· Firewall Secret Technique: Composite fireproofing technology lost in the Song Dynasty (including a complete system of firewall structure, flame retardant coatings, and fire extinguishing agents)
· Technical fault: Due to the Jingkang Incident, documents were lost, craftsmen moved south, and key technologies were unexpectedly broken.
· Reverse reconstruction: Reconstructing lost craftsmanship through scattered murals, ancient architectural remnants, oral legends, etc.
