body { background-color: #e6f2ff; /* 薄い綺麗なブルー */ font-family: "Hiragino Kaku Gothic ProN", Meiryo, sans-serif; color: #333; line-height: 1.9; padding: 3em 1.5em; max-width: 700px; margin: auto; } h1 { font-size: 1.8em; color: #004080; } h2 { font-size: 1.4em; color: #0059b3; margin-top: 2em; } p { m…