forked from Yonokid/YataiDONNijiiro
main_diff_mark 'course_decide_start' (frames 35..64): once player:difficulty_decided() (engine PR #162) the translucent 680x680 mark behind the difficulty board goes opaque over a white backing, stretching to 1.235x its height and back while a white copy flashes on top, then holds the 'course_decide' look. Opaque shapes of mark_course (course_1..5) and mark_course_white exported to Graphics/song_select/diff_mark_anim. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>