graph LR
    %% Define database and special shapes
    P[prompt]
    SG[(semantic graph)]
    VD[(vector database)]
    LLM[LLM]
    Z[response]
    
    %% Main flow paths
    P --> Q[generated query]
    P --> EM[embedding model]
    
    %% Upper path through graph elements
    Q --> SG
    SG --> W[semantic<br/>random walk]
    T[thesaurus] --> W
    W --> GA[graph analytics]
    
    %% Lower path through vector elements
    EM --> SS[vector<br/>similarity search]
    SS --> VD
    
    %% Node embeddings and chunk references
    SG -.-|chunk references| VD
    SS -->|node embeddings| SG
    
    %% Final convergence
    GA --> RI[ranked index]
    VD --> RI
    RI --> LLM
    LLM --> Z

    %% Styling classes
    classDef dataSource fill:#f4f4f4,stroke:#666,stroke-width:2px;
    classDef storage fill:#e6f3ff,stroke:#4a90e2,stroke-width:2px;
    classDef embedding fill:#fff3e6,stroke:#f5a623,stroke-width:2px;
    classDef lexical fill:#f0e6ff,stroke:#4a90e2,stroke-width:2px;
    classDef semantic fill:#f0e6ff,stroke:#9013fe,stroke-width:2px;
    classDef reference fill:#e6ffe6,stroke:#417505,stroke-width:2px;

    %% Apply styles by layer/type
    class SDS,UDS dataSource;
    class SG,VD storage;
    class EM embedding;
    class LG lexical;
    class SG semantic;
    class ONT,T reference;