/* ========================================
   Ensate Tutorials - Main Stylesheet
   ======================================== */

:root {
    /* Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #f59e0b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    
    /* Neutrals */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: #334155;
    
    /* Technology Colors */
    --react-color: #61dafb;
    --nextjs-color: #ffffff;
    --nodejs-color: #68a063;
    --vuejs-color: #42b883;
    --angular-color: #dd0031;
    --python-color: #3776ab;
    --java-color: #ed8b00;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 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);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
}

/* ========================================
   Base Styles
   ======================================== */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--primary-light);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary);
}

/* ========================================
   Header
   ======================================== */

.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(8px);
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-md) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo i {
    color: var(--primary);
    font-size: 1.75rem;
}

.logo .accent {
    color: var(--primary-light);
}

.nav {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-secondary);
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

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

/* ========================================
   Main Content
   ======================================== */

.main {
    flex: 1;
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-xl);
    width: 100%;
}

/* Breadcrumb */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) 0;
    font-size: 0.875rem;
    color: var(--text-secondary);
    flex-wrap: wrap;
}

.breadcrumb a {
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.breadcrumb a:hover {
    color: var(--primary-light);
}

.breadcrumb .separator {
    color: var(--text-muted);
}

.breadcrumb .current {
    color: var(--text-primary);
    font-weight: 500;
}

/* ========================================
   Dashboard
   ======================================== */

.dashboard-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.dashboard-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--text-primary), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.dashboard-header p {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* Search Box */
.search-box {
    position: relative;
    max-width: 500px;
    margin: 0 auto var(--spacing-2xl);
}

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

.search-box input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-md) var(--spacing-md) var(--spacing-2xl);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.search-box input::placeholder {
    color: var(--text-muted);
}

/* Tutorial Grid */
.tutorial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-xl);
}

/* Tutorial Card */
.tutorial-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

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

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

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

.tutorial-card-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-lg);
    font-size: 1.75rem;
}

.tutorial-card-icon.react {
    background: rgba(97, 218, 251, 0.15);
    color: var(--react-color);
}

.tutorial-card-icon.nextjs {
    background: rgba(255, 255, 255, 0.15);
    color: var(--nextjs-color);
}

.tutorial-card-icon.nodejs {
    background: rgba(104, 160, 99, 0.15);
    color: var(--nodejs-color);
}

.tutorial-card-icon.default {
    background: rgba(99, 102, 241, 0.15);
    color: var(--primary-light);
}

.tutorial-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.tutorial-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-lg);
}

.tutorial-card-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    color: var(--text-muted);
    font-size: 0.875rem;
}

.tutorial-card-meta i {
    color: var(--primary-light);
}

/* ========================================
   Tutorial View
   ======================================== */

.tutorial-view {
    display: flex;
    flex-direction: column;
    height: calc(100vh - 200px);
}

.tutorial-header {
    margin-bottom: var(--spacing-xl);
}

.tutorial-info h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.tutorial-info p {
    color: var(--text-secondary);
}

.tutorial-content {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: var(--spacing-xl);
    flex: 1;
    min-height: 0;
}

/* TOC Sidebar */
.toc-sidebar {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.toc-header {
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border-color);
}

.toc-header h3 {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.toc-list {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-md);
}

.toc-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-xs);
}

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

.toc-item.active {
    background: var(--primary);
    color: white;
}

.toc-item i {
    width: 20px;
    text-align: center;
    flex-shrink: 0;
}

.toc-item .name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.toc-folder {
    margin-bottom: var(--spacing-sm);
}

.toc-folder-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    cursor: pointer;
    font-weight: 600;
    color: var(--text-primary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.toc-folder-header:hover {
    background: var(--bg-tertiary);
}

.toc-folder-header i.folder-icon {
    color: var(--secondary);
}

.toc-folder-header i.toggle-icon {
    margin-left: auto;
    font-size: 0.75rem;
    color: var(--text-muted);
    transition: transform var(--transition-fast);
}

.toc-folder.collapsed .toggle-icon {
    transform: rotate(-90deg);
}

.toc-folder-children {
    padding-left: var(--spacing-lg);
    margin-top: var(--spacing-xs);
}

.toc-folder.collapsed .toc-folder-children {
    display: none;
}

/* Content Area */
.content-area {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.content-viewer {
    flex: 1;
    overflow: auto;
}

/* Viewer Toolbar */
.viewer-toolbar {
    padding: 12px 16px;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.viewer-title {
    font-weight: 500;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    flex: 1;
    min-width: 0;
}

.viewer-actions {
    display: flex;
    gap: 8px;
    flex-shrink: 0;
}

/* Fullscreen Styles */
.content-viewer:fullscreen,
.content-viewer:-webkit-full-screen,
.content-viewer:-ms-fullscreen {
    background: var(--bg-secondary);
    display: flex;
    flex-direction: column;
}

.content-viewer:fullscreen .viewer-toolbar,
.content-viewer:-webkit-full-screen .viewer-toolbar,
.content-viewer:-ms-fullscreen .viewer-toolbar {
    background: var(--bg-primary);
    padding: 16px 24px;
    border-bottom: 2px solid var(--primary);
}

.content-viewer:fullscreen iframe,
.content-viewer:-webkit-full-screen iframe,
.content-viewer:-ms-fullscreen iframe {
    flex: 1;
    height: 100%;
}

.content-viewer:fullscreen .btn,
.content-viewer:-webkit-full-screen .btn,
.content-viewer:-ms-fullscreen .btn {
    padding: var(--spacing-sm) var(--spacing-lg);
}

.content-placeholder {
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    text-align: center;
    padding: var(--spacing-xl);
}

.content-placeholder i {
    font-size: 3rem;
    margin-bottom: var(--spacing-lg);
    color: var(--primary-light);
    opacity: 0.5;
}

.content-viewer iframe {
    width: 100%;
    height: 100%;
    border: none;
    background: white;
}

/* ========================================
   Modal
   ======================================== */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: var(--spacing-xl);
}

.modal-content {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 1200px;
    height: 90vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

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

.modal-header h3 {
    font-size: 1rem;
    font-weight: 600;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.modal-actions {
    display: flex;
    gap: var(--spacing-sm);
}

.modal-body {
    flex: 1;
    overflow: hidden;
}

.modal-body iframe {
    width: 100%;
    height: 100%;
    border: none;
    background: white;
}

/* ========================================
   Buttons
   ======================================== */

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

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

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

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

.btn-close {
    background: transparent;
    color: var(--text-secondary);
    padding: var(--spacing-sm);
}

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

/* ========================================
   Loading State
   ======================================== */

.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl);
    color: var(--text-muted);
    grid-column: 1 / -1;
}

.loading i {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
    color: var(--primary);
}

/* ========================================
   Utility Classes
   ======================================== */

.hidden {
    display: none !important;
}

/* ========================================
   Footer
   ======================================== */

.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-xl);
    text-align: center;
}

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

.footer-content a {
    color: var(--primary-light);
}

.footer-tagline {
    margin-top: var(--spacing-xs);
    color: var(--text-muted);
    font-size: 0.75rem;
}

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 1024px) {
    .tutorial-content {
        grid-template-columns: 280px 1fr;
    }
}

@media (max-width: 768px) {
    .header-content {
        padding: var(--spacing-md);
    }
    
    .logo span {
        display: none;
    }
    
    .main {
        padding: var(--spacing-md);
    }
    
    .dashboard-header h1 {
        font-size: 1.75rem;
    }
    
    .tutorial-grid {
        grid-template-columns: 1fr;
    }
    
    .tutorial-content {
        grid-template-columns: 1fr;
    }
    
    .toc-sidebar {
        max-height: 300px;
    }
    
    .modal-content {
        height: 95vh;
        border-radius: var(--radius-md);
    }
    
    .modal {
        padding: var(--spacing-sm);
    }
    
    .modal-header {
        flex-wrap: wrap;
        gap: var(--spacing-sm);
    }
    
    .modal-header h3 {
        width: 100%;
        order: 1;
    }
    
    .modal-actions {
        order: 2;
        width: 100%;
        justify-content: flex-end;
    }
}

@media (max-width: 480px) {
    .nav-link span {
        display: none;
    }
    
    .tutorial-card {
        padding: var(--spacing-lg);
    }
    
    .viewer-toolbar {
        padding: 8px 12px;
    }
    
    .viewer-actions .btn-text {
        display: none;
    }
    
    .viewer-actions .btn {
        padding: var(--spacing-sm);
    }
}

/* ========================================
   Scrollbar Styles
   ======================================== */

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ========================================
   File Type Icons
   ======================================== */

.file-icon-html { color: #e44d26; }
.file-icon-pdf { color: #ff5722; }
.file-icon-zip { color: #ffc107; }
.file-icon-code { color: #4caf50; }
.file-icon-markdown { color: #2196f3; }