* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(135deg, #6a11cb 0%, #2575fc 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    color: #333;
}

.container {
    width: 100%;
    max-width: 800px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
    overflow: hidden;
    padding: 30px;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

header h1 {
    color: #2d3436;
    font-size: 2.5rem;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

header h1 i {
    color: #6a11cb;
}

.subtitle {
    color: #636e72;
    font-size: 1.1rem;
    font-weight: 300;
}

.app-card {
    background: white;
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    margin-bottom: 25px;
}

.input-section {
    display: flex;
    gap: 15px;
    margin-bottom: 25px;
}

#todoInput {
    flex: 1;
    padding: 15px 20px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 1rem;
    font-family: 'Poppins', sans-serif;
    transition: all 0.3s;
}

#todoInput:focus {
    outline: none;
    border-color: #6a11cb;
    box-shadow: 0 0 0 3px rgba(106, 17, 203, 0.1);
}

.btn-primary {
    background: linear-gradient(135deg, #6a11cb 0%, #2575fc 100%);
    color: white;
    border: none;
    padding: 15px 25px;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(106, 17, 203, 0.3);
}

.stats {
    display: flex;
    justify-content: space-around;
    background: #f8f9fa;
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 25px;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 600;
    color: #2d3436;
}

.stat-label {
    color: #636e72;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.filter-buttons {
    display: flex;
    gap: 10px;
    margin-bottom: 25px;
    justify-content: center;
}

.filter-btn {
    padding: 10px 20px;
    border: 2px solid #e0e0e0;
    background: white;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s;
}

.filter-btn.active {
    background: #6a11cb;
    color: white;
    border-color: #6a11cb;
}

.filter-btn:hover:not(.active) {
    border-color: #6a11cb;
    color: #6a11cb;
}

.todo-list {
    min-height: 200px;
    max-height: 400px;
    overflow-y: auto;
    padding-right: 10px;
}

.todo-item {
    display: flex;
    align-items: center;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 10px;
    margin-bottom: 10px;
    transition: all 0.3s;
    cursor: pointer;
}

.todo-item:hover {
    transform: translateX(5px);
    background: #e9ecef;
}

.todo-item.completed {
    opacity: 0.7;
    background: #e8f5e9;
}

.todo-checkbox {
    width: 24px;
    height: 24px;
    border: 2px solid #6a11cb;
    border-radius: 50%;
    margin-right: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    cursor: pointer;
}

.todo-checkbox.checked {
    background: #6a11cb;
    color: white;
}

.todo-text {
    flex: 1;
    font-size: 1.1rem;
}

.todo-item.completed .todo-text {
    text-decoration: line-through;
    color: #636e72;
}

.todo-delete {
    color: #e74c3c;
    opacity: 0;
    transition: opacity 0.3s;
    cursor: pointer;
    padding: 5px;
}

.todo-item:hover .todo-delete {
    opacity: 1;
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: #636e72;
}

.empty-state i {
    font-size: 4rem;
    color: #b2bec3;
    margin-bottom: 20px;
}

.empty-state h3 {
    margin-bottom: 10px;
    color: #2d3436;
}

.actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 25px;
}

.btn-secondary {
    background: #636e72;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: background 0.3s;
}

.btn-secondary:hover {
    background: #2d3436;
}

.btn-danger {
    background: #e74c3c;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: background 0.3s;
}

.btn-danger:hover {
    background: #c0392b;
}

footer {
    text-align: center;
    color: #636e72;
    padding-top: 20px;
    border-top: 1px solid #e0e0e0;
}

footer p {
    margin-bottom: 10px;
}

footer i.fa-heart {
    color: #e74c3c;
}

.hint {
    font-size: 0.9rem;
    color: #b2bec3;
    font-style: italic;
}

/* Scrollbar styling */
.todo-list::-webkit-scrollbar {
    width: 8px;
}

.todo-list::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

.todo-list::-webkit-scrollbar-thumb {
    background: #6a11cb;
    border-radius: 4px;
}

.todo-list::-webkit-scrollbar-thumb:hover {
    background: #2575fc;
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 20px;
    }
    
    header h1 {
        font-size: 2rem;
        flex-direction: column;
        gap: 10px;
    }
    
    .input-section {
        flex-direction: column;
    }
    
    .stats {
        flex-direction: column;
        gap: 15px;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .actions {
        flex-direction: column;
    }
}