Nuxt/lib/app/components/nuxt-error.vue

<template>
  <div class="__nuxt-error-page">
    <div class="container">

        <div class="row">
          <div class="column">
            <h1>{{ error.statusCode }} </h1>
            <h4> {{ $route.path }} </h4>
            <pre class="error-box"><code>{{ error.message }}</code></pre>
            <p v-if="error.statusCode === 404">
              <nuxt-link class="error-link" to="/">Back to the home page</nuxt-link>
            </p>
          </div>
        </div>

        <div class="row">
          <div class="column">
            <div class="poweredby">
              <small> Powered by <a href="https://nuxtjs.org">Nuxt.js</a> </small>
            </div>
          </div>
        </div>

    </div>
  </div>
</template>

<script>
export default {
  name: 'nuxt-error',
  props: ['error'],
  head () {
    return {
      title: this.error ? ((this.error.statusCode || 500) + ' - ' + (this.error.message || 'Error')) : '500 - Error',
      link: [
        { rel: 'stylesheet', href: 'https://cdnjs.cloudflare.com/ajax/libs/normalize/7.0.0/normalize.min.css', type: 'text/css', media: 'all' },
        { rel: 'stylesheet', href: 'https://cdnjs.cloudflare.com/ajax/libs/milligram/1.3.0/milligram.min.css', type: 'text/css', media: 'all' }
      ]
    }
  }
}
</script>

<style>
.__nuxt-error-page {
  background: #edecea;
  font-size: 1em;
  word-spacing: 1px;
  -ms-text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
}
.__nuxt-error-page .container {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  width: 100vw;
  height: 100vh;
}
.__nuxt-error-page .error-box {
  box-shadow: 0px 0px 9px #d3d3d3;
  padding: 10px;
}
.__nuxt-error-page .poweredby {
  text-align: center;
  margin-top: 10%;
}
</style>