.balloon {
    position: fixed;
    bottom: -100px;
    left: 50%;
    transform: translateX(-50%);
    background: #ff4081;
    color: white;
    padding: 12px 24px;
    border-radius: 60px;
    font-weight: bold;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    z-index: 9999;
    animation: floatUp 4s ease-out forwards;
}
@keyframes floatUp {
    0% { bottom: -100px; opacity: 1; }
    70% { bottom: 80%; opacity: 1; }
    100% { bottom: 100%; opacity: 0; }
}