.jumbotron {
    background-image: url(images/first.jpg);
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    height: 100vh;
    animation: slide 20s infinite;
   }

.earth {
    background-image: url(images/earth.png);
    background-position: center;
    background-size: contain;
    background-repeat: no-repeat;
    height: 6rem;
    animation: earth 6s infinite linear ;
}
.girl {
    background-image: url(images/girl.jpg);
    background-size: contain;
    overflow: hidden;
}



@keyframes earth {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

.abt {
    background-image: url(images/second.jpg);
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
}

@keyframes slide {
    25% {
        background-image: url(images/second.jpg);
    }
    50% {
        background-image: url(images/third.jpg);
    }
    100% {
        background-image: url(images/first.jpg);
    }
}