body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            background-color: #f5f5f5;
        }
        
        .header {
            background-color: #333;
            color: white;
            padding: 20px;
            text-align: center;
        }
        
        .input-container {
            display: flex;
            justify-content: center;
            padding: 20px;
            background-color: #444;
        }
        
        .input-container input, .input-container select, .input-container button {
            margin: 0 5px;
            padding: 8px;
        }
        
        .content {
            padding: 20px;
        }
        
        .display-text {
            font-size: 24px;
            text-align: center;
            margin: 20px 0;
            min-height: 50px;
        }
        
        .secret-page {
            display: none;
            max-width: 800px;
            margin: 0 auto;
            background-color: white;
            padding: 20px;
            border-radius: 5px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }
        
        .add-form {
            margin-top: 20px;
            padding: 15px;
            background-color: #f9f9f9;
            border-radius: 5px;
        }
        
        table {
            width: 100%;
            border-collapse: collapse;
            margin-bottom: 20px;
        }
        
        th, td {
            padding: 8px;
            text-align: left;
            border-bottom: 1px solid #ddd;
        }
        
        button {
            background-color: #4CAF50;
            color: white;
            border: none;
            padding: 8px 12px;
            cursor: pointer;
            border-radius: 3px;
        }
        
        button:hover {
            background-color: #45a049;
        }
        
        .todo-item, .list-item {
            /*display: flex;*/
            align-items: center;
            padding: 8px;
            margin: 5px 0;
            background-color: #f9f9f9;
        }
        
        .todo-item.completed, .list-item.checked {
            opacity: 0.7;
            text-decoration: line-through;
        }
        
        .todo-duration {
            margin-left: 10px;
            font-size: 0.8em;
            color: #666;
        }
        
        .reset-info {
            margin-bottom: 15px;
            padding: 10px;
            background-color: #e7f3fe;
            border-left: 5px solid #2196F3;
        }
        
        input[type="checkbox"] {
            margin-right: 5px;
        }