site.yaml wordmark_height; raster logos keep their colors

Custom wordmark sizing per site (0.5-6 rem, clamped at render), and
the light-theme invert now applies only to .svg wordmarks - the
white-stroke house style - so a client's raster logo is never
recolored.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y42TyF8Zu7NGRR2893vNcZ

src/app.rs

@@ -555,7 +555,21 @@ fn Hero(title: String, description: String, landing: bool, site: SiteConfig, cur
         None
     };
     let has_module = module.is_some();
+    // Light theme inverts white-stroke wordmarks to ink. The house
+    // mark and the sibling-site marks are all white-stroke SVGs; a
+    // raster logo is a client brand and keeps its colors.
+    let house_wordmark = site
+        .wordmark
+        .as_deref()
+        .map(|w| w.ends_with(".svg"))
+        .unwrap_or(true);
     let wordmark = site.wordmark.clone().unwrap_or_else(|| "/wordmark.svg".to_string());
+    // Clamped server-side too, but belt and braces for the inline style.
+    let wordmark_style = site
+        .wordmark_height
+        .filter(|h| (0.5..=6.0).contains(h))
+        .map(|h| format!("height: {h}rem"))
+        .unwrap_or_default();
     let site_title = site.title.clone().unwrap_or_else(|| SITE_NAME.to_string());
 
     let piece_ref: NodeRef<leptos::html::Div> = NodeRef::new();
@@ -641,8 +655,8 @@ fn Hero(title: String, description: String, landing: bool, site: SiteConfig, cur
                     }
                 })}
             <div class="hero-copy">
-                <a class="wordmark" href="/">
-                    <img src=wordmark alt=site_title/>
+                <a class="wordmark" class:wordmark-house=house_wordmark href="/">
+                    <img src=wordmark alt=site_title style=wordmark_style/>
                 </a>
                 <h1>{title}</h1>
                 <p>{description}</p>

src/content.rs

@@ -513,6 +513,11 @@ pub struct SiteConfig {
     /// `None` falls back to `/wordmark.svg`.
     #[serde(default)]
     pub wordmark: Option<String>,
+    /// Wordmark display height in rem (0.5–6.0). `None` keeps the
+    /// stylesheet's default. Raster logos look best at or below their
+    /// intrinsic pixel height.
+    #[serde(default)]
+    pub wordmark_height: Option<f32>,
     #[serde(default)]
     pub hero: HeroConfig,
 }

style/main.css

@@ -99,10 +99,10 @@
     --hero-glow: rgba(246, 245, 241, 0.85);
   }
 
-  /* The wordmark SVG is a hardcoded white stroke (also used raw in
-     dark contexts elsewhere) - flip it to ink here rather than fork
-     the asset. */
-  .wordmark img {
+  /* The house wordmark SVG is a hardcoded white stroke (also used
+     raw in dark contexts elsewhere) - flip it to ink here rather
+     than fork the asset. A content-provided logo keeps its colors. */
+  .wordmark-house img {
     filter: invert(0.92);
   }