page backround

Please how do I change the page content background to white.

I changes that of the article using

.single-post #content > article {
  padding: 10px 20px;
  margin: 0 0 30px;
  background: #ffffff none repeat scroll top left;
  background-image: none;
  border: solid 6px #0080ff;
  -moz-box-shadow: 0 0 5px rgba(0, 0, 0, .1);
  -webkit-box-shadow: 0 0 5px rgba(0, 0, 0, .1);
  -goog-ms-box-shadow: 0 0 5px rgba(0, 0, 0, .1);
  box-shadow: 0 0 5px rgba(0, 0, 0, .1);
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

example : http://www.boyantech.com/android-infected-malware-whats-next/

how do I do the same for pages

such as https://www.boyantech.com/advertise/

thanks