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

:root {
    --primary-color: #2196F3;
    --success-color: #4CAF50;
    --warning-color: #FFC107;
    --danger-color: #F44336;
    --accent-color: #9C27B0;
    --background-color: #f5f5f5;
    --surface-color: #ffffff;
    --text-primary: #212121;
    --text-secondary: #757575;
    --border-color: #e0e0e0;
    --shadow-light: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-medium: 0 4px 8px rgba(0,0,0,0.15);
    --shadow-heavy: 0 8px 24px rgba(0,0,0,0.2);
    --border-radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* Header */
.app-header {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    padding: 1rem;
    box-shadow: var(--shadow-medium);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
}

.header-content h1 {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 0;
}

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

/* Main Content */
.app-main {
    padding-bottom: 80px;
    min-height: calc(100vh - 160px);
}

.section {
    display: none;
    padding: 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

.section.active {
    display: block;
}

.section-header {
    text-align: center;
    margin-bottom: 2rem;
}

.section-header h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.section-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Workspace */
.workspace {
    position: relative;
    background: var(--surface-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    overflow: hidden;
    margin-bottom: 1rem;
}

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

.toolbar-separator {
    width: 1px;
    height: 24px;
    background: var(--border-color);
    margin: 0 0.25rem;
}

#mindMapCanvas {
    display: block;
    width: 100%;
    height: 400px;
    background: #fafafa;
    cursor: grab;
}

#mindMapCanvas:active {
    cursor: grabbing;
}

/* Node Editor */
.node-editor {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--surface-color);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-heavy);
    min-width: 300px;
    z-index: 200;
}

.node-editor.hidden {
    display: none;
}

.node-editor input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    margin-bottom: 1rem;
    transition: var(--transition);
}

.node-editor input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.color-picker {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
    justify-content: center;
}

.color-btn {
    width: 40px;
    height: 40px;
    border: 3px solid transparent;
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.color-btn:hover,
.color-btn.active {
    border-color: var(--text-primary);
    transform: scale(1.1);
}

.editor-actions {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
}

/* Buttons */
.btn-primary,
.btn-secondary,
.btn-danger,
.btn-icon {
    padding: 0.75rem 1rem;
    border: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
}

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

.btn-primary:hover {
    background: #1976D2;
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

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

.btn-secondary:hover {
    background: #616161;
}

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

.btn-danger:hover {
    background: #D32F2F;
}

.btn-icon {
    padding: 0.5rem;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 2.5rem;
    height: 2.5rem;
}

.btn-icon:hover {
    background: var(--background-color);
    color: var(--text-primary);
    transform: translateY(-1px);
}

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

.btn-icon:active {
    transform: translateY(0);
}

/* Templates Grid */
.templates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
}

.template-card {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

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

.template-preview {
    width: 100%;
    height: 120px;
    background: linear-gradient(135deg, #f8f9fa, #e9ecef);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    transition: var(--transition);
}

.template-card:hover .template-preview {
    background: linear-gradient(135deg, #e3f2fd, #bbdefb);
}

.template-info {
    flex: 1;
}

.template-info h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.template-info p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.template-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    font-size: 0.85rem;
}

.difficulty {
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
    font-weight: 500;
    font-size: 0.75rem;
}

.difficulty.easy {
    background: #e8f5e8;
    color: #2e7d32;
}

.difficulty.medium {
    background: #fff3e0;
    color: #f57c00;
}

.difficulty.hard {
    background: #ffebee;
    color: #c62828;
}

.node-count {
    color: var(--text-secondary);
}

.template-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
    margin-bottom: 1rem;
}

.tag {
    background: var(--background-color);
    color: var(--text-secondary);
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 500;
}

.template-card .use-template-btn {
    align-self: stretch;
    justify-content: center;
}

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

.project-card {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border: 2px solid transparent;
}

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

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

.project-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.project-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

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

/* Export Options */
.export-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.export-card {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
}

.export-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
}

.export-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

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

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

/* Search */
.search-container {
    max-width: 600px;
    margin: 0 auto;
}

.search-input-container {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.search-input-container input {
    flex: 1;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.search-input-container input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.search-filters {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    justify-content: center;
}

.search-filters label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.search-results {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    max-height: 400px;
    overflow-y: auto;
}

.search-result-item {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    cursor: pointer;
    transition: var(--transition);
}

.search-result-item:hover {
    background: var(--background-color);
}

.search-result-item:last-child {
    border-bottom: none;
}

.search-result-title {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.search-result-content {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* FAQ */
.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
    box-shadow: var(--shadow-light);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 1.5rem;
    background: none;
    border: none;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--background-color);
}

.faq-icon {
    font-size: 1.5rem;
    font-weight: 300;
    transition: var(--transition);
}

.faq-question[aria-expanded="true"] .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 1.5rem 1.5rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.faq-answer[hidden] {
    display: none;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    width: 100%;
    max-width: 500px;
    box-shadow: var(--shadow-heavy);
}

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

.modal-header h3 {
    margin: 0;
    font-size: 1.25rem;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.modal form {
    padding: 1.5rem;
}

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

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--surface-color);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-around;
    padding: 0.5rem 0;
    z-index: 100;
    box-shadow: 0 -2px 8px rgba(0,0,0,0.1);
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.5rem;
    text-decoration: none;
    color: var(--text-secondary);
    transition: var(--transition);
    font-size: 0.75rem;
    min-width: 60px;
}

.nav-item i {
    font-size: 1.2rem;
    margin-bottom: 0.25rem;
}

.nav-item.active {
    color: var(--primary-color);
}

.nav-item:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* Loading Indicator */
.loading-indicator {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--surface-color);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-heavy);
    text-align: center;
    z-index: 1000;
}

.loading-indicator.hidden {
    display: none;
}

.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;
    margin: 0 auto 1rem;
}

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

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1000;
}

.toast {
    background: var(--surface-color);
    color: var(--text-primary);
    padding: 1rem 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-medium);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    animation: slideInRight 0.3s ease;
}

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

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

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

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

/* Footer */
footer {
    background: var(--text-primary);
    color: white;
    text-align: center;
    padding: 1rem;
    font-size: 0.9rem;
    margin-top: 2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-content h1 {
        font-size: 1.25rem;
    }
    
    .section {
        padding: 0.5rem;
    }
    
    .section-header h2 {
        font-size: 1.5rem;
    }
    
    .toolbar {
        padding: 0.75rem;
        gap: 0.25rem;
    }
    
    .btn-primary,
    .btn-secondary,
    .btn-danger,
    .btn-icon {
        padding: 0.5rem 0.75rem;
        font-size: 0.8rem;
    }
    
    .btn-primary span,
    .btn-secondary span,
    .btn-danger span {
        display: none;
    }
    
    #mindMapCanvas {
        height: 300px;
    }
    
    .node-editor {
        min-width: 280px;
        padding: 1rem;
    }
    
    .templates-grid,
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .export-options {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        margin: 1rem;
    }
    
    .search-filters {
        flex-direction: column;
        align-items: center;
    }
    
    .nav-item {
        font-size: 0.7rem;
        padding: 0.25rem;
    }
    
    .nav-item i {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .header-actions {
        gap: 0.25rem;
    }
    
    .btn-icon {
        padding: 0.5rem;
    }
    
    .toolbar {
        flex-direction: column;
        align-items: stretch;
    }
    
    .toolbar > * {
        margin-bottom: 0.25rem;
    }
    
    .color-picker {
        flex-wrap: wrap;
    }
    
    .color-btn {
        width: 35px;
        height: 35px;
    }
    
    .modal-actions {
        flex-direction: column;
    }
    
    .project-actions {
        flex-direction: column;
    }
}

/* High DPI Displays */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    #mindMapCanvas {
        image-rendering: -webkit-optimize-contrast;
        image-rendering: crisp-edges;
    }
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --background-color: #121212;
        --surface-color: #1e1e1e;
        --text-primary: #ffffff;
        --text-secondary: #b0b0b0;
        --border-color: #333333;
    }
    
    #mindMapCanvas {
        background: #2a2a2a;
    }
    
    .template-preview {
        background: #333333;
    }
}

/* Print Styles */
@media print {
    .bottom-nav,
    .app-header,
    .toolbar {
        display: none;
    }
    
    .section {
        display: block !important;
        padding: 0;
    }
    
    .workspace {
        box-shadow: none;
        border: 1px solid #ccc;
    }
}