src/App.vue

<template>
  <div id="app">
    <router-view />
  </div>
</template>

<script>
export default {
  name: 'App'
}
</script>

<style>
#app {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  margin: 0;
  padding: 0;
  height: 100vh;
  width: 100%;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  height: 100vh;
  overflow-x: hidden;
}
</style>