body { font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", "メイリオ", sans-serif; background-color: #eaf7ff; /* しっかり薄い水色 */ color: #444; line-height: 2; max-width: 720px; margin: 3em auto; padding: 2.5em; border-radius: 16px; box-shadow: 0 4px 18px rgba(0, 0, 0, 0.06); background-image: linear-gradi…