:root {
    /* Modern Color Palette - Deep Purple to Blue Gradient */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --accent-hover: #0891b2;
    
    /* Text Colors */
    --text-color: #1e293b;
    --text-secondary: #475569;
    --text-light: #64748b;
    --text-muted: #94a3b8;
    
    /* Background Colors */
    --bg-color: #ffffff;
    --bg-light: #f8fafc;
    --bg-lighter: #f1f5f9;
    --bg-dark: #0f172a;
    --bg-darker: #020617;
    
    /* Border & Divider */
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    
    /* Shadows - Modern & Layered */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --shadow-colored: 0 10px 25px -5px rgba(99, 102, 241, 0.3);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s ease-out;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-color);
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    background-attachment: fixed;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    font-size: 16px;
    min-height: 100vh;
    overflow-x: hidden;
}

/* Ensure touch targets are at least 44x44px (iOS/Android guidelines) */
button, a, input[type="button"], input[type="submit"], .nav-link, .language-card, .book-card {
    min-height: 44px;
    min-width: 44px;
}

/* Improve text readability on mobile */
@media (max-width: 768px) {
    body {
        font-size: 17px; /* iOS optimal reading size */
        -webkit-text-size-adjust: 100%;
    }
    
    p, li {
        font-size: 16px;
        line-height: 1.75; /* Better line spacing for mobile reading */
    }
    
    h1 {
        font-size: 2rem;
        line-height: 1.3;
    }
    
    h2 {
        font-size: 1.5rem;
        line-height: 1.4;
    }
    
    h3 {
        font-size: 1.25rem;
        line-height: 1.4;
    }
}

/* Breadcrumb Navigation */
.breadcrumb {
    background: rgba(255, 255, 255, 0.5);
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-light);
    margin-bottom: 0;
}

.breadcrumb ol {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0;
    padding: 0;
    font-size: 0.875rem;
}

.breadcrumb li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.breadcrumb li::after {
    content: '›';
    color: var(--text-muted);
    margin-left: 0.5rem;
}

.breadcrumb li:last-child::after {
    display: none;
}

.breadcrumb a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
}

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

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

/* Accessibility improvements */
*:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

button:focus,
a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header */
.header {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 50%, #1e293b 100%);
    color: white;
    padding: 5rem 0 4rem;
    text-align: center;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    position: relative;
    overflow: hidden;
    min-height: 600px;
    display: flex;
    align-items: center;
}

.header-background {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(139, 92, 246, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(6, 182, 212, 0.1) 0%, transparent 50%);
    animation: pulse 20s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

.header-content {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header Badge */
.header-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 0.5rem 1.25rem;
    border-radius: var(--radius-full);
    border: 1px solid rgba(255, 255, 255, 0.2);
    margin-bottom: 2rem;
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.badge-icon {
    font-size: 1.1rem;
}

.badge-text {
    color: rgba(255, 255, 255, 0.95);
}

/* Free Badge Large */
.free-badge-large {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    background: linear-gradient(135deg, rgba(34, 197, 94, 0.2), rgba(16, 185, 129, 0.2));
    backdrop-filter: blur(10px);
    padding: 0.875rem 2rem;
    border-radius: var(--radius-full);
    border: 2px solid rgba(34, 197, 94, 0.4);
    margin-bottom: 1.5rem;
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    box-shadow: 0 4px 20px rgba(34, 197, 94, 0.2);
    animation: pulse-glow 2s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% {
        box-shadow: 0 4px 20px rgba(34, 197, 94, 0.2);
        border-color: rgba(34, 197, 94, 0.4);
    }
    50% {
        box-shadow: 0 4px 30px rgba(34, 197, 94, 0.4);
        border-color: rgba(34, 197, 94, 0.6);
    }
}

.free-icon {
    font-size: 1.25rem;
    animation: twinkle 1.5s ease-in-out infinite;
}

.free-icon:first-child {
    animation-delay: 0s;
}

.free-icon:last-child {
    animation-delay: 0.75s;
}

@keyframes twinkle {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.7; transform: scale(1.2); }
}

.free-text {
    color: #ffffff;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.free-highlight {
    color: #22c55e !important;
    font-weight: 800;
    text-shadow: 0 2px 10px rgba(34, 197, 94, 0.3);
    position: relative;
}

.free-highlight::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, transparent, #22c55e, transparent);
    opacity: 0.6;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    font-size: 3.5rem;
    font-weight: 900;
    margin-bottom: 1.5rem;
    letter-spacing: -0.03em;
}

.logo-icon {
    font-size: 4rem;
    filter: drop-shadow(0 4px 20px rgba(99, 102, 241, 0.4));
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

.logo-text {
    background: linear-gradient(135deg, #ffffff 0%, #e2e8f0 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

/* Tagline */
.tagline {
    font-size: 1.375rem;
    font-weight: 400;
    color: rgba(255, 255, 255, 0.9);
    letter-spacing: 0.01em;
    max-width: 800px;
    margin: 0 auto 2.5rem;
    line-height: 1.7;
}

.tagline strong {
    color: white;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-light), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Header Features */
.header-features {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 3rem;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(10px);
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-full);
    border: 1px solid rgba(255, 255, 255, 0.15);
    font-size: 0.95rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.95);
    transition: var(--transition);
}

.feature-item:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 1.25rem;
}

/* Header Stats */
.header-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
    margin-top: 3rem;
    padding-top: 3rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.stat-box {
    text-align: center;
    padding: 1.5rem 2rem;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    min-width: 140px;
    transition: var(--transition);
}

.stat-box:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-4px);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 900;
    background: linear-gradient(135deg, #ffffff, var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
    line-height: 1;
}

.stat-label {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Top Sponsor Banner */
.sponsor-banner-top {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.08), rgba(139, 92, 246, 0.08));
    border-bottom: 1px solid var(--border-light);
    padding: 0.75rem 0;
    position: relative;
    z-index: 999;
}

.sponsor-banner-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.sponsor-badge-top {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(99, 102, 241, 0.1);
    padding: 0.375rem 0.875rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.sponsor-badge-icon {
    font-size: 0.875rem;
}

.sponsor-badge-text {
    color: var(--primary-dark);
}

.sponsor-banner-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: rgba(99, 102, 241, 0.05);
    padding: 0.625rem 1.5rem;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(99, 102, 241, 0.15);
    text-decoration: none;
    color: var(--text-color);
    transition: var(--transition);
    font-weight: 600;
}

.sponsor-banner-link:hover {
    background: rgba(99, 102, 241, 0.1);
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.sponsor-banner-link .sponsor-icon {
    font-size: 1.5rem;
}

.sponsor-banner-link .sponsor-content {
    gap: 0;
}

.sponsor-banner-link .sponsor-title {
    font-size: 1.1rem;
    color: var(--text-color);
    font-weight: 800;
}

.sponsor-banner-link .sponsor-subtitle {
    font-size: 0.875rem;
    color: var(--primary-color);
    font-weight: 700;
}

.sponsor-banner-link .sponsor-arrow {
    font-size: 1.25rem;
    color: var(--primary-color);
    margin-left: 0.5rem;
}

.sponsor-banner-link:hover .sponsor-arrow {
    transform: translateX(4px);
}

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(30px);
    -webkit-backdrop-filter: blur(30px);
    border-bottom: 1px solid rgba(226, 232, 240, 0.8);
    padding: 1.25rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.08);
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.12);
    padding: 0.875rem 0;
    background: rgba(255, 255, 255, 0.99);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.5rem;
}

/* Brand */
.nav-brand {
    display: flex;
    align-items: center;
}

.brand-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 800;
    font-size: 1.25rem;
    transition: var(--transition);
}


.brand-icon {
    font-size: 1.75rem;
    filter: drop-shadow(0 2px 4px rgba(99, 102, 241, 0.3));
    transition: var(--transition);
}

.brand-link:hover .brand-icon {
    transform: scale(1.1) rotate(5deg);
}

.brand-link:hover .brand-text {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.brand-text {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Nav Menu */
.nav-menu {
    display: flex;
    list-style: none;
    gap: 0.25rem;
    flex-wrap: wrap;
    margin: 0;
    padding: 0;
    align-items: center;
}

.nav-menu li {
    margin: 0;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-lg);
    transition: var(--transition);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    position: relative;
    font-size: 0.95rem;
    white-space: nowrap;
}

.nav-icon {
    font-size: 1.1rem;
    transition: var(--transition);
}

.nav-link::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    opacity: 0;
    transition: var(--transition);
    z-index: -1;
}

.nav-link:hover {
    color: white;
    transform: translateY(-2px);
}

.nav-link:hover::before {
    opacity: 1;
}

.nav-link:hover .nav-icon {
    transform: scale(1.2);
}

.nav-link.active {
    color: white;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    box-shadow: var(--shadow-colored);
}

.nav-link.active::before {
    opacity: 1;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

.section-description {
    color: var(--text-secondary);
    margin-bottom: 3rem;
    font-size: 1.125rem;
    text-align: center;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.7;
    font-weight: 400;
}

.search-container {
    flex: 1;
    max-width: 600px;
}

.search-wrapper {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--bg-lighter);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-full);
    padding: 0.5rem 1rem;
    transition: var(--transition);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    position: relative;
}

.search-wrapper:focus-within {
    background: white;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1), 0 4px 12px rgba(0, 0, 0, 0.1);
    transform: translateY(-1px);
}

.search-icon {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-left: 0.5rem;
    pointer-events: none;
}

.search-wrapper:focus-within .search-icon {
    color: var(--primary-color);
}

.search-input {
    flex: 1;
    padding: 0.625rem 1rem;
    border: none;
    border-radius: var(--radius-full);
    font-size: 0.95rem;
    transition: var(--transition);
    background: transparent;
    color: var(--text-color);
    outline: none;
    min-width: 0;
}

.search-input:focus {
    outline: none;
}

.search-input::placeholder {
    color: var(--text-muted);
}

.search-btn {
    padding: 0.625rem 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
    font-size: 0.9rem;
    white-space: nowrap;
    min-height: 44px;
    flex-shrink: 0;
    position: relative;
    z-index: 1;
}

.search-btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
    background: linear-gradient(135deg, var(--primary-dark), var(--secondary-color));
}

.search-btn:active {
    transform: translateY(0);
}

.search-btn:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Ad Container */
.ad-container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
    text-align: center;
}

/* Language Selector */
.language-selector {
    margin: 4rem 0;
    padding: 3rem 0;
}

/* Free Notice */
.free-notice {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    background: linear-gradient(135deg, rgba(34, 197, 94, 0.1), rgba(16, 185, 129, 0.1));
    border: 2px solid rgba(34, 197, 94, 0.3);
    border-radius: var(--radius-lg);
    padding: 1.25rem 2rem;
    margin-bottom: 2.5rem;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
    box-shadow: 0 4px 15px rgba(34, 197, 94, 0.15);
}

@media (max-width: 768px) {
    .free-notice {
        flex-direction: column;
        padding: 1rem 1.5rem;
        text-align: center;
        gap: 0.75rem;
    }
    
    .notice-icon {
        font-size: 1.5rem;
    }
    
    .notice-text {
        font-size: 0.95rem;
        line-height: 1.6;
    }
}

.notice-icon {
    font-size: 2rem;
    animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-5px); }
}

.notice-text {
    color: var(--text-color);
    font-size: 1.05rem;
    line-height: 1.6;
    flex: 1;
}

.notice-text strong {
    color: #059669;
    font-weight: 800;
}

.language-selector h2 {
    margin-bottom: 1rem;
    color: var(--text-color);
    font-size: 2.25rem;
    font-weight: 800;
    text-align: center;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.language-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
}

.language-card {
    background: var(--bg-color);
    padding: 2rem 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
    user-select: none;
    -webkit-user-select: none;
}

.language-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: var(--transition);
}

.language-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.language-card:hover::before {
    transform: scaleX(1);
}

.language-card:active {
    transform: translateY(-4px);
}

.language-card h3 {
    color: var(--text-color);
    margin-bottom: 0.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    transition: var(--transition);
}

.language-card:hover h3 {
    color: var(--primary-color);
}

.language-card .count {
    color: var(--text-light);
    font-size: 0.875rem;
    font-weight: 500;
}

/* Books Section */
.books-section {
    margin: 4rem 0;
    padding: 0;
}

.books-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--bg-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
}

.books-header h2 {
    color: var(--text-color);
    font-size: 1.875rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.filter-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.filter-input {
    padding: 0.625rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-full);
    font-size: 0.95rem;
    transition: var(--transition);
    background: var(--bg-color);
}

.filter-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.book-count {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 600;
    padding: 0.5rem 1rem;
    background: var(--bg-lighter);
    border-radius: var(--radius-full);
}

.categories-container {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.category {
    background: var(--bg-color);
    padding: 2.5rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
    transition: var(--transition);
    margin-bottom: 2rem;
}

.category:hover {
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.category h3 {
    color: var(--text-color);
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-light);
    font-size: 1.5rem;
    font-weight: 700;
    position: relative;
    display: inline-block;
    width: 100%;
}

.category h3::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-full);
}

.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1rem;
}

.book-card {
    background: var(--bg-color);
    padding: 1.75rem;
    border-radius: var(--radius-md);
    border-left: 4px solid var(--primary-color);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    border-left: 4px solid var(--primary-color);
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.book-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--primary-color), var(--secondary-color));
    transition: var(--transition);
}

.book-card:hover {
    transform: translateY(-4px) translateX(4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.book-card:hover::before {
    width: 6px;
}

.book-card h4 {
    margin-bottom: 0.75rem;
}

.book-title {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 700;
    font-size: 1.125rem;
    display: block;
    margin-bottom: 0.75rem;
    line-height: 1.4;
    transition: var(--transition);
}

.book-title:hover {
    color: var(--primary-color);
    text-decoration: none;
}

.book-author {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.book-format {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 0.375rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    margin-top: 0.75rem;
    font-weight: 600;
    box-shadow: var(--shadow-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

mark {
    background-color: #fef08a;
    padding: 0.1rem 0.2rem;
    border-radius: 0.25rem;
}

/* Search Results */
.search-results {
    margin: 3rem 0;
}

.search-results h2 {
    margin-bottom: 1.5rem;
}

/* Loading */
.loading {
    text-align: center;
    padding: 3rem;
}

.spinner {
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Footer */
.footer {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
    color: white;
    padding: 3rem 0 1.5rem;
    margin-top: 5rem;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--primary-color), var(--secondary-color), transparent);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2.5rem;
    margin-bottom: 2.5rem;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
    padding: 0 1rem;
}

@media (max-width: 1024px) {
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
        gap: 2rem;
    }
    
    .footer {
        padding: 2.5rem 0 1.5rem;
    }
}

@media (max-width: 768px) {
    .footer {
        padding: 2rem 0 1rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
        margin-bottom: 2rem;
    }
    
    .footer-bottom {
        padding-top: 1.5rem;
        margin-top: 1.5rem;
    }
    
    .footer-stats {
        gap: 2rem;
        margin-bottom: 1.25rem;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .sponsor-section {
        margin: 1.5rem 0 1rem;
        padding: 1.25rem;
    }
    
    .search-wrapper {
        padding: 0.5rem 0.75rem;
    }
    
    .search-btn {
        padding: 0.5rem 1.25rem;
        font-size: 0.85rem;
        min-height: 40px;
    }
}

.footer-section h3 {
    color: white;
    margin-bottom: 1.25rem;
    font-size: 1.15rem;
    font-weight: 700;
    position: relative;
    padding-bottom: 0.75rem;
    letter-spacing: -0.02em;
}

.footer-section h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.25rem;
}

.footer-icon {
    font-size: 2rem;
    filter: drop-shadow(0 2px 8px rgba(99, 102, 241, 0.4));
}

.footer-about h3::after {
    display: none;
}

.footer-about p {
    line-height: 1.7;
    margin-bottom: 0;
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.75);
}

.footer-social {
    margin-top: 1.5rem;
}

.social-text {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.8;
}

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

.footer-section ul li {
    margin-bottom: 0.75rem;
    line-height: 1.6;
}

.footer-disabled {
    color: rgba(255, 255, 255, 0.4);
    cursor: default;
    pointer-events: none;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.75);
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-block;
    padding: 0.375rem 0;
    position: relative;
    font-size: 0.9rem;
}

.footer-section a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--primary-light);
    transition: width 0.3s ease;
}

.footer-section a:hover {
    color: var(--primary-light);
    text-decoration: none;
    transform: translateX(4px);
    padding-left: 0.25rem;
}

.footer-section a:hover::before {
    width: 20px;
}

@media (max-width: 1024px) {
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
        gap: 2.5rem;
    }
}

@media (max-width: 768px) {
    .footer {
        padding: 3rem 0 1.5rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2.5rem;
        text-align: center;
    }
    
    .footer-section h3::after {
        left: 50%;
        transform: translateX(-50%);
    }
    
    .footer-section a:hover {
        transform: none;
        padding-left: 0;
    }
    
    .footer-brand {
        justify-content: center;
    }
    
    .sponsor-section {
        padding: 1.5rem 1rem;
    }
    
    .sponsor-link {
        padding: 1rem 1.25rem;
    }
    
    .social-buttons-inline {
        gap: 0.5rem;
    }
    
    .social-btn-inline {
        width: 44px;
        height: 44px;
        font-size: 1.1rem;
    }
    
    .footer-stats {
        gap: 2rem;
        padding-bottom: 1.5rem;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
}

.footer-bottom {
    text-align: center;
    padding-top: 2.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.12);
    color: rgba(255, 255, 255, 0.7);
    margin-top: 2.5rem;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
    padding-left: 1rem;
    padding-right: 1rem;
}

.footer-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    padding-bottom: 2rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    min-width: 100px;
}

.stat-number {
    font-size: 1.875rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.stat-label {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.75);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Sponsor Section */
.sponsor-section {
    margin: 2rem auto 1.5rem;
    padding: 2rem 1.5rem;
    background: rgba(255, 255, 255, 0.04);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.08);
    text-align: center;
    max-width: 600px;
}

.sponsor-label {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.5);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 1.25rem;
    font-weight: 600;
}

.sponsor-links-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    align-items: center;
}

.sponsor-link {
    display: inline-flex;
    align-items: center;
    gap: 1rem;
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(10px);
    padding: 1.25rem 1.75rem;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.15);
    text-decoration: none;
    color: white;
    transition: var(--transition);
    width: 100%;
    max-width: 450px;
    justify-content: center;
}

.sponsor-link:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

.sponsor-icon {
    font-size: 2rem;
    filter: drop-shadow(0 2px 8px rgba(255, 255, 255, 0.3));
    flex-shrink: 0;
}

.sponsor-content {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.25rem;
    flex: 1;
}

.sponsor-title {
    font-size: 1.15rem;
    font-weight: 700;
    color: white;
    line-height: 1.2;
}

.sponsor-subtitle {
    font-size: 0.9rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.85);
    background: linear-gradient(135deg, var(--primary-light), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.sponsor-arrow {
    font-size: 1.5rem;
    transition: var(--transition);
    flex-shrink: 0;
}

.sponsor-link:hover .sponsor-arrow {
    transform: translateX(4px);
}

.sponsor-description {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.55);
    margin-top: 1rem;
    font-style: normal;
    line-height: 1.5;
}

/* Social Buttons Inline */
.social-buttons-inline {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
}

.social-btn-inline {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-md);
    color: white;
    text-decoration: none;
    font-size: 1.25rem;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.social-btn-inline:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-3px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

.social-btn-inline span {
    display: block;
}

.social-btn-inline.social-twitter:hover {
    background: rgba(29, 161, 242, 0.2);
    border-color: rgba(29, 161, 242, 0.4);
}

.social-btn-inline.social-facebook:hover {
    background: rgba(24, 119, 242, 0.2);
    border-color: rgba(24, 119, 242, 0.4);
}

.social-btn-inline.social-linkedin:hover {
    background: rgba(0, 119, 181, 0.2);
    border-color: rgba(0, 119, 181, 0.4);
}

.social-btn-inline.social-whatsapp:hover {
    background: rgba(37, 211, 102, 0.2);
    border-color: rgba(37, 211, 102, 0.4);
}

.footer-copyright {
    margin: 2rem 0 0;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.55);
    line-height: 1.6;
    text-align: center;
}

.footer-bottom a {
    color: var(--primary-light);
    text-decoration: none;
    transition: var(--transition);
}

.footer-bottom a:hover {
    color: white;
    text-decoration: underline;
}

#scrollTopBtn {
    position: relative;
}

#scrollTopBtn.visible::after {
    content: ' ↑';
}

/* Scroll to Top Button */
.scroll-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-xl);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
    font-size: 1.5rem;
}

.scroll-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.4);
}

.scroll-to-top:active {
    transform: translateY(-2px);
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-to-top svg {
    width: 24px;
    height: 24px;
}

/* Reading Progress Bar */
.reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: rgba(0, 0, 0, 0.05);
    z-index: 10001;
    pointer-events: none;
}

.reading-progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    width: 0%;
    transition: width 0.1s ease-out;
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
}

/* Social Share Buttons */
.footer-social {
    margin-top: 1.5rem;
}

.social-text {
    display: block;
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.social-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 0.75rem;
}

.social-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-md);
    color: white;
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 600;
    transition: var(--transition);
    backdrop-filter: blur(10px);
    min-height: 40px;
}

.social-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.4);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.social-btn span:first-child {
    font-size: 1.1rem;
}

.social-twitter:hover {
    background: rgba(29, 161, 242, 0.3);
    border-color: rgba(29, 161, 242, 0.5);
}

.social-facebook:hover {
    background: rgba(24, 119, 242, 0.3);
    border-color: rgba(24, 119, 242, 0.5);
}

.social-linkedin:hover {
    background: rgba(0, 119, 181, 0.3);
    border-color: rgba(0, 119, 181, 0.5);
}

.social-whatsapp:hover {
    background: rgba(37, 211, 102, 0.3);
    border-color: rgba(37, 211, 102, 0.5);
}

/* How to Use Section */
.how-to-use-section {
    margin: 5rem 0;
    padding: 4rem 2rem;
}

@media (max-width: 768px) {
    .how-to-use-section {
        margin: 3rem 0;
        padding: 2.5rem 1rem;
    }
    
    .steps-grid {
        grid-template-columns: 1fr !important;
        gap: 1.5rem;
    }
    
    .step-card {
        padding: 1.5rem;
    }
    
    .step-number {
        width: 50px;
        height: 50px;
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .how-to-use-section {
        padding: 2rem 0.75rem;
    }
    
    .step-card h3 {
        font-size: 1.1rem;
    }
    
    .step-card p {
        font-size: 0.95rem;
        line-height: 1.6;
    }
}
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05) 0%, rgba(139, 92, 246, 0.05) 100%);
    border-radius: var(--radius-xl);
}

.how-to-content {
    max-width: 1100px;
    margin: 0 auto;
}

.how-to-use-section .section-title {
    font-size: 2.5rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 3rem;
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.step-card {
    background: var(--bg-color);
    padding: 2.5rem 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
    transition: var(--transition);
    text-align: center;
    position: relative;
}

.step-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 800;
    margin: 0 auto 1.5rem;
    box-shadow: var(--shadow-colored);
}

.step-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.step-card p {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 0.95rem;
}

/* Reviews Section */
.reviews-section {
    margin: 5rem 0;
    padding: 0;
}

.reviews-content {
    max-width: 1200px;
    margin: 0 auto;
}

.reviews-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 3rem;
    flex-wrap: wrap;
    gap: 2rem;
}

.reviews-header .section-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.rating-summary {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.stars-display {
    font-size: 1.5rem;
    color: #fbbf24;
    letter-spacing: 2px;
}

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

.rating-text strong {
    color: var(--text-color);
    font-size: 1.25rem;
}

.btn-primary {
    padding: 0.875rem 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: var(--radius-full);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow);
    font-size: 1rem;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    padding: 0.875rem 2rem;
    background: var(--bg-lighter);
    color: var(--text-color);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-full);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-size: 1rem;
}

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

/* Review Form */
.review-form {
    background: var(--bg-color);
    padding: 2.5rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-light);
    margin-bottom: 3rem;
}

.review-form h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    font-weight: 600;
    font-size: 0.95rem;
}

.form-group input[type="text"],
.form-group textarea {
    width: 100%;
    padding: 0.875rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
    min-height: 44px; /* Touch-friendly */
    -webkit-appearance: none;
    appearance: none;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* Star Rating Input */
.star-rating {
    display: flex;
    flex-direction: row-reverse;
    justify-content: flex-end;
    gap: 0.5rem;
}

.star-rating input[type="radio"] {
    display: none;
}

.star-rating label.star {
    font-size: 2rem;
    color: #d1d5db;
    cursor: pointer;
    transition: var(--transition);
    line-height: 1;
}

.star-rating label.star:hover,
.star-rating label.star:hover ~ label.star {
    color: #fbbf24;
}

.star-rating input[type="radio"]:checked ~ label.star,
.star-rating label.star.filled {
    color: #fbbf24;
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.form-actions button {
    flex: 1;
    min-width: 120px;
    min-height: 48px; /* Touch-friendly */
}

/* Reviews Container */
.reviews-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

@media (max-width: 1024px) {
    .reviews-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.25rem;
    }
}

@media (max-width: 768px) {
    .reviews-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }
}

@media (max-width: 480px) {
    .reviews-container {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
}

.review-card {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

.review-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.review-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.reviewer-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.reviewer-avatar {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
}

.reviewer-name {
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 0.25rem;
}

.review-date {
    font-size: 0.875rem;
    color: var(--text-light);
}

.review-rating {
    color: #fbbf24;
    font-size: 1.25rem;
    letter-spacing: 2px;
}

.review-text {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 0.95rem;
}

/* Notification */
.notification {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    left: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 1rem 2rem;
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-xl);
    opacity: 0;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 10000;
    font-weight: 600;
    font-size: 1rem;
    max-width: calc(100% - 2rem);
    text-align: center;
    pointer-events: none;
}

.notification.show {
    opacity: 1;
    transform: translateY(0);
}

/* Notification Mobile Styles */
@media (max-width: 768px) {
    .notification {
        bottom: 5rem; /* Above cookie banner */
        right: 1rem;
        left: 1rem;
        padding: 0.875rem 1.5rem;
        font-size: 0.9rem;
        max-width: calc(100% - 2rem);
    }
    
    .social-buttons {
        gap: 0.625rem;
    }
    
    .social-btn {
        padding: 0.5rem 0.875rem;
        font-size: 0.85rem;
    }
    
    .reading-progress {
        height: 3px;
    }
}

@media (max-width: 480px) {
    .notification {
        bottom: 4.5rem;
        padding: 0.75rem 1rem;
        font-size: 0.85rem;
        border-radius: var(--radius-lg);
    }
}

/* Responsive */
@media (max-width: 1024px) {
    .container {
        padding: 0 1.5rem;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 3rem 0 2.5rem;
        min-height: auto;
    }
    
    .logo {
        font-size: 2.5rem;
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .logo-icon {
        font-size: 3rem;
    }
    
    .free-badge-large {
        padding: 0.75rem 1.5rem;
        font-size: 0.9rem;
        gap: 0.5rem;
        margin-bottom: 1.25rem;
    }
    
    .free-icon {
        font-size: 1.1rem;
    }
    
    .tagline {
        font-size: 1.125rem;
        padding: 0 1rem;
        margin-bottom: 2rem;
    }
    
    .header-features {
        gap: 0.75rem;
        margin-bottom: 2rem;
    }
    
    .feature-item {
        padding: 0.625rem 1.25rem;
        font-size: 0.875rem;
    }
    
    .header-stats {
        gap: 1.5rem;
        padding-top: 2rem;
    }
    
    .stat-box {
        padding: 1rem 1.5rem;
        min-width: 110px;
    }
    
    .stat-value {
        font-size: 1.75rem;
    }
    
    .header-badge {
        font-size: 0.75rem;
        padding: 0.4rem 1rem;
    }

    .free-notice {
        flex-direction: column;
        padding: 1rem 1.5rem;
        text-align: center;
    }

    .notice-icon {
        font-size: 1.75rem;
    }

    .notice-text {
        font-size: 0.95rem;
    }

    .sponsor-banner-top {
        padding: 0.625rem 0;
    }

    .sponsor-banner-content {
        flex-direction: column;
        gap: 0.5rem;
    }

    .sponsor-banner-link {
        flex-direction: row;
        padding: 0.5rem 1.25rem;
        font-size: 0.9rem;
    }

    .sponsor-banner-link .sponsor-title {
        font-size: 1rem;
    }

    .sponsor-banner-link .sponsor-subtitle {
        font-size: 0.8rem;
    }

    .sponsor-badge-top {
        font-size: 0.7rem;
        padding: 0.3rem 0.75rem;
    }
    
    .nav-content {
        flex-direction: column;
        align-items: stretch;
        gap: 1rem;
    }

    .nav-brand {
        order: 1;
        width: 100%;
        justify-content: center;
    }
    
    .nav-menu li {
        flex: 1;
        min-width: calc(33.333% - 0.5rem);
        text-align: center;
    }
    
    .nav-menu {
        order: 3;
        justify-content: center;
        width: 100%;
        flex-wrap: wrap;
        gap: 0.5rem;
    }

    .search-container {
        order: 2;
        max-width: 100%;
        width: 100%;
    }

    .search-wrapper {
        width: 100%;
    }

    .nav-link {
        padding: 0.625rem 1.25rem;
        font-size: 0.9rem;
    }

    .footer-stats {
        gap: 2rem;
    }

    .stat-number {
        font-size: 1.5rem;
    }

    .how-to-use-section {
        padding: 3rem 1.5rem;
        margin: 3rem 0;
    }

    .how-to-use-section .section-title {
        font-size: 2rem;
    }

    .steps-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .reviews-header {
        flex-direction: column;
    }

    .reviews-header .section-title {
        font-size: 2rem;
    }

    .reviews-container {
        grid-template-columns: 1fr;
    }

    .review-form {
        padding: 1.5rem;
    }
    
    .language-grid {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: 0.75rem;
    }
    
    .language-card {
        padding: 1rem;
    }
    
    .books-grid {
        grid-template-columns: 1fr;
    }
    
    .books-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .filter-controls {
        width: 100%;
    }
    
    .filter-input {
        width: 100%;
    }
    
    .category {
        padding: 1.5rem;
    }
    
}

@media (max-width: 480px) {
    .logo {
        font-size: 1.5rem;
    }
    
    .tagline {
        font-size: 0.9rem;
    }
    
    .language-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.75rem;
    }
    
    .language-card {
        padding: 1rem;
        min-height: 80px;
    }
    
    .nav-menu {
        flex-direction: column;
        gap: 0.5rem;
        width: 100%;
    }
    
    .nav-menu li {
        width: 100%;
        min-width: auto;
    }
    
    .nav-link {
        width: 100%;
        justify-content: center;
        padding: 1rem;
        min-height: 48px;
    }
    
    .navbar {
        padding: 1rem 0;
    }
    
    .section-description {
        font-size: 0.95rem;
        padding: 0 0.5rem;
    }
    
    .book-card {
        padding: 1rem;
    }
    
    .book-card h3 {
        font-size: 1rem;
    }
    
    .scroll-to-top {
        width: 48px;
        height: 48px;
        bottom: 5.5rem; /* Above cookie banner on mobile */
        right: 1.5rem;
    }
    
    /* Scroll button when cookie banner is not shown */
    body:not(:has(#cookieBanner)) .scroll-to-top {
        bottom: 1.5rem;
    }
    
    .sponsor-link {
        flex-direction: column;
        text-align: center;
        padding: 1rem 1.5rem;
    }
    
    .sponsor-content {
        align-items: center;
    }
    
    .sponsor-arrow {
        margin-left: 0;
        transform: rotate(90deg);
    }
    
    .sponsor-link:hover .sponsor-arrow {
        transform: rotate(90deg) translateX(4px);
    }
    
    .breadcrumb {
        font-size: 0.8rem;
        padding: 0.5rem 0;
    }
    
    .footer-stats {
        gap: 1rem;
        flex-direction: column;
    }
    
    .stat-item {
        margin: 0.5rem 0;
    }
    
    /* Improve mobile readability */
    .container {
        padding: 0 1rem !important;
    }
    
    h1 {
        font-size: 1.75rem;
        margin-bottom: 1rem;
    }
    
    h2 {
        font-size: 1.5rem;
        margin-bottom: 0.75rem;
    }
    
    h3 {
        font-size: 1.25rem;
    }
    
    /* Better spacing on mobile */
    section {
        padding: 2rem 0 !important;
    }
    
    /* Touch-friendly inputs */
    input[type="text"],
    input[type="search"],
    textarea {
        font-size: 16px; /* Prevents zoom on iOS */
        padding: 1rem;
        min-height: 44px;
    }
    
    /* Larger tap targets */
    .book-card {
        padding: 1.25rem;
        margin-bottom: 1rem;
    }
    
    .language-card {
        padding: 1.25rem;
    }
    
    /* Better table spacing */
    table {
        font-size: 0.9rem;
        display: block;
        overflow-x: auto;
    }
    
    /* Improve list readability */
    ul, ol {
        padding-left: 1.5rem;
        line-height: 1.8;
    }
    
    li {
        margin-bottom: 0.5rem;
    }
    
    /* Better button spacing */
    .btn-primary, .btn-secondary {
        padding: 1rem 1.5rem;
        font-size: 1rem;
        min-height: 48px;
    }
}

/* Extra small devices (phones in portrait) */
@media (max-width: 360px) {
    .logo {
        font-size: 1.25rem;
    }
    
    .tagline {
        font-size: 0.85rem;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    h2 {
        font-size: 1.25rem;
    }
    
    .container {
        padding: 0 0.75rem !important;
    }
    
    .book-card, .language-card {
        padding: 1rem;
    }
}

/* Landscape orientation optimization */
@media (max-width: 768px) and (orientation: landscape) {
    .header {
        padding: 2rem 0;
        min-height: auto;
    }
    
    .header-stats {
        padding-top: 1rem;
    }
}

/* High DPI displays */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    body {
        -webkit-font-smoothing: antialiased;
        -moz-osx-font-smoothing: grayscale;
    }
}

/* SEO Article Section */
.seo-article-section {
    margin: 5rem 0;
    padding: 3rem 0;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.03) 0%, rgba(139, 92, 246, 0.03) 100%);
    border-top: 1px solid var(--border-light);
    border-bottom: 1px solid var(--border-light);
}

.seo-article-wrapper {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 2rem;
}

.seo-article-header {
    text-align: center;
    margin-bottom: 2rem;
}

.seo-article-title {
    font-size: 2rem;
    font-weight: 800;
    line-height: 1.3;
    margin-bottom: 1.5rem;
    color: var(--text-color);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.seo-article-excerpt {
    font-size: 1.125rem;
    line-height: 1.75;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.seo-article-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
    min-height: 44px;
}

.seo-article-toggle:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.seo-article-toggle svg {
    transition: transform 0.3s ease;
}

.seo-article-toggle[aria-expanded="true"] svg {
    transform: rotate(180deg);
}

.seo-article-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease-out;
    margin-top: 2rem;
}

.seo-article-content.expanded {
    max-height: 10000px;
    transition: max-height 0.8s ease-in;
}

.seo-article-text {
    background: var(--bg-color);
    padding: 3rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
    line-height: 1.9;
    color: var(--text-color);
}

.seo-article-text h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-light);
}

.seo-article-text h3:first-child {
    margin-top: 0;
}

.seo-article-text p {
    font-size: 1.05rem;
    line-height: 1.85;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    text-align: justify;
}

.seo-article-text strong {
    color: var(--text-color);
    font-weight: 700;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.1));
    padding: 0.1rem 0.3rem;
    border-radius: 4px;
}

.seo-article-text ul {
    list-style: none;
    padding-left: 0;
    margin: 1.5rem 0;
}

.seo-article-text ul li {
    padding: 0.75rem 0;
    padding-left: 1.5rem;
    position: relative;
    line-height: 1.8;
    color: var(--text-secondary);
    font-size: 1.05rem;
}

.seo-article-text ul li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.2rem;
}

.seo-article-text a {
    color: var(--primary-color);
    text-decoration: underline;
    transition: var(--transition);
}

.seo-article-text a:hover {
    color: var(--primary-dark);
}

@media (max-width: 768px) {
    .seo-article-section {
        margin: 3rem 0;
        padding: 2rem 0;
    }
    
    .seo-article-wrapper {
        padding: 0 1rem;
    }
    
    .seo-article-title {
        font-size: 1.5rem;
        line-height: 1.4;
    }
    
    .seo-article-excerpt {
        font-size: 1rem;
    }
    
    .seo-article-text {
        padding: 2rem 1.5rem;
    }
    
    .seo-article-text h3 {
        font-size: 1.25rem;
        margin-top: 2rem;
    }
    
    .seo-article-text p {
        font-size: 1rem;
        text-align: left;
    }
    
    .seo-article-toggle {
        padding: 0.75rem 1.5rem;
        font-size: 0.95rem;
    }
}

@media (max-width: 480px) {
    .seo-article-text {
        padding: 1.5rem 1rem;
    }
    
    .seo-article-text h3 {
        font-size: 1.1rem;
    }
    
    .seo-article-text p,
    .seo-article-text ul li {
        font-size: 0.95rem;
        line-height: 1.75;
    }
}