Improve EPUB restoration, book terminology and Calibre QA workflow

src/assembly/bilingual_style.css

@@ -1,39 +1,19 @@
-/* Bilingual Translation Overrides */
-
-/* --- Common Base --- */
-.translation,
-.translation-no-indent {
-   /* text-align: justify;  <-- REMOVED: Restore original alignment (left/center/justify) */
-   line-height: 1.6;
-   clear: both;
-   /* Fix overlap with floating elements like Drop Caps */
-   margin-top: 0.5em;
-   /* Ensure separation from previous block */
-   display: block;
-   /* Ensure block formatting context */
+/* Preserve the book's alignment, indent and inline font choices. */
+.translation {
+    line-height: 1.6;
+    clear: both;
+    margin-top: 0.5em;
 }
-
-/* --- Standard Indent (2 chars) --- */
-p.translation {
-   text-indent: 2em;
+/* Units wrapped around loose text must remain visible before nested blocks. */
+span.translation[data-translation-unit] {
+    display: block;
 }
-
-/* --- No Indent (For Drop Caps) --- */
-p.translation-no-indent {
-   text-indent: 0 !important;
-   /* REMOVED: margin/padding resets that broke centering */
+/* Latin drop-cap rules can enlarge the leading digit in e.g. “20 世纪”. */
+p.translation::first-letter {
+    font-family: inherit !important;
+    font-size: 1em !important;
+    font-weight: inherit !important;
+    line-height: inherit !important;
+    color: inherit !important;
+    float: none !important;
 }
-
-/* --- Fix Drop Cap Font Mismatch --- */
-.translation span,
-.translation-no-indent span,
-.translation b,
-.translation-no-indent b,
-.translation i,
-.translation-no-indent i,
-.translation em,
-.translation-no-indent em,
-.translation strong,
-.translation-no-indent strong {
-   font-family: inherit !important;
-}