.paper1 {
    background: url("images/paper1.jpg") center;
    background-size: cover;
}

.paper2 {
    background: url("images/paper2.jpg") center;
    background-size: cover;
}

.paper3 {
    background: url("images/paper3.jpg") center;
    background-size: cover;
}

.paper4 {
    background: url("images/paper4.jpg") center;
    background-size: cover;
}

.paper5 {
    background: url("images/paper5.jpg") center;
    background-size: cover;
}

.paper6 {
    background: url("images/paper6.jpg") center;
    background-size: cover;
}

.paper7 {
    background: url("images/paper7.jpg") center;
    background-size: cover;
}

.paper8 {
    background: url("images/paper8.jpg") center;
    background-size: cover;
}

.paper9 {
    background: url("images/paper9.jpg");
}

@keyframes page1-animation-thaw {
    0%   { opacity: 0; }
    100% { opacity: 1; }
}

@keyframes page2-animation-thaw {
    0%   { opacity: 1; }
    100% { opacity: 0; }
}