Hairline Bento

A six-column bento that rules its cells off with a single hairline — the container takes the top and left edges, every cell takes right and bottom, so exactly one line lands on every edge at any span with no doubling. The cells carry no fill, no radius and no hover state.

It does not use dense auto-flow, so shapes tile in author order and reading order never separates from visual order. Below the breakpoint it is one honest column.