效果：

替换 Typora安装目录中 themes 文件夹下的  base.user.css 文件，直接替换即可，建议先备份。

css：

/* ================= 语法高亮配色 ================= */
.CodeMirror-line .cm-number { color: #b5cea8; }       /* 数字 - 浅绿色 */
.CodeMirror-line .cm-property { color: #9cdcfe; }    /* 属性 - 浅蓝色 */
.CodeMirror-line .cm-variable-3 { color: #4ec9b0; }  /* 类型/返回值 - 青蓝色 */
.CodeMirror-line .cm-qualifier { color: #d7ba7d; }   /* 限定符 - 金色 */
.CodeMirror-line .cm-variable-2 { color: #9cdcfe; }  /* 变量 - 浅蓝色 */
.CodeMirror-line .cm-meta { color: #569cd6; }        /* 宏/头文件 - 蓝色 */
.CodeMirror-line .cm-atom { color: #569cd6; }        /* true/false - 蓝色 */
.CodeMirror-line .cm-keyword { color: #c586c0; }     /* 关键字 - 紫色 */
.CodeMirror-line .cm-def { color: #dcdcaa; }         /* 函数定义 - 浅黄色 */
.CodeMirror-line .cm-variable { color: #9cdcfe; }    /* 变量 - 浅蓝色 */
.CodeMirror-line .cm-builtin { color: #dcdcaa; }     /* 内置函数 - 浅黄色 */
.CodeMirror-line .cm-comment { 
    color: #6a9955;                  /* 注释 - 绿色 */
}
.CodeMirror-line .cm-string { color: #ce9178; }      /* 字符串 - 橙红色 */
.CodeMirror-line .cm-string-2 { color: #ce9178; }    /* 模板字符串 - 橙红色 */
.CodeMirror-line .cm-operator { color: #d4d4d4; }    /* 操作符 - 白色 */
.CodeMirror-line .cm-tag { color: #569cd6; }         /* HTML标签 - 蓝色 */
.CodeMirror-line .cm-bracket { color: #808080; }     /* 括号 - 灰色 */
.CodeMirror-line .cm-attribute { color: #9cdcfe; }   /* HTML属性 - 浅蓝色 */
 
/* 计数器相关的CSS规则 如需要可启用 */
/*
.sidebar-content {
    counter-reset: h1
}
 
.outline-h1 {
    counter-reset: h2
}
 
.outline-h2 {
    counter-reset: h3
}
 
.outline-h3 {
    counter-reset: h4
}
 
.outline-h4 {
    counter-reset: h5
}
 
.outline-h5 {
    counter-reset: h6
}
 
.outline-h1>.outline-item>.outline-label:before {
    counter-increment: h1;
    content: counter(h1) " "
}
 
.outline-h2>.outline-item>.outline-label:before {
    counter-increment: h2;
    content: counter(h1) "."counter(h2) " "
}
 
.outline-h3>.outline-item>.outline-label:before {
    counter-increment: h3;
    content: counter(h1) "."counter(h2) "."counter(h3) " "
}
 
.outline-h4>.outline-item>.outline-label:before {
    counter-increment: h4;
    content: counter(h1) "."counter(h2) "."counter(h3) "."counter(h4) " "
}
 
.outline-h5>.outline-item>.outline-label:before {
    counter-increment: h5;
    content: counter(h1) "."counter(h2) "."counter(h3) "."counter(h4) "."counter(h5) " "
}
 
.outline-h6>.outline-item>.outline-label:before {
    counter-increment: h6;
    content: counter(h1) "."counter(h2) "."counter(h3) "."counter(h4) "."counter(h5) "."counter(h6) " "
}
 
#write {
    counter-reset: h1
}
 
h1 {
    counter-reset: h2
}
 
h2 {
    counter-reset: h3
}
 
h3 {
    counter-reset: h4
}
 
h4 {
    counter-reset: h5
}
 
h5 {
    counter-reset: h6
}
 
#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
 
    {
    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) " "
}
*/
 
#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;
}
 
.CodeMirror-lines {
    padding-left: 4px;
}
 
.code-tooltip {
    box-shadow: 0 1px 1px 0 rgba(0,28,36,.3);
    border-top: 1px solid #eef2f2;
}
 
.md-fences,
code,
tt {
    background-color: #f8f8f8;
    border-radius: 3px;
    padding: 0;
    padding-left: 4px !important;
    padding-right: 4px !important;
    font-size: 0.9em;
}
 
code {
    background-color: #f3f4f4;
    padding: 0 2px 0 2px;
}
 
.md-fences {
    margin-bottom: 15px;
    margin-top: 15px;
    padding-top: 8px;
    padding-bottom: 6px;
}
 
 
.md-task-list-item > input {
  margin-left: -1.3em;
}
 
@media print {
    html {
 font-size: 13px;
    }
    table,
    pre {
 page-break-inside: avoid;
    }
    pre {
 word-wrap: break-word;
    }
}
 
.md-fences {
    background-color: #f8f8f8;
}
#write pre.md-meta-block {
    padding: 1rem;
    font-size: 85%;
    line-height: 1.45;
    background-color: #f7f7f7;
    border: 0;
    border-radius: 3px;
    color: #777777;
    margin-top: 0 !important;
}
 
.mathjax-block>.code-tooltip {
    bottom: .375rem;
}
 
 
 
 
 
#write .md-fences:not([mermaid-type])  {
    padding-top: 7px;
    border-radius: 10px;
    background-color: #282c34;
    color: #eeeeee;
}
 
.code-tooltip .ty-input,
.code-tooltip input {
    color: #eee;
}
 
 
 
.CodeMirror-wrap .CodeMirror-scroll {
    padding-top: 20px;
}
 
#write .md-fences:before {
    content: "";
    z-index: 4;
    display: block;
    position: absolute;
    top: 7px;
    left: 13px;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    float: left;
    background-color: #fa3534;
}
 
#write .CodeMirror-scroll:before {
    content: "";
    display: block;
    position: absolute;
    top: 0px;
    left: 29px;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    float: left;
    z-index: 999;
    background-color: #ff9900;
}
#write .md-fences::after {
    content: "";
    z-index: 4;
    display: block;
    position: absolute;
    top: 7px;
    left: 53px;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    float: left;
    background-color: #19be6b;
}