Improve button defaults in cloze context

- Also simplify the button constructor

projects/common/models/elements/button/button.ts

@@ -24,9 +24,7 @@ export class ButtonElement extends UIElement {
     if (element.action) this.action = element.action;
     if (element.actionParam) this.actionParam = element.actionParam;
     this.position = element.position ? UIElement.initPositionProps(element.position) : undefined;
-    this.styling = {
-      ...UIElement.initStylingProps<{ borderRadius: number; }>({ borderRadius: 0, ...element.styling })
-    };
+    this.styling = UIElement.initStylingProps({ borderRadius: 0, ...element.styling });
   }
 
   getElementComponent(): Type<ElementComponent> {

projects/editor/src/app/text-editor/angular-node-views/button-component-extension.ts

@@ -3,6 +3,7 @@ import { Node, mergeAttributes } from '@tiptap/core';
 import { AngularNodeViewRenderer } from 'ngx-tiptap';
 import { ButtonElement } from 'common/models/elements/button/button';
 import { ButtonNodeviewComponent } from 'editor/src/app/text-editor/angular-node-views/button-nodeview.component';
+import { BasicStyles } from 'common/models/elements/element';
 
 const ButtonComponentExtension = (injector: Injector): Node => {
   return Node.create({
@@ -13,7 +14,15 @@ const ButtonComponentExtension = (injector: Injector): Node => {
     addAttributes() {
       return {
         model: {
-          default: new ButtonElement({ type: 'button', id: 'cloze-child-id-placeholder', height: 34 })
+          default: new ButtonElement({
+            type: 'button',
+            id: 'cloze-child-id-placeholder',
+            height: 34,
+            asLink: true,
+            styling: {
+              backgroundColor: 'transparent'
+            } as BasicStyles & { borderRadius: number; }
+          })
         }
       };
     },