This is to clarify te issue a bit.
I'm a new hand in making internet texts. From time to time, I need to leave empty space for some sentences or words. For example, I would need to make the two lines (A) into another two lines (B):
(A) Summer heat today (B) Summer heat today
In its torrid way, In its torrid way,
But when I push the words in the second line to the righthand direction,although the related words seem to have been pushed rightward, in fact that is not effective: when I come back to the finished text (to be shown to the readers), nothing has been done.
No Sir, that's not really true. "Nothing has been displayed" would match the situation much better.
As you can see in the screenshot of the source code view of your posting, the spaces are still existing in the saved entry. Your problem is, that any internet browser will merge all spaces, tabs and line breaks of the textual source, which stand in an uninterrupted row, into one space in the document output. This is a HTML-internal mechanism.
That is, what happens to you. That is, why you need a mechanism to prevent the merge, the HTML-element
<pre> with its (MLF-own but undocumented) BB-Code equivalent
Please be aware of the monotyped output of the pre-element. For most cases this is wanted and I think your use case falls into this section. But, … who knows …
Trenne niemals Müll, denn er hat nur eine Silbe!