Preserve QExcell font sizes

src/io/excellOffice.ts

@@ -936,12 +936,12 @@ function cellFormatKey(format: CellFormat | undefined) {
     return "";
   }
 
-  return `${normalized.bold ? "1" : "0"}|${normalized.italics ? "1" : "0"}|${normalized.underline ? "1" : "0"}|${normalized.textColor ?? ""}|${normalized.fillColor ?? ""}|${normalized.horizontalAlign ?? ""}|${normalized.numberFormat ?? ""}`;
+  return `${normalized.bold ? "1" : "0"}|${normalized.italics ? "1" : "0"}|${normalized.underline ? "1" : "0"}|${normalized.fontSize ?? ""}|${normalized.textColor ?? ""}|${normalized.fillColor ?? ""}|${normalized.horizontalAlign ?? ""}|${normalized.numberFormat ?? ""}`;
 }
 
 function fontStyleKey(format: CellFormat) {
-  return format.bold || format.italics || format.underline || format.textColor
-    ? `${format.bold ? "1" : "0"}|${format.italics ? "1" : "0"}|${format.underline ? "1" : "0"}|${format.textColor ?? ""}`
+  return format.bold || format.italics || format.underline || format.fontSize || format.textColor
+    ? `${format.bold ? "1" : "0"}|${format.italics ? "1" : "0"}|${format.underline ? "1" : "0"}|${format.fontSize ?? ""}|${format.textColor ?? ""}`
     : "";
 }
 
@@ -950,10 +950,12 @@ function normalizedCellFormat(format: CellFormat | undefined): CellFormat | null
   const fillColor = normalizeFillColor(format?.fillColor);
   const horizontalAlign = normalizedHorizontalAlign(format?.horizontalAlign);
   const numberFormat = normalizedNumberFormat(format?.numberFormat);
+  const fontSize = normalizedFontSize(format?.fontSize);
   const normalized: CellFormat = {
     ...(format?.bold ? { bold: true } : {}),
     ...(format?.italics ? { italics: true } : {}),
     ...(format?.underline ? { underline: true } : {}),
+    ...(fontSize ? { fontSize } : {}),
     ...(textColor ? { textColor } : {}),
     ...(fillColor ? { fillColor } : {}),
     ...(horizontalAlign ? { horizontalAlign } : {}),
@@ -966,11 +968,13 @@ function normalizedCellFormat(format: CellFormat | undefined): CellFormat | null
 function fontXmlToCellFormat(font: unknown): CellFormat {
   const record = asRecord(font);
   const textColor = normalizeFillColor(String(childRecord(record, "color").rgb || ""));
+  const fontSize = normalizedFontSize(numberAttribute(childRecord(record, "sz").val));
   return (
     normalizedCellFormat({
       bold: hasXmlElement(record, "b"),
       italics: hasXmlElement(record, "i"),
       underline: hasXmlElement(record, "u"),
+      ...(fontSize ? { fontSize } : {}),
       ...(textColor ? { textColor } : {})
     }) ?? {}
   );
@@ -989,7 +993,7 @@ function baseFontXml() {
 function formatFontXml(format: CellFormat) {
   const flags = `${format.bold ? "<b/>" : ""}${format.italics ? "<i/>" : ""}${format.underline ? "<u/>" : ""}`;
   const color = format.textColor ? `<color rgb="FF${format.textColor}"/>` : '<color theme="1"/>';
-  return `<font>${flags}<sz val="11"/>${color}<name val="Calibri"/><family val="2"/></font>`;
+  return `<font>${flags}<sz val="${format.fontSize ?? 11}"/>${color}<name val="Calibri"/><family val="2"/></font>`;
 }
 
 function formatFillXml(fillColor: string) {
@@ -1005,6 +1009,15 @@ function normalizeFillColor(value?: string) {
   return /^[0-9A-F]{6}$/.test(raw) ? raw : "";
 }
 
+function normalizedFontSize(value?: number) {
+  if (!Number.isFinite(value) || !value || value <= 0) {
+    return undefined;
+  }
+
+  const normalized = Math.round(value * 2) / 2;
+  return normalized === 11 ? undefined : normalized;
+}
+
 function normalizedHorizontalAlign(value?: string) {
   const normalized = value?.trim().toLowerCase() ?? "";
   return normalized === "left" || normalized === "center" || normalized === "right" ? normalized : "";