Checkbox Hack: Transition

Without Overlap

Line 1 of hidden content.

Line 2 of hidden content.

Line 1 of existing content.

Line 2 of existing content.

Line 3 of existing content.

With Overlap

Line 1 of hidden content.

Line 2 of hidden content.

Line 1 of existing content.

Line 2 of existing content.

Line 3 of existing content.