Mobile: center pinned post, pagination fixes, minor layout tweaks

- First (pinned) post on mobile: title and image centered
- Pagination: restored page counter on mobile, buttons above footer
- Typography and layout minor improvements

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

static/css/typography-improvements.css

@@ -185,6 +185,30 @@
     }
 }
 
+/* Мобильный: первый (закреплённый) пост — центрировать */
+@media screen and (max-width: 736px) {
+    #main > section.posts:first-of-type article {
+        text-align: center !important;
+        padding: 1.5rem 1.25rem !important;
+    }
+
+    #main > section.posts:first-of-type article header h2 {
+        text-align: center !important;
+        font-size: 1.45rem !important;
+        -webkit-line-clamp: unset !important;
+        overflow: visible !important;
+    }
+
+    #main > section.posts:first-of-type article header h2 a {
+        color: inherit;
+    }
+
+    #main > section.posts:first-of-type article .image.main {
+        margin: 0.75rem auto !important;
+        display: block !important;
+    }
+}
+
 /* Адаптивность для мобильных */
 @media (max-width: 768px) {
     #main article h1 {