.bg {
    background-size: cover;
    height: 100%;
    width: 100%;
    background-size: cover;
    background-repeat: no-repeat;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
    -o-transition: all 0.5s;
    transition: all 0.5s;
}

.bg:hover {
    -ms-transform: scale(1.1);
    -moz-transform: scale(1.1);
    -webkit-transform: scale(1.1);
    -o-transform: scale(1.1);
    transform: scale(1.1);
}

.bg-hackathon {
    background-image: url("../img/dotori_photo/iPhone\ X-XS-11\ Pro\ –\ 1@2x.png");
}

.bg-seoul {
    background-image: url("../img/seoul_photo/photo2.jpg");
}

.bg-pet {
    background-image: url("../img/pet-bg.png");
    background-size: cover;
    background-position: 50% 50%;
}

.bg-thesis {
    background-image: url("../img/thesis_photo/Slide1.png");
    background-size: cover;
    background-position: 0% 50%;
}

.bg-pura {
    background-image: url("../img/pura-bg.jpg");
    background-size: contain;
    background-position: 50% 50%;
}

.bg-dreams {
    background-image: url("../img/dreams-bg.jpg");
    background-size: contain;
    background-position: 50% 50%;
}

.bg-mse {
    background-image: url("../img/mse-bg.png");
    background-size: cover;
    background-position: 50% 50%;
}

.bg-jhu {
    background-image: url("../img/jhu_photo/photo1.jpg");
    background-size: cover;
    background-position: 50% 50%;
}