:root {
    --facebook-blue: #1877f2;
    --facebook-dark-blue: #166fe5;
    --facebook-light-blue: #e7f3ff;
    --facebook-gray: #f0f2f5;
    --facebook-border: #dddfe2;
    --facebook-text: #1c1e21;
    --facebook-text-secondary: #606770;
    --facebook-hover: #f2f2f2;
    --facebook-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
    --facebook-shadow-hover: 0 2px 4px rgba(0, 0, 0, 0.1);
    --facebook-radius: 8px;
    --facebook-radius-large: 12px;
}

[data-theme="dark"] {
    --facebook-gray: #18191a;
    --facebook-border: #3e4042;
    --facebook-text: #e4e6eb;
    --facebook-text-secondary: #b0b3b8;
    --facebook-hover: #2e2f30;
    --facebook-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
    --facebook-shadow-hover: 0 2px 4px rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--facebook-gray);
    color: var(--facebook-text);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.app-header {
    background-color: white;
    border-bottom: 1px solid var(--facebook-border);
    box-shadow: var(--facebook-shadow);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

[data-theme="dark"] .app-header {
    background-color: #242526;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo i {
    color: var(--facebook-blue);
    font-size: 24px;
}

.logo h1 {
    font-size: 20px;
    font-weight: 600;
    color: var(--facebook-text);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}

.search-box {
    position: relative;
    display: flex;
    align-items: center;
}

.search-box input {
    padding: 8px 12px 8px 40px;
    border: 1px solid var(--facebook-border);
    border-radius: 20px;
    background-color: var(--facebook-gray);
    color: var(--facebook-text);
    width: 250px;
    font-size: 14px;
    transition: all 0.3s ease;
}

.search-box input:focus {
    outline: none;
    background-color: white;
    border-color: var(--facebook-blue);
    box-shadow: 0 0 0 2px rgba(24, 119, 242, 0.2);
}

[data-theme="dark"] .search-box input:focus {
    background-color: #242526;
}

.search-box i {
    position: absolute;
    left: 15px;
    color: var(--facebook-text-secondary);
    font-size: 14px;
}

.theme-toggle {
    background: none;
    border: none;
    font-size: 18px;
    cursor: pointer;
    color: var(--facebook-text);
    padding: 8px;
    border-radius: 50%;
    transition: background-color 0.3s ease;
}

.theme-toggle:hover {
    background-color: var(--facebook-hover);
}

.main-content {
    flex: 1;
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.sidebar {
    width: 320px;
    background-color: white;
    border-right: 1px solid var(--facebook-border);
    padding: 20px;
    height: calc(100vh - 60px);
    overflow-y: auto;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

[data-theme="dark"] .sidebar {
    background-color: #242526;
}

.create-list-btn {
    width: 100%;
    padding: 12px 16px;
    background-color: var(--facebook-blue);
    color: white;
    border: none;
    border-radius: var(--facebook-radius);
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-bottom: 20px;
    transition: background-color 0.3s ease;
}

.create-list-btn:hover {
    background-color: var(--facebook-dark-blue);
}

.lists-container {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.list-item {
    padding: 12px 16px;
    border-radius: var(--facebook-radius);
    cursor: pointer;
    transition: background-color 0.3s ease;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.list-item:hover {
    background-color: var(--facebook-hover);
}

.list-item.active {
    background-color: var(--facebook-light-blue);
    color: var(--facebook-blue);
}

[data-theme="dark"] .list-item.active {
    background-color: #2d88ff;
    color: white;
}

.list-item-info h3 {
    font-size: 15px;
    font-weight: 500;
    margin-bottom: 2px;
}

.list-item-info p {
    font-size: 13px;
    color: var(--facebook-text-secondary);
}

.list-item-count {
    background-color: var(--facebook-gray);
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
    color: var(--facebook-text-secondary);
}

.content-area {
    flex: 1;
    padding: 20px;
    overflow-y: auto;
    height: calc(100vh - 60px);
}

.welcome-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    min-height: 400px;
}

.welcome-content {
    text-align: center;
    max-width: 400px;
}

.welcome-content i {
    font-size: 64px;
    color: var(--facebook-blue);
    margin-bottom: 20px;
}

.welcome-content h2 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--facebook-text);
}

.welcome-content p {
    color: var(--facebook-text-secondary);
    font-size: 16px;
}

.list-view {
    max-width: 800px;
    margin: 0 auto;
}

.list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding: 20px;
    background-color: white;
    border-radius: var(--facebook-radius-large);
    box-shadow: var(--facebook-shadow);
    transition: background-color 0.3s ease;
}

[data-theme="dark"] .list-header {
    background-color: #242526;
}

.list-info h2 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 4px;
}

.item-count {
    color: var(--facebook-text-secondary);
    font-size: 14px;
}

.list-actions {
    display: flex;
    gap: 8px;
}

.btn-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: none;
    background-color: var(--facebook-gray);
    color: var(--facebook-text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s ease;
}

.btn-icon:hover {
    background-color: var(--facebook-hover);
}

.add-item-form {
    margin-bottom: 24px;
    background-color: white;
    padding: 20px;
    border-radius: var(--facebook-radius-large);
    box-shadow: var(--facebook-shadow);
    transition: background-color 0.3s ease;
}

[data-theme="dark"] .add-item-form {
    background-color: #242526;
}

.add-item-container {
    display: flex;
    gap: 10px;
    align-items: center;
}

.add-item-input {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid var(--facebook-border);
    border-radius: var(--facebook-radius);
    font-size: 15px;
    background-color: white;
    color: var(--facebook-text);
    transition: border-color 0.3s ease;
}

[data-theme="dark"] .add-item-input {
    background-color: #2e2f30;
    border-color: #3e4042;
}

.add-item-input:focus {
    outline: none;
    border-color: var(--facebook-blue);
}

.add-item-quantity, .add-item-notes {
    width: 80px;
    padding: 12px 16px;
    border: 1px solid var(--facebook-border);
    border-radius: var(--facebook-radius);
    font-size: 15px;
    background-color: white;
    color: var(--facebook-text);
    transition: border-color 0.3s ease;
}

[data-theme="dark"] .add-item-quantity, 
[data-theme="dark"] .add-item-notes {
    background-color: #2e2f30;
    border-color: #3e4042;
}

.add-item-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: none;
    background-color: var(--facebook-blue);
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s ease;
}

.add-item-btn:hover {
    background-color: var(--facebook-dark-blue);
}

.items-container {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.item {
    background-color: white;
    padding: 16px 20px;
    border-radius: var(--facebook-radius);
    box-shadow: var(--facebook-shadow);
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: move;
    transition: all 0.3s ease;
}

[data-theme="dark"] .item {
    background-color: #242526;
}

.item:hover {
    box-shadow: var(--facebook-shadow-hover);
}

.item.dragging {
    opacity: 0.5;
    transform: scale(0.95);
}

.item.completed {
    opacity: 0.7;
}

.item.completed .item-name {
    text-decoration: line-through;
    color: var(--facebook-text-secondary);
}

.item-checkbox {
    width: 20px;
    height: 20px;
    border: 2px solid var(--facebook-border);
    border-radius: 4px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.item-checkbox.checked {
    background-color: var(--facebook-blue);
    border-color: var(--facebook-blue);
    color: white;
}

.item-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.item-name {
    font-size: 15px;
    font-weight: 500;
    color: var(--facebook-text);
}

.item-details {
    display: flex;
    gap: 12px;
    font-size: 13px;
    color: var(--facebook-text-secondary);
}

.item-quantity {
    background-color: var(--facebook-gray);
    padding: 2px 8px;
    border-radius: 12px;
}

.item-notes {
    font-style: italic;
}

.item-actions {
    display: flex;
    gap: 4px;
}

.item-btn {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: none;
    background-color: transparent;
    color: var(--facebook-text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s ease;
}

.item-btn:hover {
    background-color: var(--facebook-hover);
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background-color: white;
    border-radius: var(--facebook-radius-large);
    width: 90%;
    max-width: 400px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    transition: background-color 0.3s ease;
}

[data-theme="dark"] .modal-content {
    background-color: #242526;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 20px 0;
}

.modal-header h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--facebook-text);
}

.modal-close {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: none;
    background-color: transparent;
    color: var(--facebook-text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s ease;
}

.modal-close:hover {
    background-color: var(--facebook-hover);
}

.modal-body {
    padding: 20px;
}

.modal-input {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--facebook-border);
    border-radius: var(--facebook-radius);
    font-size: 15px;
    background-color: white;
    color: var(--facebook-text);
    margin-bottom: 20px;
    transition: border-color 0.3s ease;
}

[data-theme="dark"] .modal-input {
    background-color: #2e2f30;
    border-color: #3e4042;
}

.modal-input:focus {
    outline: none;
    border-color: var(--facebook-blue);
}

.modal-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

.btn-secondary {
    padding: 10px 20px;
    border: 1px solid var(--facebook-border);
    border-radius: var(--facebook-radius);
    background-color: white;
    color: var(--facebook-text);
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

[data-theme="dark"] .btn-secondary {
    background-color: #2e2f30;
    border-color: #3e4042;
}

.btn-secondary:hover {
    background-color: var(--facebook-hover);
}

.btn-primary {
    padding: 10px 20px;
    border: none;
    border-radius: var(--facebook-radius);
    background-color: var(--facebook-blue);
    color: white;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.btn-primary:hover {
    background-color: var(--facebook-dark-blue);
}

.toast-container {
    position: fixed;
    top: 80px;
    right: 20px;
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.toast {
    background-color: white;
    color: var(--facebook-text);
    padding: 16px 20px;
    border-radius: var(--facebook-radius);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    display: flex;
    align-items: center;
    gap: 12px;
    min-width: 300px;
    animation: slideIn 0.3s ease;
    transition: background-color 0.3s ease;
}

[data-theme="dark"] .toast {
    background-color: #242526;
}

.toast.success {
    border-left: 4px solid #42b883;
}

.toast.error {
    border-left: 4px solid #ef4444;
}

.toast.warning {
    border-left: 4px solid #f59e0b;
}

.toast i {
    font-size: 18px;
}

.toast.success i {
    color: #42b883;
}

.toast.error i {
    color: #ef4444;
}

.toast.warning i {
    color: #f59e0b;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.hidden {
    display: none !important;
}

.loading {
    text-align: center;
    padding: 40px;
    color: var(--facebook-text-secondary);
}

.search-results {
    max-width: 800px;
    margin: 0 auto;
}

.search-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 16px 20px;
    background-color: white;
    border-radius: var(--facebook-radius-large);
    box-shadow: var(--facebook-shadow);
}

.search-results-container {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.search-result-item {
    background-color: white;
    padding: 16px 20px;
    border-radius: var(--facebook-radius);
    box-shadow: var(--facebook-shadow);
    cursor: pointer;
    transition: all 0.3s ease;
}

[data-theme="dark"] .search-result-item {
    background-color: #242526;
}

.search-result-item:hover {
    box-shadow: var(--facebook-shadow-hover);
}

.search-result-item h4 {
    font-size: 15px;
    font-weight: 500;
    margin-bottom: 4px;
    color: var(--facebook-text);
}

.search-result-item p {
    font-size: 13px;
    color: var(--facebook-text-secondary);
    margin-bottom: 2px;
}

.search-result-item .list-name {
    color: var(--facebook-blue);
    font-weight: 500;
}

@media (max-width: 768px) {
    .main-content {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--facebook-border);
    }
    
    .header-content {
        padding: 0 15px;
    }
    
    .search-box input {
        width: 180px;
    }
    
    .content-area {
        padding: 15px;
    }
    
    .add-item-container {
        flex-direction: column;
        align-items: stretch;
    }
    
    .add-item-quantity, .add-item-notes {
        width: 100%;
    }
    
    .modal-content {
        width: 95%;
        margin: 20px;
    }
}