body {
    margin: 0;
    font-family: 'Open Sans', sans-serif;
    background-color: #000;
}
.navi {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    list-style: none;
    padding: 0;
    margin: 0;
    z-index: 100;
}
.navi li a {
    font-size: 3em;
    text-decoration: none;
    color: #fff;
    position: relative;
}
.navi li a:before {
    position: absolute;
    top: 0;
    left: 0;
    width: 0;
    color: #00a040;
    content: attr(data-text);
    overflow: hidden;
    transition: 0.5s;
}
.navi li a:hover:before {
    width: 100%;
}
.photo {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background-image: url(images/main.jpg);
    background-repeat: no-repeat;
    background-position: center center;
    background-size: contain;
    transition: 0.5s;
}