wo liegt mein fehler?
Dein Denkfehler liegt darin, dass du denkst, die display:none-Box würde noch Kindelemente generieren.
CSS 2.1: 9.2.4 The 'display' property
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none
This value causes an element to generate no boxes in the formatting structure (i.e., the element has no effect on layout).
Descendant elements do not generate any boxes either; this behavior cannot be overridden by setting the 'display' property on the descendants.