On the welcome screen, add a subtle background pattern that resembles a knitted sweater texture:

1. The pattern should be placed behind the "Start" button and centered text, filling the entire background of the welcome screen.
2. Use a color between the current light beige text color (#F5E7D8) and the dark brown background (#2B221A) — something that gently contrasts with both but remains soft and warm.
3. The pattern should be subtle and decorative — it should not overpower the content, but instead add texture and visual contrast.
4. Make sure the pattern is seamless and does not repeat awkwardly. Use a knitted or woven texture look (like a sweater).
5. Ensure it works well on both desktop and mobile viewports.

Do not affect the layout or button animation — only add the patterned background behind the welcome screen content.