:root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --border: #334155;
}

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

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

/* Sidebar Navigation */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: 240px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    padding: 1.5rem 0;
    overflow-y: auto;
}

.logo {
    padding: 0 1.5rem 1.5rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 1rem;
    text-align: center;
}

.logo-image {
    width: 80px;
    height: 80px;
    margin: 0 auto 0.75rem;
    border-radius: 12px;
    object-fit: cover;
}

.logo h1 {
    color: var(--accent);
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.nav-menu {
    list-style: none;
}

.nav-item {
    margin: 0.25rem 0.75rem;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.2s;
    cursor: pointer;
}

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

.nav-link.active {
    background: var(--accent);
    color: white;
}

.nav-icon {
    width: 20px;
    height: 20px;
}

/* Main Content */
.main-content {
    margin-left: 240px;
    padding: 2rem;
    min-height: 100vh;
}

/* Top Bar & Search */
.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    gap: 2rem;
}

.search-container {
    flex: 1;
    position: relative;
    max-width: 600px;
}

.search-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    width: 18px;
    height: 18px;
    color: var(--text-secondary);
    pointer-events: none;
}

.search-input {
    width: 100%;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 0.75rem 1rem 0.75rem 3rem;
    color: var(--text-primary);
    font-size: 0.95rem;
    transition: all 0.2s;
}

.search-input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 1.25rem;
}

.notification-bell {
    color: var(--text-secondary);
    cursor: pointer;
    position: relative;
}

.avatar {
    width: 36px;
    height: 36px;
    background: var(--accent);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
}

.page-header {
    margin-bottom: 2rem;
}

.page-header h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.page-header p {
    color: var(--text-secondary);
}

/* Cards Grid */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.card-title {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.card-value {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

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

.status-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
}

.status-badge.success {
    background: rgba(16, 185, 129, 0.2);
    color: var(--success);
}

.status-badge.warning {
    background: rgba(245, 158, 11, 0.2);
    color: var(--warning);
}

.status-badge.danger {
    background: rgba(239, 68, 68, 0.2);
    color: var(--danger);
}

/* Progress Bar */
.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
    margin-top: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: var(--accent);
    transition: width 0.3s;
}

/* File Upload Section */
.upload-area {
    background: var(--bg-secondary);
    border: 2px dashed var(--border);
    border-radius: 12px;
    padding: 3rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    margin-bottom: 2rem;
}

.upload-area:hover {
    border-color: var(--accent);
    background: var(--bg-tertiary);
}

.upload-area.dragover {
    border-color: var(--accent);
    background: var(--bg-tertiary);
}

.upload-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 1rem;
    opacity: 0.5;
}

.file-list {
    list-style: none;
}

.file-item {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 0.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.file-info {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex: 1;
}

.file-icon {
    width: 32px;
    height: 32px;
}

.file-name {
    font-weight: 500;
}

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

.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.2s;
}

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

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

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

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

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

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

/* Resources Gallery */
.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.resource-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

.resource-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
}

.resource-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.resource-content {
    padding: 1.5rem;
}

.resource-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.resource-category.work {
    background: rgba(59, 130, 246, 0.2);
    color: var(--accent);
}

.resource-category.personal {
    background: rgba(16, 185, 129, 0.2);
    color: var(--success);
}

.resource-title {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.resource-description {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.5;
}

.resource-link {
    color: var(--accent);
    text-decoration: none;
    font-size: 0.875rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
}

.resource-link:hover {
    text-decoration: underline;
}

/* Hidden Pages */
.page {
    display: none;
}

.page.active {
    display: block;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-secondary);
}

.empty-state svg {
    width: 96px;
    height: 96px;
    margin: 0 auto 1.5rem;
    opacity: 0.3;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s;
    }

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

    .main-content {
        margin-left: 0;
    }

    .cards-grid {
        grid-template-columns: 1fr;
    }
}