css 设置背景图的资源时用~@, 正常import时用@, @和~@的区别

为什么css里要这么用

background-image: url(~@/assets/imgs/decorate.png);

resolve: {
    extensions: ['.ts', '.tsx', '.js', '.jsx'],
    alias: {
        '@': path.resolve(__dirname, '../src'),
    },
},