URL：https://png.pngtree.com/thumb_back/fh260/background/20221006/pngtree-stairs-with-colorful-lighting-stairway-colorful-down-photo-image_1222534.jpg
掲載元：https://ja.pngtree.com/freebackground/emergency-stairs-leading-down-the-building-stairs-stair-well-escape-route-photo_3248100.html
