.CBanner
{
    width: calc(100% - 80px);
    padding: 1px 40px 40px 40px;
    text-align: center;
}

@media (min-width: 1921px)
{
    .CBanner
    {
        width: 1600px;
        padding-left: calc(50% - 800px);
        padding-right: calc(50% - 800px);
    }
}

.CBannerGray
{
    background-color: lightgray;
}