box-decoration-break

When a break splits a box, box-decoration-break decides whether its border, padding, background, corner radii and shadow belong to the box as a whole or to each piece. slice (the initial value) renders the box as if it were never broken and then cuts it at the break; clone wraps every piece independently. Both apply at line breaks and at page breaks.

1 — An inline box wrapping across lines

2 — Borders and padding at a line break

3 — box-shadow at a broken edge

4 — A block crossing a page break (see the following pages)

The same over-tall block twice, each crossing a page boundary. Under slice the border simply runs off the bottom of one page and continues at the top of the next; under clone each page's piece is closed off with its own rounded border.

5 — An inline box crossing a page break

The inline-axis counterpart of section 4, and the same distinction as section 2 — except that the break here is a page boundary rather than a line wrap. Under slice the highlight is opened once, on its first line, and the lines continuing overleaf carry no leading border or padding of their own — they resume flush against the block's content edge. Under clone the fragment opening on the new page opens with a fresh set, exactly as it would after a wrap. Each runs onto the following page.

slice — the continuation resumes flush at the content edge

5b — the same inline, cloning

clone — the continuation re-opens with its own frame