body {
    background: linear-gradient(253deg, #0cc898, #1797d2, #864fe1);
    background-size: 300% 300%;
    -webkit-animation: Background 25s ease infinite;
    -moz-animation: Background 25s ease infinite;
    animation: Background 25s ease infinite;
}

@-webkit-keyframes Background {
    0% {
        background-position: 0% 50%
    }

    50% {
        background-position: 100% 50%
    }

    100% {
        background-position: 0% 50%
    }
}

@-moz-keyframes Background {
    0% {
        background-position: 0% 50%
    }

    50% {
        background-position: 100% 50%
    }

    100% {
        background-position: 0% 50%
    }
}

@keyframes Background {
    0% {
        background-position: 0% 50%
    }

    50% {
        background-position: 100% 50%
    }

    100% {
        background-position: 0% 50%
    }
}

.full-screen {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: url('https://drive.google.com/uc?id=1JSyYhmJYzvdgU8ySvC0WvVMrjTT5HHk2');
    background-size: cover;
    background-position: center;
    width: 100%;
    height: 100%;
    display: -webkit-flex;
    display: flex;
    -webkit-flex-direction: column
    /* works with row or column */
    flex-direction: column;
    -webkit-align-items: center;
    align-items: center;
    -webkit-justify-content: center;
    justify-content: center;
    text-align: center;
}

h1 {
    color: #fff;
    font-family: 'Open Sans', sans-serif;
    font-weight: 800;
    font-size: 4em;
    letter-spacing: -2px;
    text-align: center;
    text-shadow: 1px 2px 1px rgba(0, 0, 0, .6);
}

    h1:after {
        display: block;
        color: #fff;
        letter-spacing: 1px;
        font-family: 'Poiret One', sans-serif;
        content: 'Powered by Creative Information Technologies';
        font-size: .4em;
        text-align: center;
    }

.button-line {
    font-family: 'Open Sans', sans-serif;
    text-transform: uppercase;
    letter-spacing: 2px;
    background: transparent;
    border: 1px solid #fff;
    color: #fff;
    text-align: center;
    font-size: 1.4em;
    opacity: .8;
    padding: 20px 40px;
    text-decoration: none;
    transition: all .5s ease;
    margin: 3rem auto !important;
    display: block;
}

    .button-line:hover {
        opacity: 1;
    }