UMLCn 
声明参与者
plantuml
@startuml
!include https://f.umlcn.com/c4.puml
robust "Web 浏览器" as WB
concise "Web 用户" as WU
@0
WU is 空闲
WB is 空闲
@100
WU is 等待中
WB is 处理中
@300
WB is 等待中
@enduml@startuml
!include https://f.umlcn.com/c4.puml
robust "Web 浏览器" as WB
concise "Web 用户" as WU
@0
WU is 空闲
WB is 空闲
@100
WU is 等待中
WB is 处理中
@300
WB is 等待中
@enduml