* {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f5f7fa;
            color: #333;
            line-height: 1.6;
            padding: 20px;
        }
        
        .container {
            max-width: 800px;
            margin: 0 auto;
            background-color: white;
            border-radius: 10px;
            box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
            padding: 30px;
        }
        
        h1 {
            text-align: center;
            color: #2c3e50;
            margin-bottom: 30px;
        }
        
        .input-section {
            display: flex;
            margin-bottom: 30px;
        }
        
        #taskInput {
            flex: 1;
            padding: 12px;
            border: 1px solid #ddd;
            border-radius: 4px 0 0 4px;
            font-size: 16px;
        }
        
        #addTaskBtn {
            background-color: #3498db;
            color: white;
            border: none;
            padding: 12px 20px;
            border-radius: 0 4px 4px 0;
            cursor: pointer;
            font-size: 16px;
            transition: background-color 0.3s;
        }
        
        #addTaskBtn:hover {
            background-color: #2980b9;
        }
        
        .filter-section {
            display: flex;
            justify-content: space-between;
            margin-bottom: 20px;
        }
        
        .filter-btn {
            padding: 8px 16px;
            background-color: #ecf0f1;
            border: none;
            border-radius: 4px;
            cursor: pointer;
            transition: background-color 0.3s;
        }
        
        .filter-btn.active {
            background-color: #3498db;
            color: white;
        }
        
        .task-list {
            list-style-type: none;
        }
        
        .task-item {
            display: flex;
            align-items: center;
            padding: 15px;
            background-color: #f9f9f9;
            border-radius: 4px;
            margin-bottom: 10px;
            transition: transform 0.2s;
        }
        
        .task-item:hover {
            transform: translateY(-2px);
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
        }
        
        .task-item.completed {
            background-color: #e8f6f3;
            text-decoration: line-through;
            opacity: 0.7;
        }
        
        .task-text {
            flex: 1;
            margin-left: 10px;
        }
        
        .task-actions button {
            background: none;
            border: none;
            cursor: pointer;
            margin-left: 10px;
            font-size: 16px;
        }
        
        .complete-btn {
            color: #27ae60;
        }
        
        .delete-btn {
            color: #e74c3c;
        }
        
        .empty-state {
            text-align: center;
            padding: 30px;
            color: #7f8c8d;
        }
        
        .stats {
            margin-top: 20px;
            padding-top: 20px;
            border-top: 1px solid #eee;
            display: flex;
            justify-content: space-between;
        }
        
        @media (max-width: 600px) {
            .container {
                padding: 15px;
            }
            
            .input-section {
                flex-direction: column;
            }
            
            #taskInput {
                border-radius: 4px;
                margin-bottom: 10px;
            }
            
            #addTaskBtn {
                border-radius: 4px;
            }
            
            .filter-section {
                flex-direction: column;
                gap: 10px;
            }
        }