stars.el

(defun insert-stars ()
  (let* ((line)
         (overlay)
         (start (point))
         (stars "┼┴├┤┬┴├┤┬└┘┐┌└┘┐┌└┘┐┌└┘┐┌└┘┐┌─────────│││││││││")
         (colors '("#4302da" "#5302ca" "#5302ba" "#5302ca"))
         (color (nth (random (length colors)) colors))
         (pick-char (lambda () (char-to-string (aref stars (random (length stars))))))
         (hole-start (random 30))
         (hole-length (random 10)))
    (dotimes (i 40)
      (setq line (cons (eval (list pick-char)) line)))
    (setq line (apply 'concat ";" line))
    (insert line)
    (setq overlay (make-overlay (+ 1 (point-at-bol)) (point-at-eol)))
    (overlay-put overlay 'face `(:foreground ,color :height 1 :background "#242444"))
    (newline)))

(defun insert-star-lines ()
  (let* ((hole-start (1+ (random 25)))
         (hole-length (+ 5 (random 10)))
         (hole-chars " ┼─│")
         (hole-char (char-to-string (aref hole-chars (random (length hole-chars))))))
    (dotimes (i 20)
      (insert-stars)
      (save-excursion
        (previous-line)
        (beginning-of-line)
        (forward-char hole-start)
        (dotimes (i hole-length)
          (delete-char 1)
          (insert hole-char)))
      (when (= 0 (random 3))
         (setq hole-start (1+ (random 25)))
         (setq hole-length (+ 5 (random 10)))
         (setq hole-char (char-to-string (aref hole-chars (random (length hole-chars)))))))))