.blog-section .blog-post .post-gal img {height:auto}
.banner {
    min-height: 190px;
    background-image: url('http://www.eszakmagyar.mva.hu/wp-content/uploads/2018/04/fejléctelefonnalnydr-másolata_ém.jpg');
    background-repeat: no-repeat;
    background-position: center;
    background-size: 780px 190px;
}
@media (min-width: 768px) and (max-width: 979px) { 
.blog-section .blog-post .post-gal img {height:auto}
.banner {
    min-height: 150px;
    background-image: url('http://www.eszakmagyar.mva.hu/wp-content/uploads/2018/04/fejléctelefonnalnydr-másolata_ém.jpg');
    background-repeat: no-repeat;
    background-position: center;
    background-size: 600px 150px;
}
}
@media (max-width: 767px) {
.blog-section .blog-post .post-gal img {height:auto}
.banner {
    min-height: 150px;
    background-image: url('http://www.eszakmagyar.mva.hu/wp-content/uploads/2018/04/fejléctelefonnalnydr-másolata_ém.jpg');
    background-repeat: no-repeat;
    background-position: center;
    background-size: 600px 150px;
}
}
@media (max-width: 480px) {
.blog-section .blog-post .post-gal img {height:auto}
.banner {
    min-height: 80px;
    background-image: url('http://www.eszakmagyar.mva.hu/wp-content/uploads/2018/04/fejléctelefonnalnydr-másolata_ém.jpg');
    background-repeat: no-repeat;
    background-position: center;
    background-size: 320px 80px;
}
}