CSS Box Alignment: align-content block fragmentation: simple content

CENTER
LINE 2
LINE 3

LINE 4

LINE 5
LINE 6

END
LINE 2
LINE 3

LINE 4

LINE 5
LINE 6

BASELINE
LINE 2
LINE 3

LINE 4

LINE 5
LINE 6

LAST BASELINE
LINE 2
LINE 3

LINE 4

LINE 5
LINE 6

UNSAFE CENTER
LINE 2
LINE 3

LINE 4

LINE 5
LINE 6

UNSAFE END
LINE 2
LINE 3

LINE 4

LINE 5
LINE 6