body { font-family: "Hiragino Kaku Gothic ProN", Meiryo, sans-serif; background: #d0ecf5; /* 薄めの水色 */ color: #222; line-height: 1.9; padding: 3em 1em; } .container { max-width: 800px; background: #ffffff; margin: 0 auto; padding: 2.5em; box-shadow: 0 0 12px rgba(0,0,0,0.1); border-radius: 12px; } h1…