Solved.
One more thing: do you know why some times my site does not render well and is showed broken like this?
Is only some times, but I hate it. For the header banner I have a code the you told me to show responsive banners on mobile and a traditional banner on big screens:
@media (max-width:768px) {
.bigscreen {
display:none;
width:30%;
margin: 0 auto;
}
}
@media (min-width:769px) {
.smallscreen {
display:none;
width:100%;
margin: 0 auto;
}
}