Slide-mode scroll: font -20%, sections snap mandatory at 100vh

- html font-size 22.4 → 17.92px (still +12% vs original 16)
- scroll-snap-type: proximity → mandatory
- sections min-height 100vh, centered content via flex

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

index.html

@@ -108,17 +108,21 @@
 
 html {
   scroll-behavior: smooth;
-  font-size: 22.4px; /* +40% от 16px — крупнее контент */
-  scroll-snap-type: y proximity;
+  font-size: 17.92px; /* +40% затем -20% от 22.4 */
+  scroll-snap-type: y mandatory;
 }
 
-/* Scroll-snap по основным секциям */
+/* Каждая секция = слайд на весь экран */
 .hero,
 section.section,
 .dark-section {
   scroll-snap-align: start;
   scroll-snap-stop: always;
-  scroll-margin-top: 84px; /* высота sticky-нав */
+  scroll-margin-top: 84px;
+  min-height: 100vh;
+  display: flex;
+  flex-direction: column;
+  justify-content: center;
 }
 
 /* ── POLISH: shared hover transition for all card variants ── */