/* Learning Platform Styles - Minimalistic Design */

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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e293b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --light-bg: #f8fafc;
    --border-color: #e2e8f0;
    --text-color: #334155;
    --text-light: #64748b;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background-color: #ffffff;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navigation */
.navbar {
    background-color: #ffffff;
    color: var(--text-color);
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--secondary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 0.5rem;
}

.nav-menu a {
    color: var(--text-light);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: all 0.2s;
    font-size: 0.875rem;
    font-weight: 500;
}

.nav-menu a:hover {
    color: var(--primary-color);
    background-color: var(--light-bg);
}

.nav-menu a.active {
    color: var(--primary-color);
    background-color: #eff6ff;
}

/* User Info in Navbar */
.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-name {
    color: var(--text-color);
    font-size: 0.875rem;
    font-weight: 500;
}

.logout-btn {
    background-color: transparent !important;
    padding: 0.5rem 1rem !important;
    border-radius: 6px !important;
    transition: all 0.2s !important;
    font-size: 0.875rem !important;
    color: var(--text-light) !important;
    border: 1px solid var(--border-color) !important;
}

.logout-btn:hover {
    background-color: var(--light-bg) !important;
    border-color: var(--text-light) !important;
    color: var(--text-color) !important;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    z-index: 1000;
}

.mobile-menu-toggle span {
    display: block;
    width: 22px;
    height: 2.5px;
    background-color: var(--text-color);
    border-radius: 3px;
    transition: all 0.3s ease;
}

.mobile-menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Main Content */
main {
    min-height: calc(100vh - 150px);
    padding: 4rem 0;
    max-width: 1400px;
    margin: 0 auto;
}

/* Section Wrappers */
.content-section,
.hero,
.features {
    margin-bottom: 4rem;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.text-center {
    text-align: center;
}

/* Cards */
.category-title {
    margin-top: 4rem;
    margin-bottom: 2rem;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--secondary-color);
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--border-color);
}

.category-title:first-child {
    margin-top: 0;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.card {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    transition: all 0.2s;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.card h3 {
    color: var(--secondary-color);
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
    font-weight: 600;
    line-height: 1.4;
}

.card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    font-size: 0.9375rem;
    line-height: 1.7;
    flex-grow: 1;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.625rem 1.25rem;
    background-color: var(--primary-color);
    color: white !important;
    text-decoration: none;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    font-size: 0.9375rem;
    font-weight: 500;
    transition: all 0.2s;
}

.btn:hover {
    background-color: #1d4ed8 !important;
}

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

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

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

.btn-success:hover {
    background-color: #059669;
}

/* Content Display */
.content-display {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 3rem;
    margin-top: 2rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.intro-text {
    color: var(--text-light);
    font-size: 1.125rem;
    line-height: 1.8;
    margin: 0 auto 3rem;
    max-width: 800px;
}

.content-display h1 {
    color: var(--secondary-color);
    margin-bottom: 2rem;
    font-size: 2.25rem;
    font-weight: 700;
    line-height: 1.3;
}

.content-display h2 {
    color: var(--secondary-color);
    margin-top: 3rem;
    margin-bottom: 1.5rem;
    font-size: 1.75rem;
    font-weight: 600;
    line-height: 1.4;
}

.content-display h3 {
    color: var(--text-color);
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
    font-weight: 600;
}

.content-display img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 1.5rem 0;
}

.content-display pre {
    background-color: var(--light-bg);
    padding: 1.25rem;
    border-radius: 6px;
    overflow-x: auto;
    margin: 1.5rem 0;
    border: 1px solid var(--border-color);
}

.content-display code {
    background-color: var(--light-bg);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
    color: var(--primary-color);
}

.content-display table {
    width: 100%;
    max-width: 800px;
    margin: 2rem auto;
    border-collapse: collapse;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.content-display td {
    padding: 0.875rem 1.25rem;
    font-size: 0.9375rem;
    line-height: 1.6;
    color: var(--text-color);
    border: 1px solid var(--border-color);
    text-align: center;
}

.content-display td:empty {
    background-color: var(--light-bg);
}

.content-display tr:hover td {
    background-color: var(--light-bg);
}

.content-display td strong {
    color: var(--secondary-color);
    font-weight: 600;
}

.content-display td em {
    font-style: italic;
    color: var(--text-light);
}

/* Slides Navigation */
.slide-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 3rem;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--light-bg);
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.slide-nav .btn {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    min-width: auto;
}

.slide-nav .btn-nav {
    border: 1px solid var(--border-color);
    color: var(--text-color);
}

.slide-nav .btn-nav:hover:not(:disabled) {
    border-color: var(--primary-color);
    background: #ffffff;
}

.slide-nav .btn-nav:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.slide-nav .btn-present {
    margin-left: auto;
}

.slide-nav .btn-back {
    margin-right: auto;
    border: 1px solid var(--border-color);
    color: var(--text-light);
    padding: 0.5rem 0.875rem;
}

.slide-nav .btn-back:hover {
    border-color: var(--text-color);
    background: #ffffff;
    color: var(--text-color);
}

.slide-indicator {
    text-align: center;
    color: var(--text-light);
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    background: #ffffff;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    min-width: 120px;
}

/* PowerPoint-style Presentation Mode */
.presentation-mode {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: #000;
    z-index: 9999;
    display: none;
    overflow: hidden;
}

.presentation-mode.active {
    display: flex;
    flex-direction: column;
}

.presentation-slide {
    width: 100vw;
    height: 100vh;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    overflow: auto;
    animation: slideIn 0.5s ease-in-out;
}

/* Theme variations - can be customized per slide */
.presentation-slide:nth-child(even) {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.presentation-slide:nth-child(3n) {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.presentation-slide:nth-child(4n) {
    background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

.presentation-slide:nth-child(5n) {
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
}

.presentation-slide.active {
    display: flex;
}

.presentation-slide .slide-content {
    max-width: 100%;
    width: 100%;
    max-height: 100%;
    padding: 2rem 3rem;
    color: white;
    overflow-y: auto;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    box-sizing: border-box;
}

.presentation-slide h1 {
    font-size: 4.5rem;
    margin-bottom: 1.5rem;
    color: #FFFFFF;
    animation: fadeInUp 0.6s ease-out;
    font-weight: 700;
    line-height: 1.2;
    text-shadow: 0 3px 6px rgba(0, 0, 0, 0.4);
}

.presentation-slide h2 {
    font-size: 3.5rem;
    margin-bottom: 1.25rem;
    color: #FFFFFF;
    animation: fadeInUp 0.6s ease-out 0.1s both;
    font-weight: 600;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.presentation-slide h3 {
    font-size: 2.75rem;
    margin-bottom: 1rem;
    color: #FFFFFF;
    animation: fadeInUp 0.6s ease-out 0.2s both;
    font-weight: 600;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.presentation-slide h4 {
    font-size: 2.25rem;
    margin-bottom: 0.875rem;
    color: #FFFFFF;
    animation: fadeInUp 0.6s ease-out 0.2s both;
    font-weight: 600;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.presentation-slide h5 {
    font-size: 1.875rem;
    margin-bottom: 0.75rem;
    color: #FFFFFF;
    animation: fadeInUp 0.6s ease-out 0.2s both;
    font-weight: 600;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.presentation-slide h6 {
    font-size: 1.5rem;
    margin-bottom: 0.625rem;
    color: #FFFFFF;
    animation: fadeInUp 0.6s ease-out 0.2s both;
    font-weight: 600;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.presentation-slide p,
.presentation-slide ul,
.presentation-slide ol {
    font-size: 1.8rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    animation: fadeInUp 0.6s ease-out 0.3s both;
    color: rgba(255, 255, 255, 0.95);
}

.presentation-slide ul, .presentation-slide ol {
    padding-left: 2.5rem;
}

.presentation-slide li {
    margin-bottom: 1rem;
    animation: fadeInUp 0.6s ease-out 0.4s both;
    color: rgba(255, 255, 255, 0.95);
}

.presentation-slide pre {
    font-size: 1.3rem;
    padding: 2rem;
    background: rgba(0, 0, 0, 0.3);
    border-left: 5px solid rgba(255, 255, 255, 0.5);
    animation: fadeInUp 0.6s ease-out 0.4s both;
    border-radius: 10px;
    color: #FFFFFF;
    backdrop-filter: blur(10px);
}

.presentation-slide code {
    font-size: 1.2rem;
    background: rgba(0, 0, 0, 0.3);
    padding: 0.3rem 0.6rem;
    border-radius: 5px;
    color: #FFFFFF;
}

.presentation-slide pre code {
    background: transparent;
    padding: 0;
    text-shadow: none;
}

.presentation-slide strong {
    color: #FFFFFF;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
    font-size: 1.8rem;
}

.presentation-slide em {
    color: rgba(255, 255, 255, 0.9);
    font-style: italic;
    font-size: 1.6rem;
}

.presentation-slide img {
    max-width: 100%;
    height: auto;
    border-radius: 15px;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.5);
    margin: 2rem 0;
    animation: fadeInUp 0.6s ease-out 0.5s both;
}

.presentation-slide table {
    width: 100%;
    max-width: 900px;
    margin: 2rem auto;
    border-collapse: separate;
    border-spacing: 0;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 0.6s ease-out 0.5s both;
}

.presentation-slide td {
    padding: 1.5rem 2rem;
    font-size: 1.8rem;
    line-height: 1.6;
    color: rgba(255, 255, 255, 0.95);
    border: 2px solid rgba(255, 255, 255, 0.2);
    text-align: center;
    transition: all 0.3s ease;
}

.presentation-slide td:empty {
    background: rgba(0, 0, 0, 0.1);
}

.presentation-slide tr:hover td {
    background: rgba(255, 255, 255, 0.15);
}

.presentation-slide td strong {
    color: #FFFFFF;
    font-weight: 700;
    font-size: 1.9rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
}

.presentation-slide td em {
    color: rgba(255, 255, 255, 0.9);
    font-style: italic;
    font-size: 1.7rem;
}

.presentation-slide a {
    color: #FFFFFF;
    text-decoration: underline;
    font-weight: 600;
}

.presentation-slide a:hover {
    color: rgba(255, 255, 255, 0.8);
}

.presentation-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    background: rgba(0, 0, 0, 0.9);
    color: white;
}

.presentation-progress {
    flex: 1;
    text-align: center;
    font-size: 1.2rem;
}

.presentation-buttons {
    display: flex;
    gap: 1rem;
}

.presentation-btn {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 1rem;
}

.presentation-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.presentation-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
    transform: none;
}

.btn-fullscreen {
    background: var(--primary-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    transition: all 0.3s;
    margin-left: 1rem;
}

.btn-fullscreen:hover {
    background: #3a7bc8;
    transform: translateY(-2px);
}

/* Slide Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

.slide-transition-prev {
    animation: slideInLeft 0.5s ease-in-out;
}

.slide-transition-next {
    animation: slideInRight 0.5s ease-in-out;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

/* Progress bar */
.progress-bar-container {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: rgba(255, 255, 255, 0.2);
    z-index: 10000;
}

.progress-bar {
    height: 100%;
    background: var(--primary-color);
    transition: width 0.3s ease;
    box-shadow: 0 0 10px var(--primary-color);
}

/* Keyboard shortcuts hint */
.keyboard-hint {
    position: fixed;
    bottom: 80px;
    right: 20px;
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 1rem;
    border-radius: 8px;
    font-size: 0.9rem;
    opacity: 0;
    animation: fadeInOut 4s ease-in-out;
}

@keyframes fadeInOut {
    0%, 100% { opacity: 0; }
    10%, 90% { opacity: 1; }
}

/* Quiz Styles */
.quiz-container {
    max-width: 800px;
    margin: 0 auto;
}

.question-card {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    margin-bottom: 1.5rem;
}

.question-number {
    color: var(--text-light);
    font-weight: 600;
    margin-bottom: 0.75rem;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.question-text {
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
    color: var(--secondary-color);
    font-weight: 500;
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.quiz-option {
    padding: 1rem 1.25rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
    background: #ffffff;
}

.quiz-option:hover {
    border-color: var(--primary-color);
    background-color: #eff6ff;
}

.quiz-option.selected {
    border-color: var(--primary-color);
    background-color: #eff6ff;
}

.quiz-option.correct {
    border-color: var(--success-color);
    background-color: #f0fdf4;
}

.quiz-option.incorrect {
    border-color: var(--danger-color);
    background-color: #fef2f2;
}

.quiz-controls {
    display: flex;
    justify-content: space-between;
    margin-top: 2rem;
}

.quiz-result {
    text-align: center;
    padding: 2rem;
    background: var(--light-bg);
    border-radius: 8px;
    margin-top: 2rem;
}

.quiz-result h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.score-display {
    font-size: 3rem;
    font-weight: 700;
    color: var(--success-color);
    margin: 1rem 0;
}

/* Audio Player */
.audio-player {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    margin-bottom: 2rem;
}

.audio-player h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.audio-player audio {
    width: 100%;
    margin-top: 1rem;
}

/* Video Player */
.video-player {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.video-player h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.video-progress-container {
    margin: 1rem 0;
}

.audio-progress-container {
    margin: 1rem 0;
}

.progress-bar-bg {
    background-color: #e9ecef;
    height: 8px;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-bar-fill {
    background-color: var(--success-color);
    height: 100%;
    width: 0;
    transition: width 0.3s ease;
}

.progress-text {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: #666;
}

.status-badge {
    font-weight: 600;
}

.status-badge.completed {
    color: var(--success-color);
}

.status-badge.in-progress {
    color: var(--primary-color);
}

/* PDF Viewer */
.pdf-viewer-container {
    width: 100%;
}

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

.pdf-header h1 {
    flex: 1;
    text-align: center;
    margin: 0;
}

.pdf-embed-container {
    width: 100%;
    height: 80vh;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.pdf-iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.pdf-card .pdf-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
}

.pdf-card .pdf-actions .btn {
    flex: 1;
    text-align: center;
}

/* Text-to-Speech Controls */
.tts-controls {
    background: var(--light-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1rem;
}

.tts-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tts-title {
    font-weight: 600;
    color: var(--secondary-color);
}

.tts-select {
    padding: 0.4rem 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 0.9rem;
    background: white;
}

.tts-settings {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
}

.tts-settings label {
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.tts-settings input[type="range"] {
    vertical-align: middle;
}

.tts-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 0.75rem;
}

.tts-buttons .btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.85rem;
}

.tts-status {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 0.5rem;
}

.tts-progress-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.tts-progress-container .progress-bar-bg {
    flex: 1;
}

.tts-progress-container span {
    font-size: 0.85rem;
    color: #666;
    white-space: nowrap;
}

/* Footer */
.footer {
    background-color: #ffffff;
    padding: 2rem 0;
    text-align: center;
    color: var(--text-light);
    border-top: 1px solid var(--border-color);
    font-size: 0.875rem;
}

/* Collections Styles */
.collection-viewer {
    max-width: 1000px;
    margin: 0 auto;
}

/* Audio/Video Detail Pages */
.content-detail-page {
    max-width: 900px;
    margin: 0 auto;
}

.detail-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.breadcrumb {
    font-size: 0.9rem;
    color: #666;
}

.breadcrumb span {
    margin: 0 0.25rem;
}

.detail-content {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.detail-content h1 {
    margin-bottom: 1.5rem;
    color: var(--secondary-color);
}

.media-player-container {
    margin-bottom: 2rem;
}

.detail-audio-player,
.detail-video-player {
    width: 100%;
    border-radius: 8px;
    margin-top: 1rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.detail-video-player {
    max-height: 600px;
}

.detail-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
}

.btn-nav {
    flex: 1;
    max-width: 200px;
}

.btn-disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.card-title-link {
    color: inherit;
    text-decoration: none;
    transition: color 0.2s;
}

.card-title-link:hover {
    color: var(--primary-color);
}

.card-title-link h3 {
    margin: 0 0 0.5rem 0;
}

/* Collections Styles */

.collection-header {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid var(--border-color);
}

.collection-info {
    flex: 1;
}

.collection-info h1 {
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
}

.collection-description {
    font-size: 1.1rem;
    color: #666;
    margin: 0.5rem 0 1rem;
}

.collection-badge {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.collection-items {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.collection-items h2 {
    margin-bottom: 1.5rem;
    color: var(--secondary-color);
    font-size: 1.4rem;
}

.collection-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.collection-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--light-bg);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: all 0.2s;
}

.collection-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.item-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-weight: 600;
    font-size: 0.9rem;
    flex-shrink: 0;
}

.item-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex: 1;
}

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

.item-info h3 {
    margin: 0;
    font-size: 1rem;
    color: var(--secondary-color);
}

.item-badge {
    display: inline-block;
    background: white;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    margin-left: 0.5rem;
}

.collection-card {
    position: relative;
}

.collection-stats {
    font-size: 0.9rem;
    color: #666;
    margin: 0.5rem 0;
    font-weight: 500;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

.btn-secondary {
    background-color: #6c757d;
}

.btn-secondary:hover {
    background-color: #5a6268;
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.mt-2 {
    margin-top: 2rem;
}

.mb-2 {
    margin-bottom: 2rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .container {
        padding: 0 15px;
    }

    .card-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 1.5rem;
    }
}

@media (max-width: 768px) {
    /* Navigation */
    .navbar .container {
        flex-direction: row;
        justify-content: space-between;
    }

    .logo {
        font-size: 1.3rem;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    /* Hide menu completely by default */
    .nav-menu {
        display: none;
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background-color: var(--primary-color);
        flex-direction: column;
        gap: 0;
        padding: 0;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        z-index: 999;
    }

    /* Show menu when active */
    .nav-menu.active {
        display: flex;
    }

    .nav-menu li {
        width: 100%;
        text-align: center;
        border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    .nav-menu li:last-child {
        border-bottom: none;
    }

    .nav-menu a {
        display: block;
        padding: 1rem;
        font-size: 1rem;
        width: 100%;
        border-radius: 0;
        color: white;
    }

    /* User info on mobile */
    .user-info {
        flex-direction: column;
        gap: 0.5rem;
        padding: 1rem 0;
        border-top: 1px solid rgba(255,255,255,0.1);
    }

    .user-name {
        font-size: 1rem;
    }

    .logout-btn {
        width: 90%;
        text-align: center;
        padding: 0.75rem 1rem !important;
    }

    /* Main Content */
    main {
        padding: 1rem 0;
    }

    .container {
        padding: 0 10px;
    }

    /* Cards */
    .card-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .card {
        padding: 1rem;
    }

    /* Presentation Mode */
    .presentation-slide {
        padding: 2rem 1.5rem;
        min-height: auto;
    }

    .presentation-slide h1 {
        font-size: 2.5rem;
    }

    .presentation-slide h2 {
        font-size: 2rem;
    }

    .presentation-slide h3 {
        font-size: 1.75rem;
    }

    .presentation-slide h4 {
        font-size: 1.5rem;
    }

    .presentation-slide h5 {
        font-size: 1.3rem;
    }

    .presentation-slide h6 {
        font-size: 1.2rem;
    }

    .presentation-slide p,
    .presentation-slide li {
        font-size: 1.3rem;
    }

    .presentation-slide strong {
        font-size: 1.3rem;
    }

    .presentation-slide em {
        font-size: 1.2rem;
    }

    .presentation-slide ul,
    .presentation-slide ol {
        padding-left: 2rem;
    }

    .presentation-counter {
        font-size: 1rem;
        padding: 0.5rem 1rem;
    }

    /* Slide Navigation */
    .slide-nav {
        flex-direction: column;
        gap: 0.5rem;
        padding: 1rem;
    }

    .slide-nav button {
        width: 100%;
        padding: 1rem;
        font-size: 1rem;
    }

    /* Quiz */
    .quiz-container {
        padding: 1.5rem;
    }

    .question {
        font-size: 1.2rem;
    }

    .options {
        gap: 0.75rem;
    }

    .option {
        padding: 1rem;
        font-size: 1rem;
    }

    /* Video/Audio Players */
    video, audio {
        width: 100%;
        height: auto;
    }

    /* Tables */
    table {
        font-size: 0.9rem;
    }

    /* Buttons */
    .btn {
        padding: 0.6rem 1.2rem;
        font-size: 0.95rem;
    }

    /* Hero Section */
    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .feature-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    /* Collections */
    .collection-items {
        gap: 1rem;
    }
}

@media (max-width: 480px) {
    /* Extra small devices */
    .logo {
        font-size: 1.1rem;
    }

    /* Menu already handled by 768px breakpoint */

    .presentation-slide {
        padding: 1.5rem 1rem;
    }

    .presentation-slide h1 {
        font-size: 2rem;
    }

    .presentation-slide h2 {
        font-size: 1.6rem;
    }

    .presentation-slide h3 {
        font-size: 1.4rem;
    }

    .presentation-slide p,
    .presentation-slide li {
        font-size: 1.1rem;
    }

    .card {
        padding: 0.75rem;
    }

    .quiz-container {
        padding: 1rem;
    }

    .question {
        font-size: 1.1rem;
    }

    .option {
        padding: 0.75rem;
        font-size: 0.95rem;
    }

    /* Make images responsive */
    img {
        max-width: 100%;
        height: auto;
    }

    /* Adjust presentation counter position */
    .presentation-counter {
        font-size: 0.9rem;
        padding: 0.4rem 0.8rem;
    }
}

/* Touch-friendly improvements */
@media (hover: none) and (pointer: coarse) {
    /* Increase touch targets for mobile devices */
    button, .btn, a {
        min-height: 44px;
        min-width: 44px;
    }

    .quiz-option {
        min-height: 60px;
    }

    .slide-nav button {
        min-height: 50px;
    }

    /* Improve tap highlighting */
    * {
        -webkit-tap-highlight-color: rgba(74, 144, 226, 0.3);
    }

    /* Remove hover effects on touch devices */
    .card:hover {
        transform: none;
        box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    }
}

/* Landscape mobile optimization */
@media (max-height: 500px) and (orientation: landscape) {
    .presentation-slide {
        padding: 1rem;
    }

    .presentation-slide h1 {
        font-size: 1.8rem;
    }

    .presentation-slide h2 {
        font-size: 1.5rem;
    }

    .presentation-slide p,
    .presentation-slide li {
        font-size: 1rem;
    }

    .presentation-counter {
        font-size: 0.8rem;
    }

    .slide-nav {
        padding: 0.5rem;
    }

    .slide-nav button {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
}