body { font-family: sans-serif; 
    background-image: linear-gradient(rgba(0,0,0,0.3), rgba(0,0,0,0.3)), url("うる背景.png");
    line-height: 1.6; 
    padding: 20px; 
     }
header { border-bottom: 2px solid #333; margin-bottom: 20px; }
.card { background: white; padding: 20px; border-radius: 8px; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }