body { background-color: #d0e8f2; /* 綺麗な水色 */ font-family: "Hiragino Kaku Gothic ProN", Meiryo, sans-serif; color: #222; line-height: 1.9; padding: 2.5em; max-width: 780px; margin: auto; box-shadow: 0 0 15px rgba(0,0,0,0.1); border-radius: 10px; } h1 { font-size: 1.8em; border-bottom: 2px solid #7bb…