```block
columns 3
前端 blockArrowId6<[" "]>(right) 后端
space:2 down<[" "]>(down)
硬盘 left<[" "]>(left) Database[("数据库")]

classDef front fill:#696,stroke:#333;
classDef back fill:#969,stroke:#333;
class Frontend front
class Backend,Database back
```