.dias {
    min-width: 350px;
    max-width: 1200px;
    margin: 0 auto;
    width: 86%;
}
.cartel {
           width: 100%;
}

.cartel a > img {
    width: 65%;
    margin: 10px auto;
    display: block;
}

@media screen and (max-width: 800px) {
    .cartel a > img{
    width: 100%;
    margin: 0 auto;
    display: block;
}
}