄 Changes

🐛 Fixed

• Restored the self-hosted theme config in fern/docs.yml (layout, colors, theme, footer, logo, favicon, js) and the full product css: list, so the Dev Notes kit components are styled again.

✨ Added

• Re-added fern/components/CustomFooter.tsx and the NVIDIA_{dark,light,symbol}.svg assets.

🔧 Changed

• Reverted the fern.config.json CLI pin and README global-theme notes.

🧪 Testing

• fern check passes (0 errors)
• make test (n/a — docs-only change)

✅ Checklist

• Follows commit message conventions
• Commits are signed off (DCO)
• Architecture docs updated (n/a)

Temporary hotfix. Re-land the canonical theme later by moving the product CSS into the NVIDIA/fern-components theme repo, or by having the Dev Notes kit components self-inject their CSS (component dirs are not theme-owned, so they survive the merge).

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This hotfix reverts the global-theme: nvidia migration (#713) that caused Fern to override the child repo's css: list at publish time, collapsing Dev Notes pages to unstyled HTML. All self-hosted theme configuration in docs.yml, the CustomFooter.tsx component, NVIDIA SVG assets, and the Fern CLI version pin are restored to their pre-#713 state.

• fern/docs.yml: global-theme: nvidia is removed; layout, colors, theme, footer, logo, favicon, js, and the full product css: list are reinstated so Dev Notes component styles load again.
• fern/components/CustomFooter.tsx + fern/assets/NVIDIA_*.svg: Re-added custom footer and logo SVG assets that the self-hosted config depends on.
• fern/fern.config.json: CLI pin reverted from 5.41.1 to 5.24.0.

Confidence Score: 4/5

Safe to merge; restores a known-good docs configuration that was broken by the previous PR.

The revert is straightforward and the fern check passes. The only item worth a second look is CustomFooter.tsx using the same S3-hosted logo URL for both only-light and only-dark img elements — the local dark/light SVG variants added in this PR are used by the header logo but not the footer, so dark-mode footer branding may render with the wrong logo.

fern/components/CustomFooter.tsx — both footer logo img elements share one URL; the dark-mode image should reference the local NVIDIA_dark.svg just as docs.yml's logo config does.

Important Files Changed

Filename	Overview
fern/docs.yml	Reverts global-theme: nvidia, restoring self-hosted layout/colors/logo/favicon/js/css config; product stylesheet list fully reinstated.
fern/components/CustomFooter.tsx	Re-added custom footer component; both only-light and only-dark logo img elements share the same S3 URL instead of the local dark/light SVG variants.
fern/fern.config.json	Reverts Fern CLI version pin from 5.41.1 back to 5.24.0 as part of the hotfix rollback.
fern/README.md	Documentation updated to remove global-theme references and reflect the restored self-hosted asset structure.
fern/assets/NVIDIA_dark.svg	Re-added NVIDIA logo SVG (white fill) for dark-mode use in docs.yml logo config.
fern/assets/NVIDIA_light.svg	Re-added NVIDIA logo SVG (dark fill) for light-mode use in docs.yml logo config.
fern/assets/NVIDIA_symbol.svg	Re-added NVIDIA symbol SVG used as the favicon in docs.yml.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[fern/docs.yml] -->|references| B[fern/components/CustomFooter.tsx]
    A -->|logo dark| C[fern/assets/NVIDIA_dark.svg]
    A -->|logo light| D[fern/assets/NVIDIA_light.svg]
    A -->|favicon| E[fern/assets/NVIDIA_symbol.svg]
    A -->|css list| F[fern/main.css + styles/*.css]
    A -->|js| G[Adobe DTM script]
    A -->|version| H[fern/fern.config.json v5.24.0]

    subgraph Reverted from PR #713
      I[global-theme: nvidia]
    end

    I -.->|replaced css list at publish| F
    A -->|restores| F

Loading

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
fern/components/CustomFooter.tsx:23-30
Both `only-light` and `only-dark` footer logo images point to the same S3 URL, so dark mode will render a logo intended for a light background. The local `NVIDIA_dark.svg` (white-fill) and `NVIDIA_light.svg` (dark-fill) assets added in this PR are already referenced by `docs.yml` for the header logo — the footer should follow the same pattern.

```suggestion
              <a
                className="footer-brand"
                href="https://www.nvidia.com"
                target="_blank"
                rel="noopener"
              >
                <img src="./assets/NVIDIA_light.svg" className="logo__image only-light" alt="NVIDIA" />
                <img src="./assets/NVIDIA_dark.svg" className="logo__image only-dark" alt="NVIDIA" />
```

_{Reviews (1): Last reviewed commit: "docs: revert global theme to restore dev..." | Re-trigger Greptile}

[greptile-apps]

Both only-light and only-dark footer logo images point to the same S3 URL, so dark mode will render a logo intended for a light background. The local NVIDIA_dark.svg (white-fill) and NVIDIA_light.svg (dark-fill) assets added in this PR are already referenced by docs.yml for the header logo — the footer should follow the same pattern.

Suggested change

	<a
	className="footer-brand"
	href="https://www.nvidia.com"
	target="_blank"
	rel="noopener"
	>
	<img src={logoUrl} className="logo__image only-light" alt="NVIDIA" />
	<img src={logoUrl} className="logo__image only-dark" alt="NVIDIA" />
	<a
	className="footer-brand"
	href="https://www.nvidia.com"
	target="_blank"
	rel="noopener"
	>
	<img src="./assets/NVIDIA_light.svg" className="logo__image only-light" alt="NVIDIA" />
	<img src="./assets/NVIDIA_dark.svg" className="logo__image only-dark" alt="NVIDIA" />

Prompt To Fix With AI

This is a comment left during a code review.
Path: fern/components/CustomFooter.tsx
Line: 23-30

Comment:
Both `only-light` and `only-dark` footer logo images point to the same S3 URL, so dark mode will render a logo intended for a light background. The local `NVIDIA_dark.svg` (white-fill) and `NVIDIA_light.svg` (dark-fill) assets added in this PR are already referenced by `docs.yml` for the header logo — the footer should follow the same pattern.

```suggestion
              <a
                className="footer-brand"
                href="https://www.nvidia.com"
                target="_blank"
                rel="noopener"
              >
                <img src="./assets/NVIDIA_light.svg" className="logo__image only-light" alt="NVIDIA" />
                <img src="./assets/NVIDIA_dark.svg" className="logo__image only-dark" alt="NVIDIA" />
```

How can I resolve this? If you propose a fix, please make it concise.

[github-actions]

Summary

PR #715 is a focused hotfix that reverts PR #713 (the canonical NVIDIA Fern global-theme migration, merged earlier today, 2026-05-29). The premise is well stated and easy to verify: under global-theme: nvidia, Fern treats css as a theme-owned field and replaces the child repo's css: list at publish, which silently dropped DataDesigner's product stylesheets (main.css, styles/notebook-viewer.css, authors.css, metrics-table.css, trajectory-viewer.css, blog-card.css) and left the Dev Notes pages rendering as unstyled HTML.

The change set is exactly the inverse of #713:

• fern/docs.yml — drops global-theme: nvidia and restores the explicit layout, colors, theme, footer, logo, favicon, js, and full css: list.
• fern/components/CustomFooter.tsx — restored (96 lines).
• fern/assets/NVIDIA_{dark,light,symbol}.svg — restored.
• fern/fern.config.json — pin reverted from 5.41.1 → 5.24.0.
• fern/README.md — removes the "Theme" section and the inline notes that referenced global-theme inheritance.

Scope is docs/site config only. No Python, no engine, no public API. Risk is contained to the docs build.

Findings

Correctness / convention

• The revert is faithful. Every field re-introduced in docs.yml mirrors the pre-docs: adopt canonical NVIDIA Fern global theme #713 config, and the css: list now matches the six stylesheets the Dev Notes kit and product MDX components depend on. fern check is reported as green in the PR body — consistent with what the diff shows.
• New (restored) source files carry the correct SPDX headers (SPDX-FileCopyrightText + SPDX-License-Identifier: LicenseRef-NvidiaProprietary). This matches the project's make update-license-headers convention.
• CustomFooter.tsx uses target="_blank" rel="noopener" (and noopener noreferrer on the buildwithfern link) — correct for outbound links.
• README structural diagram is updated coherently (docs.yml description, assets/, main.css line, CustomFooter.tsx re-listed under components).

Risks & things to flag

1. CLI version regression: fern.config.json 5.41.1 → 5.24.0. This is a 17-minor-version step backward. It's necessary because the global-theme behavior was Fern-version-specific, but it does mean the docs build now runs on an older toolchain. Worth tracking explicitly so the next theme attempt can re-pin forward, and so security/bugfix advisories against <5.41 don't go unnoticed.
2. No guardrail against accidental re-introduction. PR docs: adopt canonical NVIDIA Fern global theme #713 was merged 6 hours before this revert; there's nothing in the repo (a CHANGELOG note, a comment in docs.yml, or a follow-up issue link) that warns the next contributor why global-theme: nvidia is off and what specifically broke. Consider a one-line comment in docs.yml near the explicit css: list, e.g. # Do not switch to global-theme until product CSS is theme-owned or component-injected (#713 broke Dev Notes). The PR body has the long-term remediation plan, but PR bodies aren't discoverable from the file.
3. CustomFooter.tsx — SSR/hydration nit (pre-existing). currentYear = new Date().getFullYear() runs both server- and client-side. At a year boundary it can hydrate-mismatch. Not introduced by this PR (it's a faithful restoration), so not blocking — flagging only because the file is touched again here, and a useState/build-time constant would be a one-line fix if Fern's SSR ever surfaces a warning.
4. Hardcoded external image dependency (pre-existing). The footer logo points to fern-image-hosting.s3.us-east-1.amazonaws.com/.... Same caveat: not introduced here, but it's a single point of failure. The repo has the NVIDIA SVGs locally in fern/assets/ now — using one of those instead of the S3 URL would remove the external dep. Worth a follow-up, not a blocker.
5. Adobe DTM script reinstated (js: block, strategy: beforeInteractive). This is a third-party analytics tag, restored as it was pre-docs: adopt canonical NVIDIA Fern global theme #713. Mentioning only because beforeInteractive blocks rendering until the script loads; if the global-theme branch had moved this to lazyOnload, that benefit is lost in the revert. Likely intentional (NVIDIA-mandated analytics ordering) but worth confirming with whoever owns the corp analytics requirements.

Test coverage

• Marked n/a, correctly — this is a docs-only / site-config change. The relevant signal is fern check (green per PR body) and a visual confirmation that the Dev Notes pages render with their full stylesheets again. The latter isn't shown in the PR; a screenshot or preview-deploy link would strengthen the change but isn't required.

Performance / security

• No DataDesigner runtime impact.
• No new external network calls beyond what existed pre-docs: adopt canonical NVIDIA Fern global theme #713.
• The new SVG assets are small and self-contained; no embedded scripts.

Verdict

Approve as a hotfix. This is a tight, well-motivated revert that restores a known-good docs state after #713 broke Dev Notes styling in production. The diff is exactly what the PR description claims — no scope creep, no incidental changes.

Two suggestions before/after merge, neither blocking:

1. Add a short comment in fern/docs.yml (next to the explicit css: list or theme: block) noting that global-theme: nvidia was tried and reverted, with a link to this PR. Prevents a future contributor from re-applying docs: adopt canonical NVIDIA Fern global theme #713 on the assumption it was an oversight.
2. File a follow-up issue capturing the long-term plan from the PR body (move product CSS into NVIDIA/fern-components, or have the Dev Notes kit components self-inject their CSS) and the pending Fern CLI re-pin. Otherwise that context lives only in this PR description and is easy to lose.

[github-actions]

MkDocs preview: https://32f038bc.dd-docs-preview.pages.dev

Fern preview: https://nvidia-preview-pr-715.docs.buildwithfern.com/nemo/datadesigner

Fern previews include the docs-website version archive with PR changes synced into latest. Notebook tutorials are rendered without execution outputs in previews.