markdown的标题设置自动添加序号

使用Typora这款markdown编辑器之后，可以设置标题自动添加序号。

以Windows电脑为例

1. 打开Typora这款软件，点击左上角的“文件”，接着点击“偏好设置”

   

2. 选择“外观”，点击“打开主题文件夹”

   

3. 打开Typora的theme文件夹，新建样式文件base.user.css

   /** initialize css counter */
   #write {
       counter-reset: h1
   }
   
   h1 {
       counter-reset: h2
   }
   
   h2 {
       counter-reset: h3
   }
   
   h3 {
       counter-reset: h4
   }
   
   h4 {
       counter-reset: h5
   }
   
   h5 {
       counter-reset: h6
   }
   
   /** put counter result into headings */
   #write h1:before {
       counter-increment: h1;
       content: counter(h1) ". "
   }
   
   #write h2:before {
       counter-increment: h2;
       content: counter(h1) "." counter(h2) ". "
   }
   
   #write h3:before,
   h3.md-focus.md-heading:before /** override the default style for focused headings */ {
       counter-increment: h3;
       content: counter(h1) "." counter(h2) "." counter(h3) ". "
   }
   
   #write h4:before,
   h4.md-focus.md-heading:before {
       counter-increment: h4;
       content: counter(h1) "." counter(h2) "." counter(h3) "." counter(h4) ". "
   }
   
   #write h5:before,
   h5.md-focus.md-heading:before 
       counter-increment: h5;
       content: counter(h1) "." counter(h2) "." counter(h3) "." counter(h4) "." counter(h5) ". "
   }
   
   #write h6:before,
   h6.md-focus.md-heading:before {
       counter-increment: h6;
       content: counter(h1) "." counter(h2) "." counter(h3) "." counter(h4) "." counter(h5) "." counter(h6) ". "
   }
   
   /** override the default style for focused headings */
   #write>h3.md-focus:before,
   #write>h4.md-focus:before,
   #write>h5.md-focus:before,
   #write>h6.md-focus:before,
   h3.md-focus:before,
   h4.md-focus:before,
   h5.md-focus:before,
   h6.md-focus:before {
       color: inherit;
       border: inherit;
       border-radius: inherit;
       position: inherit;
       left:initial;
       float: none;
       top:initial;
       font-size: inherit;
       padding-left: inherit;
       padding-right: inherit;
       vertical-align: inherit;
       font-weight: inherit;
       line-height: inherit;
   }
   

4. 保存base.user.css文件，重启Typora软件。