[Vuejs]-Error after using "<style lang="scss" scoped>"

In vue.js you can declare global or local styles. You should and can use the <style>-tag in vue.js like this:

<style>
/* global styles */
</style>

Styles in this tag, would be valid global in your vue.js app.

<style scoped>
/* local styles */
</style>

Styles in this tag, would only be valid in the component, where you declared this <style scoped>-tag.

For more information, just read this documentation: Scoped CSS