Restyle the frontend as an editorial magazine layout

Centred wordmark over a rule of category links, a lead article above a grid of
cards, centred article headers over a narrow reading column, and a footer split
into columns. Neutral warm-grey palette with a serif display face for headings
and small uppercase labels for metadata.

frontend/app/pages/category/[slug].vue

@@ -35,11 +35,10 @@ useHead({ link: [{ rel: 'canonical', href: canonical }] })
 
 <template>
   <div>
-    <p class="breadcrumb muted">
-      <NuxtLink to="/blog">Articles</NuxtLink>
-    </p>
-
-    <h1>{{ category?.name }}</h1>
+    <header class="page-header">
+      <p class="kicker">Category</p>
+      <h1>{{ category?.name }}</h1>
+    </header>
 
     <p v-if="error">Articles could not be loaded. Please try again later.</p>
 
@@ -69,16 +68,3 @@ useHead({ link: [{ rel: 'canonical', href: canonical }] })
   </div>
 </template>
 
-<style scoped>
-.breadcrumb {
-  font-size: 0.9rem;
-}
-
-.pagination {
-  display: flex;
-  flex-wrap: wrap;
-  gap: 1.5rem;
-  align-items: center;
-  margin-top: 3rem;
-}
-</style>