header {
    position: relative;
    width: 100%;
    height: 78px;
    border: 1px solid pink;
    display: inline-flex;
}
BODY{
    background-image: url(../images/2doinforme-leo-BG2_.jpg);
    background-repeat: no-repeat;
    background-size: 100% 100%;
    background-position: right;

}
.logos {
    position: absolute;
    z-index: 9999999;
    top: 25px;
    left: 25px;
}
.logos img {
    width: 220px;
}

.btn_descarga {
    position: absolute;
    bottom: 12px;
    right: 25px;
    z-index: 99999999;
    display: inline;
}

button {
    position: relative;
    width: 236px;
    height: 114px;
    background-image: url(../images/btn_des.png);
    background-repeat: no-repeat;
    background-position: center;
    background-size: 98%;
    border: none;
    background-color: transparent;
    cursor: pointer;    
}
button:hover {
    background-image: url(../images/btn_des_over.png);
}

@media (max-width: 1200px) {
    .btn_descarga {
        display: none;
    }    
}

@media (max-width: 760px) {
    .logos {
        top: 8px;
        left: 8px;
        z-index: 0;
    }
    .logos img {
        width: 116px;
    }
    .btn_descarga {
        display: inline;
        bottom: 36px;
        right: 12px;
    } 
    button {
        width: 186px;
        height: 98px;
    }
}