feat: add prev/next article navigation with shell prompt style

Add top and bottom navigation between sequential articles with hacker aesthetic:
- Top nav: [visitor@danix.xyz articles]$ cd
- Bottom nav: [visitor@danix.xyz articles]$ ls ../
- Missing link shows dimmed placeholder (beginning/end)
- Only renders on articles, not static pages
- New partial: article-nav.html
- Styling: monospace prompt in accent color, hover links with transition

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/themes/danix-xyz-hacker/assets/css/main.css b/themes/danix-xyz-hacker/assets/css/main.css
index f618f2d..298c38b 100644
--- a/themes/danix-xyz-hacker/assets/css/main.css
+++ b/themes/danix-xyz-hacker/assets/css/main.css
@@ -574,6 +574,28 @@ html.theme-light picture img[src="/images/default_thumbnail_dark.png"] {
   .section-title {
     font-size: clamp(1.5rem, 3vw + 0.5rem, 2.5rem);
   }
+
+  /* ---- Article prev/next navigation ---- */
+  .article-nav {
+    @apply border-t border-border pt-6;
+  }
+
+  .article-nav-prompt {
+    @apply font-mono text-sm mb-2;
+    color: var(--accent);
+  }
+
+  .article-nav-links {
+    @apply flex justify-between items-center font-mono text-sm;
+  }
+
+  .article-nav-link {
+    @apply hover:text-accent transition-colors text-text;
+  }
+
+  .article-nav-placeholder {
+    @apply text-text-dim opacity-40;
+  }
 }
 
 /* Prose overrides for light theme */