/* Reset et variables CSS */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Nouvelle palette de couleurs sombres et modernes */
    --primary-color: #8b5cf6;
    --primary-light: #c4b5fd;
    --success-color: #10b981;
    --error-color: #ef4444;
    --bg-main: #0f172a;
    --bg-sidebar: #1e293b;
    --bg-card: #334155;
    --card-hover: #475569;
    --text-dark: #f8fafc;
    --text-light: #cbd5e1;
    --text-primary: #a855f7;
    --border-color: #475569;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    
    /* Variables responsives */
    --mobile-header-height: 56px;
    --mobile-menu-width: 280px;
    --touch-target-size: 44px;
    --overlay-color: rgba(0, 0, 0, 0.6);
    
    /* Tailles de police responsives */
    --text-xs: clamp(0.75rem, 2vw, 0.875rem);
    --text-sm: clamp(0.875rem, 2.5vw, 1rem);
    --text-base: clamp(1rem, 3vw, 1.125rem);
    --text-lg: clamp(1.125rem, 3.5vw, 1.25rem);
    --text-xl: clamp(1.25rem, 4vw, 1.5rem);
    --text-2xl: clamp(1.5rem, 5vw, 2rem);
    --text-3xl: clamp(2rem, 6vw, 3rem);
    --text-4xl: clamp(3rem, 8vw, 4rem);
    --text-5xl: clamp(4rem, 10vw, 6rem);
    
    /* Espacements responsives */
    --space-1: clamp(0.25rem, 1vw, 0.5rem);
    --space-2: clamp(0.5rem, 2vw, 0.75rem);
    --space-3: clamp(0.75rem, 2.5vw, 1rem);
    --space-4: clamp(1rem, 3vw, 1.5rem);
    --space-6: clamp(1.5rem, 4vw, 2rem);
    --space-8: clamp(2rem, 5vw, 3rem);
    
    /* Conteneur max-width responsive */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
    --container-2xl: 1536px;
}

/* Ajout d'un style de transition global */
* {
    transition: background-color 0.3s ease, color 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
}

/* MOBILE FIRST - Base styles (320px+) */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-dark);
    overflow-x: hidden;
}

/* Classes utilitaires */
.desktop-only {
    display: none;
}

.mobile-only {
    display: block;
}

/* === HEADER MOBILE === */
.mobile-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--mobile-header-height);
    background: linear-gradient(135deg, var(--bg-sidebar) 0%, var(--bg-card) 100%);
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
    backdrop-filter: blur(8px);
    box-shadow: var(--shadow-sm);
}

.mobile-header-content {
    display: flex;
    align-items: center;
    height: 100%;
    padding: 0 var(--space-4);
    max-width: var(--container-2xl);
    margin: 0 auto;
}

.mobile-nav-controls {
    display: flex;
    align-items: center;
    margin-right: var(--space-4);
}

.mobile-title {
    font-size: var(--text-xl);
    font-weight: 600;
    color: var(--text-dark);
    margin: 0;
    flex: 1;
    text-align: center;
}

.logo-mobile {
    display: none; /* Retiré de l'en-tête mobile */
}

/* === BOUTON HAMBURGER === */
.hamburger-button {
    background: transparent;
    border: none;
    width: var(--touch-target-size);
    height: var(--touch-target-size);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.hamburger-button:hover {
    background: var(--bg-card);
}

.hamburger-line {
    width: 24px;
    height: 2px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    transform-origin: center;
}

/* Animation hamburger vers croix */
.hamburger-button.active .hamburger-line:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}

.hamburger-button.active .hamburger-line:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

.hamburger-button.active .hamburger-line:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

/* === OVERLAY MOBILE === */
.mobile-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    height: 100dvh; /* Support pour les nouveaux navigateurs */
    background: var(--overlay-color);
    z-index: 150;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    backdrop-filter: blur(2px);
    -webkit-backdrop-filter: blur(2px); /* Support Safari */
    pointer-events: none;
}

.mobile-overlay.active {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

/* === MENU MOBILE === */
.mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    width: min(var(--mobile-menu-width), 85vw);
    height: 100vh;
    height: 100dvh; /* Support pour les nouveaux navigateurs */
    background: var(--bg-sidebar);
    z-index: 200;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border-right: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    /* Support pour iOS Safari */
    -webkit-transform: translateX(-100%);
    will-change: transform;
}

.mobile-menu.active {
    transform: translateX(0);
    -webkit-transform: translateX(0);
}

.mobile-menu-content {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    padding: var(--space-2);
}

/* === HEADER DU MENU MOBILE === */
.mobile-menu-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4);
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-card);
    min-height: var(--mobile-header-height);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-4);
}

.mobile-menu-title {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.mobile-menu-title .logo {
    width: clamp(28px, 5vw, 36px);
    height: clamp(28px, 5vw, 36px);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: var(--text-sm);
}

.mobile-menu-title span {
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--text-dark);
}

.close-mobile-menu {
    background: transparent;
    border: none;
    width: var(--touch-target-size);
    height: var(--touch-target-size);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
}

.close-mobile-menu:hover {
    background: var(--card-hover);
}

.close-icon {
    font-size: 1.5rem;
    color: var(--text-light);
    transition: color 0.3s ease;
}

.close-mobile-menu:hover .close-icon {
    color: var(--text-dark);
}

/* === SECTIONS DU MENU MOBILE === */
.mobile-menu-section {
    flex: 1;
    padding: 0;
}

.mobile-menu-item {
    border-bottom: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-2);
    overflow: hidden;
    background: var(--bg-card);
}

.mobile-menu-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.menu-item-header {
    display: flex;
    align-items: center;
    padding: var(--space-4);
    cursor: pointer;
    transition: all 0.3s ease;
    min-height: var(--touch-target-size);
}

.menu-item-header:hover {
    background: var(--card-hover);
}

.menu-item-header.active {
    background: var(--card-hover);
    color: var(--primary-light);
}

.menu-item-simple {
    display: flex;
    align-items: center;
    padding: var(--space-4);
    cursor: pointer;
    transition: all 0.3s ease;
    min-height: var(--touch-target-size);
    border-radius: var(--radius-md);
}

.menu-item-simple:hover {
    background: var(--card-hover);
    color: var(--primary-light);
}

.menu-icon {
    font-size: var(--text-lg);
    margin-right: var(--space-3);
    min-width: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.menu-text {
    flex: 1;
    font-size: var(--text-sm);
    font-weight: 500;
}

.menu-arrow {
    font-size: var(--text-xs);
    transition: transform 0.3s ease;
    color: var(--text-light);
    margin-left: var(--space-2);
}

.menu-item-header.active .menu-arrow {
    transform: rotate(180deg);
    color: var(--primary-light);
}

/* === SOUS-MENUS MOBILE === */
.menu-submenu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background: var(--bg-main);
}

.menu-submenu.active {
    max-height: 500px;
    padding: var(--space-4);
}

.mobile-menu-separator {
    height: 1px;
    background: var(--border-color);
    margin: var(--space-4) 0;
}

.mobile-menu-item.simple {
    border-bottom: none;
    margin-bottom: var(--space-2);
}

/* Styles pour les paramètres intégrés */
.settings-section {
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.setting-item {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.setting-item.warning {
    border-color: var(--error-color);
    background: rgba(239, 68, 68, 0.05);
}

.setting-label {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.setting-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.setting-button {
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    color: var(--text-light);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
    font-size: 0.9rem;
    min-height: var(--touch-target-size);
    flex: 1;
    justify-content: center;
}

.setting-button:hover {
    background: var(--card-hover);
    color: var(--text-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.setting-button.warning {
    border-color: var(--error-color);
    color: var(--error-color);
}

.setting-button.warning:hover {
    background: var(--error-color);
    color: white;
    border-color: var(--error-color);
}

.setting-button .icon {
    font-size: 1rem;
}

.setting-button .button-text {
    font-size: 0.875rem;
    font-weight: 500;
}

/* Styles pour les éléments du menu mobile */
.mobile-menu .level-groups {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.mobile-menu .group-badge {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    background-color: var(--bg-card);
    color: var(--text-light);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.mobile-menu .group-badge.active {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.2), rgba(168, 85, 247, 0.1));
    color: var(--primary-light);
    border-color: var(--primary-color);
    font-weight: 600;
}

.mobile-menu .performance-stats {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.mobile-menu .stat-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
    border-radius: var(--radius-md);
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
}

.mobile-menu .stat-row .stat-label {
    color: var(--text-light);
    font-size: 0.9rem;
}

.mobile-menu .stat-row .stat-value {
    color: var(--primary-light);
    font-weight: 600;
    font-size: 1rem;
}

/* Bouton options mobile */
.mobile-options {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-light);
    width: var(--touch-target-size);
    height: var(--touch-target-size);
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.mobile-options:hover {
    background: var(--bg-card);
    color: var(--text-dark);
}

/* Animations pour mobile */
@keyframes slideInFromLeft {
    from {
        transform: translateX(-100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

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

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

/* Animation pour les cartes avec shuffle */
.hiragana-card.shuffle {
    animation: cardShuffle 0.4s ease-in-out;
}

@keyframes cardShuffle {
    0% {
        transform: translateY(0) rotateY(0);
    }
    50% {
        transform: translateY(-10px) rotateY(90deg);
        opacity: 0.7;
    }
    100% {
        transform: translateY(0) rotateY(0);
    }
}

/* Animation pour le romaji */
@keyframes romajiChange {
    0% {
        transform: scale(1) rotateX(0);
        opacity: 1;
    }
    50% {
        transform: scale(1.1) rotateX(90deg);
        opacity: 0.3;
    }
    100% {
        transform: scale(1) rotateX(0);
        opacity: 1;
    }
}

.app-container {
    padding-top: var(--mobile-header-height);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* --- Barre Latérale (Desktop uniquement) --- */
.sidebar {
    display: none;
}

.sidebar-header {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 1.2rem;
}

.sidebar-header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-dark);
}

.sidebar-section h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.level-groups {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.group-badge {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    background-color: var(--bg-card);
    color: var(--text-light);
    border: 1px solid var(--border-color);
    cursor: default;
    transition: all 0.3s ease;
}

.group-badge.active {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.2), rgba(168, 85, 247, 0.1));
    color: var(--primary-light);
    border-color: var(--primary-color);
    font-weight: 600;
}

/* --- Contenu Principal (Mobile First) --- */
.main-content {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-4);
    overflow: hidden;
    background: linear-gradient(135deg, var(--bg-main) 0%, #1a202c 100%);
    min-height: calc(100vh - var(--mobile-header-height) - 200px);
}

.game-area {
    width: 100%;
    max-width: var(--container-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-6);
    margin: 0 auto;
    padding: var(--space-4);
}

.romaji-display {
    font-size: var(--text-4xl);
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 2px 4px rgba(139, 92, 246, 0.3);
    text-align: center;
    line-height: 1.2;
    margin: var(--space-2) 0;
}

.cards-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    gap: var(--space-3);
    justify-content: center;
    width: 100%;
    max-width: 400px;
}

.hiragana-card {
    width: 100%;
    aspect-ratio: 5/6;
    min-height: var(--touch-target-size);
    background: linear-gradient(135deg, var(--bg-card) 0%, var(--card-hover) 100%);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-3xl);
    font-weight: 500;
    color: var(--text-dark);
    cursor: pointer;
    box-shadow: var(--shadow-md);
    border: 2px solid var(--border-color);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.hiragana-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(168, 85, 247, 0.05));
    opacity: 0;
    transition: all 0.3s ease;
}

.hiragana-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 20px -5px rgba(139, 92, 246, 0.3);
}

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

.hiragana-card.correct {
    border-color: var(--success-color);
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1), rgba(16, 185, 129, 0.05));
    box-shadow: 0 0 20px rgba(16, 185, 129, 0.3);
    transform: scale(1.05);
    pointer-events: none;
    animation: correctPulse 0.6s ease-out;
}

.hiragana-card.incorrect {
    border-color: var(--error-color);
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.1), rgba(239, 68, 68, 0.05));
    box-shadow: 0 0 20px rgba(239, 68, 68, 0.3);
    animation: incorrectShake 0.6s ease-in-out;
}

@keyframes correctPulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1.05);
    }
}

@keyframes incorrectShake {
    0%, 100% {
        transform: translateX(0);
    }
    20%, 60% {
        transform: translateX(-5px);
    }
    40%, 80% {
        transform: translateX(5px);
    }
}

/* --- Barre de Stats (Footer Mobile) --- */
.stats-footer {
    background: linear-gradient(135deg, var(--bg-sidebar) 0%, #2d3748 100%);
    border-top: 1px solid var(--border-color);
    padding: var(--space-4);
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    backdrop-filter: blur(8px);
    box-shadow: var(--shadow-sm);
}

.progress-info {
    width: 100%;
}

.progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-2);
    flex-wrap: wrap;
    gap: var(--space-2);
}

.progress-header h3 {
    font-size: var(--text-xs);
    font-weight: 500;
    color: var(--text-dark);
    flex: 1;
    min-width: 200px;
    line-height: 1.3;
}

.streak-counter {
    font-size: var(--text-xs);
    font-weight: 500;
    color: var(--text-light);
    background: var(--bg-card);
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
}

.progress-bar {
    width: 100%;
    height: clamp(4px, 1vw, 8px);
    background-color: rgba(71, 85, 105, 0.5);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    border-radius: var(--radius-sm);
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    gap: var(--space-3);
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: var(--space-1);
    padding: var(--space-3);
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.stat-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.stat-label {
    font-size: var(--text-xs);
    color: var(--text-light);
    font-weight: 500;
}

.stat-value {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--primary-light);
}

/* === BREAKPOINTS PROGRESSIFS === */

/* Très petits écrans (jusqu'à 320px) */
@media (max-width: 320px) {
    :root {
        --mobile-header-height: 56px;
        --mobile-menu-width: 90vw;
        --touch-target-size: 42px;
    }
    
    .mobile-menu {
        width: 90vw;
        max-width: 90vw;
    }
    
    .mobile-menu-content {
        padding: var(--space-2);
    }
    
    .mobile-menu-header {
        padding: var(--space-3);
        flex-wrap: wrap;
        gap: var(--space-2);
    }
    
    .mobile-menu-title {
        flex: 1;
        min-width: 150px;
    }
    
    .mobile-menu-title span {
        font-size: var(--text-sm);
    }
    
    .hamburger-button {
        width: 42px;
        height: 42px;
    }
    
    .close-mobile-menu {
        width: 42px;
        height: 42px;
    }
    
    .mobile-title {
        font-size: var(--text-sm);
    }
    
    .game-area {
        gap: var(--space-3);
        padding: var(--space-2);
    }
    
    .cards-container {
        grid-template-columns: repeat(3, 1fr);
        max-width: 260px;
        gap: var(--space-2);
    }
    
    .stats {
        grid-template-columns: 1fr;
        gap: var(--space-2);
    }
    
    /* Menu items plus compacts */
    .menu-item-header,
    .menu-item-simple {
        padding: var(--space-3) var(--space-3);
        font-size: var(--text-sm);
        min-height: var(--touch-target-size);
    }
    
    .menu-item-icon {
        font-size: var(--text-base);
    }
    
    .menu-submenu.active {
        padding: var(--space-3);
    }
    
    /* Éviter le débordement horizontal */
    body {
        overflow-x: hidden;
    }
    
    .app-container {
        max-width: 100vw;
        overflow-x: hidden;
    }
}

/* Très petit mobile (320px+) */
@media (min-width: 320px) {
    :root {
        --mobile-menu-width: 280px;
    }
    
    .mobile-menu {
        width: min(280px, 85vw);
    }
    
    .game-area {
        gap: var(--space-4);
    }
    
    .cards-container {
        grid-template-columns: repeat(3, 1fr);
        max-width: 300px;
    }
    
    .stats {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* Mobile paysage (480px+) */
@media (min-width: 480px) {
    :root {
        --mobile-header-height: 64px;
        --mobile-menu-width: 320px;
    }
    
    .game-area {
        gap: var(--space-6);
        max-width: var(--container-sm);
    }
    
    .cards-container {
        max-width: 420px;
        gap: var(--space-4);
    }
    
    .stats {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--space-4);
    }
    
    .mobile-menu-content {
        padding: var(--space-4);
    }
    
    .main-content {
        padding: var(--space-6);
    }
}

/* Tablette portrait (768px+) */
@media (min-width: 768px) {
    :root {
        --mobile-header-height: 72px;
        --mobile-menu-width: 400px;
    }
    
    .mobile-menu {
        width: min(400px, 50vw);
    }
    
    .mobile-header-content {
        padding: 0 var(--space-6);
    }
    
    .mobile-title {
        font-size: var(--text-2xl);
    }
    
    .game-area {
        gap: var(--space-8);
        max-width: var(--container-md);
        padding: var(--space-6);
    }
    
    .cards-container {
        max-width: 500px;
        grid-template-columns: repeat(3, 1fr);
    }
    
    .stats-footer {
        flex-direction: row;
        align-items: center;
        padding: var(--space-6);
        gap: var(--space-6);
    }
    
    .stats {
        display: flex;
        gap: var(--space-6);
    }
    
    .stat-item {
        flex-direction: row;
        gap: var(--space-2);
        min-width: 120px;
    }
    
    .progress-info {
        max-width: 400px;
    }
    
    .progress-header h3 {
        font-size: var(--text-sm);
    }
    
    .streak-counter {
        font-size: var(--text-sm);
    }
    
    /* Menu mobile amélioré pour tablette */
    .mobile-menu-header {
        padding: var(--space-6);
    }
    
    .menu-item-header,
    .menu-item-simple {
        padding: var(--space-4) var(--space-6);
        font-size: var(--text-base);
    }
    
    .menu-submenu.active {
        padding: var(--space-6);
    }
    
    .mobile-menu-content {
        padding: var(--space-4);
    }
}

/* Tablette paysage (1024px+) - Transition vers desktop */
@media (min-width: 1024px) {
    /* Masquer le mobile, afficher le desktop */
    .mobile-header,
    .mobile-menu,
    .mobile-overlay {
        display: none;
    }
    
    .mobile-only {
        display: none;
    }
    
    .desktop-only {
        display: block;
    }
    
    /* Retour au layout desktop original */
    .app-container {
        display: grid;
        grid-template-columns: 320px 1fr;
        grid-template-rows: 1fr auto;
        height: 100vh;
        padding-top: 0;
        grid-template-areas: 
            "sidebar main"
            "sidebar footer";
    }
    
    .sidebar {
        display: flex;
        grid-area: sidebar;
        background-color: var(--bg-sidebar);
        border-right: 1px solid var(--border-color);
        padding: var(--space-8);
        flex-direction: column;
        gap: var(--space-8);
    }
    
    .main-content {
        grid-area: main;
        padding: var(--space-8);
        min-height: auto;
    }
    
    .stats-footer {
        grid-area: footer;
        flex-direction: row;
        padding: var(--space-6) var(--space-8);
    }
    
    .game-area {
        max-width: var(--container-lg);
        gap: var(--space-8);
    }
    
    .romaji-display {
        font-size: var(--text-5xl);
    }
    
    .cards-container {
        grid-template-columns: repeat(3, 1fr);
        max-width: 600px;
        gap: var(--space-6);
    }
    
    .hiragana-card {
        font-size: var(--text-4xl);
    }
    
    .stats {
        display: flex;
        gap: var(--space-8);
    }
    
    .stat-item {
        flex-direction: row;
        align-items: baseline;
        background: transparent;
        border: none;
        padding: 0;
        gap: var(--space-2);
    }
    
    .stat-label {
        font-size: var(--text-sm);
    }
    
    .stat-value {
        font-size: var(--text-xl);
    }
}
/* Nouveaux styles accordéon */
.sidebar {
    padding: 1rem;
    gap: 0.75rem;
    max-height: 100vh;
    border-right: 1px solid var(--border-color);
}

.accordion {
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    background-color: var(--bg-card);
    margin-bottom: 0.5rem;
}

.accordion-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background-color: var(--bg-card);
    cursor: pointer;
    user-select: none;
    transition: background-color 0.2s ease;
}

.accordion-header:hover {
    background-color: var(--card-hover);
}

.accordion-header h3 {
    margin: 0;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.accordion-icon {
    font-size: 0.75rem;
    color: var(--text-light);
    transition: transform 0.3s ease;
}

.accordion.active .accordion-icon {
    transform: rotate(180deg);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    background-color: var(--bg-sidebar);
}

.accordion.active .accordion-content {
    max-height: 500px;
    padding: 0.75rem;
}

/* Ajustements pour le contenu des accordéons */
.level-groups,
.performance-stats {
    padding: 0;
}

.stat-row {
    padding: 0.5rem 0.75rem;
    background-color: var(--bg-card);
    border-radius: 8px;
    margin-bottom: 0.5rem;
}

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

/* Nouveaux styles accordéon */
.sidebar {
    padding: 1rem;
    gap: 0.75rem;
    max-height: 100vh;
    border-right: 1px solid var(--border-color);
}

.accordion {
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    background-color: var(--bg-card);
    margin-bottom: 0.5rem;
}

.accordion-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background-color: var(--bg-card);
    cursor: pointer;
    user-select: none;
    transition: background-color 0.2s ease;
}

.accordion-header:hover {
    background-color: var(--card-hover);
}

.accordion-header h3 {
    margin: 0;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.accordion-icon {
    font-size: 0.75rem;
    color: var(--text-light);
    transition: transform 0.3s ease;
}

.accordion.active .accordion-icon {
    transform: rotate(180deg);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    background-color: var(--bg-sidebar);
}

.accordion.active .accordion-content {
    max-height: 500px;
    padding: 0.75rem;
}

/* Ajustements pour le contenu des accordéons */
.level-groups,
.mastery-grid,
.performance-stats {
    padding: 0;
}

.stat-row {
    padding: 0.5rem 0.75rem;
    background-color: var(--bg-card);
    border-radius: 8px;
    margin-bottom: 0.5rem;
}

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

.mastery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(45px, 1fr));
    gap: 0.5rem;
}

/* --- Responsive Design --- */
@media (max-width: 1024px) {
    .app-container {
        grid-template-columns: 1fr;
        grid-template-rows: auto 1fr auto;
        grid-template-areas: 
            "sidebar"
            "main"
            "footer";
        height: auto;
        min-height: 100vh;
    }
    .sidebar {
        flex-direction: row;
        flex-wrap: wrap;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: 1rem;
        gap: 1.5rem;
    }
    .sidebar-section {
        flex-grow: 1;
    }
    .mastery-grid {
        max-height: 150px;
    }
    .game-area {
        gap: 2rem;
        padding: 2rem 0;
    }
    .romaji-display { font-size: 6rem; }
    .hiragana-card { width: 150px; height: 180px; font-size: 4rem; }
    .stats-footer {
        flex-direction: column;
        align-items: stretch;
        gap: 1rem;
        padding: 1rem;
    }
    .stats { justify-content: space-around; }
}

@media (max-width: 480px) {
    .sidebar {
        flex-direction: column;
        align-items: stretch;
    }
    .romaji-display { 
        font-size: 4rem; 
    }
    .hiragana-card { 
        width: 120px; 
        height: 150px; 
        font-size: 3rem; 
    }
    .cards-container { 
        gap: 1rem; 
    }
    .stats { 
        gap: 1.5rem; 
    }
    .stat-value { 
        font-size: 1.1rem; 
    }
}

/* Après le style .sidebar-header */
.toolbar {
    margin-left: auto;
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.tool-button {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-light);
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.tool-button:hover {
    background: var(--bg-card);
    color: var(--text-dark);
    transform: translateY(-2px);
}

.tool-button.warning:hover {
    background: rgba(239, 68, 68, 0.1);
    border-color: var(--error-color);
    color: var(--error-color);
}

.icon {
    font-size: 1.2rem;
}

/* Ajustement responsive */
@media (max-width: 768px) {
    .sidebar-header {
        flex-wrap: wrap;
        gap: 1rem;
    }
    
    .toolbar {
        width: 100%;
        justify-content: flex-end;
    }
}

/* Ajouter ces styles */

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.modal.show {
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 1;
}

.modal-content {
    background: var(--bg-sidebar);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 500px;
    border: 1px solid var(--border-color);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
    transform: translateY(20px);
    transition: transform 0.3s ease;
}

.modal.show .modal-content {
    transform: translateY(0);
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-dark);
}

.close-button {
    background: transparent;
    border: none;
    color: var(--text-light);
    font-size: 2rem;
    cursor: pointer;
    padding: 0.5rem;
    line-height: 1;
    transition: color 0.2s ease;
}

.close-button:hover {
    color: var(--text-dark);
}

.modal-body {
    padding: 1.5rem;
}

.options-grid {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.option-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.option-label {
    font-size: 1rem;
    color: var(--text-light);
}

.option-buttons {
    display: flex;
    gap: 0.5rem;
}

.option-button {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-light);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
}

.option-button:hover {
    background: var(--card-hover);
    color: var(--text-dark);
    transform: translateY(-2px);
}

.option-button.warning:hover {
    background: rgba(239, 68, 68, 0.1);
    border-color: var(--error-color);
    color: var(--error-color);
}

.button-text {
    font-size: 0.9rem;
}

/* Ajouter après les styles accordion existants */

.performance-stats {
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem;
    border-radius: var(--radius-md);
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
}

.stat-row .stat-label {
    color: var(--text-light);
    font-size: 0.9rem;
}

.stat-row .stat-value {
    color: var(--primary-light);
    font-weight: 600;
    font-size: 1rem;
}

/* Nouvelles animations et effets */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes scaleIn {
    from {
        transform: scale(0.95);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

/* Application des animations */
.accordion {
    animation: fadeIn 0.3s ease-out;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.accordion:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.accordion.active {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.accordion-content {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.accordion.active .accordion-content {
    animation: slideIn 0.3s ease-out;
}

.group-badge {
    animation: scaleIn 0.3s ease-out;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.group-badge:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.stat-row {
    animation: slideIn 0.3s ease-out;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.stat-row:hover {
    transform: translateX(8px);
    background-color: var(--card-hover);
    border-color: var(--primary-color);
}

/* Amélioration des transitions */
.accordion-header {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.accordion-header:hover {
    background-color: var(--card-hover);
    color: var(--primary-light);
}

.accordion-icon {
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Desktop large (1200px+) */
@media (min-width: 1200px) {
    .game-area {
        max-width: 900px;
    }
    
    .romaji-display {
        font-size: 9rem;
    }
    
    .hiragana-card {
        width: 200px;
        height: 240px;
        font-size: 5.5rem;
    }
}

/* Desktop très large (1440px+) */
@media (min-width: 1440px) {
    .sidebar {
        padding: 2.5rem;
    }
    
    .main-content {
        padding: 3rem;
    }
}

/* Gestion des très petits écrans (280px-320px) */
@media (max-width: 320px) {
    .romaji-display {
        font-size: 3rem;
    }
    
    .hiragana-card {
        width: 80px;
        height: 100px;
        font-size: 2.5rem;
    }
    
    .mobile-menu {
        width: 95vw;
    }
    
    .stats {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
}

/* Orientation paysage sur mobile */
@media (max-height: 480px) and (orientation: landscape) and (max-width: 768px) {
    .mobile-header {
        height: 48px;
    }
    
    .mobile-menu {
        height: 100vh;
        height: 100dvh;
        width: min(300px, 60vw);
    }
    
    .mobile-menu-content {
        padding: var(--space-2);
    }
    
    .mobile-menu-header {
        padding: var(--space-3);
        min-height: 48px;
    }
    
    .game-area {
        gap: var(--space-3);
        padding: var(--space-2);
    }
    
    .romaji-display {
        font-size: var(--text-2xl);
        margin: var(--space-1) 0;
    }
    
    .cards-container {
        max-width: 300px;
        gap: var(--space-2);
    }
    
    .hiragana-card {
        font-size: var(--text-xl);
    }
    
    .stats-footer {
        padding: var(--space-2) var(--space-4);
    }
    
    .main-content {
        min-height: calc(100vh - 48px - 80px);
    }
    
    /* Menu items plus compacts en paysage */
    .menu-item-header,
    .menu-item-simple {
        padding: var(--space-2) var(--space-3);
        font-size: var(--text-sm);
    }
    
    .menu-submenu.active {
        padding: var(--space-3);
    }
}

/* Support pour dark mode système - le thème sombre reste par défaut */

/* Amélioration de l'accessibilité */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Mode focus élevé pour accessibilité */
@media (prefers-contrast: high) {
    :root {
        --border-color: #ffffff;
        --text-light: #ffffff;
        --primary-color: #ffffff;
        --bg-card: #000000;
        --card-hover: #333333;
    }
    
    .hiragana-card {
        border-width: 3px;
    }
}

/* Desktop large (1200px+) - Améliorations finales */
@media (min-width: 1200px) {
    .sidebar {
        width: 380px;
        padding: var(--space-8) var(--space-6);
    }
    
    .app-container {
        grid-template-columns: 380px 1fr;
    }
    
    .game-area {
        max-width: var(--container-xl);
        gap: var(--space-8);
    }
    
    .main-content {
        padding: var(--space-8);
    }
    
    .cards-container {
        max-width: 700px;
        gap: var(--space-8);
    }
    
    .stats {
        gap: var(--space-8);
    }
    
    .romaji-display {
        font-size: var(--text-5xl);
    }
    
    .hiragana-card {
        font-size: var(--text-4xl);
    }
}

/* Desktop très large (1440px+) */
@media (min-width: 1440px) {
    .sidebar {
        padding: var(--space-8);
    }
    
    .main-content {
        padding: var(--space-8) var(--space-8);
    }
    
    .game-area {
        max-width: var(--container-2xl);
    }
    
    .cards-container {
        max-width: 800px;
    }
}

/* Desktop ultra-large (1920px+) */
@media (min-width: 1920px) {
    .app-container {
        max-width: 1920px;
        margin: 0 auto;
    }
    
    .game-area {
        gap: var(--space-8);
    }
}

/* Support pour les écrans haute densité */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    .hiragana-card {
        box-shadow: var(--shadow-lg);
    }
    
    .mobile-menu {
        box-shadow: 0 0 50px rgba(0, 0, 0, 0.5);
    }
}

/* Amélioration pour les écrans tactiles */
@media (hover: none) and (pointer: coarse) {
    .hiragana-card:hover {
        transform: none;
    }
    
    .hiragana-card:active {
        transform: scale(0.95);
        background: var(--card-hover);
    }
    
    .accordion-header:hover,
    .menu-item-header:hover,
    .menu-item-simple:hover {
        background: var(--bg-card);
    }
    
    .accordion-header:active,
    .menu-item-header:active,
    .menu-item-simple:active {
        background: var(--card-hover);
        transform: scale(0.98);
    }
}