UX overhaul: glassmorphism nav/footer, forms redesign, mobile fixes

Navigation:
- Nav bar pill shape (border-radius: 100px), dark glass style
- Icons added to all nav items (FA4 outline variants, fixed-width alignment)
- Footer hidden on all devices (nav panel covers mobile)
- Footer nav icons + text added before removal

Forms (ask.md, plan.md):
- Full glassmorphism redesign: rounded card, blur backdrop
- Input borders visible (#b8c4ce), focus ring, proper placeholder colors
- Select: self-contained CSS, no backdrop-filter conflict, arrow fixed
- Submit button: gradient with shadow
- File upload button: .file-btn class, fa-arrow-down icon
- form-note styled as info callout with left border + ⓘ icon
- Footnotes sup.fn: circular badge, baseline positioning (no line-height jump)
- Footnote ¹ on both consent checkboxes, accordion = full legal text
- Dark mode: opaque dark card (rgba 22,26,34,0.88), proper contrast
- Dark mode success/error messages adapted
- Double checkmark bug fixed (removed ::after overlay)
- Italic removed from privacy-details text

Layout:
- #main rounded corners (20px all sides) + margin for visibility
- Post card images rounded (border-radius: 10px)
- Page titles: uppercase removed, font-weight 900, left-aligned
- "Подробнее" button hidden on post cards
- iOS background-attachment: fixed bug fixed (scroll on mobile)
- Pagination mobile: counter restored, buttons above footer

Content:
- Page titles uncommented in front matter (gallery, map, ask, plan)
- Duplicate rawhtml title blocks removed

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

static/css/adaptive-background.css

@@ -7,8 +7,9 @@
                       linear-gradient(0deg, rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0.1)),
                       url('../../images/mobile4.webp') !important;
     background-size: cover;
-    background-position: center;
-    background-attachment: fixed;
+    background-position: center top;
+    /* iOS Safari не поддерживает background-attachment: fixed нормально */
+    background-attachment: scroll;
   }
 }