body { background-color: #f3ede6; /* 木の色に近いナチュラルなベージュ */ color: #3c2f2f; font-family: "Hiragino Kaku Gothic ProN", Meiryo, sans-serif; line-height: 1.9; padding: 3em 1.5em; max-width: 750px; margin: auto; } h1 { font-size: 1.8em; color: #4b3621; border-bottom: 2px solid #cbbfa7; padding-bottom: 0.3e…