t/ckeditor5-ui/144: Migrated the styles to PostCSS

src/imageuploadprogress.js

@@ -14,7 +14,7 @@ import uploadingPlaceholder from '../theme/icons/image_placeholder.svg';
 import UIElement from '@ckeditor/ckeditor5-engine/src/view/uielement';
 import ImageUploadEngine from './imageuploadengine';
 
-import '../theme/imageuploadprogress.scss';
+import '../theme/imageuploadprogress.css';
 
 /**
  * Image upload progress plugin.

theme/imageuploadprogress.css

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md.
+ */
+
+/* Infinite progress bar default width. */
+:root {
+	--ck-image-upload-progress-line-width: 30px;
+}
+
+figure.image {
+	position: relative;
+	overflow: hidden;
+
+	/* Infinite progress bar on top while image is read. */
+	&.ck-infinite-progress::before {
+		content: "";
+		position: absolute;
+		top: 0;
+		right: 0;
+	}
+
+	/* Upload progress bar. */
+	& .ck-progress-bar {
+		position: absolute;
+		top: 0;
+		left: 0;
+	}
+}