/* Reset und Basis-Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #3B82F6;
    --primary-dark: #2563EB;
    --secondary-color: #8B5CF6;
    --success-color: #10B981;
    --warning-color: #F59E0B;
    --error-color: #EF4444;
    --background-color: #F8FAFC;
    --surface-color: #FFFFFF;
    --surface-hover: #F1F5F9;
    --text-color: #1E293B;
    --text-secondary: #64748B;
    --border-color: #E2E8F0;
    --border-light: #F1F5F9;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --border-radius: 0.5rem;
    --border-radius-lg: 0.75rem;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header */
.header {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem;
    gap: 1rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.logo h1 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-color);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.btn-logout {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background-color: var(--error-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-logout:hover {
    background-color: #DC2626;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-logout i {
    font-size: 1rem;
}

.search-container {
    position: relative;
    flex: 1;
    max-width: 500px;
}

.search-container input {
    width: 100%;
    padding: 0.5rem 1rem 0.5rem 2.5rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    background-color: var(--background-color);
    font-size: 0.875rem;
    transition: all 0.2s ease;
}

.search-container input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-color)20;
}

.search-container i {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.25rem;
    color: var(--text-color);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--border-radius);
}

.mobile-menu-btn:hover {
    background-color: var(--surface-hover);
}

/* Navigation */
.nav {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    padding: 0 1rem;
}

.nav-container {
    display: flex;
    gap: 0.25rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.nav-item:hover,
.nav-item.active {
    background-color: var(--surface-hover);
    color: var(--primary-color);
}

.nav-item i {
    font-size: 1rem;
}

/* Main Content */
.main {
    min-height: calc(100vh - 140px);
    padding: 2rem 0;
}

.section {
    display: none;
}

.section.active {
    display: block;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-color);
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 2rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
    font-size: 0.875rem;
}

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

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

.btn-secondary {
    background-color: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

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

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.stat-card {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: all 0.2s ease;
}

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

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background-color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
}

.stat-info h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

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

/* Quick Actions */
.quick-actions {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
}

.quick-actions h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 1.5rem;
}

.action-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: left;
}

.action-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.action-btn i {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background-color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
}

.action-btn span {
    font-weight: 600;
    color: var(--text-color);
}

/* Grid Layouts */
.documents-grid,
.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.document-card,
.note-card {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 1.5rem;
    transition: all 0.2s ease;
}

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

.document-header,
.note-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.document-icon {
    width: 40px;
    height: 40px;
    background-color: var(--error-color);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.document-title,
.note-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.document-author,
.note-content {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.document-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Learning Grid */
.learning-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.learning-card {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    text-align: center;
    transition: all 0.2s ease;
}

.learning-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.learning-icon {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background-color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 2rem;
}

.learning-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.learning-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.modal.active {
    display: flex;
}

.modal-content {
    background-color: var(--surface-color);
    border-radius: var(--border-radius-lg);
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
}

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

.modal-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.25rem;
    border-radius: var(--border-radius);
}

.close-btn:hover {
    background-color: var(--surface-hover);
}

.modal-body {
    padding: 1.5rem;
}

/* Form */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-weight: 500;
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    transition: all 0.2s ease;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-color)20;
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-actions {
    display: flex;
    gap: 0.5rem;
    justify-content: flex-end;
}

/* Loading Spinner */
.loading-spinner {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.loading-spinner.active {
    display: flex;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Toast */
.toast {
    position: fixed;
    top: 2rem;
    right: 2rem;
    background-color: var(--success-color);
    color: white;
    padding: 1rem 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    z-index: 1500;
    transform: translateX(400px);
    transition: transform 0.3s ease;
}

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

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

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

/* Mobile Responsive */
@media (max-width: 768px) {
    .header .container {
        flex-wrap: wrap;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--surface-color);
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
    }
    
    .nav.active {
        display: block;
    }
    
    .nav-container {
        flex-direction: column;
        padding: 1rem;
    }
    
    .nav-item {
        justify-content: flex-start;
    }
    
    .search-container {
        order: 3;
        width: 100%;
        max-width: none;
    }
    
    .section-header {
        flex-direction: column;
        align-items: stretch;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .action-buttons {
        grid-template-columns: 1fr;
    }
    
    .documents-grid,
    .notes-grid {
        grid-template-columns: 1fr;
    }
    
    .learning-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        margin: 1rem;
        max-height: calc(100vh - 2rem);
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .toast {
        top: 1rem;
        right: 1rem;
        left: 1rem;
        transform: translateY(-100px);
    }
    
    .toast.show {
        transform: translateY(0);
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.5rem;
    }
    
    .header .container {
        padding: 0.75rem;
    }
    
    .main {
        padding: 1rem 0;
    }
}

/* Note View Modal */
.note-view-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
}

.note-view-content {
    position: relative;
    background: white;
    border-radius: 12px;
    padding: 2rem;
    max-width: 700px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
}

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

.note-view-content .modal-header h2 {
    color: var(--text-color);
    font-size: 1.5rem;
}

.note-view-content .modal-header button {
    background: none;
    border: none;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-secondary);
}

.note-view-category, .note-view-date {
    display: inline-block;
    margin-right: 1rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.note-view-body {
    margin-top: 1rem;
    line-height: 1.6;
    color: var(--text-color);
}

/* Note Card - Gleiches Layout wie Dokumente */
.note-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.note-icon {
    font-size: 2rem;
    color: var(--secondary-color);
}

.note-body {
    cursor: pointer;
    margin-bottom: 0.5rem;
}

.note-body:hover {
    opacity: 0.8;
}

/* Note Meta - Kategorie unten rechts in Blau */
.note-category {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    background: var(--primary-color);
    color: white;
    border-radius: var(--border-radius);
    font-size: 0.75rem;
    font-weight: 600;
}

/* Note Actions - oben rechts */
.note-header .note-actions {
    display: flex;
    gap: 0.5rem;
    margin: 0;
    padding: 0;
    border: none;
}

.note-header .btn-edit, 
.note-header .btn-delete {
    padding: 0.5rem;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.2s ease;
    background: none;
    color: var(--text-secondary);
}

.note-header .btn-edit:hover {
    color: var(--primary-color);
}

.note-header .btn-delete:hover {
    color: var(--error-color);
}

/* Alte Note Meta Anpassung */
.note-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 0.5rem;
    padding-top: 0.5rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.note-meta     .note-category {
        margin-left: auto;
    }

/* Rich Text Editor Styles */
.note-editor-modal .modal-content {
    max-width: 95vw;
    height: 90vh;
    max-height: 900px;
}

.note-editor-content {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.note-toolbar {
    display: flex;
    gap: 1rem;
    padding: 0.5rem;
    background: var(--surface-hover);
    border-bottom: 1px solid var(--border-color);
    flex-wrap: wrap;
}

.toolbar-group {
    display: flex;
    gap: 0.25rem;
    padding: 0.25rem;
    border-right: 1px solid var(--border-color);
}

.toolbar-group:last-child {
    border-right: none;
}

.toolbar-btn {
    padding: 0.5rem;
    border: none;
    background: transparent;
    cursor: pointer;
    border-radius: var(--border-radius);
    color: var(--text-secondary);
    transition: all 0.2s ease;
}

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

.note-editor {
    min-height: 300px;
    max-height: 500px;
    overflow-y: auto;
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background: white;
    font-size: 0.875rem;
    line-height: 1.6;
}

.note-editor:focus {
    outline: 2px solid var(--primary-color);
}

.note-editor img {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    margin: 0.5rem 0;
}

.note-editor ul, .note-editor ol {
    margin-left: 1.5rem;
    margin-top: 0.5rem;
}

/* Drawing Modal */
.drawing-modal .modal-content {
    max-width: 95vw;
    height: 90vh;
}

.drawing-content {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.drawing-toolbar {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.drawing-canvas-container {
    flex: 1;
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    margin: 1rem 0;
}

#drawingCanvas {
    width: 100%;
    height: 100%;
    cursor: crosshair;
    touch-action: none;
}

/* Mobile optimizations */
@media (max-width: 768px) {
    .note-editor-modal .modal-content {
        max-width: 100vw;
        height: 100vh;
        max-height: none;
    }
    
    .note-toolbar {
        gap: 0.5rem;
    }
    
    .toolbar-group {
        gap: 0.125rem;
    }
    
    .toolbar-btn {
        padding: 0.375rem;
        font-size: 0.875rem;
    }
    
    .note-editor {
        min-height: 400px;
        max-height: none;
    }
    
    .drawing-modal .modal-content {
        max-width: 100vw;
        height: 100vh;
    }
}

.note-updated {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* Document Actions */
.document-actions {
    display: flex;
    gap: 0.5rem;
}

.btn-download, .btn-delete {
    padding: 0.5rem;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.2s ease;
    background: none;
    color: var(--text-secondary);
}

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

.btn-delete:hover {
    color: var(--error-color);
}

.document-category {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    background: var(--primary-color);
    color: white;
    border-radius: var(--border-radius);
    font-size: 0.75rem;
    font-weight: 600;
}
    
    .section-header h2 {
        font-size: 1.5rem;
    }
    
    .stat-card,
    .action-btn,
    .document-card,
    .note-card,
    .learning-card {
        padding: 1rem;
    }
    
    .modal-content {
        margin: 0.5rem;
    }
    
    .modal-header,
    .modal-body {
        padding: 1rem;
    }
}

/* Schnellzugriff und Kategorie-Filter */
.quick-access {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.quick-access h3 {
    font-size: 1.25rem;
    color: var(--text-color);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.category-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.category-filter {
    padding: 0.5rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    background: var(--surface-color);
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.category-filter:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.category-filter.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.category-filter i {
    font-size: 0.875rem;
}

/* Responsive für Kategorie-Filter */
@media (max-width: 768px) {
    .category-filters {
        gap: 0.5rem;
    }
    
    .category-filter {
        padding: 0.5rem 0.75rem;
        font-size: 0.75rem;
    }
}