I'll create a Windows 7 style party countdown game using only the 7.css library. This will be a fun countdown timer with party-themed elements and authentic Windows 7 styling.

This Windows 7 style party countdown game includes:

Authentic Windows 7 Features:

• Proper window structure with title bar and controls
• Classic Windows 7 blue gradient desktop background
• Authentic 7.css styling throughout
• Fieldsets for organized sections
• Classic button styling and form elements

Party Countdown Features:

• Set custom party date/time and name
• Real-time countdown display (days, hours, minutes, seconds)
• Animated progress bar showing time elapsed
• Party-themed emojis and messages
• Celebration animation when party time arrives
• Reset functionality to start over

Girl-Friendly Design:

• Pink and sparkly color scheme
• Fun party emojis (💃🥂💄👠🎵✨💅🌟)
• Encouraging messages and quotes
• Bouncing animations for extra fun
• "For the Girls" branding throughout

The app is fully functional with embedded JavaScript and uses only the 7.css library as requested. It captures the nostalgic Windows 7 aesthetic while providing a fun, interactive countdown experience perfect for planning girls' nights out or parties!