:root {
    --primary-color: #0B1F3A;
    --primary-light: #12355B;
    --accent-color: #D4A017;
    --accent-hover: #e6b22b;
    --text-main: #4B5563;
    --text-dark: #1f2937;
    --bg-main: #FFFFFF;
    --bg-light: #F5F7FA;
    --bg-dark: #0B1F3A;
    --success: #16A34A;
    --error: #EF4444;
    
    --font-main: 'Inter', sans-serif;
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
    --shadow-md: 0 10px 20px rgba(0,0,0,0.08);
    --shadow-lg: 0 20px 40px rgba(11, 31, 58, 0.15);
    
    --transition: all 0.3s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--font-main);
    color: var(--text-main);
    background-color: var(--bg-main);
    line-height: 1.6;
    font-size: 16px;
}
img { max-width: 100%; height: auto; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* Typography */
h1, h2, h3, h4, h5, h6 {
    line-height: 1.2;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--primary-color);
}
h1 { font-size: clamp(2rem, 4vw, 3.5rem); letter-spacing: -1px; }
h2 { font-size: clamp(1.8rem, 3vw, 2.5rem); }
h3 { font-size: 1.25rem; }
p { margin-bottom: 1rem; }
.lead { font-size: 1.25rem; color: var(--text-dark); }
.font-weight-bold { font-weight: 700; }
.text-primary { color: var(--primary-color) !important; }
.text-success { color: var(--success) !important; }
.text-accent { color: var(--accent-color) !important; }

/* Layout & Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Mobile First Base */
.py-large { padding-top: 3.5rem; padding-bottom: 3.5rem; }
.bg-light { background-color: var(--bg-light); }
.bg-dark { background-color: var(--bg-dark); color: white; }
.bg-dark h2, .bg-dark h3 { color: white; }
.bg-dark .lead { color: #cbd5e1; }
.text-center { text-align: center; }
.mt-4 { margin-top: 2rem; }
.mb-4 { margin-bottom: 2rem; }

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 3rem;
}
.section-header p { font-size: 1.25rem; color: var(--text-main); }

.grid-3 {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-family: inherit;
    font-size: 1rem;
}
.btn-primary { background-color: var(--accent-color); color: var(--primary-color); }
.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(212, 160, 23, 0.3);
}
.btn-outline {
    background-color: transparent;
    border: 2px solid var(--accent-color);
    color: var(--accent-color);
}
.btn-outline:hover { background-color: var(--accent-color); color: var(--primary-color); }
.btn-large { padding: 1rem 2.5rem; font-size: 1.25rem; border-radius: var(--radius-lg); }
.btn-extra-large { padding: 1.25rem 2.5rem; font-size: 1.35rem; border-radius: var(--radius-lg); }
.btn-small { padding: 0.5rem 1rem; font-size: 0.875rem; }
.btn-block { display: flex; width: 100%; }

.cta-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-top: 2rem;
    width: 100%;
}
.cta-container .btn {
    width: 100%;
    max-width: 450px;
}
@media (max-width: 768px) {
    .btn-extra-large {
        font-size: 1.15rem;
        padding: 1rem 1.5rem;
    }
}

.pulse-animation { animation: pulse 2s infinite; }
@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(212, 160, 23, 0.7); }
    70% { box-shadow: 0 0 0 15px rgba(212, 160, 23, 0); }
    100% { box-shadow: 0 0 0 0 rgba(212, 160, 23, 0); }
}

/* Navbar */
.navbar {
    padding: 1.5rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    background: transparent;
    transition: all 0.3s ease;
}
.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    padding: 0.75rem 0;
}
.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo { font-size: 1.5rem; font-weight: 800; color: var(--primary-color); }
.logo span { color: var(--accent-color); }

/* Mobile Menu Base */
.nav-links, .nav-cta { display: none; }
.mobile-menu-btn {
    display: block;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--primary-color);
    cursor: pointer;
    transition: transform 0.2s ease;
}
.mobile-menu-btn:active { transform: scale(0.9); }

.mobile-menu {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    padding: 0 1.5rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    z-index: 99;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
}
.mobile-menu.active { 
    max-height: 400px;
    padding: 1.5rem;
}
.mobile-link {
    padding: 1rem 0;
    border-bottom: 1px solid var(--bg-light);
    font-weight: 600;
    color: var(--primary-color);
    text-transform: uppercase;
    font-size: 0.9rem;
    letter-spacing: 0.5px;
    transition: color 0.3s ease, padding-left 0.3s ease;
}
.mobile-link:hover { color: var(--accent-color); padding-left: 10px; }
.mobile-menu .btn { margin-top: 1.5rem; margin-bottom: 0.5rem; }

/* Hero Section (Mobile First) */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 5rem;
    background: linear-gradient(135deg, #f0f4f8 0%, #d9e2ec 100%);
    position: relative;
    overflow: hidden;
}
.hero-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
    align-items: center;
    position: relative;
    z-index: 10;
    text-align: center;
    padding-top: 2rem;
}
.hero-text p { font-size: 1.25rem; color: var(--text-main); margin-bottom: 2.5rem; }
.hero-cta {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    width: 100%;
}
.hero-cta .btn { width: 100%; }
.trust-badges {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    justify-content: center;
}
.secure-checkout {
    font-size: 0.875rem;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
}

/* Book Mockup */
.mockup-container { perspective: 1000px; display: flex; justify-content: center; }
.book-mockup {
    width: 280px; height: 380px;
    background: linear-gradient(145deg, var(--primary-color), var(--primary-light));
    border-radius: 5px 20px 20px 5px;
    position: relative;
    transform: rotateY(-15deg) rotateX(5deg);
    box-shadow: inset 4px 0 10px rgba(0,0,0,0.1), inset -1px 0 2px rgba(255,255,255,0.3), 20px 20px 30px rgba(0,0,0,0.2);
    display: flex; flex-direction: column; justify-content: center; align-items: center;
    color: white; text-align: center; padding: 2rem; transition: transform 0.5s ease;
}
.book-mockup:hover { transform: rotateY(-5deg) rotateX(2deg); }
.book-mockup::before {
    content: ''; position: absolute; top: 0; left: 20px; bottom: 0; width: 3px;
    background: rgba(255,255,255,0.2); z-index: 2;
}
.book-cover h2 { color: var(--accent-color); font-size: 2.5rem; margin-bottom: 1rem; }
.book-pages {
    position: absolute; top: 5px; bottom: 5px; right: -10px; width: 10px; background: #fff;
    border-radius: 0 4px 4px 0; border-right: 1px solid #ddd; border-top: 1px solid #ddd; border-bottom: 1px solid #ddd;
    box-shadow: inset 2px 0 5px rgba(0,0,0,0.1);
}

/* Cards */
.card {
    background: var(--bg-main); padding: 2.5rem; border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm); transition: var(--transition); border: 1px solid rgba(0,0,0,0.05);
}
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-5px); }
.icon-circle {
    width: 60px; height: 60px; border-radius: 50%; display: flex; align-items: center;
    justify-content: center; font-size: 1.5rem; margin: 0 auto 1.5rem;
}
.icon-circle.error { background-color: rgba(239, 68, 68, 0.1); color: var(--error); }
.icon-circle.success { background-color: rgba(22, 163, 74, 0.1); color: var(--success); }

/* Solution Section (Mobile First) */
.solution-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 4rem;
    align-items: center;
}
.solution-image {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}
.check-icon { color: var(--success); font-size: 1.5rem; }

/* Benefits Grid */
.benefits-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-top: 2rem;
}

.benefit-card {
    background: var(--bg-main);
    border: 1px solid rgba(0,0,0,0.05);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    transition: all 0.25s ease;
}

.benefit-card:hover {
    transform: scale(1.03);
    box-shadow: var(--shadow-md);
    border-color: rgba(22, 163, 74, 0.2);
}

.benefit-icon {
    font-size: 1.5rem;
    color: var(--success);
    flex-shrink: 0;
    margin-top: 2px;
}

.benefit-card h4 {
    margin: 0 0 0.25rem 0;
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--primary-color);
}

.benefit-card p {
    margin: 0;
    font-size: 0.95rem;
    color: var(--text-main);
}

/* Scroll Animation Base */
.scroll-animate {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.scroll-animate.show {
    opacity: 1;
    transform: translateY(0);
    transition-delay: calc(var(--delay, 0) * 0.15s);
}

/* Modules Grid */
.list-view {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.75rem;
}
.module-card {
    background: var(--bg-main); border-radius: var(--radius-md); padding: 1rem;
    display: flex; gap: 0.75rem; align-items: center; box-shadow: var(--shadow-sm);
    border: 1px solid #eaeaea; transition: var(--transition);
}
.module-card:hover { border-color: var(--primary-light); box-shadow: var(--shadow-md); transform: translateX(5px); }
.module-number {
    font-size: 1.1rem; font-weight: 800; color: var(--accent-color); background: var(--bg-dark);
    width: 38px; height: 38px; display: flex; align-items: center; justify-content: center;
    border-radius: var(--radius-sm); flex-shrink: 0;
}
.module-info h4 { margin: 0; font-size: 1rem; color: var(--primary-color); }

/* Author Section (Mobile First) */
.author-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 4rem;
    align-items: center;
    text-align: center;
}
.avatar-placeholder {
    width: 250px; height: 250px; border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-light), #3a5b82); display: flex;
    align-items: center; justify-content: center; font-size: 5rem; color: rgba(255,255,255,0.5);
    margin: 0 auto; border: 5px solid rgba(255,255,255,0.1);
}

/* Offer Section */
.offer-box {
    max-width: 600px; margin: 0 auto; background: var(--bg-main); border-radius: var(--radius-lg);
    overflow: hidden; box-shadow: var(--shadow-lg); border: 3px solid var(--accent-color);
}
.offer-header { background: var(--primary-color); color: white; padding: 2rem; text-align: center; }
.offer-header h2 { color: white; margin-bottom: 0.5rem; }
.offer-body { padding: 2rem 1.5rem; } /* Mobile padding */
.main-offer-list li {
    padding: 0.75rem 0; border-bottom: 1px solid var(--bg-light); display: flex; gap: 1rem;
    align-items: center; font-size: 1.1rem; color: var(--text-dark);
}
.main-offer-list li:last-child { border-bottom: none; }
.price-container { text-align: center; margin: 2rem 0; padding: 1.5rem; background: var(--bg-light); border-radius: var(--radius-md); }
.old-price { text-decoration: line-through; color: var(--error); font-size: 1.1rem; font-weight: 600; }
.current-price { display: flex; align-items: baseline; justify-content: center; gap: 0.5rem; color: var(--primary-color); margin: 0.5rem 0; }
.current-price .currency { font-size: 1.5rem; font-weight: 600; }
.current-price .value { font-size: 3rem; font-weight: 800; line-height: 1; } /* Mobile font size */
.cash-price { color: var(--text-main); font-size: 1rem; font-weight: 500; }
.payment-methods { display: flex; justify-content: center; gap: 1rem; margin-top: 1.5rem; font-size: 2rem; color: #a0aec0; }

/* FAQ */
.faq-accordion { max-width: 800px; margin: 0 auto; }
.faq-item {
    border-bottom: 1px solid #eaeaea; margin-bottom: 1rem; background: var(--bg-main);
    border-radius: var(--radius-md); overflow: hidden;
}
.faq-question {
    width: 100%; text-align: left; padding: 1.5rem; background: none; border: none; font-size: 1.15rem;
    font-weight: 600; color: var(--primary-color); cursor: pointer; display: flex; justify-content: space-between;
    align-items: center; font-family: inherit; transition: var(--transition);
}
.faq-question:hover { background: var(--bg-light); }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; }
.faq-answer p { padding: 0 1.5rem 1.5rem; color: var(--text-main); margin: 0; }
.faq-item.active .faq-answer { max-height: 250px; }
.faq-item.active .faq-question i { transform: rotate(180deg); }

/* Footer */
.footer { background-color: #050E1A; color: white; padding: 4rem 0 2rem; }
.footer-content { display: flex; flex-direction: column; align-items: center; text-align: center; margin-bottom: 3rem; }
.footer-logo { font-size: 1.8rem; font-weight: 800; margin-bottom: 1rem; }
.footer-logo span { color: var(--accent-color); }
.footer-text { color: #a0aec0; max-width: 400px; margin-bottom: 2rem; }
.footer-links { display: flex; gap: 2rem; flex-wrap: wrap; justify-content: center; }
.footer-links a { color: white; transition: var(--transition); }
.footer-links a:hover { color: var(--accent-color); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 2rem; text-align: center; font-size: 0.9rem; color: #a0aec0; }

/* Desktop Enhancements (Mobile First Approach) */
@media (min-width: 768px) {
    .py-large { padding-top: 5rem; padding-bottom: 5rem; }
    
    .grid-3 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
    
    .hero-cta { flex-direction: row; justify-content: center; width: auto; }
    .hero-cta .btn { width: auto; }
    
    .offer-body { padding: 3rem 2rem; }
    .current-price .value { font-size: 4rem; }
    
    .benefits-grid { grid-template-columns: 1fr 1fr; }
    .list-view { grid-template-columns: 1fr 1fr; }
}

@media (min-width: 992px) {
    .nav-links, .nav-cta { display: flex; }
    .nav-links { gap: 2.5rem; align-items: center; }
    .nav-links a { 
        color: var(--primary-color); 
        font-weight: 600; 
        font-size: 1rem;
        transition: var(--transition); 
        position: relative; 
    }
    .nav-links a:hover { color: var(--accent-hover); }
    .nav-links a::after {
        content: '';
        position: absolute;
        bottom: -4px;
        left: 0;
        width: 0;
        height: 2px;
        background-color: var(--accent-color);
        transition: width 0.3s ease;
    }
    .nav-links a:hover::after { width: 100%; }
    
    .mobile-menu-btn { display: none; }
    
    .hero-content {
        grid-template-columns: 1fr 1fr;
        text-align: left;
        gap: 4rem;
        padding-top: 0;
    }
    
    .hero-cta { justify-content: flex-start; }
    .trust-badges { justify-content: flex-start; }
    
    .solution-content { grid-template-columns: 1fr 1.2fr; }
    
    .author-content {
        grid-template-columns: 1fr 2fr;
        text-align: left;
    }
}