.bird-flight-layer {
    position: fixed;
    inset: 0;
    z-index: 1000;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
}
.bird-flight-still {
    position: fixed;
    z-index: 1000;
    width: 86px;
    height: 86px;
    pointer-events: none;
    animation: bird-appear 1.4s ease both;
}
@keyframes bird-appear { 0%, 100% { opacity: 0; } 25%, 75% { opacity: .9; } }