fix: reduce PDF line spacing and font size for readability

app/services/pdf_generator.py

@@ -139,8 +139,8 @@ class PianoPDF:
             parent=self.styles["Normal"],
             fontName=self.base_font,
             fontSize=10,
-            spaceAfter=4*mm,
-            leading=14,
+            spaceAfter=1*mm,
+            leading=12,
         )
 
         # 表格样式
@@ -171,13 +171,13 @@ class PianoPDF:
     def add_paragraph(self, text):
         if text:
             self.elements.append(Paragraph(md_to_xml(text), self.body_style))
-            self.elements.append(Spacer(1, 3*mm))
+            self.elements.append(Spacer(1, 1*mm))
 
     def add_list(self, items):
         for item in items:
             if item:
                 self.elements.append(Paragraph(f"• {md_to_xml(item)}", self.body_style))
-        self.elements.append(Spacer(1, 3*mm))
+        self.elements.append(Spacer(1, 1*mm))
 
     def add_table(self, data):
         if not data or len(data) < 2:
@@ -189,7 +189,7 @@ class PianoPDF:
             table = Table(table_data)
             table.setStyle(self.table_style)
             self.elements.append(table)
-            self.elements.append(Spacer(1, 5*mm))
+            self.elements.append(Spacer(1, 3*mm))
 
 
 def generate_pdf(plan_id, student_name, content, output_dir, rendered_report=None, watermark_text=None):