hr {/*透明渐变水平线*/
 width:80%;
 margin:0 auto;
 border: 0;
 height: 4px;
 background-image: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.75), rgba(0, 0, 0, 0));
}


code {
  font-family: Consolas,"courier new";
  color: crimson;
  background-color: #f1f1f1;
  padding: 2px;
  font-size: 105%;
  border-radius: 8px;
  border: 1px solid #73AD21;
}