def render_behind fragment
document = fragment.document
text = fragment.text
x = fragment.left
y = fragment.baseline
align = (format_state = fragment.format_state)[:align]
if align == :center || align == :right
gap_width = (format_state.key? :width) ?
fragment.width - (document.width_of text) :
(format_state[:border_offset] || 0) * 2
x += gap_width * (align == :center ? 0.5 : 1) if gap_width > 0
end
document.word_spacing fragment.word_spacing do
document.draw_text! text, at: [x, y], kerning: document.default_kerning?
end
fragment.conceal
end