body {font-family: Arial, sans-serif; line-height:1.7; margin:0 auto; max-width:1100px; padding:40px; background:#fff;}
h1,h2,h3 {color:#003366;}
img {max-width:100%; border-radius:10px; margin:20px 0;}
a {color:#0044cc; text-decoration:none;}
a:hover {text-decoration:underline;}
ul {margin-left:20px;}
.toc {background:#f8f9fa; padding:15px 25px; border-left:4px solid #007bff; border-radius:10px;}