container {

min-width: 780px;
  max-width: 1260px;
  margin: 10px auto;
  width:expression(document.body.clientWidth < 782? "780px" :  document.body.clientWidth > 1262? "1260px" : "auto");
  background: #ffffe0;
  color:#0000ff;
  border: 2px solid #0000ff;
}

.bg {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: -5000;
}