/* =================
   Modern Course Interface
   ================= */

:root {
    /* Colors */
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --danger-color: #ef4444;
    --success-color: #22c55e;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-dark: #0f172a;
    --bg-card: #ffffff;
    --bg-sidebar: #f5f5f7;
    --bg-overlay: rgba(0, 0, 0, 0.5);
    
    /* Text Colors */
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --text-light: #94a3b8;
    --text-white: #ffffff;
    --text-sidebar: #1e293b;
    
    /* Border Colors */
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    --border-dark: #e2e8f0;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Borders & Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
    
    /* Layout */
    --sidebar-width: 320px;
    --header-height: 48px;
}

/* Dark theme */
body.dark-theme {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-card: #1e293b;
    --bg-sidebar: #1a1f2e;
    --bg-overlay: rgba(0, 0, 0, 0.7);
    
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --text-light: #64748b;
    --text-sidebar: #e2e8f0;
    
    --border-color: #334155;
    --border-light: #475569;
    --border-dark: #1e293b;
}

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

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

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

.hidden {
    display: none !important;
}

/* =================
   Role Banner
   ================= */

.role-banner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--text-white);
    padding: var(--space-sm) var(--space-lg);
    z-index: 1000;
    box-shadow: var(--shadow-md);
}

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

.role-info {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 500;
}

.banner-controls {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.theme-toggle-btn {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: var(--text-white);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
}

.theme-toggle-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-1px);
}

/* Floating Help Button */
.floating-help-btn {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, #f59e0b, #d97706);
    color: var(--text-white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    font-weight: 700;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    box-shadow: 0 8px 24px rgba(245, 158, 11, 0.3);
    z-index: 1000;
    border: 3px solid rgba(255, 255, 255, 0.2);
}

.floating-help-btn i {
    font-size: 1.5rem;
    margin-bottom: -2px;
}

.floating-help-btn span {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.floating-help-btn:hover {
    transform: scale(1.05) translateY(-2px);
    box-shadow: 0 12px 32px rgba(245, 158, 11, 0.4);
    background: linear-gradient(135deg, #fbbf24, #f59e0b);
}

.floating-help-btn:active {
    transform: scale(0.95);
}

/* Subtle pulse animation to draw attention */
@keyframes helpPulse {
    0% {
        box-shadow: 0 8px 24px rgba(245, 158, 11, 0.3);
    }
    50% {
        box-shadow: 0 8px 24px rgba(245, 158, 11, 0.5), 0 0 0 10px rgba(245, 158, 11, 0.1);
    }
    100% {
        box-shadow: 0 8px 24px rgba(245, 158, 11, 0.3);
    }
}

.floating-help-btn {
    animation: helpPulse 3s ease-in-out infinite;
}

.floating-help-btn:hover {
    animation: none;
}

/* OS Detection Indicator */
.os-header.auto-expanded {
    background: linear-gradient(135deg, var(--success-color), #16a34a);
    color: var(--text-white);
}

.os-header.auto-expanded h3 {
    color: var(--text-white);
}

.os-header.auto-expanded i {
    color: rgba(255, 255, 255, 0.8);
}

.os-header.auto-expanded::after {
    content: '(Your OS)';
    font-size: 0.75rem;
    font-weight: 500;
    opacity: 0.9;
    margin-left: var(--space-sm);
}

/* Role-Based Content Styling */
.lesson-body h2:first-child {
    margin-top: 0;
}

/* Style for role identification */
.lesson-body p:has(strong:contains("You are Team Member")) {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--text-white);
    padding: var(--space-lg);
    border-radius: var(--radius-lg);
    margin: var(--space-lg) 0;
    font-weight: 500;
}

/* Waiting/status indicators */
.lesson-body h3:contains("What You Need to Do") + p {
    background: var(--bg-secondary);
    border: 2px solid var(--success-color);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    text-align: center;
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--success-color);
}

/* Progress indicators */
.lesson-body p:contains("🔄") {
    background: var(--bg-tertiary);
    border-left: 4px solid var(--accent-color);
    padding: var(--space-lg);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    margin: var(--space-lg) 0;
    font-weight: 500;
}

/* Checklist items */
.lesson-body li:contains("✅") {
    background: rgba(34, 197, 94, 0.1);
    padding: var(--space-sm) var(--space-md);
    margin: var(--space-sm) 0;
    border-radius: var(--radius-md);
    border-left: 3px solid var(--success-color);
}

.change-role-btn {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: var(--text-white);
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.875rem;
    font-weight: 500;
}

.change-role-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-1px);
}

/* =================
   App Layout
   ================= */

.app-container {
    display: flex;
    min-height: 100vh;
    padding-top: var(--header-height);
}

.app-container.no-banner {
    padding-top: 0;
}

/* =================
   Sidebar
   ================= */

.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    color: var(--text-sidebar);
    position: fixed;
    left: 0;
    top: var(--header-height);
    bottom: 0;
    overflow-y: auto;
    overflow-x: visible;
    transform: translateX(0);
    transition: transform 0.3s ease, background-color 0.3s ease, color 0.3s ease;
    z-index: 900;
    box-shadow: var(--shadow-md);
    border-right: 1px solid var(--border-color);
}

.sidebar.hidden {
    transform: translateX(-100%);
}

/* Custom Scrollbar for Sidebar */
.sidebar::-webkit-scrollbar {
    width: 8px;
}

.sidebar::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.05);
    border-radius: var(--radius-md);
}

.sidebar::-webkit-scrollbar-thumb {
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    transition: background 0.2s ease;
}

.sidebar::-webkit-scrollbar-thumb:hover {
    background: rgba(0, 0, 0, 0.3);
}

/* Firefox scrollbar */
.sidebar {
    scrollbar-width: thin;
    scrollbar-color: rgba(0, 0, 0, 0.2) rgba(0, 0, 0, 0.05);
}

/* Dark theme scrollbar */
body.dark-theme .sidebar::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
}

body.dark-theme .sidebar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
}

body.dark-theme .sidebar::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

body.dark-theme .sidebar {
    scrollbar-color: rgba(255, 255, 255, 0.2) rgba(255, 255, 255, 0.05);
}

.sidebar-header {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: var(--space-lg);
    border-bottom: 1px solid var(--border-dark);
}

.sidebar-header h2 {
    font-size: 1.125rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.sidebar-header h2 a {
    color: inherit;
    text-decoration: none;
}

.sidebar-header h2 a:focus-visible {
    outline: 2px solid currentColor;
    outline-offset: 4px;
}

/* Sidebar Toggle Button - positioned on outer edge */
.sidebar-toggle {
    position: fixed;
    left: var(--sidebar-width);
    top: calc(var(--header-height) + var(--space-lg));
    width: 32px;
    height: 40px;
    background: var(--bg-sidebar);
    border: none;
    color: var(--text-sidebar);
    cursor: pointer;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    z-index: 901;
}

/* Show/hide toggle buttons based on sidebar state */
.sidebar.hidden ~ .main-content .sidebar-toggle {
    display: none;
}

.sidebar:not(.hidden) ~ .main-content .sidebar-toggle-show {
    display: none;
}

.sidebar-toggle:hover {
    background: var(--primary-color);
    transform: translateX(2px);
}

.sidebar-toggle i {
    font-size: 0.875rem;
    transition: transform 0.2s ease;
}

/* Show toggle button - initially hidden */
.sidebar-toggle-show {
    position: fixed;
    left: 0;
    top: calc(var(--header-height) + var(--space-lg));
    width: 32px;
    height: 40px;
    background: var(--bg-sidebar);
    border: none;
    color: var(--text-sidebar);
    cursor: pointer;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    transition: all 0.2s ease;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    z-index: 901;
    display: none;
}

.sidebar-toggle-show:hover {
    background: var(--primary-color);
    transform: translateX(2px);
}

/* Show the toggle button when sidebar is hidden */
.sidebar.hidden ~ .main-content .sidebar-toggle-show {
    display: flex;
}

.sidebar-content {
    padding: var(--space-lg);
}

/* Course Progress */
.course-progress {
    background: rgba(0, 0, 0, 0.03);
    padding: var(--space-lg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-xl);
    border: 1px solid var(--border-color);
}

body.dark-theme .course-progress {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--border-dark);
}

.progress-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--space-md);
    font-weight: 500;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--secondary-color), var(--accent-color));
    transition: width 0.5s ease;
    border-radius: var(--radius-md);
}

/* Course Outline */
.module-section {
    margin-bottom: var(--space-lg);
}

.module-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md);
    background: rgba(0, 0, 0, 0.02);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
    font-weight: 500;
}

.module-header:hover {
    background: rgba(0, 0, 0, 0.05);
}

body.dark-theme .module-header {
    background: rgba(255, 255, 255, 0.05);
}

body.dark-theme .module-header:hover {
    background: rgba(255, 255, 255, 0.1);
}

.module-header i:last-child {
    margin-left: auto;
    transition: transform 0.2s ease;
}

.module-header.expanded i:last-child {
    transform: rotate(180deg);
}

.lesson-list {
    margin-top: var(--space-sm);
    margin-left: var(--space-lg);
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, opacity 0.3s ease;
}

.lesson-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md);
    color: var(--text-light);
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: all 0.2s ease;
    margin-bottom: var(--space-xs);
    font-size: 0.875rem;
}

.lesson-item:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-sidebar);
    transform: translateX(4px);
}

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

.lesson-item.completed {
    color: var(--secondary-color);
}

.lesson-item.role-specific {
    border-left: 3px solid var(--accent-color);
    padding-left: calc(var(--space-md) - 3px);
}

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

.main-content {
    flex: 1;
    margin-left: 0;
    transition: margin-left 0.3s ease;
    min-height: 100vh;
}

.sidebar:not(.hidden) ~ .main-content {
    margin-left: var(--sidebar-width);
}

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


/* =================
   Welcome Screen
   ================= */

.welcome-screen {
    padding: var(--space-3xl) var(--space-lg);
    max-width: 1000px;
    margin: 0 auto;
}

.welcome-content {
    animation: fadeInUp 0.6s ease;
}

.welcome-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.welcome-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--space-lg);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-md);
}

.welcome-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.course-overview {
    display: grid;
    gap: var(--space-3xl);
}

.overview-section h2 {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
    color: var(--text-primary);
    font-size: 1.5rem;
}

/* Objectives Grid */
.objectives-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
}

.objective-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-lg);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
}

.objective-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.objective-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
    flex-shrink: 0;
}

/* Course Description */
.course-description {
    max-width: 800px;
    margin: 0 auto;
}

.course-description p {
    margin-bottom: var(--space-lg);
    color: var(--text-secondary);
    font-size: 1.125rem;
    line-height: 1.7;
    text-align: justify;
}

.course-description strong {
    color: var(--primary-color);
    font-weight: 600;
}

.course-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    margin-top: var(--space-xl);
    padding: var(--space-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    flex-wrap: wrap;
}

.course-stats span {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.course-stats strong {
    color: var(--primary-color);
}

/* Role Instructions */
.role-instructions {
    background: var(--bg-secondary);
    padding: var(--space-lg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-xl);
    border-left: 4px solid var(--primary-color);
}

.role-instructions p {
    margin-bottom: var(--space-md);
    color: var(--text-secondary);
    line-height: 1.6;
}

.role-instructions p:last-child {
    margin-bottom: 0;
}

.role-instructions strong {
    color: var(--primary-color);
}

.role-selection {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-3xl);
    justify-items: center;
}

.role-option {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-xl);
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    width: 100%;
    justify-content: center;
}

.role-option::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

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

.role-option:hover::before {
    transform: scaleX(1);
}

.role-option.selected {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--text-white);
}

.role-option.selected::before {
    transform: scaleX(1);
    background: var(--accent-color);
}

.role-icon {
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    color: var(--text-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    flex-shrink: 0;
    transition: all 0.3s ease;
}

.role-option.selected .role-icon {
    background: var(--text-white);
    color: var(--primary-color);
}

.role-info h3 {
    margin-bottom: var(--space-sm);
    font-size: 1.125rem;
}


.start-course-btn {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-lg) var(--space-3xl);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--text-white);
    border: none;
    border-radius: var(--radius-xl);
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 0 auto;
    box-shadow: var(--shadow-lg);
}

.start-course-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.start-course-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

/* =================
   Lesson Content
   ================= */

.lesson-content {
    padding: var(--space-3xl) var(--space-lg);
    max-width: 900px;
    margin: 0 auto;
    animation: fadeInUp 0.6s ease;
}

.lesson-header {
    margin-bottom: var(--space-3xl);
    text-align: center;
}

.lesson-header h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--space-lg);
    color: var(--text-primary);
}

.lesson-meta {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
}

.lesson-module {
    background: var(--primary-color);
    color: var(--text-white);
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-lg);
    font-weight: 500;
    font-size: 0.875rem;
}

.lesson-duration {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-lg);
    font-weight: 500;
    font-size: 0.875rem;
}

.lesson-body {
    line-height: 1.7;
    margin-bottom: var(--space-3xl);
}

.lesson-body h1,
.lesson-body h2,
.lesson-body h3,
.lesson-body h4 {
    margin-top: var(--space-xl);
    margin-bottom: var(--space-lg);
    color: var(--text-primary);
}

.lesson-body h1 {
    font-size: 1.75rem;
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: var(--space-md);
}

.lesson-body h2 {
    font-size: 1.5rem;
}

.lesson-body h3 {
    font-size: 1.25rem;
    color: var(--primary-color);
}

.lesson-body p {
    margin-bottom: var(--space-md);
    color: var(--text-secondary);
    text-align: justify;
}

/* Reduce spacing when paragraph is followed by list or code */
.lesson-body p + ul,
.lesson-body p + ol,
.lesson-body p + pre {
    margin-top: calc(var(--space-sm) * -1);
}

/* Reduce spacing when list is followed by paragraph */
.lesson-body ul + p,
.lesson-body ol + p {
    margin-top: calc(var(--space-sm) * -1);
}

/* Reduce spacing when code block is followed by paragraph or list */
.lesson-body pre + p,
.lesson-body pre + ul,
.lesson-body pre + ol {
    margin-top: var(--space-sm);
}

.lesson-body ul,
.lesson-body ol {
    margin-bottom: var(--space-md);
    padding-left: var(--space-xl);
}


.lesson-body ul {
    list-style-type: disc;
}

.lesson-body ul ul {
    list-style-type: circle;
}

.lesson-body li {
    margin-bottom: calc(var(--space-sm) / 2);
    color: var(--text-secondary);
    line-height: 1.6;
}

.lesson-body li ul,
.lesson-body li ol {
    margin-top: calc(var(--space-sm) / 2);
    margin-bottom: calc(var(--space-sm) / 2);
    padding-left: var(--space-lg);
}

.lesson-body li li {
    margin-bottom: calc(var(--space-sm) / 2);
}

.lesson-body code {
    background: var(--bg-tertiary);
    padding: 0.2em 0.4em;
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.9em;
    color: var(--text-primary);
}

.lesson-body pre {
    background: #1e3a8a;
    color: #ffffff !important;
    padding: var(--space-md);
    border-radius: var(--radius-lg);
    overflow-x: auto;
    margin: var(--space-md) 0;
    border-left: 4px solid #3b82f6;
    position: relative;
}

.lesson-body pre * {
    color: #ffffff !important;
}

body.dark-theme .lesson-body pre {
    background: #1e40af;
    border-left: 4px solid #60a5fa;
}

/* Copy button for code blocks */
.code-copy-btn {
    position: absolute;
    top: var(--space-sm);
    right: var(--space-sm);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--text-white);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    opacity: 0.7;
}

.code-copy-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    opacity: 1;
    transform: translateY(-1px);
}

.code-copy-btn.copied {
    background: rgba(34, 197, 94, 0.2);
    border-color: rgba(34, 197, 94, 0.4);
    color: #22c55e;
}

.code-copy-btn i {
    font-size: 0.7rem;
}

.lesson-body pre code {
    background: none;
    padding: 0;
    color: var(--text-white) !important;
    display: block;
    padding-right: 60px; /* Make room for copy button */
}

.lesson-body blockquote {
    border-left: 4px solid var(--primary-color);
    padding-left: var(--space-lg);
    margin: var(--space-lg) 0;
    font-style: italic;
    color: var(--text-muted);
    background: var(--bg-secondary);
    padding: var(--space-lg);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}

/* OS-Specific Collapsible Sections */
.os-section {
    margin: var(--space-lg) 0;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: var(--bg-card);
}

body.dark-theme .os-section {
    border-color: var(--border-dark);
    background: var(--bg-tertiary);
}

.os-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) var(--space-lg);
    background: var(--bg-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
    border-bottom: 1px solid var(--border-color);
}

body.dark-theme .os-header {
    background: var(--bg-dark);
    border-color: var(--border-dark);
}

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

body.dark-theme .os-header:hover {
    background: var(--bg-tertiary);
}

.os-header h3 {
    margin: 0;
    color: var(--text-primary);
    font-size: 1.125rem;
    font-weight: 600;
}

.os-header i {
    color: var(--text-secondary);
    transition: transform 0.2s ease;
    font-size: 1rem;
}

.os-header.expanded i {
    transform: rotate(180deg);
}

.os-content {
    padding: 0 var(--space-lg);
    overflow: hidden;
    transition: max-height 0.3s ease, opacity 0.3s ease, padding 0.3s ease;
    max-height: 0;
    opacity: 0;
}

.os-header.expanded + .os-content {
    padding: var(--space-lg);
}

/* OS-specific styling hints */
.os-section:has(.os-header h3:contains("Windows")) .os-header {
    border-left: 4px solid #0078d4;
}

.os-section:has(.os-header h3:contains("macOS")) .os-header,
.os-section:has(.os-header h3:contains("Mac OS")) .os-header {
    border-left: 4px solid #007aff;
}

.os-section:has(.os-header h3:contains("Linux")) .os-header,
.os-section:has(.os-header h3:contains("Ubuntu")) .os-header {
    border-left: 4px solid #ff6b35;
}

/* =================
   Troubleshooting Sections
   ================= */
   
.troubleshooting-section {
    margin: var(--space-md) 0;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.troubleshooting-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    cursor: pointer;
    transition: background-color 0.2s ease;
}

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

.troubleshooting-header h4 {
    margin: 0;
    color: var(--warning-color);
    font-size: 1rem;
}

.troubleshooting-header i {
    color: var(--text-secondary);
    transition: transform 0.3s ease;
}

.troubleshooting-header.expanded i {
    transform: rotate(180deg);
}

.troubleshooting-content {
    padding: 0 var(--space-lg);
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.3s ease, opacity 0.2s ease, padding 0.3s ease;
}

.troubleshooting-header.expanded + .troubleshooting-content {
    padding: 0 var(--space-lg) var(--space-lg);
    opacity: 1;
}

body.dark-theme .troubleshooting-section {
    background: var(--bg-secondary);
}

body.dark-theme .troubleshooting-header:hover {
    background: var(--bg-tertiary);
}

/* =================
   Waiting Box
   ================= */

.waiting-box {
    background: linear-gradient(135deg, #ff8c00, #ff7300);
    border: 2px solid #ff6b00;
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    margin: var(--space-xl) 0;
    color: white;
    box-shadow: 0 4px 12px rgba(255, 140, 0, 0.3);
    animation: waitingPulse 2s ease-in-out infinite;
}

.waiting-box .waiting-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
    font-size: 1.125rem;
    font-weight: 600;
}

.waiting-box .waiting-icon {
    font-size: 1.5rem;
    animation: waitingRotate 2s linear infinite;
}

.waiting-box .waiting-content {
    line-height: 1.6;
}

.waiting-box .waiting-content p {
    margin: 0;
    color: white;
}

.waiting-box .waiting-content strong {
    color: #fff3cd;
}

@keyframes waitingPulse {
    0%, 100% {
        box-shadow: 0 4px 12px rgba(255, 140, 0, 0.3);
    }
    50% {
        box-shadow: 0 4px 20px rgba(255, 140, 0, 0.5);
    }
}

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

body.dark-theme .waiting-box {
    background: linear-gradient(135deg, #e67e00, #d96b00);
    border-color: #cc6600;
    box-shadow: 0 4px 12px rgba(230, 126, 0, 0.4);
}

body.dark-theme .waiting-box .waiting-content strong {
    color: #fff8e1;
}

/* =================
   Collapsible Sections
   ================= */

.collapsible-section {
    margin: var(--space-md) 0;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.collapsible-header {
    background: var(--bg-tertiary);
    padding: var(--space-md) var(--space-lg);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color 0.3s ease;
    user-select: none;
}

.collapsible-header:hover {
    background: var(--bg-secondary);
}

.collapsible-header h4 {
    margin: 0;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.collapsible-header i {
    color: var(--text-secondary);
    transition: transform 0.3s ease;
    font-size: 0.9rem;
}

.collapsible-header.expanded i {
    transform: rotate(180deg);
}

.collapsible-content {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    padding: 0 var(--space-lg);
    background: var(--bg-primary);
    transition: max-height 0.3s ease, opacity 0.3s ease, padding 0.3s ease;
}

.collapsible-content.expanded {
    opacity: 1;
    padding: var(--space-lg);
}

/* Dark theme support */
body.dark-theme .collapsible-section {
    border-color: var(--border-color);
}

body.dark-theme .collapsible-header {
    background: var(--bg-tertiary);
}

body.dark-theme .collapsible-header:hover {
    background: var(--bg-secondary);
}

.lesson-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-xl) 0;
    border-top: 1px solid var(--border-color);
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    border-radius: var(--radius-lg);
    border: none;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
}

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

.nav-btn.primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

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

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

.nav-btn.complete {
    background: var(--secondary-color) !important;
    color: var(--text-white) !important;
    border: none !important;
}

.nav-btn.complete:hover {
    background: #059669;
    transform: translateY(-2px);
}

.nav-btn.complete.completed {
    background: var(--warning-color);
    color: var(--text-white);
}

.nav-btn.complete.completed:hover {
    background: #d97706;
    transform: translateY(-2px);
}

.nav-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

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

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-overlay);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1100;
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    max-width: 800px;
    width: 90vw;
    max-height: 80vh;
    overflow-y: auto;
    animation: slideInUp 0.3s ease;
}

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

.modal-header h2 {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin: 0;
}

.close-modal {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-muted);
    cursor: pointer;
    padding: var(--space-sm);
    border-radius: var(--radius-md);
    transition: all 0.2s ease;
}

.close-modal:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.modal-body {
    padding: var(--space-xl);
}

/* Help Modal Specific Styles */
.help-content p {
    margin-bottom: var(--space-md);
    line-height: 1.6;
}

.help-content a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.help-content a:hover {
    text-decoration: underline;
}

.context-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    margin: var(--space-lg) 0;
}

body.dark-theme .context-section {
    background: var(--bg-tertiary);
    border-color: var(--border-dark);
}

.context-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-md);
    font-weight: 600;
    color: var(--text-primary);
}

.context-copy-btn {
    background: var(--primary-color);
    color: var(--text-white);
    border: none;
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.context-copy-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.context-copy-btn.copied {
    background: var(--success-color);
}

.context-textarea {
    width: 100%;
    min-height: 120px;
    padding: var(--space-md);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    line-height: 1.5;
    resize: vertical;
}

body.dark-theme .context-textarea {
    background: var(--bg-dark);
    border-color: var(--border-dark);
    color: var(--text-white);
}

.help-tips {
    margin-top: var(--space-xl);
    padding: var(--space-lg);
    background: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--accent-color);
}

body.dark-theme .help-tips {
    background: rgba(255, 255, 255, 0.05);
}

.help-tips h4 {
    margin-bottom: var(--space-md);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.help-tips ul {
    list-style: none;
    padding: 0;
}

.help-tips li {
    padding: var(--space-xs) 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: var(--space-lg);
}

.help-tips li::before {
    content: '💡';
    position: absolute;
    left: 0;
}

#detectedOS {
    font-weight: 600;
    color: var(--primary-color);
}

/* =================
   Animations
   ================= */

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

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

@media (max-width: 1024px) {
    :root {
        --sidebar-width: 280px;
    }
    
    .welcome-header h1 {
        font-size: 2rem;
        flex-direction: column;
        gap: var(--space-sm);
    }
    
    .objectives-grid {
        grid-template-columns: 1fr;
    }
    
    .role-selection {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        top: 0;
        padding-top: var(--header-height);
    }
    
    .main-content {
        margin-left: 0;
    }
    
    /* Make toggle buttons mobile-friendly */
    .sidebar-toggle-show {
        width: 40px;
        height: 48px;
        top: calc(var(--header-height) + var(--space-sm));
    }
    
    .sidebar-toggle {
        width: 40px;
        height: 48px;
        right: -48px;
    }
    
    /* Ensure sidebar fills screen on mobile */
    .sidebar {
        width: 280px;
    }
    
    .role-banner {
        position: relative;
        padding-top: 0;
    }
    
    .app-container {
        padding-top: 0;
    }
    
    .banner-content {
        flex-direction: column;
        gap: var(--space-md);
        text-align: center;
    }
    
    .banner-controls {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    /* Floating help button adjustments for mobile */
    .floating-help-btn {
        bottom: 1rem;
        right: 1rem;
        width: 60px;
        height: 60px;
    }
    
    .floating-help-btn i {
        font-size: 1.25rem;
    }
    
    .floating-help-btn span {
        font-size: 0.65rem;
    }
    
    .welcome-screen {
        padding: var(--space-xl) var(--space-md);
    }
    
    .lesson-content {
        padding: var(--space-xl) var(--space-md);
    }
    
    .lesson-meta {
        flex-direction: column;
        gap: var(--space-sm);
    }
    
    .lesson-navigation {
        flex-direction: column;
        gap: var(--space-md);
    }
    
    .nav-btn {
        width: 100%;
        justify-content: center;
    }
    
    .role-option {
        flex-direction: column;
        text-align: center;
        gap: var(--space-md);
    }
    
    .course-stats {
        flex-direction: column;
        gap: var(--space-sm);
        text-align: center;
    }
}

@media (max-width: 480px) {
    .welcome-header h1 {
        font-size: 1.75rem;
    }
    
    .role-icon {
        width: 50px;
        height: 50px;
        font-size: 1.25rem;
    }
    
    .start-course-btn {
        padding: var(--space-md) var(--space-xl);
        font-size: 1rem;
    }
}