style: Update background gradient for public profile and user profile pages

- Changed the background gradient from #667eea and #764ba2 to #0f172a and #111827 for a darker theme.
- Ensured consistency in visual design across user interface components.

Author: codergautam

components/publicProfile.js

@@ -93,7 +93,7 @@ export default function PublicProfile({ profileData, eloData }) {
                 .public-profile-container {
                     min-height: 100vh;
                     width: 100%;
-                    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+                    background: linear-gradient(135deg, #0f172a 0%, #111827 100%);
                     background-attachment: fixed;
                     padding: 20px;
                     box-sizing: border-box;

pages/user.js

@@ -137,7 +137,7 @@ export default function UserProfilePage() {
       <style jsx>{`
         .user-profile-page {
           min-height: 100vh;
-          background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+          background: linear-gradient(135deg, #0f172a 0%, #111827 100%);
           background-attachment: fixed;
         }