body {
    font-family: sans-serif;
    line-height: 1.6;
    color: #333;
    background-image: linear-gradient(rgba(0,0,0,0.3), rgba(0,0,0,0.3)), url('口臭い背景.png');
    background-color: #fdfbf7;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}
header { border-bottom: 2px solid #5a7d7c; margin-bottom: 20px; }
h1, h2 { color: #5a7d7c; }
section { margin-bottom: 30px; padding: 15px; background: white; border-radius: 8px; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }