Fix MarkdownEditor css

webapp/src/components/contentBlock.scss

@@ -13,4 +13,10 @@
         margin-bottom: 17px;
         flex-grow: 1;
     }
+    > * {
+        flex: 1 1 auto;
+    }
+    > .octo-block-margin {
+        flex: 0 0 auto;
+    }
 }

webapp/src/components/markdownEditor.scss

@@ -2,7 +2,6 @@
 
 .MarkdownEditor {
 	cursor: text;
-	width: 100%;
     /* CodeMirror / SimpleMDE / EasyMDE overrides */
 
     .CodeMirror {

webapp/src/components/markdownEditor.tsx

@@ -179,7 +179,7 @@ class MarkdownEditor extends React.Component<Props, State> {
         const element =
             (<div
                 ref={this.frameRef}
-                className={`MarkdownEditor octo-editor ${this.props.className}`}
+                className={`MarkdownEditor octo-editor ${this.props.className || ''}`}
             >
                 {previewElement}
                 {editorElement}

webapp/src/styles/main.scss

@@ -190,10 +190,6 @@ hr {
 
 	width: 100%;
 	padding-right: 126px;
-
-    * {
-	    flex-shrink: 0;
-    }
 }
 
 .octo-block-margin {