body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #e0e0e0;
}

.bird-container {
    position: relative;
    width: 200px;
    height: 200px;
}

.bird-wing {
    transform-origin: center;
    animation: flap 0.5s infinite alternate;
}

@keyframes flap {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(-20deg);
    }
}