Making Discourse Fluid/Responsive

Try these styles out.

#wmd-preview img:not(.thumbnail), .cooked img:not(.thumbnail) {
max-width: 100%; /*This needs to change from 690px to 100%;*/
max-height: 500px;
}
@media screen and (max-width: 960px) {
    .topic-body {
        width: 100%;/*this needs to change from 750px to 100%;*/
    }
}

The .topic-body is the main culprit. But Mitts screenshot was showing very very slight scrollbars so it needs a revamp on that image rule as well.

Might want to put that image rule inside of the media query as well (the .topic-body media query above). Less will be affected.