body
{
 background-color: #FFFfff;
 --opacity:0.7;
  --filter:alpha(opacity=70);
 --background: url(https://images.cnblogs.com/cnblogs_com/YzpJason/1046782/o_BingWallpaper-2017-07-27.png) 
}

.postTitle 
{
 color: Black;

}