html {
    height: 100%;
    overflow: hidden;
}

body {
    margin: 0;
    padding: 0;
}

video {
    min-width: 100%;
    min-height: 100vh;
    z-index: 1;
}

.overlay {
    width: 100%;
    height: 100vh;
    position: absolute;
    top: 0;
    left: 0;
    background-image: linear-gradient(45deg, rgba(0,0,0,.1) 40%, rgba(0,0,0,.1) 40%);
    background-size: 3px 3px;
    z-index: 2;
}

#video-tag-id {
    position: fixed;
    right: 0;
    bottom: 0;
    min-width: 100%; 
    min-height: 100%;
}

.center-div {
    position: absolute;
    margin: auto;

    top: 0;
    right: 0;
    bottom: 0;
    left: 0;

    z-index: 9999;

    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.child-div {
    position: absolute;
    z-index: 99999;
    width: 100%;
    height: 100%;
    background: url('../../images/saydam.png') no-repeat center center fixed;
    background-size: 500px 500px;
    -webkit-background-size: fill;
    -moz-background-size: fill;
    -o-background-size: fill;
    background-size: fill;
    object-fit: fill;
    transition: ease-in .5s all;
}

.child-div:hover {
    background: url('../../images/gece.png') no-repeat center center fixed;
    background-size: 500px 500px;
    object-fit: fill;
}

@media (max-width: 768px) {
    .child-div {
        transform: scale(0.7);
    }
}

@media (max-width: 768px) {
    .child-div, .child-div:hover {
        background-size: contain;
    }
}