/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

/* Header styles */
.header {
    text-align: center;
    margin-bottom: 30px;
    color: white;
}

.header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Input section styles */
.todo-input-section {
    background: white;
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    margin-bottom: 25px;
}

.input-group {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
}

#todoInput {
    flex: 1;
    padding: 15px 20px;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 16px;
    transition: all 0.3s ease;
}

#todoInput:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.add-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 15px 25px;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.add-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.add-btn:active {
    transform: translateY(0);
}

/* Filter section styles */
.filter-section {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.filter-btn {
    background: #f8f9fa;
    border: 2px solid #e1e5e9;
    padding: 10px 20px;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.filter-btn:hover {
    background: #e9ecef;
    border-color: #adb5bd;
}

.filter-btn.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

/* Stats section styles */
.todo-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 25px;
}

.stat-item {
    background: white;
    padding: 20px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.stat-item:hover {
    transform: translateY(-5px);
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: bold;
    color: #667eea;
    margin-bottom: 5px;
}

.stat-label {
    color: #6c757d;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Todo list styles */
.todo-list-container {
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    margin-bottom: 25px;
}

.todo-list {
    list-style: none;
    padding: 0;
}

.todo-item {
    display: flex;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid #f1f3f4;
    transition: all 0.3s ease;
    animation: slideIn 0.3s ease;
}

.todo-item:hover {
    background: #f8f9fa;
}

.todo-item:last-child {
    border-bottom: none;
}

.todo-item.completed {
    background: #f8f9fa;
    opacity: 0.7;
}

.todo-item.completed .todo-text {
    text-decoration: line-through;
    color: #6c757d;
}

.todo-checkbox {
    width: 20px;
    height: 20px;
    margin-right: 15px;
    cursor: pointer;
    accent-color: #667eea;
}

.todo-text {
    flex: 1;
    font-size: 16px;
    line-height: 1.5;
    word-wrap: break-word;
}

.todo-actions {
    display: flex;
    gap: 10px;
}

.action-icon {
    background: none;
    border: none;
    padding: 8px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    color: #6c757d;
}

.action-icon:hover {
    background: #e9ecef;
    color: #495057;
}

.edit-icon:hover {
    color: #28a745;
}

.delete-icon:hover {
    color: #dc3545;
}

/* Empty state styles */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #6c757d;
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 20px;
    opacity: 0.5;
}

.empty-state h3 {
    margin-bottom: 10px;
    color: #495057;
}

/* Actions section styles */
.actions-section {
    display: flex;
    gap: 15px;
    justify-content: center;
}

.action-btn {
    background: #6c757d;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.action-btn:hover {
    background: #5a6268;
    transform: translateY(-2px);
}

#clearCompleted:hover {
    background: #dc3545;
}

#clearAll:hover {
    background: #dc3545;
}

/* Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    .header h1 {
        font-size: 2rem;
    }
    
    .input-group {
        flex-direction: column;
    }
    
    .todo-stats {
        grid-template-columns: 1fr;
    }
    
    .actions-section {
        flex-direction: column;
    }
    
    .filter-section {
        flex-wrap: wrap;
    }
}

@media (max-width: 480px) {
    .todo-item {
        padding: 15px;
    }
    
    .todo-text {
        font-size: 14px;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
}