.containers{max-width:500px;margin:0 auto;padding:20px;background-color:#f5f5f5}h1{text-align:center;margin-bottom:20px}form{display:flex;margin-bottom:10px}input[type=text]{flex:1;padding:5px;font-size:16px}button{padding:5px 10px;font-size:16px;margin-left:10px;background-color:#4caf50;color:#fff;border:none;cursor:pointer}button:hover{background-color:#45a049}ul{list-style-type:none;padding:0}li{display:flex;justify-content:space-between;align-items:center;padding:10px;border-bottom:1px solid #ddd}.completed{text-decoration:line-through;color:#888}li:last-child{border-bottom:none}button.delete-btn{background-color:#f44336}button.delete-btn:hover{background-color:#d32f2f}button.complete-btn{background-color:#4caf50}button.complete-btn:hover{background-color:#45a049}