/**
 * course.css
 * Kurs sayfası: section grid, note cards, video/audio list, flashcards, tests
 * Glassmorphism tasarım sistemi ile uyumlu
 * Featured video ve note animations entegre edildi
 */

.content-wrapper-page {
    margin: 0;
    padding: 20px;
    max-width: 100%;
}

.content-section.is-hidden {
    display: none;
}

.content-section.is-active {
    display: block;
}

.note-source-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.note-source-cards.is-hidden {
    display: none;
}

/* ========== COURSE HEADER ========== */
.course-header {
    margin-bottom: var(--spacing-2xl);
}

.course-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient-purple-cyan);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

.course-header .subtitle {
    font-size: 1rem;
    color: var(--text-muted);
}

/* ========== BREADCRUMB ========== */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.breadcrumb a {
    color: var(--text-muted);
    transition: color var(--transition-fast);
}

.breadcrumb a:hover {
    color: var(--accent-purple);
}

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

.breadcrumb i.fa-chevron-right {
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* ========== COURSE SECTIONS GRID ========== */
.course-sections-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
}

.section-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: transform 0.4s cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 0.4s ease, border-color 0.4s ease, background 0.4s ease;
    text-align: center;
    position: relative;
    overflow: hidden;
    animation: scaleUp 0.5s cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

.section-btn:nth-child(1) {
    animation-delay: 0.1s;
}

.section-btn:nth-child(2) {
    animation-delay: 0.15s;
}

.section-btn:nth-child(3) {
    animation-delay: 0.2s;
}

.section-btn:nth-child(4) {
    animation-delay: 0.25s;
}

.section-btn:nth-child(5) {
    animation-delay: 0.3s;
}

.section-btn::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    background: radial-gradient(circle at center, rgba(255, 255, 255, 0.08) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.4s;
}

.section-btn:hover {
    background: var(--glass-bg-hover);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-4px) scale3d(1.02, 1.02, 1);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.3), var(--shadow-glow-purple);
}

.section-btn:hover::after {
    opacity: 1;
}

.section-btn.active {
    background: var(--accent-purple-glow);
    border-color: var(--accent-purple);
}

.section-btn i {
    font-size: 2rem;
    color: var(--accent-purple);
    transition: transform var(--transition-normal);
}

.section-btn:hover i {
    transform: scale(1.1);
}

.section-btn.active i {
    color: var(--text-primary);
}

.section-btn span {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.section-btn.active span {
    color: var(--text-primary);
}

.section-btn .badge {
    font-size: 0.7rem;
    padding: 2px 8px;
}

/* ========== SECTION CONTENT CONTAINER ========== */
.section-content {
    animation: sectionFadeIn 0.4s ease-out;
}

@keyframes sectionFadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========== NOTES SECTION ========== */
.notes-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.notes-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.note-card {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: transform 0.4s cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 0.4s ease, border-color 0.4s ease, background 0.4s ease;
    position: relative;
    overflow: hidden;
    animation: fadeInUp 0.5s cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

.note-card:nth-child(1) {
    animation-delay: 0.1s;
}

.note-card:nth-child(2) {
    animation-delay: 0.2s;
}

.note-card:nth-child(3) {
    animation-delay: 0.3s;
}

.note-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--gradient-purple-cyan);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.note-card:hover {
    background: var(--glass-bg-hover);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-4px) scale3d(1.01, 1.01, 1);
    box-shadow: 0 16px 32px rgba(0, 0, 0, 0.4);
}

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

.note-card.active {
    border-color: var(--accent-purple);
    background: var(--accent-purple-glow);
}

.note-card.active::before {
    opacity: 1;
}

.note-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
}

.note-card-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.note-card-icon.gemini {
    background: var(--accent-cyan-glow);
    color: var(--accent-cyan);
}

.note-card-icon.chatgpt {
    background: var(--success-bg);
    color: var(--success);
}

.note-card-icon.notebooklm {
    background: var(--accent-purple-glow);
    color: var(--accent-purple);
}

.note-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.note-card p {
    font-size: 0.875rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.note-card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--glass-border);
}

.note-card-meta {
    font-size: 0.8rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

/* Note Viewer Container */
.note-viewer-container {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    animation: noteViewerSlideIn 0.4s ease-out;
}

@keyframes noteViewerSlideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.note-viewer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg) var(--spacing-xl);
    border-bottom: 1px solid var(--glass-border);
    background: rgba(0, 0, 0, 0.2);
}

.note-viewer-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.note-viewer-title h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

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

.note-viewer-content {
    padding: var(--spacing-2xl);
    max-height: 70vh;
    overflow-y: auto;
}

/* ========== VIDEO LIST ========== */
.video-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.video-item {
    display: flex;
    gap: var(--spacing-md);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-sm);
    cursor: pointer;
    transition: transform 0.4s cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 0.4s ease, border-color 0.4s ease, background 0.4s ease;
    animation: scaleUp 0.5s cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

.video-item:nth-child(1) {
    animation-delay: 0.1s;
}

.video-item:nth-child(2) {
    animation-delay: 0.15s;
}

.video-item:nth-child(3) {
    animation-delay: 0.2s;
}

.video-item:nth-child(4) {
    animation-delay: 0.25s;
}

.video-item:nth-child(5) {
    animation-delay: 0.3s;
}

.video-item:hover {
    background: var(--glass-bg-hover);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateX(8px) scale3d(1.01, 1.01, 1);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
}

.video-thumbnail {
    position: relative;
    width: 200px;
    height: 112px;
    border-radius: var(--radius-md);
    overflow: hidden;
    flex-shrink: 0;
}

.video-thumbnail img,
.video-thumbnail video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    background: var(--gradient-purple-cyan);
}

.play-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.4);
    transition: all var(--transition-fast);
}

.video-item:hover .play-overlay {
    background: rgba(0, 0, 0, 0.6);
}

.play-overlay i {
    font-size: 2.5rem;
    color: var(--text-primary);
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
    transition: transform var(--transition-fast);
}

.video-item:hover .play-overlay i {
    transform: scale(1.2);
}

.video-duration {
    position: absolute;
    bottom: 8px;
    right: 8px;
    background: rgba(0, 0, 0, 0.85);
    color: var(--text-primary);
    padding: 2px 8px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
}

.video-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: var(--spacing-xs);
}

.video-info h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.video-info p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.video-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 0.8rem;
    color: var(--text-muted);
}

.video-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

/* Featured Video */
.featured-video {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    margin-bottom: var(--spacing-xl);
    transition: all var(--transition-normal);
}

.featured-video:hover {
    border-color: var(--glass-border-hover);
    box-shadow: var(--shadow-lg);
}

.featured-video .video-thumbnail {
    width: 100%;
    height: 400px;
    border-radius: 0;
}

.featured-video .video-info {
    padding: var(--spacing-xl);
}

.featured-video .video-info h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

/* ========== AUDIO LIST ========== */
.audio-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

/* Audio Speed Control */
.audio-speed-control {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--accent-purple);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.audio-speed-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.audio-seek-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.audio-seek-row .course-audio-time {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    min-width: 2.5em;
}

.audio-seek-row .course-audio-time-sep {
    color: var(--text-secondary);
    font-weight: 600;
}

.audio-seek-row .course-audio-slider-wrap {
    flex: 1;
    min-width: 120px;
    position: relative;
    height: 8px;
    background: var(--glass-bg);
    border-radius: 4px;
    overflow: visible;
    cursor: pointer;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

.audio-seek-row .course-audio-seek {
    position: absolute;
    width: 100%;
    height: 100%;
    margin: 0;
    opacity: 0;
    cursor: pointer;
    z-index: 2;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

.audio-seek-row .course-audio-slider-wrap::after {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: var(--course-audio-progress, 0%);
    background: var(--accent-purple);
    border-radius: 4px;
    pointer-events: none;
    z-index: 1;
}

.audio-speed-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 600;
}

.audio-speed-label i {
    color: var(--accent-purple);
}

.audio-speed-buttons {
    display: flex;
    gap: var(--spacing-xs);
    flex-wrap: wrap;
    align-items: center;
}

.audio-speed-btn {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.audio-speed-btn:hover {
    background: var(--glass-bg-hover);
    border-color: var(--accent-purple);
    color: var(--text-primary);
}

.audio-speed-btn.active {
    background: var(--accent-purple);
    border-color: var(--accent-purple);
    color: white;
}

/* Mobil: ses kaydırıcı dokunma alanı büyütüldü (44px), çift dokunma gecikmesi kaldırıldı */
@media (max-width: 768px) {
    .audio-seek-row .course-audio-slider-wrap {
        min-height: 44px;
        height: 44px;
        display: flex;
        align-items: center;
    }

    .audio-seek-row .course-audio-slider-wrap::after {
        top: 50%;
        transform: translateY(-50%);
        height: 8px;
    }

    .audio-seek-row .course-audio-seek {
        min-height: 44px;
        height: 100%;
        top: 0;
        bottom: 0;
    }
}

@media (max-width: 480px) {
    .audio-speed-control {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }

    .audio-speed-buttons {
        width: 100%;
        justify-content: space-between;
    }

    .audio-speed-btn {
        flex: 1;
        text-align: center;
        padding: var(--spacing-sm);
        min-height: 44px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
        -webkit-tap-highlight-color: transparent;
        touch-action: manipulation;
    }

    .audio-seek-row {
        width: 100%;
    }
}

.audio-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    transition: all var(--transition-normal);
}

.audio-item:hover {
    background: var(--glass-bg-hover);
    border-color: var(--glass-border-hover);
}

.audio-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-md);
    background: var(--gradient-purple-cyan);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    box-shadow: var(--shadow-glow-purple);
}

.audio-icon i {
    font-size: 1.5rem;
    color: var(--text-primary);
}

.audio-info {
    flex: 1;
}

.audio-info h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.audio-info p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.audio-meta {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-sm);
    font-size: 0.8rem;
    color: var(--text-muted);
}

.audio-meta span {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

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

.btn-play-audio,
.btn-download-audio {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    border: none;
    cursor: pointer;
}

.btn-play-audio {
    background: var(--gradient-purple-cyan);
    color: var(--text-primary);
    box-shadow: var(--shadow-glow-purple);
}

.btn-play-audio:hover {
    transform: scale(1.1);
}

.btn-download-audio {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
}

.btn-download-audio:hover {
    background: var(--glass-bg-hover);
    color: var(--text-primary);
}

/* ========== FLASHCARDS ========== */
.flashcard-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xl);
}

.flashcard-wrapper {
    width: 100%;
    max-width: 600px;
    height: 350px;
    perspective: 1000px;
}

.flashcard {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
}

.flashcard.flipped {
    transform: rotateY(180deg);
}

.flashcard-front,
.flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    text-align: center;
}

.flashcard-front {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
}

.flashcard-back {
    background: var(--gradient-purple-cyan);
    transform: rotateY(180deg);
}

.flashcard-front h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.4;
}

.flashcard-back p {
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--text-primary);
}

/* Flip hint: kartın altında, kontrollerin üstünde; mobilde kartla karışmasın */
.flashcard-wrapper+.flip-hint,
.flip-hint {
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.8rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    flex-shrink: 0;
}

.flashcard-back .flip-hint {
    color: rgba(255, 255, 255, 0.7);
}

@media (max-width: 768px) {
    .flip-hint {
        margin-top: 1rem;
        margin-bottom: 0.75rem;
        border-top: 1px solid var(--glass-border, rgba(255, 255, 255, 0.1));
        padding-top: 0.75rem;
    }

    .flashcard-wrapper {
        max-height: 50vh;
        height: 280px;
    }
}

/* Flashcard Controls */
.flashcard-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-lg);
}

.flashcard-nav-btn {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-full);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.flashcard-nav-btn:hover {
    background: var(--glass-bg-hover);
    color: var(--text-primary);
    border-color: var(--accent-purple);
}

.flashcard-nav-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.flashcard-flip-btn {
    padding: var(--spacing-md) var(--spacing-2xl);
    background: var(--gradient-purple-cyan);
    color: var(--text-primary);
    border: none;
    border-radius: var(--radius-full);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-glow-purple);
}

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

/* Flashcard Progress */
.flashcard-progress {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    width: 100%;
    max-width: 600px;
}

.flashcard-progress-bar {
    width: 100%;
    height: 6px;
    background: rgba(0, 0, 0, 0.3);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.flashcard-progress-fill {
    height: 100%;
    background: var(--gradient-purple-cyan);
    border-radius: var(--radius-full);
    transition: width 0.3s ease;
}

.flashcard-progress-text {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* ========== TESTS / QUIZ ========== */
.tests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.test-card {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    transition: all var(--transition-normal);
}

.test-card:hover {
    background: var(--glass-bg-hover);
    border-color: var(--glass-border-hover);
    transform: translateY(-4px);
}

.test-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.test-header i {
    font-size: 1.75rem;
    color: var(--accent-purple);
}

.test-badge {
    padding: 4px 12px;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
}

.test-badge.new {
    background: var(--accent-cyan-glow);
    color: var(--accent-cyan);
}

.test-badge.completed {
    background: var(--success-bg);
    color: var(--success);
}

.test-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

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

.test-meta {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    font-size: 0.8rem;
    color: var(--text-muted);
}

.test-meta span {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.test-score {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-lg);
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.score {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient-cyan-green);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.score-label {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ========== DIFFICULTY SELECTOR ========== */
.difficulty-selector {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.difficulty-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.difficulty-btn:hover {
    background: var(--glass-bg-hover);
    color: var(--text-primary);
}

.difficulty-btn.active.easy {
    background: var(--success-bg);
    border-color: var(--success);
    color: var(--success);
}

.difficulty-btn.active.medium {
    background: var(--warning-bg);
    border-color: var(--warning);
    color: var(--warning);
}

.difficulty-btn.active.hard {
    background: var(--danger-bg);
    border-color: var(--danger);
    color: var(--danger);
}

/* Difficulty badges */
.difficulty-badge {
    padding: 2px 8px;
    border-radius: var(--radius-full);
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
}

.difficulty-badge.easy {
    background: var(--success-bg);
    color: var(--success);
}

.difficulty-badge.medium {
    background: var(--warning-bg);
    color: var(--warning);
}

.difficulty-badge.hard {
    background: var(--danger-bg);
    color: var(--danger);
}

/* ========== NOTE CONTENT ANIMATIONS ========== */
.formatted-content {
    color: var(--text-primary);
    line-height: 1.8;
}

.formatted-content h1,
.formatted-content h2,
.formatted-content h3,
.formatted-content h4 {
    color: var(--text-primary);
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    position: relative;
}

.formatted-content h1 {
    font-size: 1.75rem;
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--glass-border);
}

.formatted-content h2 {
    font-size: 1.5rem;
}

.formatted-content h3 {
    font-size: 1.25rem;
}

.formatted-content p {
    margin-bottom: var(--spacing-md);
    transition: all var(--transition-fast);
}

.formatted-content p:hover {
    padding-left: var(--spacing-sm);
    border-left: 2px solid var(--accent-purple);
}

.formatted-content a {
    color: var(--accent-cyan);
    text-decoration: none;
    position: relative;
}

.formatted-content a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent-cyan);
    transition: width var(--transition-fast);
}

.formatted-content a:hover::after {
    width: 100%;
}

.formatted-content ul,
.formatted-content ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-xl);
}

.formatted-content li {
    margin-bottom: var(--spacing-sm);
    position: relative;
}

.formatted-content ul li::marker {
    color: var(--accent-purple);
}

.formatted-content ol li::marker {
    color: var(--accent-cyan);
    font-weight: 600;
}

.formatted-content blockquote {
    background: var(--glass-bg);
    border-left: 4px solid var(--accent-purple);
    padding: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-style: italic;
    color: var(--text-secondary);
}

.formatted-content code {
    background: rgba(0, 0, 0, 0.3);
    padding: 2px 8px;
    border-radius: var(--radius-sm);
    font-family: 'Fira Code', monospace;
    font-size: 0.9em;
    color: var(--accent-cyan);
}

.formatted-content pre {
    background: rgba(0, 0, 0, 0.4);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    overflow-x: auto;
    margin: var(--spacing-lg) 0;
}

.formatted-content pre code {
    background: transparent;
    padding: 0;
    color: var(--text-primary);
}

.formatted-content table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-lg) 0;
}

.formatted-content th,
.formatted-content td {
    padding: var(--spacing-md);
    border: 1px solid var(--glass-border);
    text-align: left;
}

.formatted-content th {
    background: rgba(0, 0, 0, 0.3);
    font-weight: 600;
    color: var(--text-primary);
}

.formatted-content tr:hover {
    background: var(--glass-bg);
}

.formatted-content img {
    max-width: 100%;
    border-radius: var(--radius-md);
    margin: var(--spacing-lg) 0;
}

.formatted-content hr {
    border: none;
    height: 1px;
    background: var(--glass-border);
    margin: var(--spacing-xl) 0;
}

/* ========== BUTTONS ========== */
.btn-download {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-download:hover {
    background: var(--gradient-purple-cyan);
    border-color: transparent;
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.btn-full {
    width: 100%;
}

/* ========== EMPTY STATE ========== */
.content-empty {
    text-align: center;
    padding: var(--spacing-3xl);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
}

.content-empty i {
    font-size: 4rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-lg);
    opacity: 0.5;
}

.content-empty h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.content-empty p {
    color: var(--text-muted);
}

/* ========== RESPONSIVE ========== */
@media (max-width: 992px) {
    .course-sections-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }

    .section-btn {
        padding: var(--spacing-md);
    }

    .section-btn i {
        font-size: 1.5rem;
    }
}

@media (max-width: 768px) {
    .course-header h1 {
        font-size: 1.75rem;
    }

    .video-item {
        flex-direction: column;
    }

    .video-thumbnail {
        width: 100%;
        height: 200px;
    }

    .audio-item {
        flex-direction: column;
        text-align: center;
    }

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

    .audio-meta {
        justify-content: center;
    }

    .audio-actions {
        width: 100%;
        justify-content: center;
    }

    .notes-grid,
    .tests-grid {
        grid-template-columns: 1fr;
    }

    .flashcard-wrapper {
        height: 300px;
    }

    .flashcard-front h3 {
        font-size: 1.25rem;
    }

    .flashcard-back p {
        font-size: 1rem;
    }

    .flashcard-controls {
        flex-wrap: wrap;
    }

    .featured-video .video-thumbnail {
        height: 250px;
    }

    .notes-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 480px) {
    .course-sections-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .section-btn span {
        font-size: 0.8rem;
    }

    .difficulty-selector {
        flex-direction: column;
    }

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

    .note-viewer-header {
        flex-direction: column;
        gap: var(--spacing-md);
    }

    .note-viewer-actions {
        width: 100%;
    }

    .note-viewer-actions .btn-download {
        flex: 1;
    }
}

/* ========== MATERIALS LIST ========== */
.materials-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-md);
}

/* ========== MATERIAL ITEMS ========== */
.material-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    transition: all 0.2s ease;
    flex-wrap: nowrap;
}

.material-item:hover {
    border-color: var(--glass-border-hover, rgba(255, 255, 255, 0.15));
}

.material-icon {
    width: 36px;
    height: 36px;
    min-width: 36px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1rem;
    flex-shrink: 0;
}

.material-info {
    flex: 1 1 auto;
    min-width: 0;
}

.material-info h3 {
    margin: 0 0 2px 0;
    font-size: 0.95rem;
    color: var(--text-primary);
    word-break: break-word;
    line-height: 1.3;
}

.material-meta {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.material-meta span:first-child {
    font-weight: 600;
    text-transform: uppercase;
}

.material-actions {
    display: flex;
    gap: 6px;
    align-items: center;
    flex-shrink: 0;
}

.material-actions .btn-share-link,
.material-actions .btn-play-video,
.material-actions .btn-edit-item,
.material-actions .btn-delete-item,
.material-actions .btn-view-material,
.material-actions a {
    width: 30px;
    height: 30px;
    min-width: 30px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: opacity 0.2s, transform 0.2s;
}

.material-actions .btn-share-link {
    background: transparent;
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
}

.material-actions .btn-share-link:hover {
    border-color: var(--accent-purple);
    color: var(--accent-purple);
}

.material-actions .btn-view-material,
.material-actions a[download] {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
}

.material-actions .btn-view-material:hover,
.material-actions a[download]:hover {
    opacity: 0.9;
    background: var(--glass-bg-hover);
}

/* Material items - responsive */
@media (max-width: 768px) {
    .materials-list {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
        gap: var(--spacing-sm);
    }

    .material-item {
        padding: var(--spacing-sm) var(--spacing-md);
        gap: var(--spacing-sm);
    }

    .material-info h3 {
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .materials-list {
        grid-template-columns: 1fr;
    }

    .material-item {
        padding: var(--spacing-sm) var(--spacing-md);
        gap: var(--spacing-sm);
    }

    .material-icon {
        width: 32px;
        height: 32px;
        min-width: 32px;
        font-size: 0.9rem;
    }

    .material-info {
        min-width: 80px;
    }

    .material-info h3 {
        font-size: 0.875rem;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .material-meta {
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .material-actions .btn-share-link,
    .material-actions .btn-play-video,
    .material-actions .btn-edit-item,
    .material-actions .btn-delete-item,
    .material-actions .btn-view-material,
    .material-actions a {
        width: 28px;
        height: 28px;
        min-width: 28px;
    }
}