fix: mobile horizontal overflow and hero responsiveness

- Remove scrollbar-gutter: stable, add overflow-x: hidden on html
- Cap section-glow pseudo-element width to viewport on mobile
- Scale down hero logo, text, spacing, and button for small screens (iPhone SE)

src/app/globals.css

@@ -19,7 +19,7 @@
 
 html {
   scroll-behavior: smooth;
-  scrollbar-gutter: stable;
+  overflow-x: hidden;
 }
 
 body {

src/app/styles/theme.css

@@ -71,7 +71,7 @@
   top: 0;
   left: 50%;
   transform: translateX(-50%);
-  width: 600px;
+  width: min(600px, 100%);
   height: 400px;
   background: radial-gradient(ellipse, rgba(201, 169, 110, 0.05), transparent 70%);
   pointer-events: none;