html, body {height: 100%;}
body {
    background-image: url(images/background-3.jpg);
    background-color: #000000;
    background-repeat: no-repeat;
    background-position: center center;
    background-size: auto 100%;
}

.logo_wrap {
    width: 100%;
    padding-top: 5%;
}
.logo_img {
    width: 260px;
    display: block;
    margin-left: auto;
    margin-right: auto;
    opacity: 0.6;
}

.buttons_wrap {
    width: 100%;
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    justify-content: center;
    justify-content: -webkit-center;
    justify-content: -ms-center;
    justify-content: -moz-center;
    flex-wrap: wrap;
    flex-wrap: -webkit-wrap;
    flex-wrap: -moz-wrap;
    flex-wrap: -ms-wrap;
}

.round_btn {
    border-radius: 100%;
    /*width: 100px;*/
}

.round_btn img {
    width: 280px;
    border-radius: 100%;
    transition: 0.7s;
    margin-left: 50px;
    margin-right: 50px;
    margin-bottom: 50px;
    display: block;
}

.text_wrap {
    color: #ffffff;
    font-family: "Avenir";
    font-weight: 100;
    letter-spacing: 2px;
    line-height: 28px;
    text-align: center;
}

.body_txt {
    width: 80%;
    margin-left: auto;
    margin-right: auto;
}
.body_txt_fixed {
    width: 90%;
    margin-left: auto;
    margin-right: auto;
    text-align: justify;
}

footer {
    position: absolute;
    right: 0;
    bottom: 30px;
    left: 0;
    text-align: center;
    font-size: 0.7em;
    font-family: "Avenir";
    font-weight: lighter;
    color: #ffffff;
    letter-spacing: 2px;
    line-height: 28px;
    padding-left: 5%;
    padding-right: 5%;
}

@media only screen and (min-width: 700px) {
    .logo_img:hover {
        
    }
    
    .btn_img:hover {
        transform: scale(1.1);
        -webkit-transform: scale(1.1);
        box-shadow: 0px 0px 15px #fff;
    }
    
    .buttons_wrap {
        margin-top: 50px;    
    }
    .body_txt_fixed {
        width: 50%;
    }
}

@media only screen and (min-width: 1920px) {
    .body_txt_fixed {
        width: 40%;
    }
}