Vue项目中如何用Less实现主题切换？

<code class="bash">npm install less less-loader --save-dev</code>

<code class="javascript">module.exports = {
  css: {
    loaderOptions: {
      less: {
        javascriptEnabled: true // 启用JavaScript
      }
    }
  }
}</code>

<code class="less">@primary-color: #007bff; // 蓝色主题
@secondary-color: #6c757d; // 灰色主题

// 或者定义多个主题
.light-theme {
  @primary-color: #007bff;
  @secondary-color: #6c757d;
}

.dark-theme {
  @primary-color: #343a40;
  @secondary-color: #f8f9fa;
}</code>

<code class="vue"><template>
  <div :style="{ backgroundColor: `var(--primary-color)` }">
    <p :style="{ color: `var(--secondary-color)` }">这是我的文本</p>
  </div>
</template>

<script>
export default {
  name: 'MyComponent',
  data() {
    return {
      currentTheme: 'light-theme' // 默认主题
    }
  },
  mounted() {
    this.setTheme(this.currentTheme);
  },
  methods: {
    setTheme(theme) {
      document.documentElement.classList.remove('light-theme', 'dark-theme');
      document.documentElement.classList.add(theme);
    }
  }
}
</script></code>

<code class="javascript">methods: {
  toggleTheme() {
    this.currentTheme = this.currentTheme === 'light-theme' ? 'dark-theme' : 'light-theme';
    this.setTheme(this.currentTheme);
  }
}</code>

<code class="vue"><button @click="toggleTheme">切换主题</button></code>

<code class="less">@import './theme.less';</code>