Simple Mermaid Renderer

flowchart TD
    A[Start] --> B{Is it a weekend?}
    B -->|Yes| C[Go to the park]
    B -->|No| D[Go to work]
    C --> E[Have fun]
    D --> E
    E --> F[End]

sequenceDiagram
    participant User
    participant System
    participant Database
    
    User->>System: Login request
    System->>Database: Query user data
    Database-->>System: Return user info
    alt Valid credentials
        System-->>User: Login successful
    else Invalid credentials
        System-->>User: Login failed
    end

classDiagram
    class Animal {
        +name: string
        +age: int
        +makeSound(): void
    }
    
    class Dog {
        +breed: string
        +bark(): void
    }
    
    class Cat {
        +color: string
        +meow(): void
    }
    
    Animal <|-- Dog
    Animal <|-- Cat