flowchart LR
    A["Fragmented, non-standard<br/>EMRs per institution —<br/>hard to interconnect data"] --"HL7 FHIR —<br/>a RESTful API standard"--> B["Resource-based<br/>standardization of health data"] --"Interoperability<br/>achieved"--> C["An integrated<br/>digital healthcare platform"]

    style A fill:#FFEBEE,stroke:#D32F2F,color:#000
    style B fill:#E3F2FD,stroke:#1976D2,color:#000
    style C fill:#E8F5E9,stroke:#388E3C,color:#000
  

    flowchart TD
    subgraph R1["　"]
        direction LR
        RES["Resource<br/>Patient, Observation,<br/>MedicationRequest, Encounter —<br/>around 80 standard resources"]
        API["RESTful API<br/>CRUD-based standard operations —<br/>GET/POST/PUT/DELETE,<br/>JSON/XML formats"]
    end
    subgraph R2["　"]
        direction LR
        PRF["Profile<br/>defines country/institution-specific<br/>constraints — Korea FHIR IG,<br/>supports Extensions"]
        SEC["Security/authentication<br/>SMART on FHIR —<br/>OAuth 2.0/OpenID Connect,<br/>patient-consent-based access"]
    end

    style RES fill:#E3F2FD,stroke:#1976D2,color:#000
    style API fill:#F3E5F5,stroke:#7B1FA2,color:#000
    style PRF fill:#FFF3E0,stroke:#F57C00,color:#000
    style SEC fill:#E8F5E9,stroke:#388E3C,color:#000
    style R1 fill:none,stroke:none
    style R2 fill:none,stroke:none
  

    flowchart LR
    subgraph SRC["Data Sources"]
        direction TB
        S1["EMR/HIS<br/>(hospital information systems)"]
        S2["LIS/PACS<br/>(lab/imaging systems)"]
        S3["PHR/wearables<br/>(personal health records)"]
    end

    subgraph FHIR_SRV["FHIR Server"]
        direction TB
        F1["FHIR Repository<br/>standard resource storage"]
        F2["FHIR API<br/>RESTful interface"]
    end

    subgraph APP["Application Services"]
        direction TB
        A1["AI diagnostic support,<br/>clinical decision-making"]
        A2["PHR app —<br/>patient self-access"]
        A3["Public health analytics,<br/>epidemiological investigation"]
    end

    SRC --> FHIR_SRV --> APP

    style SRC      fill:#E3F2FD,stroke:#1976D2,color:#1E3A5F
    style FHIR_SRV fill:#1E3A5F,stroke:#1E3A5F,color:#fff
    style APP      fill:#E8F5E9,stroke:#388E3C,color:#1B5E20