npm install node-sass --save-dev  //安裝node-sass
npm install sass-loader --save-dev //安裝sass-loader
npm install style-loader --save-dev //安裝style-loader

<template>
  <div id="DarkModelPage">
    
  </div>
</template>

<script>
export default {
  
}
</script>

<style scoped lang="scss">

</style>

$themes: (
 light: (
  background_color: #cccccc,//背景色
  text-color: rgba(0, 0, 0, 0.65), // 主文本色
 ),
 dark: (
  background_color: #181c27,//背景
  text-color: rgba(255, 255, 255, 0.65), // 主文本色
 )
);

@import "./_themes.scss";

//遍歷主題map
@mixin themeify {
 @each $theme-name, $theme-map in $themes {
  //!global 把局部變量強升為全局變量
  $theme-map: $theme-map !global;
  //判斷html的data-theme的屬性值 #{}是sass的插值表達式
  //& sass嵌套里的父容器標識  @content是混合器插槽，像vue的slot
  [data-theme="#{$theme-name}"] & {
   @content;
  }
 }
}

//聲明一個根據(jù)Key獲取顏色的function
@function themed($key) {
 @return map-get($theme-map, $key);
}

//獲取背景顏色
@mixin background_color($color) {
 @include themeify {
  background: themed($color)!important;
 }
}
//獲取字體顏色
@mixin font_color($color) {
 @include themeify {
  color: themed($color)!important;
 }
}

@import "@/assets/scss/common/_handle.scss";
/**
自定義的公共樣式...
**/

<template>
  <div id="DarkModelPage">
    <div>
      <h1 class="title">天小天個人網(wǎng)</h1>
      <a class="btn" @click="modelBrn">模式切換</a>
    </div>
  </div>
</template>

<script>
export default {
  name: "DarkModelPage",
  data(){
    return {
     dark:false,
    }
  },
  methods:{
    modelBrn(){
      this.dark = !this.dark;
      if(this.dark){
        window.document.documentElement.setAttribute( "data-theme", 'dark' );
      }else{
         window.document.documentElement.setAttribute( "data-theme", 'light' );
      }
    },
  },
  mounted() {
    window.document.documentElement.setAttribute( "data-theme", 'light' );
  },
}
</script>

<style scoped lang="scss">
@import '@/assets/scss/common/common';

#DarkModelPage{
  //在此使用了背景顏色變量
  @include background_color("background_color");
  //再次使用了文字顏色變量
  @include font_color("text-color");

  width: 100vw;
  height: 100vh;
  display: flex;
  justify-content:center;
  align-items: center;
  transition: background 1s , color 0.6s;
  .title{
    margin-bottom: 20px;
  }
  .btn{
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100px;
    height: 40px;
    margin: 0 auto;
  }
}
</style>