.photo-stack::before,
.photo-stack::after {
    background-position: center;
    background-size: cover;
    background-repeat: no-repeat;
}

.photo-stack::before {
    background-image: url("hero-wedding.png?v=1");
}

.photo-stack::after {
    background-image: url("hero-birthday.png?v=1");
}