add css file

src/app/components/participant/_diaglogs/submit-comment/submit-comment.component.html

@@ -8,10 +8,5 @@
 </button>
 
 <button mat-raised-button color="primary" (click)="closeDialog('send')">
-  <button mat-raised-button color="warn" (click)="onNoClick()">
-    {{ 'comment-page.back' | translate }}
-  </button>
-
-  <button mat-raised-button color="primary" (click)="send(comment.subject, comment.body)">
     {{ 'comment-page.send' | translate}}
-  </button>
+</button>

src/app/components/participant/_diaglogs/submit-comment/submit-comment.component.scss

+button {
+  margin-right: 20px;
+  min-width: 80px;
+}