body{background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAA2SURBVHgB7dExCgAwCEPRtHTK/c+atXoCHURw8K/CQ8j5HoIkRWdcFFtgAvCynUmi9YMFJgAG0zUKALF+3J0AAAAASUVORK5CYII=);background-attachment:fixed}body.dark{background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAA3SURBVHgB7dHBCQAgDEPRr7hH9h8rk+gG9VAKPTTXwCOQBVyCSIpqNskM0AE4v59tU7pggA7AA3zPBH7YvDhuAAAAAElFTkSuQmCC)}