中间层

• 口(mouth; rectangular frame)ASSOCIATIVE
• 丨(vertical line through the middle; axis)ASSOCIATIVE

An arrow hitting the center of a target frame is the bull's-eye—that's CENTER.

• 門(door; leaf)RADICAL
• 日(sun; light)ASSOCIATIVE

A beam of sunlight shining through a crack in the door creates the empty space in between.

• 尸(corpse; roof (covering))RADICAL
• 云(cloud)PHONETIC

Layers of houses stacked on top of each other like tiered clouds beneath a roof.