# ZB.MOM.WW.Theme

Shared Technical-Light UI kit for the ZB.MOM.WW SCADA family: design tokens + IBM Plex
fonts (static web assets) and a canonical side-rail shell + widgets. The kit ships one
.NET 10 Razor Class Library (RCL) with CSS custom-property tokens, the three IBM Plex
woff2 fonts, and side-rail layout CSS — all served from `_content/ZB.MOM.WW.Theme/…` —
plus a set of Blazor SSR components that carry no inline colours and reuse the token
classes. Bootstrap 5 is **not** vendored; each app keeps its own Bootstrap link.

The kit ships **no JavaScript**: every interactive affordance — the narrow-viewport
side-rail hamburger and the collapsible nav sections — is a native CSS-only
`<details>`/`<summary>` disclosure, so the chrome works unchanged in static Blazor SSR
with only Bootstrap **CSS** present (no Bootstrap collapse JS bundle required).

## Adopt

1. Reference the NuGet package in your app; keep your own Bootstrap 5 `<link>` in `App.razor`.
2. In `App.razor` `<head>`, **after** your Bootstrap link, add `<ThemeHead />`:
   ```razor
   <link rel="stylesheet" href="..." />  @* Bootstrap — yours, not vendored by the kit *@
   <ThemeHead />
   ```
3. Make your `MainLayout` a thin delegate to `ThemeShell` — `@layout` cannot pass
   parameters, so `ThemeShell` is a regular component and `MainLayout` is a 3-line wrapper:

   ```razor
   @* Layouts/MainLayout.razor *@
   @inherits LayoutComponentBase
   <ThemeShell Product="OtOpcUa" Accent="#2f5fd0">
       <Nav>
           <NavRailSection Title="Navigation">
               <NavRailItem Href="/" Text="Overview" Match="NavLinkMatch.All" />
               <NavRailItem Href="/clusters" Text="Clusters" />
           </NavRailSection>
       </Nav>
       <RailFooter>@* session info / sign-out link *@</RailFooter>
       <ChildContent>@Body</ChildContent>
   </ThemeShell>
   ```

Add `@using ZB.MOM.WW.Theme` to your `_Imports.razor` so all components are available
without per-file usings.

### Login page

Use `<LoginCard>` for the sign-in form. The card posts to a server endpoint
(`/auth/login` by default) so `SignInAsync` can run before the response starts.
You **must** inject `<AntiforgeryToken/>` inside the card and **validate `ReturnUrl`
server-side** before redirecting (open-redirect risk):

```razor
<LoginCard Product="OtOpcUa" Action="/auth/login" ReturnUrl="@safeReturnUrl" Error="@errorMsg">
    <AntiforgeryToken />
</LoginCard>
```

## Components

| Component | Parameters (key) | Notes |
|---|---|---|
| `ThemeHead` | — | Emits `<link>` tags for `theme.css` and `layout.css`. Place in `<head>` after Bootstrap. |
| `ThemeShell` | `Product`*, `Accent`, `Logo`, `Nav`, `RailFooter`, `ChildContent` | Side-rail chassis. Not a layout — delegated to from `MainLayout`. `Accent` overrides `--accent` token. |
| `BrandBar` | `Product`*, `Logo` | Brand glyph + product name; rendered inside `ThemeShell`'s rail header. |
| `NavRailItem` | `Href`*, `Text`*, `Icon`, `Match` | Wraps `<NavLink class="rail-link">`. |
| `NavRailSection` | `Title`*, `Expanded` (default `true`), `ChildContent` | CSS-only collapsible `<details>` group; no JS, works in static SSR. |
| `StatusPill` (`StatusState`) | `State`* (`Ok`/`Warn`/`Bad`/`Idle`/`Info`), `ChildContent` | Inline chip. `StatusState` enum is in `ZB.MOM.WW.Theme`. |
| `LoginCard` | `Product`*, `Action` (default `/auth/login`), `ReturnUrl`, `Error`, `ChildContent` | Static form-POST sign-in card. Inject `<AntiforgeryToken/>` via `ChildContent`; validate `ReturnUrl` server-side. |
| `TechButton` (`ButtonVariant`) | `Variant` (`Primary`/`Secondary`/`Danger`/`Ghost`), `Type`, `Busy`, `ChildContent`, splatted attrs | `Busy` disables the button and shows a spinner. `ButtonVariant` enum is in `ZB.MOM.WW.Theme`. |
| `TechCard` | `Title`, `Header`, `ChildContent`, `Footer`, `Class` | Panel with optional head/body/footer slots. |
| `TechField` | `Label`*, `Hint`, `Error`, `ChildContent` | Form field wrapper with label, hint text, and inline error. |

\* `EditorRequired` parameter.

Flat namespace: all components and enums live in `ZB.MOM.WW.Theme`. One `@using` covers everything.

## Static assets

Served at `_content/ZB.MOM.WW.Theme/…` by the ASP.NET static-web-asset pipeline:

| Path | Contents |
|---|---|
| `css/theme.css` | Design tokens (`--accent`, `--ok`, `--warn`, …), typography, utility helpers |
| `css/layout.css` | Side-rail shell layout, collapsible nav, `StatusPill` variants, card/field helpers, Bootstrap `.btn` sizing |

**Bootstrap button sizing (new in 0.4.0).** The kit now normalizes `.btn` / `.btn-sm` against its
0.9rem body via `--bs-btn-*` variable overrides, because Bootstrap hard-codes
`--bs-btn-font-size: 1rem`. Several consuming apps had written this same block into their own
stylesheets; **trim the local copy when you bump to 0.4.0** — trim rather than delete, because a
local `.btn` may also carry app-specific *shape* declarations the kit does not ship.

**This is not universal, and checking it takes two greps, not one.** An earlier version of this note
claimed all five consumers carried the block. They do not — and the follow-up correction, that the
missing-block app would therefore be *restyled* by the bump, was also wrong.

| Question | Check |
|---|---|
| Does the app declare its own `.btn` sizing? | `grep bs-btn-font-size`, excluding `lib/bootstrap` |
| Does the app **use** Bootstrap buttons at all? | count `class="…"` values carrying a bare `btn` token |

HistorianGateway answers **no to both** — all 15 of its buttons use the kit's own `.rail-btn` chassis
class — so the kit's `.btn` rule matches nothing there and bumping it changes nothing visible. The
first question alone is misleading in both directions: "no local block" does **not** imply "the kit
now supplies sizing the app was missing."
Size buttons by overriding the `--bs-btn-*` variables, never by redeclaring box properties — the
`.btn-group` seam and radius machinery reads those variables, so a literal `font-size` at equal
specificity silently reduces `.btn-sm` to a padding-only difference.

Rail-footer actions: `class="rail-btn"` is the inline default; add `rail-btn-block`
(`class="rail-btn rail-btn-block"`) for a full-width footer button. Use the modifier rather than
redeclaring `.rail-btn` in an app stylesheet — a local override that sets `width: 100%` overflows
the rail, because the width resolves against the containing block and the inline version's
`0 0.6rem` side margins are then added on top.

| `fonts/ibm-plex-sans-400.woff2` | IBM Plex Sans Regular |
| `fonts/ibm-plex-sans-600.woff2` | IBM Plex Sans SemiBold |
| `fonts/ibm-plex-mono-500.woff2` | IBM Plex Mono Medium |

`theme.css` declares `@font-face` with `url('../fonts/…')` — correct relative path from
`css/` to `fonts/`. (OtOpcUa's original `url('fonts/…')` was a latent 404; the kit fixes it.)

All colours are CSS custom-property tokens declared once in `theme.css`'s `:root` block —
no hardcoded hex appears outside it. Derived border/hover/wash shades (e.g. `--ok-border`,
`--warn-ink`, `--info-bg`, `--hover-bg`, `--active-bg`, `--zebra-bg`) are named tokens too,
so a token-block edit re-themes the whole kit.

## Build

```bash
# from ZB.MOM.WW.Theme/
dotnet build -c Release   # TreatWarningsAsErrors — expect 0 warnings
dotnet test               # 38 bUnit tests
./build/pack.sh           # → ./artifacts/ZB.MOM.WW.Theme.0.1.0.nupkg
```