/* WebDev Academy - Complete CSS Styles */

/* Base styles matching your design */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-blue: #4F46E5;
    --secondary-blue: #6366F1;
    --light-blue: #818CF8;
    --primary-purple: #7C3AED;
    --secondary-purple: #8B5CF6;
    --light-purple: #A78BFA;
    --dark-bg: #1a1a2e;
    --darker-bg: #16213e;
    --card-bg: #2a2d47;
    --text-light: #ffffff;
    --text-gray: #e2e8f0;
    --text-muted: #94a3b8;
    --success-green: #10B981;
    --error-red: #EF4444;
    --warning-yellow: #F59E0B;
    --accent-gradient: linear-gradient(135deg, var(--primary-blue), var(--primary-purple));
    --card-gradient: linear-gradient(145deg, var(--card-bg), rgba(124, 58, 237, 0.1));
    --border-color: rgba(129, 140, 248, 0.3);
    --code-bg: #1e1e2e;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--dark-bg) 0%, var(--darker-bg) 100%);
    color: var(--text-light);
    min-height: 100vh;
    overflow-x: hidden;
    scroll-behavior: smooth;
    line-height: 1.6;
}

/* Animated background */
.particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
}

.star {
    position: absolute;
    width: 2px;
    height: 2px;
    background: #ffffff;
    border-radius: 50%;
    animation: twinkle 4s ease-in-out infinite;
    opacity: 0.6;
}

@keyframes twinkle {
    0%, 100% { opacity: 0.3; transform: scale(1); }
    50% { opacity: 0.8; transform: scale(1.2); }
}

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

@keyframes slideInLeft {
    from { opacity: 0; transform: translateX(-30px); }
    to { opacity: 1; transform: translateX(0); }
}

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

@keyframes slideInDown {
    from { transform: translateY(-100%); }
    to { transform: translateY(0); }
}

@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Header */
.header {
    background: rgba(42, 45, 71, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    animation: slideInDown 0.5s ease;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.logo {
    font-size: 2rem;
    font-weight: bold;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    font-size: 1.5rem;
}

.progress-overview {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--card-bg);
    padding: 0.5rem 1rem;
    border-radius: 25px;
    border: 1px solid var(--border-color);
}

.overall-progress-bar {
    width: 200px;
    height: 8px;
    background: rgba(129, 140, 248, 0.2);
    border-radius: 4px;
    overflow: hidden;
}

.overall-progress-fill {
    height: 100%;
    background: var(--accent-gradient);
    transition: width 0.5s ease;
}

.progress-text {
    font-size: 0.9rem;
    color: var(--text-gray);
}

/* Main Layout */
.main-container {
    display: flex;
    max-width: 1400px;
    margin: 0 auto;
    min-height: calc(100vh - 80px);
    gap: 2rem;
    padding: 2rem;
}

/* Sidebar */
.sidebar {
    width: 300px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    height: fit-content;
    position: sticky;
    top: 100px;
    animation: slideInLeft 0.5s ease;
}

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

.course-section {
    margin-bottom: 1.5rem;
}

.section-title {
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--light-blue);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lesson-list {
    list-style: none;
    margin-left: 1rem;
}

.lesson-item {
    padding: 0.5rem 1rem;
    margin-bottom: 0.25rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border: 1px solid transparent;
}

.lesson-item:hover {
    background: rgba(129, 140, 248, 0.1);
    border-color: var(--primary-blue);
    transform: translateX(5px);
}

.lesson-item.active {
    background: var(--accent-gradient);
    color: white;
}

.lesson-item.completed {
    opacity: 0.7;
}

.lesson-item.completed::after {
    content: '✓';
    color: var(--success-green);
    font-weight: bold;
}

/* Content Area */
.content-area {
    flex: 1;
    animation: fadeIn 0.5s ease;
}

.lesson-container {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    animation: scaleIn 0.5s ease;
}

.lesson-header {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.lesson-title-main {
    font-size: 2rem;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.lesson-subtitle {
    color: var(--text-gray);
}

.lesson-content {
    line-height: 1.8;
    color: var(--text-gray);
}

.lesson-content h2 {
    color: var(--light-blue);
    margin: 2rem 0 1rem;
    font-size: 1.5rem;
}

.lesson-content h3 {
    color: var(--light-purple);
    margin: 1.5rem 0 0.75rem;
    font-size: 1.2rem;
}

.lesson-content p {
    margin-bottom: 1rem;
}

.lesson-content ul, .lesson-content ol {
    margin: 1rem 0 1rem 2rem;
}

.lesson-content li {
    margin-bottom: 0.5rem;
}

/* Code Editor */
.code-editor-container {
    background: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    margin: 1.5rem 0;
    overflow: hidden;
}

.editor-header {
    background: rgba(0, 0, 0, 0.3);
    padding: 0.75rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}

.editor-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-gray);
    font-size: 0.9rem;
}

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

.editor-btn {
    background: var(--accent-gradient);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.editor-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

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

.editor-tabs {
    display: flex;
    background: rgba(0, 0, 0, 0.2);
    border-bottom: 1px solid var(--border-color);
}

.editor-tab {
    padding: 0.75rem 1.5rem;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.3s ease;
    border-bottom: 2px solid transparent;
    font-size: 0.9rem;
}

.editor-tab:hover {
    color: var(--text-gray);
    background: rgba(129, 140, 248, 0.1);
}

.editor-tab.active {
    color: var(--light-blue);
    border-bottom-color: var(--light-blue);
    background: rgba(129, 140, 248, 0.2);
}

.code-editor {
    display: none;
    padding: 1rem;
    min-height: 300px;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-light);
    background: var(--code-bg);
    border: none;
    outline: none;
    resize: vertical;
    width: 100%;
}

.code-editor.active {
    display: block;
}

.output-container {
    background: white;
    border-top: 1px solid var(--border-color);
    min-height: 200px;
    padding: 1rem;
}

.output-header {
    background: rgba(0, 0, 0, 0.05);
    padding: 0.5rem 1rem;
    margin: -1rem -1rem 1rem;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.output-title {
    color: #333;
    font-size: 0.9rem;
    font-weight: 500;
}

#output-frame, #welcome-output-frame {
    width: 100%;
    min-height: 150px;
    border: none;
}

/* Interactive Examples */
.interactive-demo {
    background: rgba(129, 140, 248, 0.1);
    border: 1px solid var(--primary-blue);
    border-radius: 12px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.demo-title {
    color: var(--light-blue);
    font-size: 1.1rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Quiz Styles */
.quiz-container {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    margin: 2rem 0;
}

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

.quiz-title {
    font-size: 1.5rem;
    color: var(--light-blue);
    margin-bottom: 0.5rem;
}

.quiz-progress {
    background: rgba(129, 140, 248, 0.2);
    border-radius: 10px;
    height: 8px;
    margin: 1rem 0;
    overflow: hidden;
}

.quiz-progress-bar {
    background: var(--accent-gradient);
    height: 100%;
    transition: width 0.3s ease;
}

.question-card {
    background: rgba(129, 140, 248, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.question-text {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: var(--text-light);
}

.answer-options {
    display: grid;
    gap: 0.75rem;
}

.answer-option {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.answer-option:hover {
    background: rgba(129, 140, 248, 0.2);
    border-color: var(--primary-blue);
    transform: translateX(5px);
}

.answer-option.selected {
    background: var(--accent-gradient);
    border-color: var(--secondary-blue);
}

.answer-option input[type="radio"] {
    display: none;
}

.radio-custom {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    position: relative;
    transition: all 0.3s ease;
}

.answer-option.selected .radio-custom {
    border-color: white;
}

.answer-option.selected .radio-custom::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 10px;
    height: 10px;
    background: white;
    border-radius: 50%;
}

.quiz-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
}

.quiz-btn {
    background: var(--accent-gradient);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.quiz-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(79, 70, 229, 0.3);
}

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

.quiz-intro {
    text-align: center;
    padding: 2rem;
}

.quiz-results {
    text-align: center;
    padding: 2rem;
}

.score-display {
    font-size: 3rem;
    font-weight: bold;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1rem;
}

/* Tools Panel */
.tools-panel {
    position: fixed;
    right: -400px;
    top: 80px;
    width: 400px;
    height: calc(100vh - 80px);
    background: var(--card-bg);
    border-left: 1px solid var(--border-color);
    transition: right 0.3s ease;
    z-index: 99;
    overflow-y: auto;
}

.tools-panel.open {
    right: 0;
}

.tools-toggle {
    position: fixed;
    right: 2rem;
    bottom: 2rem;
    width: 60px;
    height: 60px;
    background: var(--accent-gradient);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    font-size: 1.5rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
    z-index: 98;
}

.tools-toggle:hover {
    transform: scale(1.1);
    box-shadow: 0 8px 20px rgba(79, 70, 229, 0.4);
}

.tools-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.tools-title {
    font-size: 1.3rem;
    color: var(--light-blue);
    margin-bottom: 1rem;
}

.tools-tabs {
    display: flex;
    gap: 0.5rem;
}

.tool-tab {
    padding: 0.5rem 1rem;
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-gray);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tool-tab:hover {
    background: rgba(129, 140, 248, 0.2);
    border-color: var(--primary-blue);
}

.tool-tab.active {
    background: var(--accent-gradient);
    color: white;
    border-color: transparent;
}

.tool-content {
    padding: 1.5rem;
    display: none;
}

.tool-content.active {
    display: block;
}

/* Color Picker Tool */
.color-picker-tool {
    display: grid;
    gap: 1rem;
}

.color-input-group {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.color-input {
    width: 60px;
    height: 40px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
}

.color-value {
    flex: 1;
    background: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.5rem 1rem;
    color: var(--text-light);
    font-family: monospace;
}

.color-formats {
    background: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
}

.color-format {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
    font-family: monospace;
    font-size: 0.9rem;
}

.copy-btn {
    background: var(--accent-gradient);
    color: white;
    border: none;
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.8rem;
    transition: all 0.3s ease;
}

.copy-btn:hover {
    transform: scale(1.05);
}

.saved-color {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    cursor: pointer;
    border: 2px solid var(--border-color);
    transition: all 0.3s ease;
}

.saved-color:hover {
    transform: scale(1.1);
    border-color: var(--primary-blue);
}

/* Code Formatter Tool */
.code-formatter {
    display: grid;
    gap: 1rem;
}

.formatter-input, .formatter-output {
    background: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    font-family: monospace;
    font-size: 14px;
    color: var(--text-light);
    min-height: 150px;
    resize: vertical;
}

.formatter-controls {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.formatter-btn {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-light);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.formatter-btn:hover {
    background: var(--accent-gradient);
    border-color: transparent;
}

/* Reference Tool */
.reference-tool {
    display: grid;
    gap: 1rem;
}

.reference-search {
    background: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem 1rem;
    color: var(--text-light);
    width: 100%;
}

.reference-categories {
    display: grid;
    gap: 0.5rem;
}

.reference-category {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.reference-category:hover {
    background: rgba(129, 140, 248, 0.2);
    border-color: var(--primary-blue);
    transform: translateX(5px);
}

.reference-category-title {
    color: var(--light-blue);
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.reference-category-desc {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.reference-details {
    background: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-top: 1rem;
    max-height: 400px;
    overflow-y: auto;
}

.reference-item {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.reference-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.reference-item-title {
    color: var(--light-blue);
    font-family: monospace;
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.reference-item-desc {
    color: var(--text-gray);
    margin-bottom: 0.5rem;
}

.reference-item-example {
    background: rgba(0, 0, 0, 0.3);
    padding: 0.75rem;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Tip Boxes */
.tip-box {
    background: rgba(16, 185, 129, 0.1);
    border-left: 4px solid var(--success-green);
    padding: 1rem;
    margin: 1rem 0;
    border-radius: 4px;
}

.tip-box.warning {
    background: rgba(245, 158, 11, 0.1);
    border-left-color: var(--warning-yellow);
}

.tip-box.error {
    background: rgba(239, 68, 68, 0.1);
    border-left-color: var(--error-red);
}

.tip-title {
    font-weight: bold;
    margin-bottom: 0.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Code Syntax */
.code-inline {
    background: var(--code-bg);
    color: #f92672;
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.9em;
}

.code-block {
    background: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    margin: 1rem 0;
    overflow-x: auto;
    font-family: monospace;
    font-size: 14px;
    line-height: 1.5;
}

.code-block pre {
    margin: 0;
    color: var(--text-light);
}

/* Lesson Navigation */
.lesson-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.nav-btn {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-light);
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-btn:hover {
    background: var(--accent-gradient);
    border-color: transparent;
    transform: translateY(-2px);
}

.nav-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.complete-btn {
    background: var(--accent-gradient);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.complete-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(79, 70, 229, 0.3);
}

.complete-btn.completed {
    background: var(--success-green);
}

/* Achievements */
.achievement-popup {
    position: fixed;
    top: 100px;
    right: -400px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    transition: right 0.5s ease;
    z-index: 200;
    max-width: 350px;
}

.achievement-popup.show {
    right: 2rem;
}

.achievement-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.achievement-icon {
    font-size: 2.5rem;
}

.achievement-title {
    font-size: 1.2rem;
    color: var(--light-blue);
    font-weight: bold;
}

.achievement-desc {
    color: var(--text-gray);
    font-size: 0.9rem;
}

/* Loading States */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
}

/* Tooltips */
.tooltip {
    position: relative;
    display: inline-block;
}

.tooltip .tooltiptext {
    visibility: hidden;
    width: 200px;
    background-color: var(--darker-bg);
    color: var(--text-light);
    text-align: center;
    border-radius: 8px;
    padding: 0.75rem;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    margin-left: -100px;
    opacity: 0;
    transition: opacity 0.3s;
    font-size: 0.85rem;
    border: 1px solid var(--border-color);
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}

/* Highlighting for search */
.highlight {
    background: rgba(251, 191, 36, 0.3);
    padding: 0.1rem 0.2rem;
    border-radius: 3px;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .main-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        position: static;
        margin-bottom: 2rem;
    }

    .tools-panel {
        width: 100%;
        right: -100%;
    }
}

@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }

    .lesson-title-main {
        font-size: 1.5rem;
    }

    .code-editor-container {
        font-size: 12px;
    }

    .editor-tabs {
        overflow-x: auto;
    }

    .tools-toggle {
        width: 50px;
        height: 50px;
        font-size: 1.2rem;
    }

    .progress-overview {
        width: 100%;
        justify-content: center;
    }

    .overall-progress-bar {
        width: 150px;
    }

    .achievement-popup {
        right: -100%;
        max-width: calc(100vw - 4rem);
    }

    .achievement-popup.show {
        right: 1rem;
    }

    .lesson-nav {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-btn {
        width: 100%;
        justify-content: center;
    }

    .complete-btn {
        width: 100%;
    }

    .editor-actions {
        flex-wrap: wrap;
    }

    .tools-panel {
        width: 100%;
    }

    .reference-details {
        max-height: 300px;
    }
}

/* Print Styles */
@media print {
    body {
        background: white;
        color: black;
    }

    .sidebar, .tools-toggle, .tools-panel, .achievement-popup {
        display: none;
    }

    .lesson-container {
        background: white;
        border: 1px solid #ccc;
        box-shadow: none;
    }

    .code-block {
        background: #f5f5f5;
        border: 1px solid #ddd;
    }
}

/* Additional utility classes */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.hidden {
    display: none !important;
}