flowchart LR
    A["Highly coupled design<br/>vulnerable to change<br/>spaghetti code"] --"Applying the<br/>5 SOLID principles"--> B["Separation of responsibilities,<br/>extensibility, substitutable structure"] --"Improved<br/>maintainability & reusability"--> C["Software architecture<br/>resilient to change"]

    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
        SRP["SRP<br/>Single Responsibility Principle<br/>A class should have<br/>only one reason to change"]
        OCP["OCP<br/>Open/Closed Principle<br/>Open for extension,<br/>closed for modification"]
        LSP["LSP<br/>Liskov Substitution Principle<br/>A subclass must be fully<br/>substitutable for its parent class"]
    end

    style SRP fill:#E3F2FD,stroke:#1976D2,color:#000
    style OCP fill:#F3E5F5,stroke:#7B1FA2,color:#000
    style LSP fill:#FFF3E0,stroke:#F57C00,color:#000
    style R1  fill:none,stroke:none
  

    flowchart TD
    subgraph R1["　"]
        direction LR
        ISP["ISP<br/>Interface Segregation Principle<br/>Clients should not depend<br/>on methods they don't use"]
        DIP["DIP<br/>Dependency Inversion Principle<br/>High-level modules should not<br/>depend directly on low-level modules"]
    end

    style ISP fill:#FFEBEE,stroke:#D32F2F,color:#000
    style DIP fill:#E8F5E9,stroke:#388E3C,color:#000
    style R1  fill:none,stroke:none
  

    flowchart LR
    subgraph BAD["ISP Violation (Fat Interface)"]
        direction TB
        FI["IWorker<br/>work / eat / sleep"]
        R["Robot"] --> FI
        H["Human"] --> FI
    end

    subgraph GOOD["ISP Compliance (Segregated Interfaces)"]
        direction TB
        IW["IWorkable<br/>work"]
        IE["IEatable<br/>eat"]
        IS["ISleepable<br/>sleep"]
        R2["Robot"] --> IW
        H2["Human"] --> IW
        H2 --> IE
        H2 --> IS
    end

    style BAD  fill:#FFEBEE,stroke:#D32F2F,color:#B71C1C
    style GOOD fill:#E8F5E9,stroke:#388E3C,color:#1B5E20
  

    flowchart LR
    subgraph DIP_GOOD["DIP Compliance (Depending on Interfaces)"]
        direction TB
        UC["UseCase<br/>high-level module"] --> RI["Repository Interface<br/>abstraction"]
        IMPL["JpaRepositoryImpl<br/>low-level implementation"] --> RI
    end

    style UC   fill:#1E3A5F,stroke:#1E3A5F,color:#fff
    style RI   fill:#E3F2FD,stroke:#1976D2,color:#000
    style IMPL fill:#E8F5E9,stroke:#388E3C,color:#000