/* ========================================
   CSS Variables & Root Styles
   ======================================== */
:root {
    /* Light Mode Colors */
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f3f5;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --text-tertiary: #adb5bd;
    --border-color: #dee2e6;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    
    /* Brand Colors */
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary: #64748b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    
    /* Category Colors */
    --cat-research: #8b5cf6;
    --cat-curriculum: #3b82f6;
    --cat-lecture: #10b981;
    --cat-admin: #f59e0b;
    --cat-other: #6b7280;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Borders */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
    
    /* Layout */
    --header-height: 70px;
    --sidebar-width: 280px;
}

/* Dark Mode */
body.dark-mode {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-tertiary: #64748b;
    --border-color: #334155;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.4);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background var(--transition-normal), color var(--transition-normal);
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    outline: none;
    transition: all var(--transition-fast);
}

input, select, textarea {
    font-family: inherit;
    outline: none;
}

a {
    text-decoration: none;
    color: inherit;
}

/* ========================================
   Header
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    z-index: 100;
}

.header-content {
    height: 100%;
    padding: 0 var(--spacing-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-xl);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo i {
    font-size: 2rem;
    color: var(--primary);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--info));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.search-bar {
    position: relative;
    width: 400px;
}

.search-bar i {
    position: absolute;
    left: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-tertiary);
}

.search-bar input {
    width: 100%;
    padding: 0.625rem var(--spacing-md) 0.625rem 2.5rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.search-bar input:focus {
    background: var(--bg-secondary);
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.clear-search {
    position: absolute;
    right: var(--spacing-sm);
    top: 50%;
    transform: translateY(-50%);
    background: none;
    color: var(--text-tertiary);
    padding: var(--spacing-xs);
}

.clear-search:hover {
    color: var(--text-primary);
}

/* Buttons */
.primary-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 0.625rem 1.25rem;
    background: var(--primary);
    color: white;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

.primary-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.secondary-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 0.625rem 1.25rem;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 0.875rem;
    border: 1px solid var(--border-color);
}

.secondary-btn:hover {
    background: var(--bg-secondary);
    border-color: var(--primary);
}

.secondary-btn.small {
    padding: 0.5rem 0.875rem;
    font-size: 0.8125rem;
}

.icon-btn {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
}

.icon-btn:hover {
    background: var(--bg-secondary);
    color: var(--primary);
    border-color: var(--primary);
}

.icon-btn-small {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
}

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

/* ========================================
   Layout
   ======================================== */
.container {
    display: flex;
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height));
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
    overflow-y: auto;
    position: fixed;
    height: calc(100vh - var(--header-height));
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: 0.75rem var(--spacing-md);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-weight: 500;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-item i {
    font-size: 1.125rem;
    width: 20px;
}

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

.nav-item.active {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
}

.nav-item .count {
    margin-left: auto;
    padding: 0.25rem 0.5rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
}

.sidebar-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.sidebar-section h3 {
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-tertiary);
    font-weight: 600;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.section-header h3 {
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-tertiary);
    font-weight: 600;
}

.category-list, .custom-lists {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.category-item, .list-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 0.5rem var(--spacing-sm);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.category-item:hover, .list-item:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.category-badge {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    flex-shrink: 0;
}

.list-item i {
    width: 16px;
    font-size: 0.875rem;
}

.list-item .count {
    margin-left: auto;
    color: var(--text-tertiary);
    font-size: 0.75rem;
}

.sidebar-footer {
    margin-top: auto;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.sidebar-footer .secondary-btn {
    width: 100%;
    justify-content: center;
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: var(--spacing-xl);
    min-height: calc(100vh - var(--header-height));
}

.view {
    display: none;
}

.view.active {
    display: block;
    animation: fadeIn var(--transition-normal);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.view-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-xl);
    gap: var(--spacing-lg);
}

.view-header h2 {
    font-size: 2rem;
    font-weight: 700;
}

.view-header .subtitle {
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
}

.view-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.view-toggle {
    display: flex;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 0.25rem;
}

.toggle-btn {
    padding: 0.5rem 0.75rem;
    background: transparent;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
}

.toggle-btn.active {
    background: var(--bg-secondary);
    color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.sort-select {
    padding: 0.625rem var(--spacing-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.875rem;
}

.filter-dropdown {
    position: relative;
}

.filter-panel {
    display: none;
    position: absolute;
    top: calc(100% + 0.5rem);
    right: 0;
    width: 250px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-md);
    z-index: 50;
}

.filter-panel.active {
    display: block;
    animation: slideDown var(--transition-fast);
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.filter-panel h4 {
    font-size: 0.875rem;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

.filter-panel h4:first-child {
    margin-top: 0;
}

.filter-panel label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-xs) 0;
    font-size: 0.875rem;
    cursor: pointer;
}

.filter-panel input[type="checkbox"] {
    width: 16px;
    height: 16px;
    cursor: pointer;
}

/* ========================================
   Dashboard
   ======================================== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.stat-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.stat-icon {
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    font-size: 1.5rem;
    color: white;
}

.stat-icon.blue { background: linear-gradient(135deg, #3b82f6, #2563eb); }
.stat-icon.green { background: linear-gradient(135deg, #10b981, #059669); }
.stat-icon.orange { background: linear-gradient(135deg, #f59e0b, #d97706); }
.stat-icon.purple { background: linear-gradient(135deg, #8b5cf6, #7c3aed); }

.stat-info h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.stat-info p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.dashboard-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.dashboard-section.full-width {
    grid-column: 1 / -1;
}

.dashboard-section h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

.recent-documents {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.recent-doc-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.recent-doc-item:hover {
    background: var(--bg-primary);
    transform: translateX(4px);
}

.recent-doc-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    font-size: 1.25rem;
}

.recent-doc-icon.pdf { color: #ef4444; }
.recent-doc-icon.docx { color: #3b82f6; }

.recent-doc-info {
    flex: 1;
}

.recent-doc-info h4 {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.recent-doc-info p {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.chart-container {
    position: relative;
    height: 300px;
}

.document-list-simple {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.storage-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.storage-info-item {
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    text-align: center;
}

.storage-info-item h4 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
    color: var(--primary);
}

.storage-info-item p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.storage-progress {
    margin-top: var(--spacing-sm);
    height: 8px;
    background: var(--bg-primary);
    border-radius: 4px;
    overflow: hidden;
}

.storage-progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--success), var(--primary));
    transition: width var(--transition-normal);
}

.storage-progress-bar.warning {
    background: linear-gradient(90deg, var(--warning), var(--danger));
}

/* ========================================
   Documents Grid
   ======================================== */
.documents-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.document-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.document-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.document-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--info));
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.document-card:hover::before {
    opacity: 1;
}

.doc-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: var(--spacing-md);
}

.doc-icon-large {
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    font-size: 2rem;
}

.doc-icon-large.pdf { color: #ef4444; }
.doc-icon-large.docx { color: #3b82f6; }

.doc-actions-quick {
    display: flex;
    gap: var(--spacing-xs);
}

.doc-action-btn {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    opacity: 0;
    transform: scale(0.8);
    transition: all var(--transition-fast);
}

.document-card:hover .doc-action-btn {
    opacity: 1;
    transform: scale(1);
}

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

.doc-action-btn.favorite.active {
    color: #f59e0b;
}

.doc-info {
    margin-bottom: var(--spacing-md);
}

.doc-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.doc-meta {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.doc-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-md);
}

.tag {
    padding: 0.25rem 0.625rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.tag.category {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
}

/* Empty State */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl);
    text-align: center;
    color: var(--text-secondary);
    min-height: 400px;
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-tertiary);
}

.empty-state h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.empty-state p {
    margin-bottom: var(--spacing-lg);
}

/* ========================================
   Duplicates
   ======================================== */
.duplicates-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.duplicate-group {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.duplicate-group-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

.duplicate-group-header h4 {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--warning);
}

.duplicate-items {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.duplicate-item {
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    position: relative;
}

.duplicate-item-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.duplicate-item-info p {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.duplicate-item-actions {
    display: flex;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

.duplicate-item-actions button {
    flex: 1;
    padding: 0.5rem;
    font-size: 0.75rem;
}

/* ========================================
   Modal
   ======================================== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(4px);
}

.modal.active {
    display: flex;
    animation: fadeIn var(--transition-normal);
}

.modal-content {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    width: 90%;
    max-width: 600px;
    max-height: 90vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    animation: slideUp var(--transition-normal);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-content.large {
    max-width: 1000px;
}

.modal-content.small {
    max-width: 400px;
}

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

.modal-header h2 {
    font-size: 1.5rem;
}

.close-modal {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
}

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

.modal-body {
    padding: var(--spacing-xl);
    overflow-y: auto;
}

/* Info Box */
.info-box {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(37, 99, 235, 0.1);
    border-left: 4px solid var(--primary-color);
    border-radius: var(--radius-md);
}

.info-box i {
    color: var(--primary-color);
    font-size: 1.25rem;
    flex-shrink: 0;
}

.info-box p {
    margin: 0;
    line-height: 1.6;
}

.info-box ul {
    list-style: disc;
    margin: 0;
}

.info-box li {
    margin-bottom: 0.25rem;
}

/* Modal Actions */
.modal-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: flex-end;
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

.modal-actions .primary-btn,
.modal-actions .secondary-btn {
    flex: 0 0 auto;
}

/* Drop Zone */
.drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    text-align: center;
    transition: all var(--transition-fast);
}

.drop-zone.dragover {
    border-color: var(--primary);
    background: rgba(37, 99, 235, 0.05);
}

.drop-zone i {
    font-size: 3rem;
    color: var(--text-tertiary);
    margin-bottom: var(--spacing-md);
}

.drop-zone h3 {
    margin-bottom: var(--spacing-sm);
}

.drop-zone p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.drop-zone .hint {
    font-size: 0.875rem;
    margin-top: var(--spacing-md);
}

.upload-progress {
    margin-top: var(--spacing-lg);
}

.upload-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.upload-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.upload-item-icon {
    font-size: 1.5rem;
}

.upload-item-info {
    flex: 1;
}

.upload-item-info h4 {
    font-size: 0.875rem;
    margin-bottom: var(--spacing-xs);
}

.progress-bar {
    height: 4px;
    background: var(--bg-primary);
    border-radius: 2px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--primary);
    transition: width var(--transition-normal);
}

.upload-item-status {
    font-size: 0.875rem;
    color: var(--success);
}

/* Document Detail */
.document-detail {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: var(--spacing-xl);
}

.detail-sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.doc-preview {
    aspect-ratio: 1;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: var(--text-tertiary);
}

.doc-actions {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.action-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-weight: 500;
}

.action-btn:hover {
    background: var(--bg-primary);
    border-color: var(--primary);
}

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

.detail-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.detail-section h3 {
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
}

.metadata-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
}

.metadata-item {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.metadata-item label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.metadata-item p {
    font-weight: 500;
}

.tags-container {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.tag-editable {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.375rem 0.75rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
}

.tag-editable button {
    background: none;
    color: var(--text-secondary);
    padding: 0;
    margin-left: var(--spacing-xs);
}

.tag-editable button:hover {
    color: var(--danger);
}

.notes-textarea {
    width: 100%;
    min-height: 150px;
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    resize: vertical;
    margin-bottom: var(--spacing-md);
}

.notes-textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.list-select {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
}

/* Input Field */
.input-field {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.input-field:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.full-width {
    width: 100%;
}

/* Icon Picker */
.icon-picker {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.icon-picker button {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
}

.icon-picker button:hover {
    background: var(--bg-primary);
    color: var(--primary);
}

.icon-picker button.selected {
    border-color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
}

/* Toast */
.toast {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    z-index: 2000;
    transform: translateY(150%);
    transition: transform var(--transition-normal);
}

.toast.show {
    transform: translateY(0);
}

.toast i {
    font-size: 1.25rem;
    color: var(--success);
}

.toast.error i {
    color: var(--danger);
}

.toast.warning i {
    color: var(--warning);
}

/* ========================================
   Pagination
   ======================================== */
.pagination-controls {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
}

.pagination-info {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.pagination-buttons {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    flex-wrap: wrap;
    justify-content: center;
}

.pagination-btn {
    min-width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-weight: 500;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.pagination-btn:hover:not(.disabled) {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    transform: translateY(-1px);
}

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

.pagination-btn.disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.pagination-ellipsis {
    padding: 0 var(--spacing-sm);
    color: var(--text-tertiary);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1200px) {
    .search-bar {
        width: 300px;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 992px) {
    :root {
        --sidebar-width: 240px;
    }
    
    .logo h1 {
        font-size: 1.25rem;
    }
    
    .documents-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    }
    
    .document-detail {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .header-content {
        padding: 0 var(--spacing-md);
    }
    
    .search-bar {
        display: none;
    }
    
    .sidebar {
        transform: translateX(-100%);
        transition: transform var(--transition-normal);
        z-index: 90;
    }
    
    .sidebar.mobile-open {
        transform: translateX(0);
    }
    
    .main-content {
        margin-left: 0;
        padding: var(--spacing-md);
    }
    
    .view-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .view-actions {
        width: 100%;
        flex-wrap: wrap;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-md);
    }
    
    .stat-card {
        flex-direction: column;
        text-align: center;
    }
    
    .documents-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        width: 95%;
        max-height: 95vh;
    }
    
    .modal-body {
        padding: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .logo h1 {
        display: none;
    }
    
    .primary-btn span, .secondary-btn span {
        display: none;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .metadata-grid {
        grid-template-columns: 1fr;
    }
}