Css should be scoped

[LuigiElleBalotta]

I had a problem with the CSS:

a <style> tag is injected in the HTML, without a scope so it not only affect blockUI related code.

Example:

<div *ngIf="isLoading$ | async" class="loader widget-loader flex flex-col justify-center items-center">
    <mat-spinner class="loader__spinner" diameter="30"></mat-spinner>
</div>

This code uses a mat-spinner: it was graphically was bugged because of the class loader used by BlockUI css