innerSelected = () => {
            if (line.substring(bookmark.start, bookmark.end + suffix.length).endsWith(suffix)) {
                const result = beforeText.match(/<span .*?>/g);
                if (!result) return;
                const last = result[result.length - 1];
                if (last && beforeText.endsWith(last)) {
                    return last
                }
            }
        }
There are four possible user selection scenarios, for example: `123<span style="color:#FF0000;">abc</span>defg`
  a. No selection.
  b. Standard selection (e.g., "efg").
  c. Selection within an existing styled span (e.g., "abc"): Modify the outer text.
  d. Selection encompassing an entire styled span (e.g., `<span style="color:#FF0000;">abc</span>`): Modify the inner text.