title: Resolving "Cannot read property 'unprefixed' of undefined" on npm run serve with animate.css package
body: <p>I am developing an application using Vue, Quasar, and the animate.css package for CSS animations in my website. Everything has been going smoothly until recently I was having an issue with the <code>npm run build</code> command, which leads to the error in the title. Upon some investigation, I tried to install the <code>postcss-rtlcss</code> package, which led to this error occurring on <code>npm run serve</code> as well. Please note that I am relatively new to the Vue and node.js ecosystem, so please let me know if I am doing something completely wrong.</p>
  <p>The error upon running <code>npm run serve</code></p>
  <pre><code>ERROR  Failed to compile with 1 error                                                                                                                                          10:28:49 PM
  
  error  in ./node_modules/animate.css/animate.css
  
  Syntax Error: TypeError: Cannot read property 'unprefixed' of undefined
  
  
   @ ./node_modules/animate.css/animate.css 4:14-163 15:3-20:5 16:22-171
   @ ./src/main.js
   @ multi (webpack)-dev-server/client?http://10.0.0.251:8080&amp;sockPath=/sockjs-node ./node_modules/@vue/cli-service/node_modules/webpack/hot/dev-server.js ./src/main.js
  </code></pre>
  <p>In addition to this, here is my package.json.</p>
  <pre><code>{
    &quot;name&quot;: &quot;socialapp&quot;,
    &quot;version&quot;: &quot;0.1.0&quot;,
    &quot;private&quot;: true,
    &quot;scripts&quot;: {
      &quot;serve&quot;: &quot;vue-cli-service serve&quot;,
      &quot;build&quot;: &quot;vue-cli-service build&quot;,
      &quot;lint&quot;: &quot;vue-cli-service lint&quot;
    },
    &quot;dependencies&quot;: {
      &quot;@quasar/extras&quot;: &quot;^1.0.0&quot;,
      &quot;animate.css&quot;: &quot;^4.1.1&quot;,
      &quot;core-js&quot;: &quot;^3.6.5&quot;,
      &quot;css-loader&quot;: &quot;^6.2.0&quot;,
      &quot;quasar&quot;: &quot;^2.0.0&quot;,
      &quot;vue&quot;: &quot;^3.1.4&quot;,
      &quot;vue-body-class&quot;: &quot;^3.0.2&quot;,
      &quot;vue-router&quot;: &quot;^4.0.0-0&quot;,
      &quot;vue-style-loader&quot;: &quot;^4.1.3&quot;,
      &quot;webpack&quot;: &quot;^4.45.0&quot;
    },
    &quot;devDependencies&quot;: {
      &quot;@vue/cli-plugin-babel&quot;: &quot;~4.5.0&quot;,
      &quot;@vue/cli-plugin-eslint&quot;: &quot;~4.5.0&quot;,
      &quot;@vue/cli-plugin-router&quot;: &quot;^4.5.13&quot;,
      &quot;@vue/cli-service&quot;: &quot;~4.5.0&quot;,
      &quot;@vue/compiler-sfc&quot;: &quot;^3.0.0&quot;,
      &quot;babel-eslint&quot;: &quot;^10.1.0&quot;,
      &quot;eslint&quot;: &quot;^6.7.2&quot;,
      &quot;eslint-plugin-vue&quot;: &quot;^7.0.0&quot;,
      &quot;postcss-rtl&quot;: &quot;^1.2.3&quot;,
      &quot;sass&quot;: &quot;1.32.12&quot;,
      &quot;sass-loader&quot;: &quot;^10.1.0&quot;,
      &quot;vue-cli-plugin-quasar&quot;: &quot;~4.0.1&quot;
    },
    &quot;eslintConfig&quot;: {
      &quot;root&quot;: true,
      &quot;env&quot;: {
        &quot;node&quot;: true
      },
      &quot;extends&quot;: [
        &quot;plugin:vue/vue3-essential&quot;,
        &quot;eslint:recommended&quot;
      ],
      &quot;parserOptions&quot;: {
        &quot;parser&quot;: &quot;babel-eslint&quot;
      },
      &quot;rules&quot;: {}
    },
    &quot;browserslist&quot;: [
      &quot;&gt; 1%&quot;,
      &quot;last 2 versions&quot;,
      &quot;not dead&quot;
    ]
  }
  </code></pre>
  <p>Please let me know in a comment if you need anything else from me and I will try my best to provide it. Thank you for your help.</p>