/* ===== CSS Variables ===== */
:root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-card: #1e293b;
    --bg-hover: #334155;
    --bg-overlay: rgba(0, 0, 0, 0.6);

    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --border-color: #334155;
    --border-light: #475569;

    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --primary-light: rgba(59, 130, 246, 0.1);

    --success: #10b981;
    --success-bg: rgba(16, 185, 129, 0.1);
    --success-border: rgba(16, 185, 129, 0.2);

    --danger: #ef4444;
    --danger-bg: rgba(239, 68, 68, 0.1);
    --danger-border: rgba(239, 68, 68, 0.2);

    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.1);
    --warning-border: rgba(245, 158, 11, 0.2);

    --info: #06b6d4;
    --info-bg: rgba(6, 182, 212, 0.1);
    --info-border: rgba(6, 182, 212, 0.2);

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    --sidebar-width: 260px;
    --topbar-height: 64px;

    --transition: all 0.2s ease;
}

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

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

/* ===== Layout ===== */
.app-container {
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr;
    height: 100vh;
    overflow: hidden;
}

/* ===== Sidebar ===== */
.sidebar {
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    transition: transform 0.3s ease;
    z-index: 100;
}

.sidebar-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 1rem;
}

.logo i {
    font-size: 1.75rem;
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.375rem 0.75rem;
    background: var(--success-bg);
    border: 1px solid var(--success-border);
    border-radius: var(--radius);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--success);
}

.status-dot {
    width: 8px;
    height: 8px;
    background: var(--success);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.sidebar-nav {
    flex: 1;
    padding: 1rem 0;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 1.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
    border-left: 3px solid transparent;
}

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

.nav-item.active {
    background: var(--primary-light);
    color: var(--primary);
    border-left-color: var(--primary);
    font-weight: 600;
}

.nav-item i {
    width: 20px;
    text-align: center;
}

.sidebar-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border-color);
}

.system-info {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.info-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.info-item i {
    width: 16px;
}

/* ===== Main Content ===== */
.main-content {
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--bg-primary);
}

.top-bar {
    height: var(--topbar-height);
    padding: 0 2rem;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.top-bar-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.menu-toggle {
    display: none;
    width: 40px;
    height: 40px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 1.25rem;
    align-items: center;
    justify-content: center;
}

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

.top-bar-left h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.top-bar-right {
    display: flex;
    gap: 0.5rem;
}

.icon-btn {
    width: 40px;
    height: 40px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.content-area {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
}

/* ===== Tab Content ===== */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* ===== Stats Grid ===== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: var(--transition);
}

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

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    flex-shrink: 0;
}

.stat-icon.success {
    background: var(--success-bg);
    color: var(--success);
    border: 1px solid var(--success-border);
}

.stat-icon.danger {
    background: var(--danger-bg);
    color: var(--danger);
    border: 1px solid var(--danger-border);
}

.stat-icon.info {
    background: var(--info-bg);
    color: var(--info);
    border: 1px solid var(--info-border);
}

.stat-icon.warning {
    background: var(--warning-bg);
    color: var(--warning);
    border: 1px solid var(--warning-border);
}

.stat-info {
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* ===== Card ===== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    margin-bottom: 1.5rem;
}

.card.full-height {
    height: calc(100vh - var(--topbar-height) - 4rem - 1.5rem);
    display: flex;
    flex-direction: column;
}

.card.full-height .table-container {
    flex: 1;
    overflow-y: auto;
}

.card-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
}

.card-header h2 {
    font-size: 1.125rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
}

.card-header h2 i {
    color: var(--primary);
}

.card-description {
    padding: 1rem 1.5rem 0;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.card-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.card-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
}

/* ===== Quick Actions ===== */
.quick-actions {
    padding: 1.5rem;
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.875rem;
}

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

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

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

/* ===== Activity List ===== */
.activity-list {
    padding: 1.5rem;
}

.activity-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    border-radius: var(--radius);
    margin-bottom: 0.75rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
}

.activity-item:last-child {
    margin-bottom: 0;
}

.activity-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.activity-icon.success {
    background: var(--success-bg);
    color: var(--success);
}

.activity-icon.danger {
    background: var(--danger-bg);
    color: var(--danger);
}

.activity-info {
    flex: 1;
    min-width: 0;
}

.activity-info h4 {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.activity-info p {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.activity-meta {
    text-align: right;
    flex-shrink: 0;
}

.activity-meta span {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* ===== Table ===== */
.table-container {
    overflow-x: auto;
}

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

.data-table th {
    padding: 1rem 1.25rem;
    text-align: left;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    white-space: nowrap;
}

.data-table th i {
    margin-right: 0.5rem;
}

.data-table td {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-secondary);
}

.data-table tbody tr {
    transition: var(--transition);
}

.data-table tbody tr:hover {
    background: var(--bg-hover);
}

.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-muted);
}

.empty-state i {
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state p {
    font-size: 0.875rem;
}

/* ===== Status Badges ===== */
.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.375rem 0.75rem;
    border-radius: var(--radius);
    font-size: 0.75rem;
    font-weight: 600;
}

.status-badge.success {
    background: var(--success-bg);
    color: var(--success);
    border: 1px solid var(--success-border);
}

.status-badge.danger {
    background: var(--danger-bg);
    color: var(--danger);
    border: 1px solid var(--danger-border);
}

/* ===== Forms ===== */
.form-grid {
    padding: 1.5rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.form-group label i {
    color: var(--primary);
}

.form-group input,
.form-group select {
    padding: 0.75rem 1rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: var(--transition);
    width: 100%;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.form-group input::placeholder {
    color: var(--text-muted);
}

.input-group {
    padding: 1.5rem;
    display: flex;
    gap: 0.75rem;
}

.input-group input {
    flex: 1;
    padding: 0.75rem 1rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-size: 0.875rem;
    min-width: 0;
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

/* ===== Buttons ===== */
.btn {
    padding: 0.625rem 1rem;
    border: 1px solid transparent;
    border-radius: var(--radius);
    font-weight: 500;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
}

.btn-sm {
    padding: 0.5rem 0.75rem;
    font-size: 0.75rem;
}

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

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

.btn-outline {
    background: transparent;
    border-color: var(--border-color);
    color: var(--text-secondary);
}

.btn-outline:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

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

.btn-danger:hover {
    background: #dc2626;
}

/* ===== Files Filter Bar ===== */
.files-filter {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    align-items: center;
}

.files-filter input[type="text"] {
    flex: 1;
    min-width: 180px;
}

.files-filter input,
.files-filter select {
    padding: 0.5rem 0.75rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: var(--transition);
}

.files-filter input:focus,
.files-filter select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.files-filter input::placeholder {
    color: var(--text-muted);
}

/* ===== Files Pagination ===== */
.files-pagination {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border-color);
    align-items: center;
    justify-content: space-between;
}

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

.pagination-controls {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.pagination-controls label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

.pagination-controls select {
    padding: 0.375rem 0.5rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-size: 0.8125rem;
}

.pagination-info {
    font-size: 0.875rem;
    color: var(--text-primary);
    min-width: 5.5rem;
    text-align: center;
}

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

/* ===== Info Grid ===== */
.info-grid {
    padding: 1.5rem;
}

.info-row {
    display: flex;
    justify-content: space-between;
    padding: 0.875rem 0;
    border-bottom: 1px solid var(--border-color);
    gap: 1rem;
    flex-wrap: wrap;
}

.info-row:last-child {
    border-bottom: none;
}

.info-label {
    color: var(--text-secondary);
    font-weight: 500;
}

.info-value {
    color: var(--text-primary);
    font-weight: 600;
    font-family: 'Courier New', monospace;
    word-break: break-all;
}

/* ===== Loading State ===== */
.loading-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem 1rem;
    color: var(--text-muted);
    gap: 1rem;
}

.loading-state i {
    font-size: 2rem;
}

/* ===== Toast ===== */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    box-shadow: var(--shadow-xl);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    z-index: 1000;
    transition: all 0.3s ease;
}

.toast.hidden {
    opacity: 0;
    transform: translateY(1rem);
    pointer-events: none;
}

.toast.success {
    border-left: 4px solid var(--success);
}

.toast.error {
    border-left: 4px solid var(--danger);
}

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

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

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

/* ===== File Link ===== */
.file-link {
    color: var(--primary);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    transition: var(--transition);
}

.file-link:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* ===== Sidebar Overlay (Mobile) ===== */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: var(--bg-overlay);
    z-index: 99;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.sidebar-overlay.active {
    display: block;
    opacity: 1;
}

/* ===== Responsive: Tablet ===== */
@media (max-width: 1024px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ===== Responsive: Mobile ===== */
@media (max-width: 768px) {
    .app-container {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        width: var(--sidebar-width);
        transform: translateX(-100%);
        box-shadow: var(--shadow-xl);
        z-index: 101;
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .menu-toggle {
        display: flex;
    }

    .top-bar {
        padding: 0 1rem;
    }

    .top-bar-left h1 {
        font-size: 1.125rem;
    }

    .content-area {
        padding: 1rem;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.75rem;
    }

    .stat-card {
        padding: 1rem;
    }

    .stat-icon {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }

    .stat-value {
        font-size: 1.25rem;
    }

    .card-header {
        padding: 1rem 1.25rem;
    }

    .card-header h2 {
        font-size: 1rem;
    }

    .card-actions {
        width: 100%;
    }

    .card-actions .btn {
        flex: 1;
        justify-content: center;
    }

    .quick-actions {
        padding: 1rem;
        flex-direction: column;
    }

    .action-btn {
        justify-content: center;
    }

    .form-grid {
        padding: 1rem;
        grid-template-columns: 1fr;
    }

    .input-group {
        padding: 1rem;
        flex-direction: column;
    }

    .activity-list {
        padding: 1rem;
    }

    .activity-item {
        padding: 0.75rem;
    }

    .activity-icon {
        width: 32px;
        height: 32px;
        font-size: 0.875rem;
    }

    .activity-info h4 {
        font-size: 0.8rem;
    }

    .activity-meta span:first-child {
        display: none;
    }

    .data-table th,
    .data-table td {
        padding: 0.75rem 0.75rem;
        font-size: 0.8rem;
    }

    .info-grid {
        padding: 1rem;
    }

    .card-footer {
        padding: 1rem 1.25rem;
    }

    .toast {
        bottom: 1rem;
        right: 1rem;
        left: 1rem;
        padding: 0.875rem 1rem;
    }
}

/* ===== Responsive: Small Mobile ===== */
@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr 1fr;
        gap: 0.5rem;
    }

    .stat-label {
        font-size: 0.7rem;
    }

    .stat-value {
        font-size: 1.125rem;
    }

    .top-bar-right .icon-btn:not(:first-child) {
        display: none;
    }

    .action-btn span {
        font-size: 0.8rem;
    }
}

/* ===== Light Theme ===== */
body.light-theme {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f5f9;
    --bg-card: #ffffff;
    --bg-hover: #f1f5f9;
    --bg-overlay: rgba(0, 0, 0, 0.4);

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;

    --border-color: #e2e8f0;
    --border-light: #cbd5e1;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: var(--radius);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-light);
}