Need to resize image banners on mobile

[GinaB2]

Hi, 

I need help with resizing my images for mobile. This is the code I currently have in place: 

.banner__media:first-child {
width: 100%;
}
.banner__media + .banner__media {
display: none;
}
@media screen and (max-width: 760px) {
.banner__media:first-child {
display: none;
}
.banner__media + .banner__media {
width: 100%;
display: block !important;
}
}
@media screen and (max-width: 760px) {
.banner--content-align-mobile-center .banner__buttons--multiple > * {
min-width: 4rem !important;
padding: 0 2.5rem !important;
}
}

I have added a second image- to be used on mobile but it is still not showing correctly. The image is 360 x 360 px for mobile. Also the buttons are too big for mobile 

Is anyone able to help with this?