Nuxtjs deleting all from layouts/default.vue

Question

I am following tutorial where guy put his header component into layouts/default.vue component. I did same except mine was inside nuxt folder, so nuxt/layouts/default.vue... I guess its just older version of nuxt but, problem is that everyting i put there, component and styles are deleted after refresing my app, all that is left was default template with component. I dont know what is happening. This is code from default.vue

<template>
  <div class="container">
    <AppHeader/>
    <nuxt/>
  </div>
</template>

<script>
import AppHeader from "@/components/AppHeader";
export default {
  components: {
    AppHeader
  }
};
</script>


<style>
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
body {
  font-family: Arial, Helvetica, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  background: #f4f4f4;
}
a {
  color: #666;
  text-decoration: none;
}
ul {
  list-style: none;
}
.container {
  max-width: 800px;
  margin: 2rem auto;
  overflow: hidden;
  padding: 1rem 2rem;
  background: #fff;
}
</style>

EDIT: My actual question is how do i put global components in nuxt, navbar for example? Am i doing something wrong above?