#flyers img {
    display: block;
    margin-left: 12%;
    margin-right: 12%;
    margin-bottom: 30px;
    width: 77%;
    height: auto;
} 

#catalog {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    background: #f4f4f4;
}

#catalog iframe {
    width: 70%;
    height: 1200px;
    border: none;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

@media screen and (max-width: 576px) {
    #flyers img {
        display: block;
        margin-left: auto;
        margin-right: auto;
        margin-bottom: 30px;
        width: 100%;
        height: auto;
    } 

    #catalog iframe {
        width: 95%;
        height: 1000px;
    }
   }