From ba65b18d297d8ecd7ba54a9274fddfdca292b62e Mon Sep 17 00:00:00 2001
From: tleininger <thomas.leininger@kardex.com>
Date: Thu, 1 Oct 2026 16:48:52 +0200
Subject: [PATCH] Rework post page (lead, pager), add skip link, unified focus
 ring, reduced motion and keyboard-accessible menu

---
 Elternbeirat.Web.Tests/PostNeighborsTests.cs  |  57 +++++++
 Elternbeirat.Web.Tests/RouteSmokeTests.cs     |  76 ++++++++-
 .../Components/Layout/MainLayout.razor        |  34 +++-
 .../Components/Layout/MainLayout.razor.cs     |   6 +
 .../Components/Layout/MainLayout.razor.css    |  41 ++++-
 .../Features/Events/EventCard.razor.css       |   5 -
 Elternbeirat.Web/Features/Home/Home.razor.css |   9 +-
 .../Features/Posts/PostCard.razor.css         |   5 -
 .../Features/Posts/PostDetail.razor           |  41 +++--
 .../Features/Posts/PostDetail.razor.cs        |   5 +
 .../Features/Posts/PostDetail.razor.css       | 117 ++++++++++++--
 .../Features/Posts/PostNeighbors.cs           |  65 ++++++++
 Elternbeirat.Web/Shared/IconSet.cs            |   5 +-
 Elternbeirat.Web/wwwroot/app.css              | 147 +++++++++++++++---
 14 files changed, 544 insertions(+), 69 deletions(-)
 create mode 100644 Elternbeirat.Web.Tests/PostNeighborsTests.cs
 create mode 100644 Elternbeirat.Web/Features/Posts/PostNeighbors.cs

diff --git a/Elternbeirat.Web.Tests/PostNeighborsTests.cs b/Elternbeirat.Web.Tests/PostNeighborsTests.cs
new file mode 100644
index 0000000..636c0b9
--- /dev/null
+++ b/Elternbeirat.Web.Tests/PostNeighborsTests.cs
@@ -0,0 +1,57 @@
+using Elternbeirat.Contracts;
+using Elternbeirat.Web.Features.Posts;
+
+namespace Elternbeirat.Web.Tests;
+
+/// <summary>
+/// Unit tests for the older/newer post next to a post. The list comes newest
+/// first, as from PocketBase; "previous" is the older post. Pure logic, no
+/// PocketBase needed.
+/// </summary>
+public class PostNeighborsTests
+{
+    // Newest first, like PocketBaseClient.GetPostsAsync.
+    private static readonly Post[] Posts = [Post("march"), Post("february"), Post("january")];
+
+    private static Post Post(string slug) =>
+        new() { Id = slug, Title = slug, Slug = slug };
+
+    [Fact]
+    public void Middle_post_has_the_older_as_previous_and_the_newer_as_next()
+    {
+        var neighbors = PostNeighbors.Of(Posts, "february");
+
+        neighbors.Previous?.Slug.ShouldBe("january");
+        neighbors.Next?.Slug.ShouldBe("march");
+    }
+
+    [Fact]
+    public void Newest_post_has_no_next()
+    {
+        var neighbors = PostNeighbors.Of(Posts, "march");
+
+        neighbors.Previous?.Slug.ShouldBe("february");
+        neighbors.Next.ShouldBeNull();
+    }
+
+    [Fact]
+    public void Oldest_post_has_no_previous()
+    {
+        var neighbors = PostNeighbors.Of(Posts, "january");
+
+        neighbors.Previous.ShouldBeNull();
+        neighbors.Next?.Slug.ShouldBe("february");
+    }
+
+    [Fact]
+    public void Only_post_has_no_neighbors() =>
+        PostNeighbors.Of([Post("only")], "only").ShouldBe(new PostNeighbors(null, null));
+
+    [Fact]
+    public void Unknown_slug_has_no_neighbors() =>
+        PostNeighbors.Of(Posts, "december").ShouldBe(new PostNeighbors(null, null));
+
+    [Fact]
+    public void Slug_is_compared_case_insensitively() =>
+        PostNeighbors.Of(Posts, "February").Next?.Slug.ShouldBe("march");
+}
diff --git a/Elternbeirat.Web.Tests/RouteSmokeTests.cs b/Elternbeirat.Web.Tests/RouteSmokeTests.cs
index 33999fb..6d62cfe 100644
--- a/Elternbeirat.Web.Tests/RouteSmokeTests.cs
+++ b/Elternbeirat.Web.Tests/RouteSmokeTests.cs
@@ -60,7 +60,16 @@ public sealed partial class RouteSmokeTests : IDisposable
     /// Every route that a visitor can reach through the navigation, the FAQ hub
     /// or the news section. The post slugs match the fixture's seed.
     /// </summary>
-    public static TheoryData<string> KnownRoutes =>
+    public static TheoryData<string> KnownRoutes => [.. Routes];
+
+    /// <summary>
+    /// The <see cref="KnownRoutes"/> that render an HTML page, i.e. all but the
+    /// calendar feed.
+    /// </summary>
+    public static TheoryData<string> PageRoutes =>
+        [.. Routes.Where(route => !route.EndsWith(".ics", StringComparison.Ordinal))];
+
+    private static readonly string[] Routes =
     [
         "/",
         "/board",
@@ -453,6 +462,71 @@ public sealed partial class RouteSmokeTests : IDisposable
         visible.ShouldNotContain("Oktober 2026");
     }
 
+    [Fact]
+    public async Task Post_page_has_the_title_as_its_only_h1()
+    {
+        var client = _factory.CreateClient();
+
+        var html = await client.GetStringAsync(new Uri("/posts/new-board", UriKind.Relative));
+
+        Regex.Count(html, "<h1[ >]").ShouldBe(1);
+        html.ShouldContain(">Neuer Vorstand</h1>");
+    }
+
+    [Fact]
+    public async Task Newest_post_links_only_to_the_older_one()
+    {
+        // The fixture has two posts: new-board (newer) and new-hall (older).
+        // "Vorheriger Beitrag" is the older post, so the newest post has no "next".
+        var client = _factory.CreateClient();
+
+        var html = await client.GetStringAsync(new Uri("/posts/new-board", UriKind.Relative));
+
+        html.ShouldContain("href=\"/posts/new-hall\" rel=\"prev\"");
+        html.ShouldNotContain("rel=\"next\"");
+    }
+
+    [Fact]
+    public async Task Oldest_post_links_only_to_the_newer_one()
+    {
+        var client = _factory.CreateClient();
+
+        var html = await client.GetStringAsync(new Uri("/posts/new-hall", UriKind.Relative));
+
+        html.ShouldContain("href=\"/posts/new-board\" rel=\"next\"");
+        html.ShouldNotContain("rel=\"prev\"");
+    }
+
+    [Theory]
+    [MemberData(nameof(PageRoutes))]
+    public async Task Every_page_starts_with_a_skip_link_to_its_own_content(string route)
+    {
+        // The skip link must carry the page's own path: with <base href="/"> a bare
+        // "#main" would lead back to the home page. It must also bypass Blazor's
+        // enhanced navigation, which scrolls but does not move the focus.
+        var client = _factory.CreateClient();
+
+        var html = await client.GetStringAsync(new Uri(route, UriKind.Relative));
+
+        html.ShouldContain($"""<a class="skip-link" href="{route}#main" data-enhance-nav="false" """);
+        html.ShouldContain("Zum Inhalt springen</a>");
+        html.ShouldContain("""<main id="main" """);
+    }
+
+    [Fact]
+    public async Task Menu_toggle_is_a_named_checkbox_tied_to_the_menu()
+    {
+        // The CSS-only hamburger: the checkbox is what keyboard and screen-reader
+        // users operate, so it needs a name and must point at the menu it opens.
+        var client = _factory.CreateClient();
+
+        var html = await client.GetStringAsync(new Uri("/", UriKind.Relative));
+
+        html.ShouldContain("aria-controls=\"main-nav\"");
+        html.ShouldContain("Hauptmenü anzeigen</span>");
+        html.ShouldContain("<nav id=\"main-nav\"");
+    }
+
     /// <summary>
     /// Matches a resource reference that points at an absolute URL, with or without
     /// scheme (<c>https://</c>, <c>http://</c> or protocol-relative <c>//</c>): the
diff --git a/Elternbeirat.Web/Components/Layout/MainLayout.razor b/Elternbeirat.Web/Components/Layout/MainLayout.razor
index b78e43f..918e404 100644
--- a/Elternbeirat.Web/Components/Layout/MainLayout.razor
+++ b/Elternbeirat.Web/Components/Layout/MainLayout.razor
@@ -6,6 +6,15 @@
    immediately), it pins to the top and stays there while the page scrolls. The
    footer is kept at the bottom on short pages by a min-height on <main>, not by a
    flex wrapper -- see MainLayout.razor.css. *@
+
+@* Skip link: the first stop for the Tab key, straight past the menu to the content.
+   The href carries the current path because of <base href="/"> in App.razor: a
+   bare "#main" would resolve to "/#main" and lead every subpage back home.
+   data-enhance-nav="false" leaves the jump to the browser: blazor.web.js would
+   otherwise take the click, only scroll to <main> and keep the focus on the link,
+   so the next Tab would land in the header menu again. *@
+<a class="skip-link" href="@SkipLinkHref" data-enhance-nav="false">Zum Inhalt springen</a>
+
 <header class="site-header">
         <div class="header-inner">
             @* Two-line lettering next to the signet: the body's name large, the
@@ -18,16 +27,23 @@
                 </span>
             </a>
 
-            @* CSS-only mobile menu: the hidden checkbox holds the open/closed
-               state, the label is the hamburger button, and :checked reveals the
-               nav below (see MainLayout.razor.css). No JavaScript, no @@rendermode
-               -- works under static SSR. *@
-            <input type="checkbox" id="nav-toggle" class="nav-toggle" />
-            <label for="nav-toggle" class="nav-toggle-label" aria-label="Menü öffnen und schließen">
+            @* CSS-only mobile menu: the checkbox holds the open/closed state, the
+               label is the hamburger button, and :checked reveals the nav below (see
+               MainLayout.razor.css). No JavaScript, no @@rendermode -- works under
+               static SSR. The checkbox is only visually hidden on a phone, not
+               removed, so it is what keyboard and screen-reader users operate: Tab
+               reaches it, Space toggles it, and its checked state is the menu's
+               open/closed state, announced as such ("Hauptmenü anzeigen,
+               Kontrollkästchen, aktiviert"). Its name is the label's hidden text;
+               aria-controls ties it to the menu it opens. aria-expanded would need
+               JavaScript to keep it in sync, the native checked state does not. *@
+            <input type="checkbox" id="nav-toggle" class="nav-toggle visually-hidden" aria-controls="main-nav" />
+            <label for="nav-toggle" class="nav-toggle-label">
                 <span class="nav-toggle-bar"></span>
+                <span class="visually-hidden">Hauptmenü anzeigen</span>
             </label>
 
-            <nav class="main-nav" aria-label="Hauptmenü">
+            <nav id="main-nav" class="main-nav" aria-label="Hauptmenü">
                 @* The home link comes from PocketBase like every other entry (the
                    "home" page carries location "header"), so it is rendered by the
                    loop below -- no separate hard-coded home link, which would show
@@ -40,7 +56,9 @@
         </div>
     </header>
 
-    <main class="content">
+    @* The skip link's target. tabindex="-1" makes it focusable by the link alone
+       (not by Tab), so after the jump the next Tab continues inside the content. *@
+    <main id="main" class="content" tabindex="-1">
         @Body
     </main>
 
diff --git a/Elternbeirat.Web/Components/Layout/MainLayout.razor.cs b/Elternbeirat.Web/Components/Layout/MainLayout.razor.cs
index 32ea7c0..2d23812 100644
--- a/Elternbeirat.Web/Components/Layout/MainLayout.razor.cs
+++ b/Elternbeirat.Web/Components/Layout/MainLayout.razor.cs
@@ -23,6 +23,12 @@ public partial class MainLayout
     private IReadOnlyList<NavLinkItem> _header = [];
     private IReadOnlyList<NavLinkItem> _footer = [];
 
+    // The skip link's target on this very page: path and query of the request plus
+    // the fragment. See the comment on the skip link in the markup for why it cannot
+    // be a bare "#main".
+    private string SkipLinkHref =>
+        $"{HttpContext?.Request.PathBase}{HttpContext?.Request.Path}{HttpContext?.Request.QueryString}#main";
+
     // Berlin's year, not the server's (UTC) -- see FooterYear.
     private readonly int _year = FooterYear.For(TimeProvider.System.GetUtcNow());
 
diff --git a/Elternbeirat.Web/Components/Layout/MainLayout.razor.css b/Elternbeirat.Web/Components/Layout/MainLayout.razor.css
index 1a7b9b5..2b9a7f5 100644
--- a/Elternbeirat.Web/Components/Layout/MainLayout.razor.css
+++ b/Elternbeirat.Web/Components/Layout/MainLayout.razor.css
@@ -62,6 +62,12 @@
     color: var(--color-on-header);
 }
 
+/* On the blue gradient the global brand-blue focus ring would vanish; white
+   stays visible on both ends of it. */
+.brand:focus-visible {
+    outline-color: var(--color-focus-inverse);
+}
+
 /* The signet lives in its own component (Signet.razor), so its <svg> carries that
    component's scope attribute, not this one's; ::deep reaches it from here. */
 .brand ::deep .signet {
@@ -97,7 +103,9 @@
 }
 
 /* The hamburger button and its state checkbox are hidden on wide screens; the
-   media query below turns them on for narrow ones. */
+   media query below turns them on for narrow ones. display:none (beating the
+   global .visually-hidden the checkbox also carries) takes the checkbox out of the
+   tab order here, where there is no menu to open. */
 .nav-toggle,
 .nav-toggle-label {
     display: none;
@@ -205,6 +213,11 @@
     text-decoration: underline;
 }
 
+/* Same reason as the brand link in the header: a light ring on the dark band. */
+.footer-nav a:focus-visible {
+    outline-color: var(--color-focus-inverse);
+}
+
 /* Copyright: a thin rule separates it from the columns. The rule spans the content
    width, not the whole window, so it lines up with the columns above. */
 .footer-copyright {
@@ -228,6 +241,19 @@
         justify-content: space-between;
     }
 
+    /* The checkbox comes back as a real, focusable control -- only visually hidden
+       (global .visually-hidden), so Tab stops on it and Space toggles the menu. It
+       lives under the label, so the focus ring is drawn there instead. */
+    .nav-toggle {
+        display: block;
+    }
+
+    .nav-toggle:focus-visible + .nav-toggle-label {
+        outline: 3px solid var(--color-focus-inverse);
+        outline-offset: 2px;
+        border-radius: var(--radius);
+    }
+
     /* Show the hamburger button. */
     .nav-toggle-label {
         display: block;
@@ -271,20 +297,29 @@
         transform: translateY(-2px) rotate(-45deg);   /* back up by its own height */
     }
 
-    /* The nav takes its own row and is hidden until the checkbox is checked. */
+    /* The nav takes its own row and is hidden until the checkbox is checked.
+       max-height:0 alone would only hide it from the eye: its links would still
+       be Tab stops and still be read out. visibility:hidden takes them out of
+       both. Transitioning visibility delays the switch to hidden until the fold
+       has finished, so closing still animates. Opening uses the transition of the
+       :checked rule below, which leaves visibility out: the links must be Tab
+       stops the moment Space is pressed, not 0.2s later. */
     .main-nav {
         flex-basis: 100%;
         flex-direction: column;
         gap: 0;
         max-height: 0;
         overflow: hidden;
-        transition: max-height 0.2s ease;
+        visibility: hidden;
+        transition: max-height 0.2s ease, visibility 0.2s;
     }
 
     /* Checked state: reveal the stacked links. The max-height caps the open menu
        to the space below the sticky header; a longer list scrolls inside it
        instead of running off the screen. */
     .nav-toggle:checked ~ .main-nav {
+        visibility: visible;
+        transition: max-height 0.2s ease;
         max-height: 70vh;
         overflow-y: auto;
         margin-top: 0.5rem;
diff --git a/Elternbeirat.Web/Features/Events/EventCard.razor.css b/Elternbeirat.Web/Features/Events/EventCard.razor.css
index e45c830..1f3fd3e 100644
--- a/Elternbeirat.Web/Features/Events/EventCard.razor.css
+++ b/Elternbeirat.Web/Features/Events/EventCard.razor.css
@@ -27,11 +27,6 @@
     color: var(--color-text);
 }
 
-.event-card-link:focus-visible {
-    outline: 3px solid var(--color-focus);
-    outline-offset: 2px;
-}
-
 .event-details {
     display: flex;
     flex-direction: column;
diff --git a/Elternbeirat.Web/Features/Home/Home.razor.css b/Elternbeirat.Web/Features/Home/Home.razor.css
index 143f199..d922e29 100644
--- a/Elternbeirat.Web/Features/Home/Home.razor.css
+++ b/Elternbeirat.Web/Features/Home/Home.razor.css
@@ -90,7 +90,7 @@
 }
 
 .hero .btn:focus-visible {
-    outline-color: var(--color-on-header);
+    outline-color: var(--color-focus-inverse);
 }
 
 /* --- Next event ---------------------------------------------------------------
@@ -116,7 +116,7 @@
 /* The ring sits outside the card, on the gradient, so it is white like the
    hero's button rings. */
 .next-event:focus-visible {
-    outline: 3px solid var(--color-on-header);
+    outline-color: var(--color-focus-inverse);
     outline-offset: 3px;
 }
 
@@ -208,11 +208,6 @@
     color: var(--color-text);
 }
 
-.tile-link:focus-visible {
-    outline: 3px solid var(--color-focus);
-    outline-offset: 2px;
-}
-
 /* The icon in a soft round tint. */
 .tile-icon {
     flex-shrink: 0;
diff --git a/Elternbeirat.Web/Features/Posts/PostCard.razor.css b/Elternbeirat.Web/Features/Posts/PostCard.razor.css
index 7ef89d0..f0947a1 100644
--- a/Elternbeirat.Web/Features/Posts/PostCard.razor.css
+++ b/Elternbeirat.Web/Features/Posts/PostCard.razor.css
@@ -23,11 +23,6 @@
     color: var(--color-text);
 }
 
-.post-card:focus-visible {
-    outline: 3px solid var(--color-focus);
-    outline-offset: 2px;
-}
-
 /* Icon and date on one line. The icon belongs to Icon's own scope, so it is
    reached through ::deep. */
 .post-date {
diff --git a/Elternbeirat.Web/Features/Posts/PostDetail.razor b/Elternbeirat.Web/Features/Posts/PostDetail.razor
index ec7cc4c..3023e66 100644
--- a/Elternbeirat.Web/Features/Posts/PostDetail.razor
+++ b/Elternbeirat.Web/Features/Posts/PostDetail.razor
@@ -8,16 +8,39 @@
 else if (_post is not null)
 {
     <PageTitle>@_post.Title</PageTitle>
-    <nav>
-        <a href="/posts">&larr; Alle Beiträge</a>
-    </nav>
-    <article>
-        <div class="post-content">
-            <PostDate Value="_post.Date" />
-            <h2>@_post.Title</h2>
-            <div class="markdown-body">@Body</div>
-        </div>
+    @* A plain link, not a <nav>: one link is no navigation block, and an unlabelled
+       second <nav> next to the main menu would only add noise for screen readers. *@
+    <a class="btn btn-quiet" href="/posts"><Icon Name="arrow-left" Size="18" />Alle Beiträge</a>
+
+    <article class="post">
+        <header class="post-header">
+            <p class="post-meta"><Icon Name="calendar" Size="16" /><PostDate Value="_post.Date" /></p>
+            <h1>@_post.Title</h1>
+        </header>
+        <div class="markdown-body post-body">@Body</div>
     </article>
+
+    @if (_neighbors.Previous is not null || _neighbors.Next is not null)
+    {
+        @* Older post on the left, newer on the right, like a timeline. A missing side
+           leaves its cell empty, so the remaining link keeps its place. *@
+        <nav class="post-pager" aria-label="Weitere Beiträge">
+            @if (_neighbors.Previous is { } previous)
+            {
+                <a class="post-pager-link post-pager-previous" href="/posts/@previous.Slug" rel="prev">
+                    <span class="post-pager-label"><Icon Name="arrow-left" Size="16" />Vorheriger Beitrag</span>
+                    <span class="post-pager-title">@previous.Title</span>
+                </a>
+            }
+            @if (_neighbors.Next is { } next)
+            {
+                <a class="post-pager-link post-pager-next" href="/posts/@next.Slug" rel="next">
+                    <span class="post-pager-label">Nächster Beitrag<Icon Name="arrow-right" Size="16" /></span>
+                    <span class="post-pager-title">@next.Title</span>
+                </a>
+            }
+        </nav>
+    }
 }
 @* No post and not unavailable: the slug was unknown; NavigationManager.NotFound()
    already ran in OnParametersSetAsync and renders the not-found page. *@
diff --git a/Elternbeirat.Web/Features/Posts/PostDetail.razor.cs b/Elternbeirat.Web/Features/Posts/PostDetail.razor.cs
index 7eb1aef..b61fe08 100644
--- a/Elternbeirat.Web/Features/Posts/PostDetail.razor.cs
+++ b/Elternbeirat.Web/Features/Posts/PostDetail.razor.cs
@@ -32,6 +32,10 @@ public partial class PostDetail
 
     private Post? _post;
 
+    // The older and newer post for the "Vorheriger / Nächster Beitrag" links at the
+    // end; both empty until loaded or when the post stands alone.
+    private PostNeighbors _neighbors = new(null, null);
+
     // Set when the content source could not be reached or read. The markup then
     // shows a "temporarily unavailable" note instead of a not-found page, matching
     // the 503 this sets on the response.
@@ -48,6 +52,7 @@ public partial class PostDetail
             var posts = await PocketBase.GetPostsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
             _post = posts.FirstOrDefault(
                 post => string.Equals(post.Slug, Slug, StringComparison.OrdinalIgnoreCase));
+            _neighbors = PostNeighbors.Of(posts, Slug);
         }
         catch (PocketBaseUnavailableException exception)
         {
diff --git a/Elternbeirat.Web/Features/Posts/PostDetail.razor.css b/Elternbeirat.Web/Features/Posts/PostDetail.razor.css
index f7dd27b..cbf12b6 100644
--- a/Elternbeirat.Web/Features/Posts/PostDetail.razor.css
+++ b/Elternbeirat.Web/Features/Posts/PostDetail.razor.css
@@ -1,15 +1,108 @@
-/* Push the whole article body down from the "all posts" link above it. Wraps the
-   date, heading and body, so scoped CSS applies (the date sits in the PostDate
-   child component and would not be reachable on its own). The date's own look
-   comes from PostDate.razor.css. */
-.post-content {
-    margin-top: 1.5rem;
+/* The article: a reading column of about 68 characters with generous leading, so a
+   long post reads like a page, not like a form. Everything inside follows this
+   width -- the global 42rem cap on paragraphs, lists and boxes is lifted here, or
+   the text would stop short of the column it sits in. */
+.post {
+    max-width: 68ch;
+    margin-top: var(--space-4);
+    line-height: 1.75;
 }
 
-/* The post title is the first h2 in the content, sitting right under its date, so
-   drop the large default heading gap above it (h1..h4 carry --space-5 top margin
-   globally); date and title belong together. Scoped to :first-of-type so h2
-   subheadings inside the Markdown body keep their normal spacing. */
-.post-content h2:first-of-type {
-    margin-top: var(--space-1);
+.post ::deep :is(p, ul, ol, blockquote, .aufruf, .hinweis) {
+    max-width: none;
+}
+
+/* Date above the title as a quiet meta line, with the same calendar icon as on the
+   post cards. The title follows directly, so the gap between them stays small
+   (h1 carries no top margin globally). */
+.post-meta {
+    display: flex;
+    align-items: center;
+    gap: var(--space-1);
+    margin: 0 0 var(--space-2);
+    color: var(--color-text-soft);
+    font-size: 0.95rem;
+    font-weight: 600;
+}
+
+.post-meta ::deep .icon {
+    color: var(--color-accent-dark);
+}
+
+/* The first paragraph as the lead: larger and in the soft tone, so it reads as an
+   introduction. Pure CSS on the editor's Markdown -- if a post starts with a
+   heading or a list instead, there simply is no lead. Same text colour token as
+   the rest, so it keeps AA contrast in both schemes. */
+.post-body ::deep > p:first-child {
+    color: var(--color-text-soft);
+    font-size: 1.2rem;
+    line-height: 1.65;
+}
+
+/* Older/newer post at the end: two cards side by side, older on the left, newer on
+   the right. The grid keeps each in its column even if the other is missing. Hover
+   = border and shadow, nothing moves. */
+.post-pager {
+    display: grid;
+    grid-template-columns: 1fr 1fr;
+    gap: var(--space-3);
+    max-width: 68ch;
+    margin-top: var(--space-6);
+    padding-top: var(--space-4);
+    border-top: 1px solid var(--color-border);
+}
+
+.post-pager-link {
+    display: flex;
+    flex-direction: column;
+    gap: var(--space-1);
+    padding: var(--space-3) var(--space-4);
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius);
+    background: var(--color-bg);
+    color: var(--color-text);
+    text-decoration: none;
+    transition: box-shadow var(--transition), border-color var(--transition);
+}
+
+.post-pager-link:hover {
+    border-color: var(--color-brand);
+    box-shadow: var(--shadow-hover);
+    color: var(--color-text);
+}
+
+.post-pager-next {
+    grid-column: 2;
+    text-align: right;
+}
+
+.post-pager-label {
+    display: inline-flex;
+    align-items: center;
+    gap: var(--space-1);
+    color: var(--color-text-soft);
+    font-size: 0.85rem;
+    font-weight: 700;
+}
+
+.post-pager-next .post-pager-label {
+    align-self: flex-end;
+}
+
+.post-pager-title {
+    color: var(--color-brand);
+    font-weight: 700;
+    line-height: 1.3;
+}
+
+/* On a phone the two cards stack: a half-width card would squeeze a long title
+   into a narrow column. Older first, as in the wide layout. */
+@media (max-width: 40rem) {
+    .post-pager {
+        grid-template-columns: 1fr;
+    }
+
+    .post-pager-next {
+        grid-column: 1;
+    }
 }
diff --git a/Elternbeirat.Web/Features/Posts/PostNeighbors.cs b/Elternbeirat.Web/Features/Posts/PostNeighbors.cs
new file mode 100644
index 0000000..998d996
--- /dev/null
+++ b/Elternbeirat.Web/Features/Posts/PostNeighbors.cs
@@ -0,0 +1,65 @@
+using Elternbeirat.Contracts;
+
+namespace Elternbeirat.Web.Features.Posts;
+
+/// <summary>
+///     The posts next to a given post in time: the one published before it and the
+///     one published after it.
+/// </summary>
+/// <param name="Previous">
+///     The older post, or <see langword="null"/> if the post is the oldest.
+/// </param>
+/// <param name="Next">
+///     The newer post, or <see langword="null"/> if the post is the newest.
+/// </param>
+/// <remarks>
+///     "Previous" and "next" follow time, as a reader moving through the news would:
+///     "Vorheriger Beitrag" is the older one, "Nächster Beitrag" the newer one. The
+///     list order of the posts page (newest first) is the other way round, which is
+///     why the direction is pinned down here instead of being left to the markup.
+/// </remarks>
+/// <seealso cref="PostDetail"/>
+public sealed record PostNeighbors(Post? Previous, Post? Next)
+{
+    /// <summary>
+    ///     Finds the neighbours of the post with the given slug.
+    /// </summary>
+    /// <param name="posts">
+    ///     All public posts, newest first, as <c>PocketBaseClient.GetPostsAsync</c>
+    ///     returns them.
+    /// </param>
+    /// <param name="slug">The slug of the post being shown.</param>
+    /// <returns>
+    ///     The older and the newer post. Both are <see langword="null"/> if the slug is
+    ///     not in the list, or if it is the only post.
+    /// </returns>
+    /// <remarks>
+    ///     The slug is compared case-insensitively, like the route lookup in
+    ///     <see cref="PostDetail"/>, so a page reached as <c>/posts/New-Board</c> still
+    ///     gets its neighbours.
+    /// </remarks>
+    /// <example>
+    ///     <code>
+    ///         // posts = [March, February, January] (newest first)
+    ///         var neighbors = PostNeighbors.Of(posts, "february");
+    ///         // neighbors.Previous is January, neighbors.Next is March
+    ///     </code>
+    /// </example>
+    public static PostNeighbors Of(IReadOnlyList<Post> posts, string slug) =>
+        IndexOf(posts, slug) is var index and >= 0
+            ? new PostNeighbors(
+                Previous: index + 1 < posts.Count ? posts[index + 1] : null,
+                Next: index > 0 ? posts[index - 1] : null)
+            : new PostNeighbors(null, null);
+
+    /// <summary>
+    ///     The position of the post with <paramref name="slug"/>, or <c>-1</c>.
+    /// </summary>
+    private static int IndexOf(IReadOnlyList<Post> posts, string slug) =>
+        posts
+            .Select((post, index) => (post, index))
+            .FirstOrDefault(
+                entry => string.Equals(entry.post.Slug, slug, StringComparison.OrdinalIgnoreCase),
+                (null!, -1))
+            .index;
+}
diff --git a/Elternbeirat.Web/Shared/IconSet.cs b/Elternbeirat.Web/Shared/IconSet.cs
index 1bb863b..ccde8b9 100644
--- a/Elternbeirat.Web/Shared/IconSet.cs
+++ b/Elternbeirat.Web/Shared/IconSet.cs
@@ -12,7 +12,8 @@ namespace Elternbeirat.Web.Shared;
 ///     <para>
 ///         Source: Lucide (<c>lucide.dev</c>), ISC license; the icons derived from
 ///         Feather (<c>calendar</c>, <c>clock</c>, <c>download</c>,
-///         <c>external-link</c>, <c>help-circle</c>, <c>info</c>, <c>arrow-right</c>)
+///         <c>external-link</c>, <c>help-circle</c>, <c>info</c>, <c>arrow-right</c>,
+///         <c>arrow-left</c>)
 ///         are MIT, Copyright (c) 2013-present Cole Bemis. Both licenses only ask that
 ///         the notice travels with the copy, which this comment does. Only the inner
 ///         elements are stored; <see cref="Icon"/> supplies the shared
@@ -55,6 +56,8 @@ public static class IconSet
                 """<circle cx="12" cy="12" r="10"/><path d="M9.09 9a3 3 0 0 1 5.83 1c0 2-3 3-3 3"/><path d="M12 17h.01"/>""",
             ["newspaper"] =
                 """<path d="M15 18h-5"/><path d="M18 14h-8"/><path d="M4 22h16a2 2 0 0 0 2-2V4a2 2 0 0 0-2-2H8a2 2 0 0 0-2 2v16a2 2 0 0 1-4 0v-9a2 2 0 0 1 2-2h2"/><rect width="8" height="4" x="10" y="6" rx="1"/>""",
+            ["arrow-left"] =
+                """<path d="m12 19-7-7 7-7"/><path d="M19 12H5"/>""",
             ["arrow-right"] =
                 """<path d="M5 12h14"/><path d="m12 5 7 7-7 7"/>""",
             ["external-link"] =
diff --git a/Elternbeirat.Web/wwwroot/app.css b/Elternbeirat.Web/wwwroot/app.css
index eb658f2..540f44b 100644
--- a/Elternbeirat.Web/wwwroot/app.css
+++ b/Elternbeirat.Web/wwwroot/app.css
@@ -11,20 +11,22 @@
     --color-brand-dark: #1f5477;
     --color-brand-tint: #eaf3f9;
 
-    /* The header bar's background: the IGMH blue at full strength. Its own token
-       (not --color-brand) both because it only ever carries white text (so it needs
-       no darkening) and because it must stay a deep blue in dark mode, where
-       --color-brand is lightened for text/links. */
-    --color-header: #328fc6;
+    /* The header bar's background: the IGMH blue, eased one step deeper. The
+       original #328fc6 carries white menu text at only 3.6:1, below AA for normal
+       text; #2a77a6 is the same hue at 4.9:1. Its own token (not --color-brand)
+       because it only ever carries white text and must stay a deep blue in dark
+       mode, where --color-brand is lightened for text/links. */
+    --color-header: #2a77a6;
 
-    /* Text and menu states on the header. White text, and two translucent white
-       washes for the menu pills: they lighten whatever part of the gradient sits
-       behind a link, so one value works from the blue end to the green end. The
-       active pill is the stronger one, so "where am I" outranks "where is the
-       mouse". */
+    /* Text and menu states on the header. White text, and two translucent dark
+       washes for the menu pills: they deepen whatever part of the gradient sits
+       behind a link, so one value works from the blue end to the green end and the
+       white text gains contrast instead of losing it (a white wash dropped the
+       active pill to 2.7:1). The active pill is the stronger one, so "where am I"
+       outranks "where is the mouse". */
     --color-on-header: #fff;
-    --color-nav-hover: rgba(255, 255, 255, 0.12);
-    --color-nav-active: rgba(255, 255, 255, 0.2);
+    --color-nav-hover: rgba(0, 0, 0, 0.12);
+    --color-nav-active: rgba(0, 0, 0, 0.2);
 
     /* Footer: a dark brand blue, so the page visibly ends there. Light text in two
        steps (headings and the name brighter, links softer); both stay >= 7:1 on the
@@ -90,6 +92,11 @@
        one; on the gradient the hero switches it to white. */
     --color-focus: #1f5477;
 
+    /* The focus ring on the dark brand surfaces (header, hero gradient, footer),
+       where the dark ring above would vanish: white in both schemes, >= 4.9:1 on
+       every one of them. */
+    --color-focus-inverse: #fff;
+
     /* Headings. Its own token (not --color-brand) so headings and links can differ:
        in dark mode headings become a soft white while links keep the brand blue. */
     --color-heading: #2b6f9c;
@@ -147,6 +154,27 @@
        because heavy letters at large sizes otherwise look spaced out. */
     --font-weight-heading: 800;
     --letter-spacing-heading: -0.015em;
+
+    /* WCAG AA check of the colour pairs, light / dark (computed, October 2026).
+       Text needs 4.5:1, large text and focus rings/graphics 3:1.
+         text on card / page ............... 15.9 / 6.2    14.6 / 7.2
+         soft text on card / page .......... 7.5 / 6.2     6.9 / 7.2
+         soft text on green / blue tint .... 6.8 / 5.6     6.6 / 5.7
+         link (brand) on card / page ....... 5.4 / 7.5     5.0 / 8.7
+         link on green / blue tint ......... 5.0 / 6.7     4.8 / 6.9
+         heading on card / page ............ 5.4 / 9.3     5.0 / 10.9
+         white on header / gradient green .. 4.9 / 5.5     5.2 / 6.4
+         white on menu pill hover / active . 6.0 / 6.6     6.9 / 7.6
+         footer heading / link on footer ... 10.4 / 10.5   7.4 / 6.9
+         white on button / button hover .... 5.4 / 5.5     8.1 / 8.1
+         light button text ................. 8.1 / 9.7    (hover 7.2 / 8.3)
+         white on calendar band ............ 5.2 / 6.4
+         avatar blue / green ............... 7.2 / 8.6     5.9 / 6.7
+         focus ring on page / card ......... 7.5 / 11.0    8.1 / 9.4
+         white ring on header / footer ..... 4.9 / 5.5     11.4 / 16.6
+         green markers on card (graphic) ... 3.8 / 7.5
+       All pass. Exempt as pure decoration: the light green --color-accent (card
+       stripes, heading bars, the active-menu stroke), which never carries text. */
 }
 
 /* Dark mode: follows the visitor's OS setting automatically (prefers-color-scheme).
@@ -164,7 +192,8 @@
         --color-brand-dark: #a3d5f4;   /* hover goes lighter, not darker, on dark */
         --color-brand-tint: #223038;
 
-        --color-header: #266f9c;       /* the IGMH blue eased down, to sit calmly on dark */
+        --color-header: #266f9c;       /* the IGMH blue eased down, to sit calmly on
+                                          dark; white on it 5.5:1 */
 
         --color-footer: #10202e;       /* a deep night blue: darker than the page, so
                                           the band still reads as the page's end */
@@ -310,6 +339,56 @@ h1:focus {
     outline: none;
 }
 
+/* Keyboard focus, one look for the whole site: a thick ring in --color-focus with a
+   little air between ring and element, so it never melts into a card's border or a
+   button's fill. :focus-visible, not :focus -- the ring shows for keyboard users
+   and stays away after a mouse click. Covers every focusable thing a page has:
+   links (and with them every card, which is one big link), buttons, the <summary>
+   of each disclosure, form fields and anything made focusable with tabindex. Dark
+   brand surfaces (header, hero, footer) switch the colour to
+   --color-focus-inverse. */
+:is(a, button, summary, input, select, textarea, [tabindex]):focus-visible {
+    outline: 3px solid var(--color-focus);
+    outline-offset: 2px;
+}
+
+/* <main> takes focus from the skip link (tabindex="-1") only so the next Tab
+   continues inside the content; a ring around the whole page would just be noise. */
+main:focus {
+    outline: none;
+}
+
+/* Skip link: the first thing on every page, so keyboard and screen-reader users
+   can jump past the header menu straight to the content. Off screen until it gets
+   focus, then it drops in at the top left over the sticky header -- a link that
+   is only hidden visually stays in the tab order, display:none would remove it. */
+.skip-link {
+    position: absolute;
+    top: var(--space-2);
+    left: var(--space-2);
+    z-index: 100;
+    padding: var(--space-2) var(--space-4);
+    border-radius: var(--radius-sm);
+    background: var(--color-button-light);
+    box-shadow: var(--shadow-lg);
+    color: var(--color-on-button-light);
+    font-weight: 700;
+    text-decoration: none;
+    transform: translateY(-200%);
+}
+
+/* It lands on the header, so it takes the light button look and the white ring
+   of the dark brand surfaces. Shown instantly, no transition: it is a jump aid,
+   not an effect. */
+.skip-link:focus {
+    transform: none;
+    outline-color: var(--color-focus-inverse);
+}
+
+.skip-link:hover {
+    color: var(--color-on-button-light);
+}
+
 /* Text for screen readers only: off screen visually, still read aloud. For places
    where the visible form is decoration (the calendar sheet) and the spoken form
    must carry the full information. Not display:none -- that hides it from screen
@@ -353,11 +432,6 @@ h1:focus {
                 color var(--transition), border-color var(--transition);
 }
 
-.btn:focus-visible {
-    outline: 3px solid var(--color-focus);
-    outline-offset: 2px;
-}
-
 .btn-primary {
     background: var(--color-button);
     border-color: var(--color-button);
@@ -382,6 +456,21 @@ h1:focus {
     color: var(--color-brand);
 }
 
+/* Quiet = no frame at all, just the brand-blue label; hover lays the blue tint
+   behind it. For a way back ("Alle Beiträge") that should be easy to find but not
+   compete with the page's content. The negative inline margin lines the label up
+   with the text below while the hover tint still gets its padding. */
+.btn-quiet {
+    margin-inline: calc(-1 * var(--space-3));
+    padding-inline: var(--space-3);
+    color: var(--color-brand);
+}
+
+.btn-quiet:hover {
+    background: var(--color-brand-tint);
+    color: var(--color-brand);
+}
+
 /* Header navigation links. These live here (global), not in MainLayout.razor.css:
    NavLink renders plain <a> elements without a scoped-CSS attribute, so a scoped
    ".main-nav a" rule would not match them -- the links would fall back to the
@@ -403,6 +492,12 @@ h1:focus {
     background: var(--color-nav-hover);
 }
 
+/* The dark default ring would vanish on the blue header (2.3:1); white stands out
+   on the whole gradient. */
+.main-nav a:focus-visible {
+    outline-color: var(--color-focus-inverse);
+}
+
 /* NavLink adds .active to the current route's link: a stronger pill plus a short
    green stroke under the text mark where the visitor is. The stroke is drawn by
    ::after, not a border, so it follows the text width inside the rounded pill. */
@@ -1029,3 +1124,19 @@ h1:focus {
     border: none;
     border-top: 1px solid var(--color-border);
 }
+
+/* Reduced motion: visitors who asked their system for less movement get none.
+   The site has no animations, only short transitions (hover colours, the
+   hamburger turning into an X, the mobile menu folding open); these are cut to
+   an instant here. Near zero rather than none, so anything that waits for a
+   transition to end still gets its event. */
+@media (prefers-reduced-motion: reduce) {
+    *,
+    ::before,
+    ::after {
+        transition-duration: 0.01ms !important;
+        animation-duration: 0.01ms !important;
+        animation-iteration-count: 1 !important;
+        scroll-behavior: auto !important;
+    }
+}