/* CSS Variables */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #f59e0b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-card: #1e293b;
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    --border: #334155;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
    
    --radius: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    --transition: all 0.3s ease;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans Devanagari', 'Poppins', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 70px;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
    z-index: 1000;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-light);
}

.nav-brand i {
    font-size: 1.75rem;
}

.nav-links {
    display: flex;
    gap: 0.5rem;
}

.nav-links a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--radius);
    transition: var(--transition);
    font-weight: 500;
}

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

.nav-user {
    display: flex;
    align-items: center;
    gap: 1rem;
}

#userStreak {
    font-size: 1.1rem;
    font-weight: 600;
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

/* Main Content */
main {
    padding-top: 90px;
    padding-bottom: 2rem;
    max-width: 1400px;
    margin: 0 auto;
    padding-left: 2rem;
    padding-right: 2rem;
}

/* Sections */
.section {
    display: none;
    animation: fadeIn 0.4s ease;
}

.section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 3rem 0;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--primary-light), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.wave {
    display: inline-block;
    animation: wave 2s ease-in-out infinite;
}

@keyframes wave {
    0%, 100% { transform: rotate(0deg); }
    25% { transform: rotate(20deg); }
    75% { transform: rotate(-10deg); }
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    margin-top: 2rem;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.stat-card i {
    font-size: 2rem;
    color: var(--primary-light);
    margin-bottom: 0.75rem;
}

.stat-card h3 {
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.stat-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

/* Quick Actions */
.quick-actions {
    margin: 3rem 0;
}

.quick-actions h2 {
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.action-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
}

.action-btn {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

.action-btn:hover {
    background: var(--bg-tertiary);
    border-color: var(--primary);
    transform: translateY(-3px);
}

.action-btn i {
    font-size: 2rem;
    color: var(--primary-light);
}

.action-btn span {
    font-weight: 500;
}

/* Daily Challenge */
.daily-challenge {
    margin-top: 3rem;
}

.daily-challenge h2 {
    margin-bottom: 1.5rem;
}

.challenge-card {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.challenge-info h3 {
    font-size: 1.25rem;
    margin-bottom: 0.25rem;
}

.challenge-info p {
    opacity: 0.9;
    margin: 0;
}

.challenge-progress {
    text-align: right;
    min-width: 200px;
}

.challenge-progress .progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(255,255,255,0.2);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.challenge-progress .progress-fill {
    height: 100%;
    background: white;
    border-radius: 4px;
    transition: width 0.3s ease;
}

/* Section Header */
.section-header {
    margin-bottom: 2rem;
}

.section-header h1 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.section-header h1 i {
    color: var(--primary-light);
}

/* Category Filter */
.category-filter {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.6rem 1.2rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

/* Flashcard */
.flashcard-container {
    max-width: 700px;
    margin: 0 auto;
}

.flashcard {
    width: 100%;
    height: 400px;
    perspective: 1000px;
    cursor: pointer;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s;
    transform-style: preserve-3d;
}

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

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

.flashcard-back {
    transform: rotateY(180deg);
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    border-color: var(--primary);
}

.category-badge {
    position: absolute;
    top: 1.5rem;
    left: 1.5rem;
    padding: 0.4rem 1rem;
    background: var(--primary);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.flashcard-front h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    max-width: 90%;
}

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

.flashcard-back h3 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
}

.flashcard-back p {
    font-size: 1rem;
    opacity: 0.9;
    max-width: 90%;
}

/* Flashcard Controls */
.flashcard-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    margin-top: 2rem;
}

.control-btn {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 1px solid var(--border);
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

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

.card-counter {
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.flashcard-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
}

.action-btn-secondary {
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
}

.action-btn-secondary:hover {
    background: var(--bg-tertiary);
}

.action-btn-secondary:first-child:hover {
    border-color: var(--success);
    color: var(--success);
}

.action-btn-secondary:last-child:hover {
    border-color: var(--danger);
    color: var(--danger);
}

/* Quiz Setup */
.quiz-setup {
    text-align: center;
    padding: 2rem 0;
}

.quiz-setup h2 {
    margin-bottom: 2rem;
}

.quiz-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    max-width: 900px;
    margin: 0 auto;
}

.quiz-cat-btn {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 2rem;
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

.quiz-cat-btn:hover {
    background: var(--bg-tertiary);
    border-color: var(--primary);
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.quiz-cat-btn i {
    font-size: 2.5rem;
    color: var(--primary-light);
}

.quiz-cat-btn span {
    font-size: 1.1rem;
    font-weight: 600;
}

.quiz-cat-btn small {
    color: var(--text-secondary);
}

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

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

.quiz-progress {
    flex: 1;
    margin-right: 2rem;
}

.quiz-progress .progress-bar {
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.quiz-progress .progress-fill {
    height: 100%;
    background: var(--primary);
    border-radius: 4px;
    transition: width 0.3s ease;
}

.quiz-timer {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--secondary);
}

.question-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 2rem;
    margin-bottom: 2rem;
}

.question-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.options-grid {
    display: grid;
    gap: 1rem;
}

.option-btn {
    padding: 1rem 1.5rem;
    background: var(--bg-tertiary);
    border: 2px solid transparent;
    border-radius: var(--radius);
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

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

.option-btn.selected {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.1);
}

.option-btn.correct {
    border-color: var(--success);
    background: rgba(16, 185, 129, 0.1);
}

.option-btn.wrong {
    border-color: var(--danger);
    background: rgba(239, 68, 68, 0.1);
}

.option-letter {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--bg-card);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: var(--primary-light);
}

.quiz-actions {
    display: flex;
    justify-content: space-between;
}

.btn-primary,
.btn-secondary {
    padding: 0.875rem 2rem;
    border-radius: var(--radius);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

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

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

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

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

/* Quiz Results */
.quiz-results {
    text-align: center;
    padding: 3rem 0;
}

.result-icon {
    font-size: 5rem;
    margin-bottom: 1rem;
}

.quiz-results h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
}

.result-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    max-width: 700px;
    margin: 0 auto 2rem;
}

.result-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
}

.result-label {
    display: block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.result-value {
    display: block;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary-light);
}

.result-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

/* Progress Section */
.progress-overview {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.progress-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 2rem;
    text-align: center;
}

.progress-circle {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 0 auto 1.5rem;
}

.progress-circle svg {
    transform: rotate(-90deg);
    width: 100%;
    height: 100%;
}

.progress-bg {
    fill: none;
    stroke: var(--bg-tertiary);
    stroke-width: 8;
}

.progress-bar {
    fill: none;
    stroke: var(--primary);
    stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 283;
    stroke-dashoffset: 283;
    transition: stroke-dashoffset 1s ease;
}

.progress-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.progress-text span {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-light);
}

.progress-text small {
    color: var(--text-secondary);
}

.category-progress {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 2rem;
}

.category-progress h3 {
    margin-bottom: 1.5rem;
}

.progress-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.progress-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.progress-label {
    display: flex;
    justify-content: space-between;
    font-weight: 500;
}

.progress-label i {
    color: var(--primary-light);
    margin-right: 0.5rem;
}

.progress-item .progress-bar {
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
}

.progress-item .progress-fill {
    height: 100%;
    background: var(--primary);
    border-radius: 4px;
    transition: width 0.5s ease;
}

/* Achievements */
.achievements {
    margin-bottom: 3rem;
}

.achievements h2 {
    margin-bottom: 1.5rem;
}

.achievement-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.achievement-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
    transition: var(--transition);
}

.achievement-card:not(.locked) {
    border-color: var(--secondary);
    background: linear-gradient(135deg, var(--bg-card), rgba(245, 158, 11, 0.1));
}

.achievement-card.locked {
    opacity: 0.6;
}

.achievement-card.locked .achievement-icon {
    filter: grayscale(100%);
}

.achievement-icon {
    font-size: 2.5rem;
    margin-bottom: 0.75rem;
}

.achievement-card h4 {
    margin-bottom: 0.25rem;
}

.achievement-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

/* Study Stats */
.study-stats h2 {
    margin-bottom: 1.5rem;
}

.stats-grid-2 {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

.stat-box {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.stat-box i {
    font-size: 2rem;
    color: var(--primary-light);
}

.stat-box h4 {
    font-size: 1.75rem;
    color: var(--text-primary);
}

.stat-box p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

/* Timer Section */
.timer-container {
    max-width: 600px;
    margin: 0 auto;
}

.timer-display {
    margin-bottom: 2rem;
}

.timer-circle {
    position: relative;
    width: 280px;
    height: 280px;
    margin: 0 auto;
}

.timer-circle svg {
    transform: rotate(-90deg);
    width: 100%;
    height: 100%;
}

.timer-bg {
    fill: none;
    stroke: var(--bg-tertiary);
    stroke-width: 6;
}

.timer-progress {
    fill: none;
    stroke: var(--primary);
    stroke-width: 6;
    stroke-linecap: round;
    stroke-dasharray: 283;
    stroke-dashoffset: 0;
    transition: stroke-dashoffset 1s linear;
}

.timer-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.timer-text span {
    display: block;
    font-size: 4rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

.timer-text small {
    color: var(--text-secondary);
    font-size: 1rem;
}

.timer-controls {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.timer-btn {
    padding: 1rem 2rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1rem;
    font-weight: 500;
}

.timer-btn:hover {
    background: var(--bg-tertiary);
}

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

.timer-settings {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.timer-settings h3 {
    margin-bottom: 1.5rem;
}

.setting-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.setting-row:last-child {
    margin-bottom: 0;
}

.duration-selector {
    display: flex;
    gap: 0.5rem;
}

.duration-selector button {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
}

.duration-selector button.active,
.duration-selector button:hover {
    background: var(--primary);
    border-color: var(--primary);
}

.timer-sessions {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
}

.timer-sessions h3 {
    margin-bottom: 1rem;
}

.session-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.session-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius);
}

.session-time {
    font-weight: 500;
}

.session-duration {
    color: var(--text-secondary);
}

.empty-state {
    color: var(--text-muted);
    text-align: center;
    padding: 2rem;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--success);
    color: white;
    padding: 1rem 1.5rem;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transform: translateX(150%);
    transition: transform 0.3s ease;
    z-index: 2000;
    box-shadow: var(--shadow-lg);
}

.toast.show {
    transform: translateX(0);
}

/* Responsive Design */
@media (max-width: 1200px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .action-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .stats-grid-2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .navbar {
        padding: 0 1rem;
    }
    
    .nav-links {
        display: none;
    }
    
    main {
        padding-left: 1rem;
        padding-right: 1rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .action-grid {
        grid-template-columns: 1fr;
    }
    
    .challenge-card {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .progress-overview {
        grid-template-columns: 1fr;
    }
    
    .achievement-grid {
        grid-template-columns: 1fr;
    }
    
    .stats-grid-2 {
        grid-template-columns: 1fr;
    }
    
    .result-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .flashcard {
        height: 350px;
    }
    
    .quiz-categories {
        grid-template-columns: 1fr;
    }
}

/* Animations */
@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.pulse {
    animation: pulse 2s infinite;
}

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

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

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

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