added theming support with 3 themes (only 2 selectable for now)

switched from css to scss default style system

cleaned up unused code in app component

upated youtube search results styling

downloading video from home screen now shows local progress bar under that video

src/styles.scss

@@ -0,0 +1,70 @@
+/* You can add global styles to this file, and also import other style files */
+
+@import '@angular/material/prebuilt-themes/indigo-pink.css';
+
+//@import './app-theme';
+/* You can add global styles to this file, and also import other style files */
+// @import "../node_modules/@angular/material/prebuilt-themes/purple-green.css";
+@import "palette.scss";
+
+html, body { height: 100%; }
+body { margin: 0; font-family: Roboto, "Helvetica Neue", sans-serif; }
+
+@import '~@angular/material/theming';
+// Plus imports for other components in your app.
+
+/*// Typography
+$custom-typography: mat-typography-config(
+  $font-family: Raleway,
+  $headline: mat-typography-level(24px, 48px, 400),
+  $body-1: mat-typography-level(16px, 24px, 400)
+);
+@include angular-material-typography($custom-typography);
+*/
+// Default colors
+$my-app-primary: mat-palette($mat-light-blue, 700, 100, 800);
+$my-app-accent:  mat-palette($mat-blue, 700, 100, 800);
+$my-app-warn: mat-palette($mat-red, 700, 100, 800);
+
+$my-app-theme: mat-light-theme($my-app-primary, $my-app-accent, $my-app-warn);
+@include angular-material-theme($my-app-theme);
+
+// Dark theme
+$dark-primary: mat-palette($mat-indigo);
+$dark-accent:  mat-palette($mat-blue);
+$dark-warn:    mat-palette($mat-deep-orange);
+
+$dark-theme:   mat-dark-theme($dark-primary, $dark-accent, $dark-warn);
+
+.dark-theme {
+  @include angular-material-theme($dark-theme);
+}
+
+// Light theme
+$light-primary: mat-palette($mat-grey, 200, 500, 300);
+$light-accent: mat-palette($mat-brown, 200);
+$light-warn: mat-palette($mat-deep-orange, 200);
+
+$light-theme: mat-light-theme($light-primary, $light-accent, $light-warn);
+
+.light-theme {
+  @include angular-material-theme($light-theme)
+}
+
+.no-outline {
+  outline: none;
+}
+
+
+// Include the common styles for Angular Material. We include this here so that you only
+// have to load a single css file for Angular Material in your app.
+// Be sure that you only ever include this mixin once!
+@include mat-core();
+
+// @import '../node_modules/@angular/material/theming';
+
+.centered {
+    margin: 0 auto;
+    left: 50%;
+    top: 50%;
+}