/*添加按钮*/
.cnblogs-markdown pre {
  position: relative;
}
.cnblogs-markdown pre > span {
  position: absolute;
  top: 0;
  right: 0;
  border-radius: 2px;
  padding: 0 10px;
  font-size: 12px;
  background: rgba(0, 0, 0, 0.4);
  color: #fff;
  cursor: pointer;
  display:none;
}
.cnblogs-markdown pre:hover > span {
  display:block;
}
.cnblogs-markdown pre > .copyed {
  background: #67c23a;
}

/*屏蔽广告*/
#site_nav_under {
    display: none;
}
.c_ad_block, .ad_text_commentbox {
    display: none;
    margin: 0;
    padding: 0;
}
#ad_under_google {
    height: 0;
    overflow: hidden;
}
#ad_under_google a {
    display: none;
}
#ad_t2{
 display: none;
    margin: 0;
    padding: 0;

}
#under_post_card1{
   display:none;
}
#under_post_card2{
    display: none;
}
#HistoryToday{
    display: none;
}
#comment_form_container{
    display:none;
}
#div_digg{
   display:none;
}
#green_channel{
   display:none;
}
#cnblogs_c1{
   display:none;
}
#cnblogs_c2{
   display:none;
}
#cnblogs_ch{
  display: none;
}
<script>console.log("顶部标题栏屏蔽开始；"); document.all.top_nav.style.display='none'; console.log("顶部标题栏屏蔽完成；");</script>