/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #3498db;
    --primary-hover: #2980b9;
    --secondary-color: #95a5a6;
    --secondary-hover: #7f8c8d;
    --success-color: #27ae60;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --bg-color: #f5f6fa;
    --card-bg: #ffffff;
    --text-primary: #2c3e50;
    --text-secondary: #7f8c8d;
    --border-color: #dfe6e9;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.15);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: all 0.2s ease;
    --sidebar-width: 280px;
    --header-height: 60px;
    --toolbar-height: 50px;
    --status-height: 35px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    min-height: 100vh;
}

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

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--header-height);
    padding: 0 20px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 16px;
    flex: 1;
    min-width: 0;
}

.header-left h1 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.header-left h1 i {
    color: var(--primary-color);
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 4px;
    flex-wrap: wrap;
    font-size: 0.875rem;
}

.breadcrumb-item {
    display: flex;
    align-items: center;
    gap: 4px;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    cursor: pointer;
}

.breadcrumb-item:hover {
    background: var(--bg-color);
    color: var(--text-primary);
}

.breadcrumb-item.active {
    color: var(--text-primary);
    font-weight: 500;
}

.breadcrumb-separator {
    color: var(--text-secondary);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

.folder-info {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-family: monospace;
    background: var(--bg-color);
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    max-width: 300px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Toolbar */
.toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--toolbar-height);
    padding: 0 20px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    flex-wrap: wrap;
    gap: 12px;
}

.toolbar-left,
.toolbar-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

.view-mode-select,
.sort-select,
.sort-order-select {
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--card-bg);
    color: var(--text-primary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    min-width: 140px;
}

.view-mode-select:hover,
.sort-select:hover,
.sort-order-select:hover {
    border-color: var(--primary-color);
}

.search-input {
    padding: 8px 14px;
    padding-left: 36px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-color);
    color: var(--text-primary);
    font-size: 0.875rem;
    width: 250px;
    transition: var(--transition);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%237f8c8d' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Ccircle cx='11' cy='11' r='8'%3E%3C/circle%3E%3Cline x1='21' y1='21' x2='16.65' y2='16.65'%3E%3C/line%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: 10px center;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    background-color: var(--card-bg);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.15);
}

.search-input::placeholder {
    color: var(--text-secondary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 8px 16px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 0.8rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-hover);
}

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

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

.btn-danger {
    background: var(--danger-color);
    color: white;
}

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

.btn-float {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    box-shadow: var(--shadow-md);
    padding: 0;
}

.btn-toggle-sidebar {
    background: var(--bg-color);
    color: var(--text-primary);
}

.btn-toggle-sidebar:hover {
    background: var(--border-color);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Main Content */
.main-content {
    display: flex;
    flex: 1;
    overflow: hidden;
    position: relative;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--card-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    height: 100%;
    position: relative;
    z-index: 50;
    transition: transform 0.3s ease;
}

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-header h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.sidebar-header h3 i {
    color: var(--primary-color);
    font-size: 1rem;
}

.sidebar-content {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.folder-tree {
    font-size: 0.875rem;
}

.folder-tree-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    user-select: none;
}

.folder-tree-item:hover {
    background: var(--bg-color);
}

.folder-tree-item.active {
    background: rgba(52, 152, 219, 0.1);
    color: var(--primary-color);
    font-weight: 500;
}

.folder-tree-item i {
    width: 16px;
    text-align: center;
    color: var(--text-secondary);
}

.folder-tree-item.active i {
    color: var(--primary-color);
}

.folder-tree-item .folder-name {
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.folder-tree-children {
    margin-left: 20px;
    border-left: 1px solid var(--border-color);
    padding-left: 8px;
}

.folder-tree-toggle {
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    flex-shrink: 0;
}

.folder-tree-toggle:hover {
    background: var(--bg-color);
    color: var(--text-primary);
}

.folder-tree-toggle i {
    font-size: 0.7rem;
    transition: transform 0.2s ease;
}

.folder-tree-toggle.expanded i {
    transform: rotate(90deg);
}

/* File Area */
.file-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
}

.file-container {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
}

/* Grid View */
.file-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
}

.file-grid-item {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: var(--transition);
    cursor: pointer;
    position: relative;
}

.file-grid-item:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.file-grid-item.selected {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
}

.file-grid-thumbnail {
    aspect-ratio: 1;
    background: var(--bg-color);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    position: relative;
}

.file-grid-thumbnail img,
.file-grid-thumbnail video {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.file-grid-thumbnail .file-icon {
    font-size: 3rem;
    color: var(--text-secondary);
}

.file-grid-thumbnail .video-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}

.file-grid-thumbnail:hover .video-overlay {
    opacity: 1;
}

.file-grid-thumbnail .video-overlay i {
    color: white;
    font-size: 2.5rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.file-grid-info {
    padding: 12px;
}

.file-grid-name {
    font-size: 0.875rem;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: 4px;
}

.file-grid-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.file-grid-actions {
    position: absolute;
    top: 8px;
    right: 8px;
    display: flex;
    gap: 4px;
    opacity: 0;
    transition: var(--transition);
}

.file-grid-item:hover .file-grid-actions {
    opacity: 1;
}

.file-grid-action {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: rgba(255,255,255,0.9);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.file-grid-action:hover {
    background: var(--primary-color);
    color: white;
}

/* List View */
.file-list {
    width: 100%;
}

.file-list-table {
    width: 100%;
    border-collapse: collapse;
}

.file-list-table th,
.file-list-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.file-list-table th {
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    background: var(--bg-color);
    position: sticky;
    top: 0;
    z-index: 10;
}

.file-list-table tbody tr {
    transition: var(--transition);
    cursor: pointer;
}

.file-list-table tbody tr:hover {
    background: var(--bg-color);
}

.file-list-table tbody tr.selected {
    background: rgba(52, 152, 219, 0.05);
}

.file-list-name {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.875rem;
}

.file-list-icon {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    background: var(--bg-color);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.file-list-icon i {
    font-size: 1.25rem;
    color: var(--text-secondary);
}

.file-list-icon.image i { color: #e74c3c; }
.file-list-icon.video i { color: #9b59b6; }
.file-list-icon.audio i { color: #f39c12; }
.file-list-icon.folder i { color: #f39c12; }
.file-list-icon.document i { color: #3498db; }
.file-list-icon.archive i { color: #e67e22; }
.file-list-icon.code i { color: #2ecc71; }

.file-list-name-text {
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-list-size,
.file-list-date,
.file-list-type {
    font-size: 0.8rem;
    color: var(--text-secondary);
    white-space: nowrap;
}

.file-list-actions {
    display: flex;
    gap: 4px;
    opacity: 0;
    transition: var(--transition);
}

.file-list-table tbody tr:hover .file-list-actions {
    opacity: 1;
}

.file-list-action {
    width: 28px;
    height: 28px;
    border-radius: var(--radius-sm);
    background: var(--bg-color);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-secondary);
    transition: var(--transition);
}

.file-list-action:hover {
    background: var(--primary-color);
    color: white;
}

/* Empty State */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    min-height: 300px;
    color: var(--text-secondary);
    text-align: center;
    padding: 40px;
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 16px;
    opacity: 0.5;
}

.empty-state p {
    font-size: 1.1rem;
}

/* Loading State */
.loading-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    min-height: 200px;
    color: var(--text-secondary);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 16px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Status Bar */
.status-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--status-height);
    padding: 0 20px;
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.status-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

/* Modal */
.modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.7);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    max-width: 90vw;
    max-height: 90vh;
    width: 100%;
    max-width: 800px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    animation: modalIn 0.2s ease;
}

@keyframes modalIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1rem;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
}

.modal-close {
    width: 32px;
    height: 32px;
    border: none;
    background: transparent;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.modal-close:hover {
    background: var(--bg-color);
    color: var(--text-primary);
}

.modal-body {
    flex: 1;
    overflow: auto;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #1a1a1a;
    min-height: 300px;
    position: relative;
}

.modal-body img {
    max-width: 100%;
    max-height: 70vh;
    object-fit: contain;
}

.modal-body video {
    max-width: 100%;
    max-height: 70vh;
}

.modal-body .file-preview-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    text-align: center;
    padding: 40px;
}

.modal-body .file-preview-placeholder i {
    font-size: 4rem;
    margin-bottom: 16px;
    opacity: 0.7;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    padding: 16px 20px;
    border-top: 1px solid var(--border-color);
    background: var(--bg-color);
}

/* Context Menu */
.context-menu {
    position: fixed;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    min-width: 180px;
    z-index: 2000;
    overflow: hidden;
}

.context-menu-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-primary);
}

.context-menu-item:hover {
    background: var(--bg-color);
}

.context-menu-item i {
    width: 16px;
    text-align: center;
    color: var(--text-secondary);
}

.context-menu-divider {
    height: 1px;
    background: var(--border-color);
    margin: 4px 0;
}

/* Toast */
.toast-container {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 3000;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.toast {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 20px;
    background: var(--card-bg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    border-left: 4px solid var(--primary-color);
    animation: toastIn 0.3s ease;
    min-width: 280px;
    max-width: 400px;
}

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

.toast.success { border-left-color: var(--success-color); }
.toast.error { border-left-color: var(--danger-color); }
.toast.warning { border-left-color: var(--warning-color); }

.toast-icon {
    font-size: 1.25rem;
}

.toast.success .toast-icon { color: var(--success-color); }
.toast.error .toast-icon { color: var(--danger-color); }
.toast.warning .toast-icon { color: var(--warning-color); }
.toast.info .toast-icon { color: var(--primary-color); }

.toast-message {
    flex: 1;
    font-size: 0.875rem;
}

.toast-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.toast-close:hover {
    background: var(--bg-color);
    color: var(--text-primary);
}

/* Mobile Toggle Button */
#mobileToggleSidebar {
    position: fixed;
    bottom: 20px;
    left: 20px;
    z-index: 60;
}

/* Responsive */
@media (max-width: 1024px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: var(--header-height);
        bottom: var(--status-height);
        transform: translateX(-100%);
        z-index: 200;
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .sidebar-overlay {
        display: none;
        position: fixed;
        inset: 0;
        background: rgba(0,0,0,0.3);
        z-index: 150;
    }
    
    .sidebar-overlay.open {
        display: block;
    }
    
    #mobileToggleSidebar {
        display: flex !important;
    }
    
    .toolbar {
        flex-direction: column;
        align-items: stretch;
        height: auto;
        padding: 12px 16px;
    }
    
    .toolbar-left,
    .toolbar-right {
        justify-content: space-between;
    }
    
    .search-input {
        flex: 1;
        min-width: 0;
    }
    
    .view-mode-select,
    .sort-select,
    .sort-order-select {
        min-width: 120px;
        flex: 1;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 0 12px;
    }
    
    .header-left h1 {
        font-size: 1.1rem;
    }
    
    .breadcrumb {
        display: none;
    }
    
    .folder-info {
        display: none;
    }
    
    .file-container {
        padding: 12px;
    }
    
    .file-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 12px;
    }
    
    .file-list-table th:nth-child(3),
    .file-list-table td:nth-child(3),
    .file-list-table th:nth-child(4),
    .file-list-table td:nth-child(4) {
        display: none;
    }
    
    .status-bar {
        padding: 0 12px;
        font-size: 0.7rem;
    }
    
    .modal-content {
        margin: 10px;
        max-height: calc(100vh - 20px);
    }
    
    .modal-body {
        min-height: 200px;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* Selection */
::selection {
    background: rgba(52, 152, 219, 0.3);
}

/* Focus visible for accessibility */
*:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Drag and drop visual feedback */
.file-grid-item.drag-over {
    border-color: var(--primary-color);
    background: rgba(52, 152, 219, 0.05);
}

.file-list-table tbody tr.drag-over {
    background: rgba(52, 152, 219, 0.05);
}