Design an elegant, professional, modern landing page for the 999Yes application.

The page features a blue, white, and gold color scheme, with the logo positioned at the top. A “Rejoindre 999Yes” button opens the referral link directly, while a “Partager” button triggers the Android share menu with the message “Rejoins-moi sur 999Yes avec mon lien de parrainage :”. A concise section explains the app’s purpose. The interface is quick, fluid, and optimized for Android phones. Flutter code is clean, organized, commented, and maintainable, with a structure that allows future feature additions. Testing instructions for Android and steps to prepare a Google Play Store release are also supplied.