body{background-color:#1a1a1a;color:#f0f0f0;font-family:Arial,sans-serif;margin:0;padding:0}.checklist-container{max-width:800px;margin:20px auto;padding:20px;background-color:#2b2b2b;border-radius:8px;box-shadow:0 0 10px rgba(0,0,0,.5)}h1{text-align:center;color:#e0e0e0}.section,h1{margin-bottom:20px}h2{color:silver;font-size:1.2em;margin-bottom:10px}ul{list-style:none;padding:0}li{margin-bottom:10px}label,li{display:flex;align-items:center}label{font-size:1em}input[type=checkbox]{margin-right:10px;accent-color:#4caf50}label:hover{color:#fff}input:checked+label{text-decoration:line-through;color:#888}