/* Yabancı Dil Öğrenim Seti - Basit ve Odaklanmış Tasarım */

/* Sabit arka plan (overlay/blur yok) */
body {
    background-image: url('../images/bg.jpg');
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center center;
    background-attachment: fixed;
    /* Okunabilirlik için hafif koyulaştırma */
    background-color: rgba(0, 0, 0, 0.35);
    background-blend-mode: multiply;
}

/* TEMP: Dil değiştirme butonunu geçici olarak gizle */
#languageBtn { display: none !important; }

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

/* (moved to end of file for higher priority) */

/* Üst ortalanmış logo (index-v3.html) */
.top-logo {
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 12px 0 8px;
    position: relative;
    z-index: 5;
}
.top-logo > img,
.top-logo > picture img {
    display: block;
    margin: 0 auto; /* kesin ortalama */
}
.top-logo img {
    width: 100%;
    max-width: 300px;
    height: auto;
    object-fit: contain;
    filter: drop-shadow(0 2px 6px rgba(0,0,0,0.15));
}

/* Sidebar (index-v3.html) menü başlığı için logo düzeni */
.sidebar-menu .menu-header {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center; /* logo ortada */
}
.sidebar-menu .menu-header h3 { margin: 0; line-height: 1; }
.sidebar-menu .menu-header .menu-header-logo {
    height: 24px; /* kontrol: çok büyük görünmesin */
    width: auto;
    display: block;
    object-fit: contain;
}
.sidebar-menu .menu-header .menu-close {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
}

/* İçerik, sabit şeridin altında kalmasın diye alt boşluk ekle */
@media (min-width: 769px) {
    body {
        padding-bottom: calc(72px + env(safe-area-inset-bottom)) !important;
        overflow-y: hidden !important;         /* dikey scroll'u kapat */
        scrollbar-width: none !important;      /* Firefox */
    }
    html { overflow-y: hidden !important; }    /* bazı tarayıcılar için */
    body::-webkit-scrollbar {                  /* WebKit */
        width: 0 !important;
        height: 0 !important;
        background: transparent !important;
    }
}

/* Final override: non-mobile her genişlikte 4 sütun zorunlu */
@media (min-width: 769px) {
    .books-row {
        display: grid !important;
        grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
        gap: var(--spacing-md) !important;
        overflow: visible !important;
        scroll-snap-type: none !important;
    }
}

/* Features Dock - malzemelerin altında, tam genişlikte tek sıra kayan şerit */

.features-dock {
    position: fixed !important; /* her zaman görünür kıl */
    left: 0 !important;
    right: 0 !important;
    bottom: calc(12px + env(safe-area-inset-bottom)) !important; /* iOS güvenli alan */
    width: min(100%, 1200px) !important; /* geniş ekranlarda merkezde, dar ekranlarda tam genişlik */
    margin: 0 auto !important;
    height: 48px !important; /* kompakt yükseklik */
    padding: 0 12px !important;
    display: block !important;
    overflow: hidden !important;
    border-radius: 12px; /* alt şerit stili */
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: 2000 !important;
}

/* Non-mobil için ekstra hareket gerekmez; fixed konumda */

.features-dock .marquee-inner {
    display: inline-flex;
    gap: 12px;
    align-items: center;
    white-space: nowrap;
    width: max-content; /* içerik kadar genişlik */
    animation: features-marquee 60s linear infinite;
}

.features-dock:hover .marquee-inner {
    animation-play-state: paused; /* hover ile durdur */
}

/* Modal açıkken dock etkileşimini kapat: yanlış tıklamaları önle */
body.feature-modal-open .features-dock {
    pointer-events: none !important;
    cursor: default !important;
}

@keyframes features-marquee {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

.feature-chip {
    height: 36px;
    padding: 0 14px;
    border-radius: 9999px;
    /* iOS glass pill: layered translucency + highlight */
    background: linear-gradient(180deg, rgba(255,255,255,0.30), rgba(255,255,255,0.16));
    border: 1px solid var(--feature-chip-border, rgba(255,255,255,0.45));
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--feature-chip-fg, #0f1220);
    cursor: pointer; /* clickable */
    pointer-events: auto;
    box-shadow: 0 10px 26px rgba(0,0,0,0.14);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    /* inner highlight */
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.60), 0 10px 26px rgba(0,0,0,0.14);
}

.feature-chip[aria-disabled="true"] {
    opacity: 0.6;
    cursor: default;
    pointer-events: none; /* Disabled olanlar tıklanmasın */
}

.feature-chip .chip-label { font-family: 'SF Pro Display', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; }
.feature-chip.clickable { cursor: pointer; }
.feature-chip:hover { box-shadow: inset 0 1px 0 rgba(255,255,255,0.65), 0 14px 30px rgba(0,0,0,0.18); }

/* Dock'a bağlanan küçük yuvarlak ek parça (tag etkisi) */
.feature-chip::after { content: none !important; display: none !important; }

.feature-chip {
    height: 40px;
    padding: 0 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    border: 1px solid var(--feature-chip-border, rgba(255,255,255,0.4));
    background: #f2f2f2;
    color: var(--feature-chip-fg, #2f2f2f);
    cursor: default;
}

/* Feature Modal */
.feature-modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 3000; /* features-dock(2000) üstünde */
}
.feature-modal-overlay.active { display: flex; }
.feature-modal-content {
    background: white;
    width: min(640px, 90%);
    max-height: 80vh;
    border-radius: 16px;
    box-shadow: var(--shadow-2xl);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}
.feature-modal-header { padding: 16px 20px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid #eee; }
.feature-modal-body { padding: 16px 20px; overflow-y: auto; background: #fafafa; }
.feature-modal-close { background: transparent; border: none; cursor: pointer; font-size: 18px; }

:root {
    /* Renk Paleti */
    --primary-blue: #007AFF;
    --secondary-blue: #5AC8FA;
    --success-green: #34C759;
    --warning-orange: #FF9500;
    --error-red: #FF3B30;
    --purple: #AF52DE;
    
    /* Gri Tonları */
    --gray-50: #FAFAFA;
    --gray-100: #F5F5F7;
    --gray-200: #E5E5EA;
    --gray-300: #D1D1D6;
    --gray-400: #AEAEB2;
    --gray-500: #8E8E93;
    --gray-600: #636366;
    --gray-700: #48484A;
    --gray-800: #2C2C2E;
    --gray-900: #1C1C1E;
    
    /* Arka Plan */
    --background: #FFFFFF;
    --background-secondary: #F9F9F9;
    --surface-glass: rgba(255, 255, 255, 0.9);
    
    /* Metin */
    --text-primary: #000000;
    --text-secondary: #3C3C43;
    --text-tertiary: #8E8E93;
    
    /* Tipografi */
    --font-family: 'SF Pro Display', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    
    /* Font Boyutları */
    --font-size-xs: 11px;
    --font-size-sm: 13px;
    --font-size-base: 15px;
    --font-size-lg: 17px;
    --font-size-xl: 19px;
    --font-size-2xl: 22px;
    --font-size-3xl: 28px;
    --font-size-4xl: 34px;
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 20px;
    --spacing-2xl: 24px;
    --spacing-3xl: 32px;
    --spacing-4xl: 40px;
    --spacing-5xl: 48px;
    --spacing-6xl: 64px;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 20px;
    --radius-3xl: 24px;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1), 0 10px 10px rgba(0, 0, 0, 0.04);
    --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.25);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.2s ease;
    --transition-slow: 0.3s ease;
    --transition-spring: 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

body {
    font-family: var(--font-family);
    /* Arka plan görselini ezmemek için sadece metin ve layout özellikleri */
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    min-height: 100vh;
    padding: 0;
    margin: 0;
}

/* Ana Container */
.app-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-3xl);
    position: relative;
}

/* Kitap Seti Container */
/* Mobil için container ayarları */
@media (max-width: 768px) {
    /* Mobilde hamburger butonları gizle - gerek yok */
    .menu-toggle.left-toggle,
    .menu-toggle.right-toggle,
    .menu-toggle {
        display: none !important;
        visibility: hidden !important;
        opacity: 0 !important;
        pointer-events: none !important;
    }
    
    /* Mobilde ana içeriği gizle */
    .app-container {
        display: none !important;
    }
    
    /* Mobilde logo gizle */
    .top-logo {
        display: none !important;
    }
    
    /* Mobilde features dock gizle */
    .features-dock,
    .language-selector {
        display: none !important;
    }

    /* Mobilde sol menü otomatik açık ve tam ekran */
    .sidebar-menu.left {
        width: 100vw !important;
        height: 100vh !important;
        left: 0 !important;
        right: 0 !important;
        top: 0 !important;
        bottom: 0 !important;
        z-index: 9999 !important;
        transform: translateX(0) !important; /* Her zaman açık */
        position: fixed !important;
    }
    
    /* Sağ menüyü gizle - sadece sol menü yeterli */
    .sidebar-menu.right {
        display: none !important;
    }

    /* Menü içeriği tam ekran */
    .sidebar-menu.left .menu-content {
        width: 100vw !important;
        height: 100vh !important;
        border-radius: 0 !important;
        box-shadow: none !important;
        padding-bottom: env(safe-area-inset-bottom);
        background: rgba(255, 255, 255, 0.98) !important;
        backdrop-filter: blur(20px) !important;
    }
    
    /* Menü kapatma butonunu gizle - kapatmaya gerek yok */
    #leftMenuClose,
    #rightMenuClose {
        display: none !important;
    }

    .book-set-container {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        align-items: flex-start;
        gap: var(--spacing-2xl);
        padding: var(--spacing-2xl);
        min-height: 60vh;
        padding-bottom: var(--spacing-4xl);
        position: relative;
    }
}

/* Kitap Kartı - Kitap Öğesi */
.book-item {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: var(--spacing-xl);
    margin-bottom: 120px; /* Aç butonu için extra alan */
    cursor: pointer;
    transition: all var(--transition-base);
    transform-origin: center bottom;
    will-change: transform;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    z-index: 10; /* Kitaplar üstte olsun */
}

.book-item.dragging {
    z-index: 1000;
    transform: scale(1.1) rotate(5deg);
    filter: drop-shadow(0 20px 40px rgba(0, 0, 0, 0.3));
}

.book-item.selected {
    z-index: 100;
}

.book-item.opening {
    animation: bookOpenAnimation 0.8s ease-in-out;
}

.book-item:active {
    transform: scale(0.98);
}

/* Kitap Kapağı */
.book-cover {
    width: 200px;
    height: 280px;
    border-radius: var(--radius-xl);
    overflow: visible;
    background: transparent;
    position: relative;
    transition: all var(--transition-base);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.book-cover:hover .book-cover-image {
    transform: translateY(-4px) scale(1.02);
    filter: drop-shadow(0 20px 40px rgba(0, 0, 0, 0.3));
}

.book-cover img,
.book-cover-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: all var(--transition-base);
    border-radius: var(--radius-xl);
    filter: drop-shadow(0 10px 25px rgba(0, 0, 0, 0.2));
}

.book-item.opening .book-cover {
    transform: perspective(1000px) rotateY(-15deg);
    box-shadow: 0 25px 50px rgba(0, 122, 255, 0.3);
}

/* Ünite Butonu - Sağ Alt Köşe */
.book-units-btn {
    position: absolute;
    bottom: 12px;
    right: 12px;
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.95);
    border: none;
    border-radius: var(--radius-full);
    color: var(--primary-blue);
    font-size: var(--font-size-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 15;
    border: 2px solid rgba(0, 122, 255, 0.2);
}

.book-units-btn:hover {
    background: var(--primary-blue);
    color: white;
    transform: scale(1.1);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-blue);
}

.book-units-btn:active {
    transform: scale(0.95);
}

/* Ünite Paneli - Responsive Slide Menü */
.book-units-panel {
    position: absolute;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: var(--shadow-2xl);
    border: 1px solid rgba(255, 255, 255, 0.3);
    max-width: 0;
    max-height: 0;
    overflow: hidden;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 20;
    opacity: 0;
}

/* Desktop - Panel sabit konum - Final */
@media (min-width: 769px) {
    /* Tüm non-mobil genişliklerde kitaplar 4 sütun, fazlası alt satıra geçsin */
    .books-row {
        display: grid !important;
        grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
        gap: var(--spacing-md) !important;
        overflow: visible !important;
        scroll-snap-type: none !important;
    }
    .books-row .book-item {
        margin-bottom: 30px !important; /* alt boşluk kompakt */
    }
    .book-units-panel {
        position: absolute;
        top: 0;
        left: 50%; /* Kitapların sağında */
        width: 55%; /* Panel genişliği */
        height: 500px; /* Sabit yükseklik */
        border-radius: var(--radius-2xl);
        border: 1px solid rgba(255, 255, 255, 0.3);
        transform: translateX(-100%) scale(0.95); /* Soldan gelir */
        z-index: 50;
        opacity: 0;
        overflow: hidden; /* Normal overflow */
        transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94); /* Smooth easing */
        pointer-events: none; /* Başlangıçta tıklanamaz */
        background: rgba(255, 255, 255, 0.95); /* Arka plan ekle */
        backdrop-filter: blur(20px); /* Blur efekti */
        box-shadow: var(--shadow-2xl); /* Gölge ekle */
    }
    
    .book-units-panel.units-panel-active {
        transform: translateX(0) scale(1); /* Yerine gelir */
        opacity: 1;
        pointer-events: auto; /* Aktifken tıklanabilir */
        overflow: hidden; /* Normal overflow */
    }
    
    .book-set-container {
        display: flex;
        flex-wrap: wrap;
        justify-content: center; /* Her zaman merkezi hizala */
        align-items: flex-start;
        gap: var(--spacing-2xl);
        padding: var(--spacing-2xl);
        min-height: 60vh;
        padding-bottom: var(--spacing-4xl);
        position: relative; /* Panel için positioning context */
    }
    
    /* Kitapları sola hizala */
    .book-item {
        flex: 0 0 auto; /* Sabit boyut */
    }
    
    /* Ek materyalleri alta al */
    .extra-material {
        order: 100;
        flex-basis: calc(25% - var(--spacing-2xl));
    }
}

/* Mobil - Aşağı doğru açılma */
@media (max-width: 768px) {
    .book-units-panel {
        top: 100%;
        left: 0;
        right: 0;
        border-radius: 0 0 var(--radius-2xl) var(--radius-2xl);
        border-top: none;
        transform: translateY(-20px);
    }
    
    .book-units-panel.units-panel-active {
        max-height: 350px;
        transform: translateY(0);
        opacity: 1;
    }
    
    .book-item.book-with-panel {
        margin-bottom: 400px; /* Modal Sistemi */
    }
}

.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(10px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-2xl);
    border: 1px solid rgba(255, 255, 255, 0.3);
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    overflow: hidden;
    transform: scale(0.9) translateY(20px);
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.modal-overlay.active .modal-content {
    transform: scale(1) translateY(0);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-xl);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
}

.modal-book-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.modal-book-cover {
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.8);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.modal-book-details h2 {
    margin: 0;
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
}

.modal-book-details p {
    margin: var(--spacing-xs) 0 0 0;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.modal-close {
    background: rgba(255, 255, 255, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-full);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-base);
    color: var(--text-secondary);
}

.modal-close:hover {
    background: var(--danger-red);
    color: white;
    transform: scale(1.1);
}

.modal-body {
    padding: var(--spacing-xl);
    max-height: 60vh;
    overflow-y: auto;
}

/* Modal içindeki ünite listesi */
.modal-body .units-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.unit-item {
    background: rgba(255, 255, 255, 0.9) !important;
    border: 1px solid rgba(255, 255, 255, 0.3) !important;
    border-radius: var(--radius-lg) !important;
    padding: var(--spacing-lg) !important;
    cursor: pointer !important;
    transition: all var(--transition-base) !important;
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    opacity: 1 !important;
    visibility: visible !important;
    position: relative !important;
    z-index: 1 !important;
}

/* .unit-item:hover {
    background: var(--primary-blue) !important;
    color: white !important;
    transform: translateY(-2px) !important;
    box-shadow: var(--shadow-lg) !important;
    opacity: 1 !important;
    visibility: visible !important;
} */

.unit-info {
    flex: 1;
}

.unit-name {
    font-weight: 600;
    font-size: var(--font-size-base);
    margin-bottom: var(--spacing-xs);
}

.unit-page {
    font-size: var(--font-size-sm);
    opacity: 0.8;
}

.unit-icon {
    font-size: var(--font-size-sm);
    opacity: 0.6;
    transition: all var(--transition-base);
}

/* .unit-item:hover .unit-icon {
    opacity: 1;
    transform: translateX(4px);
} */

/* Dil Seçici */
.language-selector {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 100;
}

.language-btn {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-full);
    padding: var(--spacing-sm) var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-weight: 600;
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    box-shadow: var(--shadow-md);
}

.language-btn:hover {
    background: var(--primary-blue);
    color: white;
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
}

.language-btn i {
    font-size: var(--font-size-sm);
}

/* Mobil responsive */
@media (max-width: 768px) {
    .language-selector {
        top: var(--spacing-md);
        right: var(--spacing-md);
    }
    
    .modal-content {
        width: 95%;
        max-height: 90vh;
    }
    
    .modal-header {
        padding: var(--spacing-lg);
    }
    
    .modal-body {
        padding: var(--spacing-lg);
    }
    
    .modal-body .units-list {
        grid-template-columns: 1fr;
    }
}

/* Desktop - Tam ekran header */
@media (min-width: 769px) {
    .units-panel-header {
        padding: var(--spacing-2xl) var(--spacing-3xl);
        border-bottom: 1px solid rgba(255, 255, 255, 0.3);
        display: flex;
        justify-content: space-between;
        align-items: center;
        background: rgba(0, 122, 255, 0.1);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        min-height: 100px;
    }
    
    .panel-header-info {
        display: flex;
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .panel-book-title {
        font-size: var(--font-size-2xl);
        font-weight: 700;
        color: var(--text-primary);
        margin: 0;
        line-height: 1.2;
    }
    
    .panel-book-subtitle {
        font-size: var(--font-size-base);
        color: var(--text-secondary);
        margin: 0;
        opacity: 0.8;
    }
    
    .units-panel-close {
        width: 48px;
        height: 48px;
        font-size: var(--font-size-xl);
        background: rgba(255, 255, 255, 0.9);
        box-shadow: var(--shadow-md);
    }
    
    .units-panel-close:hover {
        background: white;
        transform: scale(1.1);
        box-shadow: var(--shadow-lg);
    }
}

/* Mobil - Kompakt header */
@media (max-width: 768px) {
    .units-panel-header {
        padding: var(--spacing-lg) var(--spacing-xl);
        border-bottom: 1px solid rgba(255, 255, 255, 0.3);
        display: flex;
        justify-content: space-between;
        align-items: center;
        background: rgba(0, 122, 255, 0.1);
        min-height: 80px;
    }
    
    .panel-header-info {
        display: flex;
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .panel-book-title {
        font-size: var(--font-size-lg);
        font-weight: 600;
        color: var(--text-primary);
        margin: 0;
        line-height: 1.3;
    }
    
    .panel-book-subtitle {
        font-size: var(--font-size-sm);
        color: var(--text-secondary);
        margin: 0;
        opacity: 0.8;
    }
    
    .units-panel-close {
        width: 36px;
        height: 36px;
        font-size: var(--font-size-base);
        background: rgba(255, 255, 255, 0.9);
        box-shadow: var(--shadow-sm);
    }
}

/* Ortak stiller */
.units-panel-close {
    border: none;
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Desktop - Panel body final */
@media (min-width: 769px) {
    .units-panel-body {
        padding: var(--spacing-lg) !important;
        height: 400px !important; /* Sabit yükseklik - header için alan bırak */
        overflow-y: auto !important; /* Scroll gerekirse */
        display: flex !important;
        align-items: flex-start !important;
        justify-content: center !important;
    }
}

/* Mobil - Kompakt panel body */
@media (max-width: 768px) {
    .units-panel-body {
        padding: var(--spacing-lg);
        max-height: 280px;
        overflow-y: auto;
    }
}

/* Desktop - Grid layout yan yana panel için - Final */
@media (min-width: 769px) {
    .book-units-panel .units-panel-body .units-list {
        display: grid !important;
        grid-template-columns: repeat(2, 1fr) !important; /* 2 sütun yan yana panel için */
        gap: var(--spacing-sm) !important;
        padding: 0 !important;
        width: 100% !important;
        max-width: none !important;
        margin: 0 !important;
        min-height: 350px !important; /* Minimum yükseklik garanti et */
    }
    
    /* Büyük ekranlarda 3 sütun */
    @media (min-width: 1400px) {
        .book-units-panel .units-panel-body .units-list {
            grid-template-columns: repeat(3, 1fr) !important;
        }
    }
}

/* Mobil - Column layout */
@media (max-width: 768px) {
    .units-list {
        display: flex;
        flex-direction: column;
        gap: var(--spacing-xs);
    }
}

/* Desktop - Kompakt ünite item'ları yan yana panel için - Final */
@media (min-width: 769px) {
    .book-units-panel .units-panel-body .units-list .unit-panel-item {
        padding: var(--spacing-md) !important;
        background: rgba(255, 255, 255, 0.9) !important; /* Normal beyaz arka plan */
        border-radius: var(--radius-md) !important;
        cursor: pointer !important;
        transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94) !important; /* Smooth transition */
        display: flex !important;
        justify-content: space-between !important;
        align-items: center !important;
        border: 1px solid rgba(255, 255, 255, 0.3) !important; /* Normal border */
        opacity: 0 !important; /* Başlangıçta gizli - animasyon için */
        transform: translateX(-20px) scale(0.95) !important; /* Animasyon başlangıcı */
        height: 70px !important; /* Kompakt yükseklik */
        margin-bottom: var(--spacing-xs) !important;
        color: var(--text-primary) !important; /* Normal text rengi */
        box-shadow: var(--shadow-sm) !important; /* Hafif gölge */
    }
    
    /* Hover efekti */
    .book-units-panel .units-panel-body .units-list .unit-panel-item:hover {
        background: var(--primary-blue) !important;
        color: white !important;
        transform: translateX(8px) scale(1) !important;
        box-shadow: var(--shadow-md) !important;
    }
}

/* Mobil - Aynı boyutta ünite item'ları */
@media (max-width: 768px) {
    .unit-panel-item {
        padding: var(--spacing-md);
        background: rgba(255, 255, 255, 0.8);
        border-radius: var(--radius-md);
        cursor: pointer;
        transition: all var(--transition-base);
        display: flex;
        justify-content: space-between;
        align-items: center;
        border: 1px solid rgba(255, 255, 255, 0.3);
        opacity: 0;
        transform: translateX(-20px);
        height: 65px; /* Sabit yükseklik */
    }
}

.unit-panel-item.unit-panel-visible {
    opacity: 1;
    transform: translateX(0) scale(1);
    transition-delay: calc(var(--unit-delay) * 30ms); /* Daha hızlı cascade */
}

.unit-panel-item:hover {
    background: var(--primary-blue);
    color: white;
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
}

.unit-panel-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    flex: 1;
    min-width: 0; /* Text overflow için gerekli */
}

/* Desktop - Büyük ünite isimleri */
@media (min-width: 769px) {
    .unit-panel-name {
        font-weight: 600;
        font-size: var(--font-size-base);
        line-height: 1.4;
        margin-bottom: var(--spacing-xs);
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    }
    
    .unit-panel-page {
        font-size: var(--font-size-sm);
        opacity: 0.7;
        font-weight: 500;
        white-space: nowrap;
    }
}

/* Mobil - Kompakt ünite isimleri */
@media (max-width: 768px) {
    .unit-panel-name {
        font-weight: 600;
        font-size: var(--font-size-sm);
        line-height: 1.3;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    }
    
    .unit-panel-page {
        font-size: var(--font-size-xs);
        opacity: 0.7;
        white-space: nowrap;
    }
}

.unit-panel-icon {
    font-size: var(--font-size-sm);
    opacity: 0.6;
    transition: all var(--transition-base);
}

.unit-panel-item:hover .unit-panel-icon {
    opacity: 1;
    transform: translateX(4px);
}

.units-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    padding: var(--spacing-2xl);
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

.units-loading i {
    color: var(--primary-blue);
}

/* Kitap Durumları - Desktop Gizleme - Layout Kayması Yok */
.book-set-container .book-item.book-hidden-desktop {
    opacity: 0 !important;
    transform: scale(0.7) !important;
    pointer-events: none !important;
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94) !important;
    visibility: hidden !important; /* Layout korunur */
}

.book-set-container .extra-material.material-hidden-desktop {
    opacity: 0 !important;
    transform: scale(0.7) !important;
    pointer-events: none !important;
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94) !important;
    visibility: hidden !important; /* Layout korunur */
}

/* Alternatif gizleme - animasyonlu */

/* Update Banner */
#updateBanner {
    position: fixed;
    top: 16px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 99999;
    width: min(92%, 840px);
}

.update-banner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 12px 14px;
    background: rgba(255,255,255,0.95);
    color: #111;
    border: 1px solid #e5e5ea;
    border-radius: 12px;
    box-shadow: 0 10px 24px rgba(0,0,0,0.15);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    cursor: pointer;
}

.update-banner .banner-close {
    position: absolute;
    top: -8px;
    right: -8px;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: 1px solid #e5e5ea;
    background: #fff;
    color: #333;
    font-size: 16px;
    line-height: 22px;
    display: grid;
    place-items: center;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0,0,0,0.12);
}
.update-banner .banner-close:hover { background: #f2f2f7; }

.update-banner .info { display: flex; align-items: center; gap: 10px; }
.update-banner .info i { color: #ff9500; font-size: 18px; }
.update-banner .info .text { display: flex; flex-direction: column; line-height: 1.2; }
.update-banner .info .text strong { font-size: 14px; }
.update-banner .info .text span { font-size: 13px; color: #444; }

.update-banner .actions .btn.primary {
    padding: 8px 12px;
    border-radius: 10px;
    background: #007aff;
    color: #fff;
    border: none;
    font-size: 13px;
}
.update-banner .actions .btn.primary:hover { background: #0062cc; }

/* Book cover actions (open + units) */
.book-item .book-cover {
    position: relative;
}

.book-item .book-cover .cover-actions {
    position: absolute;
    right: 10px;
    bottom: 10px;
    display: flex;
    gap: 8px;
}

.book-item .book-cover .cover-actions .book-open-btn,
.book-item .book-cover .cover-actions .book-units-btn {
    width: 42px;
    height: 42px;
    border-radius: 10px;
    border: 1px solid #e5e5ea;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: grid;
    place-items: center;
    cursor: pointer;
    box-shadow: 0 6px 14px rgba(0,0,0,0.15);
}

.book-item .book-cover .cover-actions .book-open-btn i,
.book-item .book-cover .cover-actions .book-units-btn i {
    font-size: 16px;
    color: #333;
}

.book-item .book-cover .cover-actions .book-open-btn:hover,
.book-item .book-cover .cover-actions .book-units-btn:hover {
    background: #fff;
}

@media (min-width: 769px) {
    .book-item.book-hidden-desktop.with-animation {
        opacity: 0 !important;
        transform: scale(0.7) translateY(-30px) !important;
        pointer-events: none !important;
        transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1) !important;
        margin: 0 !important;
        visibility: hidden !important;
        max-height: 0 !important;
        overflow: hidden !important;
    }
    
    .extra-material.material-hidden-desktop.with-animation {
        opacity: 0 !important;
        transform: scale(0.7) translateY(-30px) !important;
        pointer-events: none !important;
        transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1) !important;
        margin: 0 !important;
        visibility: hidden !important;
        max-height: 0 !important;
        overflow: hidden !important;
    }
}

/* Kitap Durumları - Mobil */
.book-set-container .book-item.book-hidden {
    display: none !important; /* Mobilde de tamamen gizle */
}

.book-set-container .extra-material.material-hidden {
    display: none !important; /* Mobilde de tamamen gizle */
}

/* Ortak Kitap Durumları */
.book-item.book-active {
    z-index: 100;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (min-width: 769px) {
    .book-item.book-active {
        transform: scale(1.05); /* Desktop'ta vurgu */
        box-shadow: var(--shadow-2xl); /* Gölge ekle */
    }
}

@media (max-width: 768px) {
    .book-item.book-active {
        transform: scale(1.05); /* Mobilde vurgu */
        box-shadow: var(--shadow-2xl); /* Gölge ekle */
    }
}

.book-cover-placeholder {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    text-align: center;
    padding: var(--spacing-lg);
}

.book-title-cover {
    font-size: var(--font-size-lg);
    font-weight: 600;
    line-height: 1.3;
    text-align: center;
    margin-top: var(--spacing-md);
}

.book-cover-placeholder i {
    font-size: 48px;
    margin-bottom: var(--spacing-md);
    opacity: 0.9;
}

.book-cover-placeholder .book-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    line-height: 1.3;
}

/* Kitap Bilgileri */
.book-info {
    position: absolute;
    bottom: -80px;
    left: 0;
    right: 0;
    text-align: center;
    opacity: 1;
    transform: translateY(0);
    transition: all var(--transition-base);
    pointer-events: auto;
}

.book-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: white;
    margin-bottom: var(--spacing-xs);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.book-subtitle {
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.8);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
    margin-bottom: var(--spacing-md);
}

/* Kitap Aç Butonu */
.book-open-btn {
    background: rgba(255, 255, 255, 0.95);
    color: var(--primary-blue);
    border: none;
    border-radius: var(--radius-lg);
    padding: var(--spacing-sm) var(--spacing-xl);
    font-size: var(--font-size-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin: 0 auto;
    min-width: 80px;
    justify-content: center;
    z-index: 20; /* Buton en üstte olsun */
    position: relative;
    right: 50px;
}

.book-open-btn:hover {
    background: white;
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
}

.book-open-btn:active {
    transform: scale(0.95);
}

/* Ek Materyal Butonu */
.extra-material {
    width: 160px;
    height: 160px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: var(--radius-2xl);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-base);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: var(--shadow-lg);
    margin: var(--spacing-xl);
    margin-top: var(--spacing-4xl); /* Kitap butonlarından uzaklaştır */
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    z-index: 5; /* Kitaplardan altta olsun */
}

.extra-material:hover {
    transform: translateY(-8px) scale(1.05);
    box-shadow: var(--shadow-2xl);
    background: rgba(255, 255, 255, 1);
}

.extra-material i {
    font-size: var(--font-size-4xl);
    color: var(--primary-blue);
    transition: all var(--transition-base);
}

.extra-material:hover i {
    transform: scale(1.1);
    color: var(--secondary-blue);
}

.extra-material .material-title {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
    line-height: 1.3;
}

.extra-material .material-subtitle {
    font-size: var(--font-size-xs);
    color: var(--text-tertiary);
    text-align: center;
}

/* Sandviç Menü Stilleri */
.sidebar-menu {
    position: fixed;
    top: 0;
    bottom: 0;
    width: 350px;
    z-index: 1500;
    transition: transform var(--transition-base);
}

.sidebar-menu.left {
    left: 0;
    transform: translateX(-100%);
}

.sidebar-menu.right {
    right: 0;
    transform: translateX(100%);
}

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

/* Menü Toggle Butonu - Desktop'ta görünür */
.menu-toggle {
    display: flex;
    position: fixed;
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.95);
    border: none;
    border-radius: var(--radius-xl);
    color: var(--primary-blue);
    font-size: var(--font-size-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: var(--shadow-lg);
    align-items: center;
    justify-content: center;
    z-index: 10000;
}

.menu-toggle.left-toggle {
    top: 50%;
    left: 20px;
    transform: translateY(-50%);
}

.menu-toggle.right-toggle {
    top: 50%;
    right: 20px;
    transform: translateY(-50%);
}

/* Hover efektleri kaldırıldı */

/* Menü İçeriği */
.menu-content {
    width: 320px;
    height: 100%;
    background: white;
    position: relative;
    box-shadow: var(--shadow-2xl);
}

.sidebar-menu.left .menu-content {
    border-radius: 0 var(--radius-2xl) var(--radius-2xl) 0;
}

.sidebar-menu.right .menu-content {
    border-radius: var(--radius-2xl) 0 0 var(--radius-2xl);
}

/* Menü Bölüm Başlıkları */
.menu-section-header {
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
    background: var(--color-background-secondary);
}

.menu-section-header h4 {
    margin: 0;
    font-size: var(--font-size-md);
    font-weight: 600;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Menü Kitap Öğeleri */
.menu-book-item {
    border-bottom: 1px solid #e0e0e0;
}

.menu-book-header {
    padding: 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    transition: background-color 0.3s;
    min-height: 52px; /* Dokunmatik hedefi */
}

.menu-book-header:hover {
    background-color: #f5f5f5;
}

/* Sidebar: kitap satırı için özel sınıflar */
.menu-book-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.menu-book-icon {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 20px;
}

/* Büyük dokunmatik hedefli accordion toggle */
.menu-accordion-toggle {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
}
.menu-accordion-toggle:active {
    background: #eee;
}

.menu-book-details {
    display: flex;
    flex-direction: column;
}

.menu-book-name {
    font-size: 16px;
    font-weight: 600;
    color: #000;
    margin-bottom: 2px;
}

.menu-book-subtitle {
    font-size: 12px;
    color: #666;
}

.accordion-icon {
    color: var(--color-text-secondary);
    transition: transform var(--transition-base);
}

/* Menü Ünite Listesi */
.menu-units-list {
    background-color: var(--color-background-secondary);
    border-top: 1px solid var(--color-border);
}

.units-loading {
    padding: var(--spacing-lg);
    text-align: center;
    color: var(--color-text-secondary);
}

.units-loading i {
    margin-right: var(--spacing-sm);
}

/* Menü Ek Materyal Öğeleri */
.menu-extra-item {
    padding: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    cursor: pointer;
    transition: background-color var(--transition-base);
}

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

.extra-icon {
    font-size: 20px;
    width: 40px;
    text-align: center;
}

.extra-details {
    display: flex;
    flex-direction: column;
}

.extra-name {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: 2px;
}

.extra-subtitle {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

/* Menü Header */
.menu-header {
    padding: var(--spacing-3xl);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(0, 122, 255, 0.1);
}

.menu-header h3 {
    font-family: var(--font-family);
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

.menu-close {
    width: 36px;
    height: 36px;
    border: none;
    background: rgba(255, 255, 255, 0.8);
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
}

.menu-close:hover {
    background: white;
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

/* Menü Body */
.menu-body {
    flex: 1;
    padding: var(--spacing-xl);
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: rgba(0, 122, 255, 0.3) transparent;
}

.menu-body::-webkit-scrollbar {
    width: 6px;
}

.menu-body::-webkit-scrollbar-track {
    background: transparent;
}

.menu-body::-webkit-scrollbar-thumb {
    background: rgba(0, 122, 255, 0.3);
    border-radius: 3px;
}

.menu-body::-webkit-scrollbar-thumb:hover {
    background: rgba(0, 122, 255, 0.5);
}

/* Accordion Stilleri */
.accordion-item {
    margin-bottom: var(--spacing-md);
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: var(--shadow-sm);
}

.accordion-header {
    padding: var(--spacing-lg);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all var(--transition-base);
    background: rgba(255, 255, 255, 0.9);
}

.accordion-header:hover {
    background: rgba(0, 122, 255, 0.1);
}

.accordion-header.active {
    background: rgba(0, 122, 255, 0.15);
    color: var(--primary-blue);
}

.accordion-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-weight: 600;
    font-size: var(--font-size-base);
}

.accordion-title i {
    font-size: var(--font-size-lg);
    color: var(--primary-blue);
}

.accordion-arrow {
    font-size: var(--font-size-sm);
    transition: transform var(--transition-base);
}

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

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-base);
    background: rgba(255, 255, 255, 0.95);
}

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

.accordion-body {
    padding: var(--spacing-lg);
    padding-top: 0;
}

/* Ünite Listesi - Menü İçinde */
.menu-unit-item {
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-xs);
    background: rgba(255, 255, 255, 0.8);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

/* .menu-unit-item:hover {
    background: var(--primary-blue);
    color: white;
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
} */

.menu-unit-item:last-child {
    margin-bottom: 0;
}

.unit-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.unit-name-menu {
    font-weight: 600;
    font-size: var(--font-size-sm);
}

.unit-page-menu {
    font-size: var(--font-size-xs);
    opacity: 0.7;
}

.unit-icon {
    font-size: var(--font-size-sm);
    opacity: 0.6;
}

/* Ek Materyaller - Menü İçinde */
.menu-extra-item {
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    background: rgba(255, 255, 255, 0.8);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.menu-extra-item:hover {
    background: var(--success-green);
    color: white;
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
}

.menu-extra-item:last-child {
    margin-bottom: 0;
}

.extra-icon {
    font-size: var(--font-size-lg);
    width: 24px;
    text-align: center;
}

.extra-info {
    flex: 1;
}

.extra-title-menu {
    font-weight: 600;
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-xs);
}

.extra-subtitle-menu {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin: 0;
    font-weight: 500;
}

/* Dokunmatik İpucu */
.touch-hint {
    position: absolute;
    bottom: var(--spacing-3xl);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: rgba(255, 255, 255, 0.9);
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-full);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    opacity: 0.8;
    animation: fadeInOut 3s ease-in-out infinite;
}

.touch-hint i {
    font-size: var(--font-size-lg);
    color: var(--primary-blue);
}

.touch-hint p {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin: 0;
    font-weight: 500;
}

@keyframes fadeInOut {
    0%, 100% { opacity: 0.8; }
    50% { opacity: 0.4; }
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content,
.preview-content {
    background: var(--surface-glass);
    border-radius: var(--radius-3xl);
    box-shadow: var(--shadow-2xl);
    max-width: 800px;
    width: 95%;
    max-height: 85vh;
    overflow: hidden;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.modal-content {
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.modal-header {
    padding: var(--spacing-3xl);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.modal-book-info {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
    flex: 1;
}

.modal-book-cover {
    width: 50px;
    height: 70px;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    flex-shrink: 0;
}

.modal-book-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.modal-book-details h2 {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
    margin: 0 0 var(--spacing-xs) 0;
}

.modal-book-details p {
    font-size: var(--font-size-sm);
    color: var(--text-tertiary);
    margin: 0;
}

.modal-close {
    width: 32px;
    height: 32px;
    border: none;
    background: rgba(255, 255, 255, 0.8);
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 1);
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

.modal-body {
    padding: var(--spacing-xl);
    flex: 1;
    overflow: hidden;
}

/* Ünite Grid */
.units-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: var(--spacing-md);
    padding: var(--spacing-xl);
    max-height: 60vh;
    overflow-y: auto;
}

.unit-item {
    background: rgba(255, 255, 255, 0.9);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    min-height: 60px;
}

/* .unit-item:hover {
    background: var(--primary-blue);
    color: white;
    transform: translateX(8px);
    box-shadow: var(--shadow-lg);
} */

.unit-name {
    font-weight: 600;
    font-size: var(--font-size-base);
    transition: color var(--transition-base);
}

.unit-page {
    font-size: var(--font-size-sm);
    opacity: 0.7;
    transition: opacity var(--transition-base);
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 3000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.loading-overlay.active {
    opacity: 1;
    visibility: visible;
}

.loading-content {
    text-align: center;
    color: var(--text-primary);
}

.loading-spinner i {
    font-size: 48px;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-lg);
    display: block;
}

.loading-title {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin: 0 0 var(--spacing-sm) 0;
}

.loading-subtitle {
    font-size: var(--font-size-base);
    color: var(--text-secondary);
    margin: 0;
}

/* Responsive Design - Mobil */
@media (max-width: 768px) {
    .app-container {
        padding: var(--spacing-xl);
    }
    
    .book-set-container {
        gap: var(--spacing-2xl);
        flex-direction: column;
        align-items: center;
        padding-bottom: var(--spacing-3xl);
    }
    
    .book-item {
        margin-bottom: 100px; /* Mobilde daha az boşluk */
    }
    
    .extra-material {
        margin-top: var(--spacing-2xl); /* Mobilde daha az boşluk */
    }
    
    
    /* Mobil'de kapak görselleri küçük */
    .book-cover {
        width: 120px;
        height: 160px;
    }
    
    .book-info {
        bottom: -70px;
        opacity: 1;
        transform: translateY(0);
        pointer-events: auto;
    }
    
    .book-title {
        font-size: var(--font-size-base);
    }
    
    .book-subtitle {
        font-size: var(--font-size-xs);
    }
    
    .book-open-btn {
        padding: var(--spacing-xs) var(--spacing-md);
        font-size: var(--font-size-xs);
        min-width: 60px;
    }
    
    .book-units-btn {
        width: 40px;
        height: 40px;
        bottom: 8px;
        right: 8px;
        font-size: var(--font-size-base);
    }
    
    .extra-material {
        width: 120px;
        height: 120px;
    }
    
    .extra-material i {
        font-size: var(--font-size-3xl);
    }
    
    .extra-material .material-title {
        font-size: var(--font-size-sm);
    }
    
    
    /* Mobil'de hamburger butonları gizli (yukarıdaki kurallar geçerli) */
    
    .menu-header {
        padding: var(--spacing-xl);
    }
    
    .menu-header h3 {
        font-size: var(--font-size-lg);
    }
}

@media (max-width: 480px) {
    .app-container {
        padding: var(--spacing-lg);
    }
    
    .book-set-container {
        gap: var(--spacing-xl);
        flex-direction: column;
        align-items: center;
    }
    
    /* Çok küçük ekranlarda kapaklar daha da küçük */
    .book-cover {
        width: 100px;
        height: 140px;
    }
    
    .book-info {
        bottom: -60px;
    }
    
    .book-title {
        font-size: var(--font-size-sm);
    }
    
    .book-subtitle {
        font-size: var(--font-size-xs);
    }
    
    .book-units-btn {
        width: 36px;
        height: 36px;
        font-size: var(--font-size-sm);
    }
    
    .extra-material {
        width: 100px;
        height: 100px;
    }
    
    .modal-content {
        max-width: 95%;
        width: 95%;
    }
    
    .units-grid {
        grid-template-columns: 1fr;
        padding: var(--spacing-md);
        gap: var(--spacing-sm);
    }
    
    .modal-header {
        padding: var(--spacing-xl);
    }
    
    .modal-body {
        padding: var(--spacing-xl);
    }
}

/* Dokunmatik Ekran Optimizasyonları */
@media (pointer: coarse) {
    .book-item,
    .extra-material,
    .unit-item,
    .modal-close {
        min-height: 44px;
        min-width: 44px;
    }
    
    .book-item:active {
        transform: scale(0.95);
    }
    
    .extra-material:active {
        transform: scale(0.95);
    }
    
    .unit-item:active {
        transform: scale(0.98);
    }
}

/* Accessibility */
.book-item:focus,
.extra-material:focus,
.unit-item:focus,
.modal-close:focus {
    outline: 2px solid var(--primary-blue);
    outline-offset: 2px;
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .book-item:hover {
        transform: none;
    }
    
    .touch-hint {
        animation: none;
    }
}

/* Rowed layout: force materials to second row */
.books-row,
.materials-row {
    width: 100%;
    display: grid;
    gap: var(--spacing-2xl);
}

/* Books row: tek satır, yatay kaydırma ve snap */
.books-row {
    display: flex;
    flex-wrap: nowrap;           /* Tek satır */
    overflow-x: auto;            /* Yatay scroll */
    overflow-y: visible;
    -webkit-overflow-scrolling: touch;
    gap: var(--spacing-2xl);
    justify-content: center;     /* İçeriği ortala (taşmıyorsa) */
    padding-bottom: 0; /* Scroll bar üstü boşluk */
    scroll-snap-type: x mandatory;
    scrollbar-width: none; /* Firefox */
}
.books-row::-webkit-scrollbar {
    height: 0; /* Alttaki scroll'u gizle */
}
.books-row::-webkit-scrollbar-thumb {
    background: transparent;
}

.books-row .book-item {
    flex: 0 0 auto;              /* Sabit genişlikli kartlar */
    scroll-snap-align: start;    /* Snap başlangıcı */
    margin-bottom: 30px;        /* Mevcut buton boşluğu korunur */
}


/* Remove extra top margin on materials in dedicated row */
.materials-row .extra-material {
    margin-top: 0;
    width: 100%;
    height: var(--mat-tile, 160px);
}

@media (max-width: 768px) {
    .books-row,
    .materials-row {
        gap: var(--spacing-xl);
    }
}

/* Materials grid with dynamic columns (controlled via inline --mat-cols) */
.materials-row {
    --mat-cols: 4;
    --mat-tile: 160px;
    grid-template-columns: repeat(var(--mat-cols), minmax(140px, 1fr));
}

/* Zorunlu merkezleme: JS, az öğe olduğunda bu sınıfı ekler */
.materials-row.materials-centered {
    display: flex !important;
    flex-wrap: nowrap !important;
    justify-content: center !important;
    align-items: stretch !important;
}

@media (max-width: 1280px) {
    .materials-row { --mat-cols: 3; --mat-tile: 150px; }
}

@media (max-width: 1024px) {
    .materials-row { --mat-cols: 3; --mat-tile: 140px; }
}

@media (max-width: 768px) {
    .materials-row { --mat-cols: 2; --mat-tile: 140px; }
}

/* Geniş ekranlar (>=1281px): Aç butonu + yanında kalsın */
@media (min-width: 1281px) {
    /* Başlıklar görünür kalsın */
    .book-info { display: block !important; }
    .book-open-btn {
        position: absolute !important;
        bottom: 12px !important;
        right: 60px !important; /* + butonunun solunda */
        width: 44px !important;
        height: 44px !important;
        padding: 0 !important;
        border-radius: var(--radius-full) !important;
        background: rgba(255, 255, 255, 0.95) !important;
        color: var(--primary-blue) !important;
        border: 2px solid rgba(0, 122, 255, 0.2) !important;
        display: inline-flex !important;
        align-items: center !important;
        justify-content: center !important;
        box-shadow: var(--shadow-md) !important;
        backdrop-filter: blur(10px) !important;
        -webkit-backdrop-filter: blur(10px) !important;
        z-index: 16 !important;
        font-size: var(--font-size-lg) !important;
    }
    .book-open-btn:hover { background: var(--primary-blue) !important; color: #fff !important; transform: scale(1.1) !important; box-shadow: var(--shadow-lg) !important; border-color: var(--primary-blue) !important; }
    .book-open-btn:active { transform: scale(0.95) !important; }
    .book-open-btn span { display: none !important; }
    .book-open-btn::before { content: none !important; }
}
/* Dar ekranlar (mobil değil) için kitapları grid'e geçir ve kapakları küçült */
@media (min-width: 1025px) and (max-width: 1280px) {
    .books-row {
        display: grid !important;
        grid-template-columns: repeat(4, minmax(180px, 1fr)) !important;
        gap: var(--spacing-lg) !important; /* GAP küçültüldü */
        overflow: visible !important;
        scroll-snap-type: none !important;
    }
    .book-cover { width: 180px; height: 252px; }
    .book-item { margin-bottom: 72px; } /* alt boşluk daha da az */
    /* İkincil öğeleri daha kompakt yap, tek satıra yaklaşsın */
    .materials-row {
        display: flex !important;
        flex-wrap: nowrap !important;
        justify-content: center !important;
        gap: var(--spacing-md) !important;
    }
    .extra-material {
        width: 96px !important;
        height: 96px !important;
        padding: 10px !important;
    }
    /* Metinler görünür kalsın (küçük) */
    .extra-material i { font-size: 40px !important; }
    .extra-material .material-title { display: block !important; font-size: 18px !important; line-height: 1.1; text-align: center; }
    .extra-material .material-subtitle { display: block !important; font-size: 10px !important; opacity: 0.75; line-height: 1.1; text-align: center; }

    /* Aç butonunu + ile birebir aynı stile getir (44x44, yuvarlak) */
    .book-open-btn {
        position: absolute !important;
        bottom: 12px !important;
        right: 60px !important; /* + butonunun solunda 4px boşlukla */
        width: 44px !important;
        height: 44px !important;
        padding: 0 !important;
        border-radius: var(--radius-full) !important;
        background: rgba(255, 255, 255, 0.95) !important;
        color: var(--primary-blue) !important;
        border: 2px solid rgba(0, 122, 255, 0.2) !important;
        display: inline-flex !important;
        align-items: center !important;
        justify-content: center !important;
        box-shadow: var(--shadow-md) !important;
        backdrop-filter: blur(10px) !important;
        -webkit-backdrop-filter: blur(10px) !important;
        z-index: 16 !important;
        font-size: var(--font-size-lg) !important;
    }
    .book-open-btn:hover { background: var(--primary-blue) !important; color: #fff !important; transform: scale(1.1) !important; box-shadow: var(--shadow-lg) !important; border-color: var(--primary-blue) !important; }
    .book-open-btn:active { transform: scale(0.95) !important; }
    .book-open-btn span { display: none !important; }
    .book-open-btn::before { content: none !important; }
}

/* Final override: Non-mobile tüm genişliklerde 4 sütun sabit */
@media (min-width: 769px) {
    .books-row {
        display: grid !important;
        grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
        gap: var(--spacing-md) !important;
        overflow-x: visible !important;
        overflow-y: visible !important;
        scroll-snap-type: none !important;
    }
    .books-row .book-item {
        flex: initial !important;
        scroll-snap-align: initial !important;
        margin-bottom: 120px !important;
    }
}

/* Materials: non-mobilde 4'e kadar tek satır, fazlası ikinci satıra geçsin */
@media (min-width: 769px) {
    .materials-row:not(.materials-centered) {
        display: grid !important;
        grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
        gap: var(--spacing-md) !important;
        align-items: stretch !important;
        justify-items: stretch !important;
    }
    .materials-row .extra-material {
        width: 100% !important;
        height: 140px !important; /* kompakt ve tutarlı karo yüksekliği */
    }
}

@media (min-width: 901px) and (max-width: 1024px) {
    .books-row {
        display: grid !important;
        grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
        gap: var(--spacing-md) !important; /* GAP küçültüldü */
        overflow: visible !important;
        scroll-snap-type: none !important;
    }
    .book-cover { width: 170px; height: 238px; }
    .book-item { margin-bottom: 56px; }
    .materials-row {
        display: flex !important;
        flex-wrap: nowrap !important;
        justify-content: center !important;
        gap: var(--spacing-xs) !important;
    }
    .extra-material {
        width: 84px !important;
        height: 84px !important;
        padding: 8px !important;
    }
    .extra-material i { font-size: 40px !important; }
    .extra-material .material-title { display: block !important; font-size: 18px !important; line-height: 1.1; text-align: center; }
    .extra-material .material-subtitle { display: block !important; font-size: 9px !important; opacity: 0.75; line-height: 1.1; text-align: center; }

    /* Kitap başlıklarını gizle, Aç butonunu + butonunun yanına al */
    .book-info { display: none !important; }
    .book-open-btn {
        position: absolute !important;
        bottom: 12px !important;
        right: 60px !important; /* + butonunun solunda 4px boşlukla */
        width: 44px !important;
        height: 44px !important;
        padding: 0 !important;
        border-radius: var(--radius-full) !important;
        background: rgba(255, 255, 255, 0.95) !important;
        color: var(--primary-blue) !important;
        border: 2px solid rgba(0, 122, 255, 0.2) !important;
        display: inline-flex !important;
        align-items: center !important;
        justify-content: center !important;
        box-shadow: var(--shadow-md) !important;
        backdrop-filter: blur(10px) !important;
        -webkit-backdrop-filter: blur(10px) !important;
        z-index: 16 !important;
        font-size: var(--font-size-lg) !important;
    }
    .book-open-btn:hover { background: var(--primary-blue) !important; color: #fff !important; transform: scale(1.1) !important; box-shadow: var(--shadow-lg) !important; border-color: var(--primary-blue) !important; }
    .book-open-btn:active { transform: scale(0.95) !important; }
    .book-open-btn span { display: none !important; }
    .book-open-btn::before { content: none !important; }
}

@media (min-width: 769px) and (max-width: 900px) {
    .books-row {
        display: grid !important;
        grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
        gap: var(--spacing-sm) !important; /* GAP küçültüldü */
        overflow: visible !important;
        scroll-snap-type: none !important;
    }
    .book-cover { width: 160px; height: 224px; }
    .book-item { margin-bottom: 48px; }
    .materials-row {
        display: flex !important;
        flex-wrap: nowrap !important;
        justify-content: center !important;
        gap: 6px !important;
    }
    .extra-material {
        width: 72px !important;
        height: 72px !important;
        padding: 6px !important;
    }
    .extra-material i { font-size: 20px !important; }
    .extra-material .material-title { display: block !important; font-size: 9.5px !important; line-height: 1.1; text-align: center; }
    .extra-material .material-subtitle { display: block !important; font-size: 9px !important; opacity: 0.75; line-height: 1.1; text-align: center; }

    /* Kitap başlıklarını gizle, Aç butonunu + butonunun yanına al */
    .book-info { display: none !important; }
    .book-open-btn {
        position: absolute !important;
        bottom: 10px !important;
        right: 56px !important; /* + butonunun solunda 4px boşlukla */
        width: 44px !important;
        height: 44px !important;
        padding: 0 !important;
        border-radius: var(--radius-full) !important;
        background: rgba(255, 255, 255, 0.95) !important;
        color: var(--primary-blue) !important;
        border: 2px solid rgba(0, 122, 255, 0.2) !important;
        display: inline-flex !important;
        align-items: center !important;
        justify-content: center !important;
        box-shadow: var(--shadow-md) !important;
        backdrop-filter: blur(10px) !important;
        -webkit-backdrop-filter: blur(10px) !important;
        z-index: 16 !important;
        font-size: var(--font-size-lg) !important;
    }
    .book-open-btn:hover { background: var(--primary-blue) !important; color: #fff !important; transform: scale(1.1) !important; box-shadow: var(--shadow-lg) !important; border-color: var(--primary-blue) !important; }
    .book-open-btn:active { transform: scale(0.95) !important; }
    .book-open-btn span { display: none !important; }
    .book-open-btn::before { content: none !important; }
}