:root {
    --primary-color: #de2723;
    --text-color: #333;
    --background-color: #ffffff;
    --secondary-bg: #f8f9fa;
    --button-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    --border-radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: Verdana, Arial, sans-serif;
    background-color: var(--background-color);
    min-height: 100dvh;
    color: var(--text-color);
    background-color: white;
    overflow-x: hidden;
}

/* Header */
.app-header {
    background: var(--primary-color);
    color: white;
    padding: 1rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

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

.header-center h1 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: bold;
    letter-spacing: 1px;
    color: white;
}

.menu-button {
    background: none;
    border: none;
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.menu-button:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* Menü Panel */
.menu-panel {
    position: fixed;
    top: 0;
    left: -300px;
    width: 300px;
    height: 100dvh;
    background: white;
    z-index: 1000;
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.1);
    transition: left 0.3s ease;
}

.menu-panel.active {
    left: 0;
}

.menu-header {
    background: var(--primary-color);
    color: white;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.menu-header h3 {
    margin: 0;
    font-size: 1.2rem;
    color: white;
}

.close-menu {
    background: none;
    border: none;
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.close-menu:hover {
    background: rgba(255, 255, 255, 0.1);
}

.menu-content {
    padding: 1rem;
}

.menu-section {
    margin-bottom: 2rem;
}

.menu-section h4 {
    color: #666;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 0.5rem;
}

.menu-section ul {
    list-style: none;
    padding: 0;
}

.menu-section li {
    margin: 0.5rem 0;
}

.menu-section a {
    color: var(--text-color);
    text-decoration: none;
    display: block;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    transition: var(--transition);
}

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

.menu-section a.active {
    background: var(--primary-color);
    color: white;
}

/* Ana İçerik */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.app-content {
    flex: 1;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
}

.setup-screen {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--button-shadow);
    min-height: auto;
    display: flex;
    flex-direction: column;
}

.screen-content {
    padding: 1rem;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    max-width: 1000px;
    max-height: 1800px;
    margin: 0 auto;
    width: 100%;
}

.screen-content h2 {
    text-align: center;
    font-size: 2rem;
    color: var(--text-color);
    margin-bottom: 2rem;
    font-weight: bold;
}

/* Anahtar Seçimi */
.clef-selection {
    display: flex;
    gap: 2rem;
    justify-content: center;
    margin: 2rem 0;
}

.clef-button {
    background: white;
    border: 3px solid #ddd;
    border-radius: 16px;
    padding: 2.5rem;
    cursor: pointer;
    width: 240px;
    height: 280px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
    transition: all 0.3s ease;
    box-shadow: var(--button-shadow);
}

.clef-button:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.clef-button.selected {
    border-color: var(--primary-color);
    background: rgba(222, 39, 35, 0.05);
}

.clef-image {
    width: 140px;
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s ease;
}

.clef-button.selected .clef-image {
    transform: scale(1.1);
}

.clef-button img {
    max-width: 100%;
    height: auto;
}

.clef-button span {
    font-size: 1.2rem;
    font-weight: bold;
    color: #333;
    transition: color 0.3s ease;
}

.clef-button.selected span {
    color: var(--primary-color);
}

/* Navigasyon Butonları */
.navigation-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
}

.action-button {
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    min-width: 160px;
    justify-content: center;
}

.action-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.action-button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.action-button i {
    font-size: 1rem;
}

/* Nota Seçim Ekranı */
.note-selection {
    max-width: 900px;
    margin: 0 auto;
    padding: 1rem;
}

.select-all-container {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 1rem 0;
}

.question-count-selector {
    text-align: center;
    margin: 2rem 0;
}

.question-count-selector h3 {
    color: var(--text-color);
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
}

.question-count-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.count-button {
    background: white;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.count-button:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(222, 39, 35, 0.2);
}

.count-button.selected {
    background: var(--primary-color);
    color: white;
}

.selection-title {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 1.5rem;
    color: var(--text-color);
}

.note-group {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
}

.note-group.single {
    margin: 1rem 0;
}

.note-button {
    background: white;
    border: 2px solid #ddd;
    border-radius: 8px;
    padding: 0.8rem;
    min-width: 80px;
    font-size: 1.2rem;
    text-transform: uppercase;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    position: relative;
}

.note-button span {
    position: relative;
    z-index: 1;
}

.note-button:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.note-button.selected {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(222, 39, 35, 0.2);
}

.select-all {
    text-align: center;
    margin: 2rem 0;
}

.checkbox-wrapper {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
    padding: 0.8rem 1.5rem;
    background: var(--secondary-bg);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.checkbox-wrapper:hover {
    background: #e9ecef;
}

.checkbox-wrapper input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.checkbox-text {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--text-color);
}

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

.action-button.secondary {
    background: var(--secondary-bg);
    color: var(--text-color);
}

.action-button.secondary:hover {
    background: #e9ecef;
}

/* Quiz Ekranı */
.quiz-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
}

.quiz-header {
    text-align: center;
    margin-bottom: 3rem;
}

.quiz-header h2 {
    font-size: 2rem;
    color: var(--text-color);
    margin-bottom: 1rem;
}

.quiz-progress {
    font-size: 1.2rem;
    color: #666;
}

.quiz-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

.note-display {
    width: 100%;
    max-width: 400px;
    aspect-ratio: 2/1;
    margin: 2rem auto;
    display: flex;
    align-items: center;
    justify-content: center;
}

.note-display img {
    max-width: 100%;
   
}

.options-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1rem;
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
}

.quiz-option {
    background: white;
    border: 2px solid #ddd;
    border-radius: 8px;
    padding: 1rem;
    font-size: 1.2rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.quiz-option:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.quiz-option.correct {
    background: #4CAF50;
    border-color: #4CAF50;
    color: white;
}

.quiz-option.wrong {
    background: #f44336;
    border-color: #f44336;
    color: white;
}

.quiz-option:disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

.feedback-message {
    text-align: center;
    margin: 2rem 0;
    min-height: 60px;
}

.feedback-success,
.feedback-error {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: 8px;
    font-size: 1.2rem;
    font-weight: bold;
}

.feedback-success {
    background: #E8F5E9;
    color: #2E7D32;
}

.feedback-error {
    background: #FFEBEE;
    color: #C62828;
}

.feedback-success i,
.feedback-error i {
    font-size: 1.5rem;
}

.quiz-results {
    text-align: center;
    padding: 3rem;
}

.quiz-results h2 {
    font-size: 2.5rem;
    color: var(--text-color);
    margin-bottom: 2rem;
}

.quiz-results p {
    font-size: 1.2rem;
    margin: 1rem 0;
    color: #666;
}

.quiz-results button {
    margin-top: 2rem;
    padding: 1rem 3rem;
    font-size: 1.2rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.quiz-results button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

/* Yükleme Ekranı */
#loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--primary-color);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    color: white;
}

.logo-container {
    margin-bottom: 2rem;
    text-align: center;
}

.maestro-logo {
    height: 40px;
    width: auto;
}

.headphone-advice {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Header */
.app-header {
    background: var(--primary-color);
    color: white;
    padding: 1rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

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

.header-center h1 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: bold;
    letter-spacing: 1px;
}

.menu-button {
    background: none;
    border: none;
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.menu-button:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* Ana İçerik */
.app-content {
    padding: 1rem;
}

/* Kurs Listesi */
.course-list {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    max-width: 800px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.course-button {
    background: white;
    border: 2px solid var(--primary-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    text-decoration: none;
    color: var(--primary-color);
    font-weight: bold;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.course-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--primary-color);
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    z-index: 0;
}

.course-button:hover::before {
    transform: translateX(0);
}

.course-button span {
    font-size: 1.3rem;
    letter-spacing: 1.5px;
    position: relative;
    z-index: 1;
    transition: color 0.3s ease;
}

.course-button i {
    color: var(--primary-color);
    font-size: 1.3rem;
    position: relative;
    z-index: 1;
    transition: color 0.3s ease;
}

.course-button:hover span,
.course-button:hover i {
    color: white;
}

/* Seçim Butonları */
.clef-button {
    background: white;
    border: 3px solid #ddd;
    border-radius: 8px;
    padding: 1.5rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    min-width: 160px;
    position: relative;
    overflow: hidden;
}

.clef-button::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(222, 39, 35, 0.1);
    opacity: 0;
    transition: opacity 0.2s ease;
}

.clef-button:hover {
    border-color: var(--primary-color);
}

.clef-button:hover::after {
    opacity: 1;
}

.clef-button img {
    height: 80px;
    width: auto;
    transition: transform 0.2s ease;
}

.clef-button span {
    color: #333;
    font-weight: bold;
    font-size: 1.1rem;
    transition: color 0.2s ease;
}

.clef-button.selected {
    border-color: var(--primary-color);
    border-width: 3px;
    background: rgba(222, 39, 35, 0.05);
}

.clef-button.selected img {
    transform: scale(1.05);
}
.clef-button.selected span {
    color: var(--primary-color);
}

/* Seçim Ekranları */
.clef-selection {
    display: flex;
    gap: 2rem;
    justify-content: center;
    margin: 2rem 0;
}

.setup-screen h2 {
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-color);
    font-size: 1.5rem;
}

/* Devam Butonu */
.action-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 2rem;
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    border-radius: 8px;
    border: none;
    color: white;
    background: linear-gradient(45deg, var(--primary-color), #ff6b6b);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(229, 57, 53, 0.3);
    min-width: 120px;
    text-transform: uppercase;
}

.action-button i {
    font-size: 1.1rem;
    transition: transform 0.3s ease;
}

.action-button:hover i {
    transform: translateX(3px);
}

.action-button.secondary:hover i {
    transform: translateX(-3px);
}

.action-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(229, 57, 53, 0.4);
}

.action-button:disabled {
    background: #bdbdbd;
    color: rgba(255,255,255,0.8);
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

.action-button.secondary {
    background: transparent;
    color: #757575;
    box-shadow: none;
    font-weight: 600;
    font-size: 0.9rem;
    padding: 0.75rem 1.5rem;
    min-width: 100px;
    opacity: 0.8;
}

.action-button.secondary:hover {
    color: #757575;
    background: rgba(0, 0, 0, 0.05);
}

/* Navigasyon Butonları */
.navigation-buttons {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 1.5rem;
    width: 100%;
}

.navigation-buttons button {
    flex: 1;
    max-width: 160px;
}

.note-button {
    min-width: 55px;
    height: 40px;
    padding: 0;
    background: #fff;
    border: 2px solid transparent;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    color: #424242;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    cursor: pointer;
    box-shadow: 0 2px 4px rgba(0,0,0,0.08);
}

.note-button:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-1px);
}

.note-button.selected {
    border: 2px solid var(--primary-color);
    color: white;
    font-weight: 600;
    background: var(--primary-color);
}

.note-button.special {
    background: #2196f3;
    border-color: #1976d2;
    color: white;
}

.note-button.special:hover {
    background: #1976d2;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(33, 150, 243, 0.3);
}

.note-button.special.selected {
    background: #1565c0;
    border-color: #0d47a1;
}

.next-button,
.prev-button {
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
}

.next-button:disabled {
    background: #ccc;
    cursor: not-allowed;
    opacity: 0.7;
}

.prev-button {
    background: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.next-button:not(:disabled):hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.prev-button:hover {
    background: var(--primary-color);
    color: white;
}

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

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

/* Menü Panel */
.menu-panel {
    position: fixed;
    top: 0;
    left: -300px;
    width: 300px;
    height: 100vh;
    background: white;
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.1);
    z-index: 2000;
    transition: var(--transition);
}

.menu-panel.active {
    left: 0;
}

.menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    background: var(--primary-color);
    color: white;
}

.menu-header h3 {
    margin: 0;
    color: white;
}

.close-menu {
    background: none;
    border: none;
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.close-menu:hover {
    background: rgba(255, 255, 255, 0.1);
}

.menu-nav {
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.menu-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    text-decoration: none;
    color: var(--text-color);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.menu-item i {
    width: 24px;
    text-align: center;
    font-size: 1.2rem;
    color: var(--primary-color);
}

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

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

.menu-item.active i {
    color: white;
}

.note-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--button-shadow);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

/* Kurs Listesi */
.course-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
    max-width: 800px;
    margin: 0 auto;
}

.course-button {
    background: white;
    border: none;
    border-radius: var(--border-radius);
    padding: 1rem 1.5rem;
    text-decoration: none;
    color: var(--text-color);
    font-weight: bold;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
    box-shadow: var(--button-shadow);
}

.course-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.course-button span {
    font-size: 1.2rem;
}

.course-button i {
    color: var(--primary-color);
    font-size: 1.2rem;
}

.course-button {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: white;
    color: var(--primary-color);
    padding: 1rem 1.5rem;
    border-radius: 10px;
    text-decoration: none;
    font-weight: bold;
    box-shadow: var(--button-shadow);
    transition: transform 0.2s;
}

.course-button:hover {
    transform: translateY(-2px);
}

.course-button i {
    font-size: 1.2rem;
}

.course-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 2rem;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.course-item:hover {
    transform: translateY(-5px);
}

/* Modal Pencereler */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
}

.modal-content {
    background: var(--background-color);
    color: var(--text-color);
    padding: 2rem;
    border-radius: 8px;
    width: 90%;
    max-width: 500px;
    margin: 2rem auto;
}

/* Form Elemanları */
form input {
    width: 100%;
    padding: 0.8rem;
    margin: 0.5rem 0;
    border: 1px solid #ddd;
    border-radius: 4px;
}

.social-login {
    margin-top: 1rem;
}

.social-login button {
    width: 100%;
    padding: 0.8rem;
    margin: 0.5rem 0;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

/* Responsive Tasarım */
@media (max-width: 768px) {
    .course-grid {
        grid-template-columns: 1fr;
        padding: 1rem;
    }
    
    header {
        flex-direction: column;
        text-align: center;
    }
    
    nav {
        margin-top: 1rem;
        #startButton {
            display: block;
            margin: 3rem auto 0;
            min-width: 240px;
            height: 56px;
            font-size: 1.1rem;
            letter-spacing: 1px;
            border-radius: 100px;
            background: var(--primary-color);
            box-shadow: 0 4px 12px rgba(222, 39, 35, 0.3);
        }

        #startButton:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(222, 39, 35, 0.4);
        }
        .question-count {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 2rem;
            margin: 2rem auto;
            max-width: 800px;
            padding: 0 1rem;
        }

        .count-button {
            background: white;
            border: none;
            border-radius: 12px;
            padding: 2rem;
            cursor: pointer;
            width: 100%;
            height: auto;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 1.5rem;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            box-shadow: var(--button-shadow);
            position: relative;
        }

        .count-button .count-icon {
            font-size: 3.5rem;
            font-weight: 700;
            color: var(--primary-color);
            line-height: 1;
            transition: transform 0.3s ease;
        }

        .count-button span {
            font-size: 1.2rem;
            font-weight: 600;
            color: #333;
            transition: color 0.3s ease;
        }

        .count-button:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
        }

        .count-button.selected {
            background: var(--primary-color);
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(222, 39, 35, 0.4);
        }

        .count-button.selected .count-icon,
        .count-button.selected span {
            color: white;
        }
        .select-all {
            display: flex;
            justify-content: center;
            margin: 0.75rem 0;
        }

        .select-all .navigation-buttons {
            margin: 0;
        }
        .note-selection {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
            margin: 0.75rem 0;
            padding: 0 0.25rem;
        }

        .selection-title {
            text-align: center;
            font-size: 1rem;
            font-weight: 500;
            color: #424242;
            margin-bottom: 0.5rem;
        }
    }
}

.note-selection {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    padding: 0.5rem;
    margin: 0.5rem 0;
    background: white;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.08);
}

.note-group {
    display: flex;
    gap: 0.25rem;
    justify-content: center;
}

.note-group.single {
    justify-content: center;
}

.note-group.single .note-button {
    min-width: 90px;
}

.clef-selection {
    display: flex;
    gap: 2rem;
    justify-content: center;
    margin: 2rem 0;
}

.clef-button {
    background: white;
    border: none;
    border-radius: 16px;
    padding: 2rem;
    cursor: pointer;
    width: 160px;
    height: 200px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: var(--button-shadow);
}

.clef-button:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
}

.clef-button.selected {
    border: 3px solid var(--primary-color);
    transform: scale(1.05);
}

.clef-button img {
    height: 100px;
    width: auto;
    margin-bottom: 1rem;
}

.clef-name {
    color: var(--primary-color);
    font-weight: bold;
}

.select-all {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 1.5rem 0;
}

.checkbox-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    user-select: none;
}

.checkbox-container input {
    display: none;
}

.checkmark {
    width: 24px;
    height: 24px;
    background: white;
    border-radius: 6px;
    position: relative;
    display: inline-block;
    transition: all 0.2s;
}

.checkbox-container input:checked + .checkmark {
    background: var(--primary-color);
}

.checkbox-container input:checked + .checkmark:after {
    content: '\2714';
    position: absolute;
    color: white;
    font-size: 16px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.app-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 1rem;
    min-height: calc(100vh - 70px);
    position: relative;
}

/* Quiz Ekranı */
.quiz-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
    padding: 1rem;
}

.quiz-progress {
    width: 100%;
    text-align: center;
    font-size: 1.2rem;
    color: var(--text-color);
}

.note-display {
    width: 100%;
    max-width: 300px;
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
}

.note-display img {
    max-width: 100%;
    height: auto;
}

.note-options {
    width: 100%;
    max-width: 500px;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 1rem;
    margin: 0 auto;
}

.quiz-option {
    background: white;
    border: 2px solid #ddd;
    border-radius: 8px;
    padding: 1rem;
    font-size: 1.2rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s ease;
}

.quiz-option:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.quiz-option.correct {
    background: #4CAF50;
    color: white;
    border-color: #388E3C;
}

.quiz-option.wrong {
    background: #f44336;
    color: white;
    border-color: #d32f2f;
}

.quiz-option:disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

.feedback-message {
    text-align: center;
    font-size: 1.2rem;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feedback-success {
    color: #4CAF50;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.feedback-error {
    color: #f44336;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.quiz-results h2 {
    color: var(--text-color);
    margin-bottom: 1.5rem;
}

.quiz-results p {
    font-size: 1.2rem;
    margin: 0.5rem 0;
    color: var(--text-color);
}

.quiz-results button {
    margin-top: 2rem;
    padding: 1rem 2rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

.quiz-results button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.setup-screen {
    display: none;
    height: 100%;
    opacity: 0;
    transform: translateX(100%);
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    animation: slideIn 0.5s ease forwards;
    background: var(--background-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--button-shadow);
}

.setup-screen.active {
    display: block;
}

.setup-screen.exit {
    animation: slideOut 0.5s ease forwards;
}

.screen-content {
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 2rem;
    gap: 2rem;
}

.screen-content h2 {
    text-align: center;
    font-size: 1.5rem;
    margin-bottom: 1rem;
    font-family: Verdana, Arial, sans-serif;
}

h1, h2, h3 {
    color: var(--text-color);
    text-align: center;
    margin-bottom: 2rem;
    font-family: Verdana, Arial, sans-serif;
}

.action-button {
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    min-width: 100px;
    position: relative;
    overflow: hidden;
    box-shadow: var(--button-shadow);
}