quitale el ancho a #page en el css para que quede así
Código CSS:
Ver original#page {
background-attachment: scroll;
background-clip: border-box;
background-color: transparent;
background-image: url("../images/6_b.jpg");
background-origin: padding-box;
background-position: center top;
background-repeat: no-repeat;
background-size: contain !important;
border-color: transparent;
border-style: none;
margin-left: auto;
margin-right: auto;
min-height: 1066.26px;
padding-bottom: 1px;
z-index: 1;
}