[examples] Update Next.js example CSS styling.

[huozhi]

Update exmaple of nextjs, it's not scrollable in mobile viewport

The style is outdated, re-create the nextjs with create-next-app to apply the style changes from vercel/next.js#28096

Code Review

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[codecov]

Codecov Report

Merging #7337 (82d2b4c) into main (f18bca9) will decrease coverage by 5.81%.
The diff coverage is 67.69%.

❗ Current head 82d2b4c differs from pull request most recent head 22b0ce9. Consider uploading reports for the commit 22b0ce9 to get more accurate results

@@            Coverage Diff             @@
##             main    #7337      +/-   ##
==========================================
- Coverage   54.98%   49.17%   -5.82%     
==========================================
  Files          85      135      +50     
  Lines        3592     5426    +1834     
  Branches      841     1358     +517     
==========================================
+ Hits         1975     2668     +693     
- Misses       1611     2750    +1139     
- Partials        6        8       +2     

Impacted Files	Coverage Δ
packages/cli/src/commands/deploy/args.ts	100.00% <ø> (ø)
packages/cli/src/types.ts	100.00% <ø> (ø)
packages/cli/src/commands/deploy/index.ts	20.05% <18.75%> (ø)
packages/cli/src/commands/pull.ts	80.48% <80.48%> (ø)
packages/cli/src/commands/env/pull.ts	76.66% <100.00%> (ø)
packages/cli/src/util/metrics.ts	95.00% <0.00%> (-5.00%)	⬇️
packages/cli/src/util/get-update-command.ts	73.33% <0.00%> (-0.44%)	⬇️
packages/cli/test/mocks/user.ts	100.00% <0.00%> (ø)
packages/cli/src/util/output/error.ts	31.25% <0.00%> (ø)
packages/cli/src/util/get-project-name.ts	100.00% <0.00%> (ø)
... and 75 more

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[leerob]

Thank you!