Add global mobile-friendly CSS rules

src/app/globals.css

@@ -109,6 +109,8 @@ html.dark .article-img {
 
 html {
   scroll-behavior: smooth;
+  -webkit-text-size-adjust: 100%;
+  text-size-adjust: 100%;
 }
 body {
   font-family: var(--font-family);
@@ -117,6 +119,23 @@ body {
   -moz-osx-font-smoothing: grayscale;
 }
 
+/* Mobile-friendly improvements for every screen */
+button, a, input, select, textarea, summary, [role="button"], [role="menuitem"] {
+  touch-action: manipulation;
+}
+
+/* Momentum scrolling on iOS */
+* {
+  -webkit-overflow-scrolling: touch;
+}
+
+/* Prevent iOS zoom on input focus */
+@media (max-width: 48rem) {
+  input, select, textarea {
+    font-size: 16px;
+  }
+}
+
 /* Semantic colors: safe across every complete light/dark preset. */
 .theme-text-muted {
   color: var(--color-text-muted-readable);