How desktop (Vector 2022) vs mobile (Minerva) web skins work in ProtoWiki — the boot-time resolution of ?skin= URL param + stored Web skin preference + viewport into a data-skin attribute on <html>, the per-component skin prop for embedding mobile previews on desktop pages, and the read-only useSkin() hook. Skins are a web-only axis; native app prototypes use data-app-platform instead. Use when adding skin-specific styles, embedding a mobile preview, debugging the responsive breakpoint, or wiring a "show mobile" toggle.
How desktop (Vector 2022) vs mobile (Minerva) web skins work in ProtoWiki — the boot-time resolution of ?skin= URL param + stored Web skin preference + viewport into a data-skin attribute on <html>, the per-component skin prop for embedding mobile previews on desktop pages, and the read-only useSkin() hook. Skins are a web-only axis; native app prototypes use data-app-platform instead. Use when adding skin-specific styles, embedding a mobile preview, debugging the responsive breakpoint, or wiring a "show mobile" toggle.
ProtoWiki — skins
ProtoWiki ships two Wikipedia-shaped skins:
Vector 2022 (data-skin="desktop") — the modern desktop skin.
Minerva (data-skin="mobile") — the mobile-web skin.
Skins control layout (column count, sticky rails, search-bar visibility,
font-sizes) but not colours — those are the
theme's job.
Skins are the web axis only. Minerva (data-skin="mobile") is mobile
web, not the native apps. App prototypes (platform: 'app') have no skin at
all — their platform axis is iOS vs Android on <html data-app-platform>. See
protowiki-app-prototyping.
How the global skin is resolved
At boot, src/theme.ts decides the global skin in this order:
?skin=desktop or ?skin=mobile URL param, if either is present.
The stored Web skin preference (config.webSkin: auto / desktop /
mobile), set in the gallery's Appearance settings.
Otherwise (), viewport: → , else .
This matches (): desktop chrome
() stays until ; below that, mobile chrome ().
auto
window.innerWidth >= 640
desktop
mobile
FakeMediaWiki
SpecialView/style.css
nav-desktop
640px
nav-mobile
The result is set as data-skin="…" on <html>. When neither the URL param nor
the stored preference is pinning the value, the boot script subscribes to a
media-query listener so the global skin updates live as the viewport crosses
640 px.
?skin= URL param wins permanently for that session (no live subscription
when the URL forces a value).
How CSS skins work
Skin affects layout via data-skin="desktop" vs data-skin="mobile"
on component roots (ChromeWrapper, ArticleLive, ArticleSnapshot, ArticleCustom, ChromeHeader, etc.).
Desktop vs mobile rules live next to those components in scoped <style>
blocks (e.g. .article[data-skin='mobile'] { … } for tighter article padding).
Vector chrome additionally uses @media (max-width: 1120px) inside
VectorChromeHeader.vue to hide inline search and show the search icon — same idea as
FakeMediaWiki’s .nav-item-search / .nav-button-search toggle — and
@media (max-width: 768px) to hide desktop-only tools such as the watchlist mock
(FakeMediaWiki’s .nav-button-desktop). Those are layout breakpoints inside desktop
chrome, not skin changes; global skin still flips only at 640px
unless ?skin= pins it.
Subtree skin overrides use the same data-skin attributes; prefer those over ad hoc
@media for skin switching.
Per-subtree skin prop
Every wrapper (and every other themable component) accepts an optional
skin prop. When set, it renders data-skin="…" on the component's root
element, locally re-skinning everything inside that subtree.
<!-- Mobile preview embedded in an otherwise-desktop page -->
<MobileWrapper>
<ChromeWrapper skin="mobile">
<ArticleLive article="Albert Einstein" />
</ChromeWrapper>
</MobileWrapper>
When skin is unset, wrappers resolve effectivedata-skin from Vue
inject (inside ChromeWrapper) or from global boot state on <html>, so
nested previews stay consistent.
MobileWrapper
centres the column and adds neutral side gutters on wide viewports; set
skin="mobile" on ChromeWrapper inside it for Minerva chrome.
useSkin() — read-only hook
src/composables/useSkin.ts exports a hook that returns a reactive
read-only Ref<'desktop' | 'mobile'> reflecting the GLOBAL skin (the
value on <html>):
It does not mutate page state, and it does not reflect local
subtree overrides set via the skin prop. A component that received a
skin prop already knows its effective skin; it doesn't need this hook.
Use this only when CSS attribute selectors aren't enough — e.g., a piece
of layout that has to vary structurally with skin, or a debug overlay
that displays the current global skin.
ResourceLoader styles for .mw-parser-output
ProtoWiki ships Wikipedia Vector 2022 and Minerva ResourceLoader bundles
under src/styles/wiki-skins/, scoped so each rule applies only inside an
.mw-parser-output subtree under the matching [data-skin] attribute (desktop /
mobile). Both bundles load together from main.ts after Codex / global CSS, and
subtree skin previews pick up the right parser styling.
Why scope to .mw-parser-output? RL bundles are written for full Wikipedia chrome,
so they include rules like a { padding: 0 !important }, a:hover { text-decoration: underline }, and body { font-family: … }. Without scoping, they squash Cdx buttons
that render as <a>, underline Cdx cards on hover, and override our chrome styling
generally. We draw chrome with Codex; we only need RL for article HTML rendered
through ArticleRenderer (ArticleLive / ArticleSnapshot / ArticleCustom nest ArticleRenderer under ArticleWrapper).
scripts/scope-wiki-skin-css.mjs runs in two passes:
Prefix. Every selector is rewritten under the matching skin prefix.
Bare root selectors (html, body, :root, optionally with pseudo-classes)
collapse onto [data-skin="…"] .mw-parser-output. Compound root selectors
(html.skin-theme-clientpref-os, etc.) stay intact under the skin prefix —
they're dormant in our app because we never set those root classes, and
keeping them dormant prevents OS-dark or clientpref-night rules from fighting
data-theme.
Drop collapsed-root rules. Anything whose final selector is exactly
[data-skin="…"] .mw-parser-output is removed. Those are page-level
declarations from RL — Vector's body { background-color: var(--background-color-neutral-subtle); … }
page chrome, plus token re-paints inside @media (prefers-color-scheme: dark).
ProtoWiki provides all of that itself: body typography in global.css,
page background / colour in our wrappers, theme tokens via data-theme.
Letting RL paint the article column with the page palette would mean the
article body shows up in --background-color-neutral-subtle instead of
--background-color-base, and the OS dark preference would locally redefine
the entire token palette inside parser output regardless of data-theme.
Refresh periodically with npm run snapshot:wiki-skins. Details:
wiki-snapshot-data.
If a future feature needs RL chrome rules to apply outside .mw-parser-output, edit
scripts/scope-wiki-skin-css.mjs — but plan to also write Codex-side overrides to
beat the !important rules RL ships.
Common pitfalls
Don't use @media (max-width: …) in skin CSS. Use [data-skin]
attribute selectors. The viewport is already resolved into data-skin.
Don't watch window.innerWidth from your component. Use the
useSkin() hook, which is reactive and reflects the boot-time
resolution + viewport listener.
Don't try to read the local skin override from useSkin(). It only
reflects <html>. A component that received a skin prop already has
the answer in props.
Don't pass skin inside an app prototype. App chrome has no skin;
<ArticleLive app> pins itself to mobile. Reach for
protowiki-app-prototyping instead.
