"Double Pyramid Solitaire (Solitairex) is a retro-styled, browser-based take on Thomas Warfield’s two-deck variant of Pyramid solitaire. Two overlapping 10-row pyramids (a total of 50 face-up cards) are laid out on the table, and you clear them by pairing exposed cards whose ranks add to 13—Kings go off singly, while all other values must be matched (e.g., Ace + Queen, 4 + 9). A st