:root {
    --primary-color: #0f172a; /* Slate 900 */
    --secondary-color: #3b82f6; /* Blue 500 */
    --accent-color: #f59e0b; /* Amber 500 */
    --background-light: #f8fafc; /* Slate 50 */
    --text-color: #334155; /* Slate 700 */
    --text-light: #64748b; /* Slate 500 */
    --white: #ffffff;
    --heading-font: 'Playfair Display', serif;
    --body-font: 'Inter', sans-serif;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--body-font);
    color: var(--text-color);
    background-color: var(--background-light);
    line-height: 1.6;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--heading-font);
    color: var(--primary-color);
    line-height: 1.3;
    margin-bottom: 1rem;
}

p {
    margin-bottom: 1.5rem;
    font-size: 1.125rem;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

.text-container {
    max-width: 800px;
    margin: 0 auto;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
    0% { transform: scale(1); box-shadow: 0 0 0 0 rgba(245, 158, 11, 0.7); }
    70% { transform: scale(1.05); box-shadow: 0 0 0 15px rgba(245, 158, 11, 0); }
    100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(245, 158, 11, 0); }
}

.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.animate-on-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* Top Bar */
.top-bar {
    background-color: var(--primary-color);
    color: var(--white);
    text-align: center;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: 1px;
}

.top-bar p {
    margin: 0;
    font-size: 0.9rem;
}

/* Image Utilities */
.rounded-image {
    width: 100%;
    height: auto;
    border-radius: 16px;
    object-fit: cover;
}

.shadowed {
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

.m-0 {
    margin: 0 !important;
}

.text-center {
    text-align: center;
}

/* Split Section Layout */
.split-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.split-section.reverse .split-text {
    order: 2;
}
.split-section.reverse .split-image {
    order: 1;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #fdfbfb 0%, #ebedee 100%);
    padding: 5rem 0;
    border-bottom: 1px solid #e2e8f0;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 3rem;
    align-items: center;
}

.main-headline {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.hero-content {
    margin: 0 0 2rem 0;
}

.book-cover-image {
    width: 100%;
    max-width: 450px;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    display: block;
    margin: 0 auto;
}

.lead {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--primary-color);
}

.cta-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--white);
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.125rem;
    transition: var(--transition);
    border: 2px solid transparent;
}

.cta-button:hover {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

/* Sections General */
.section {
    padding: 5rem 0;
}

/* Problem Section */
.problem-section {
    background-color: var(--white);
}

.problem-section h2 {
    font-size: 2.25rem;
    text-align: left;
    margin-bottom: 2rem;
}

.highlight-text {
    font-weight: 600;
    color: var(--primary-color);
    font-size: 1.25rem;
    border-left: 4px solid var(--secondary-color);
    padding-left: 1.5rem;
}

.quote-box {
    background-color: #f1f5f9;
    padding: 2rem;
    border-radius: 12px;
    margin: 2.5rem 0;
    font-style: italic;
    text-align: center;
}

.quote-box p {
    margin: 0;
    font-size: 1.25rem;
    color: var(--primary-color);
}

/* Science Section */
.science-section h2 {
    font-size: 2.25rem;
    text-align: center;
    margin-bottom: 2rem;
}

.question-box {
    background-color: #fffbeb; /* amber-50 */
    border: 1px solid #fde68a; /* amber-200 */
    padding: 2rem;
    border-radius: 12px;
    margin: 2rem 0;
    text-align: center;
}

.question-box p {
    margin: 0;
    color: #92400e; /* amber-900 */
}

/* Inclusion Section */
.inclusion-section {
    background-color: var(--primary-color);
    color: var(--white);
}

.inclusion-section h2.light-text,
.inclusion-section p.light-text {
    color: var(--white);
}

.inclusion-section h2 {
    font-size: 2.25rem;
    text-align: left;
    margin-bottom: 2rem;
}

.highlight-box-light {
    background-color: rgba(255, 255, 255, 0.1);
    border-left: 4px solid var(--accent-color);
    padding: 1.5rem;
    border-radius: 0 8px 8px 0;
}

.highlight-box-light p {
    font-weight: 600;
    font-size: 1.125rem !important;
}

/* Product Section */
.product-section {
    background-color: var(--white);
}

.product-section h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 2rem;
}

.product-name {
    color: var(--secondary-color);
    font-style: italic;
}

.product-section h3 {
    text-align: center;
    font-size: 1.5rem;
    margin: 3rem 0;
    font-family: var(--body-font);
    font-weight: 600;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature-card {
    background-color: var(--background-light);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    transition: transform 0.3s ease;
    border: 1px solid #e2e8f0;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature-card h4 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.feature-card p {
    font-size: 1rem;
    margin: 0;
}

/* Offer Section */
.offer-section {
    background: linear-gradient(to bottom, var(--background-light) 0%, #e2e8f0 100%);
}

.gain-image {
    max-width: 600px;
    margin: 0 auto;
    display: block;
}

.logical-options {
    margin: 3rem 0;
}

.logical-options h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.option {
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
}

.option-1 {
    background-color: #fef2f2; /* red-50 */
    border: 1px solid #fecaca; /* red-200 */
}

.option-1 p {
    color: #991b1b;
    margin: 0;
}

.option-2 {
    background-color: #ecfdf5; /* emerald-50 */
    border: 1px solid #a7f3d0; /* emerald-200 */
}

.option-2 p {
    color: #065f46;
    margin: 0;
    font-weight: 600;
}

.pricing-card {
    background-color: var(--white);
    padding: 3rem 2rem;
    border-radius: 24px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    text-align: center;
    margin-top: 4rem;
    border-top: 8px solid var(--accent-color);
}

.publisher {
    text-transform: uppercase;
    letter-spacing: 2px;
    font-size: 0.875rem;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.price-wrapper {
    margin-bottom: 2rem;
}

.old-price {
    font-size: 1.5rem;
    color: var(--text-light);
    text-decoration: line-through;
    margin-bottom: 0.5rem;
}

.new-price {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
    margin: 0;
    font-family: var(--heading-font);
}

.guarantee {
    font-size: 1.125rem;
    margin-bottom: 2.5rem;
}

.btn-primary {
    display: block;
    width: 100%;
    background-color: #059669; /* emerald-600 */
    color: var(--white);
    padding: 1.25rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.125rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    transition: var(--transition);
    border: none;
    margin-bottom: 1.5rem;
    box-shadow: 0 10px 15px -3px rgba(5, 150, 105, 0.3);
}

.btn-primary:hover {
    background-color: #047857; /* emerald-700 */
    transform: translateY(-2px);
    box-shadow: 0 15px 20px -3px rgba(5, 150, 105, 0.4);
}

.animate-pulse {
    animation: pulse 2s infinite;
}

.secure-checkout {
    font-size: 0.875rem;
    color: var(--text-light);
    margin: 0;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    text-align: center;
    padding: 3rem 0;
}

footer p {
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
}

.footer-disclaimer {
    color: #94a3b8;
    font-size: 0.75rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Responsive */
@media (max-width: 992px) {
    .hero-grid, .split-section {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .split-section.reverse .split-text {
        order: 1;
    }
    .split-section.reverse .split-image {
        order: 2;
    }
    
    .book-cover-image {
        max-width: 350px;
    }
    
    .problem-section h2, .inclusion-section h2 {
        text-align: center;
    }
}

@media (max-width: 768px) {
    .main-headline {
        font-size: 2rem;
        text-align: center;
    }
    
    .hero-content {
        text-align: center;
    }
    
    .hero-grid .cta-button {
        display: block;
        margin: 0 auto;
        text-align: center;
        max-width: 300px;
    }

    .section {
        padding: 4rem 0;
    }
    
    h2 {
        font-size: 2rem !important;
    }
    
    .pricing-card {
        padding: 2rem 1.5rem;
    }
    
    .new-price {
        font-size: 3rem;
    }
    
    .btn-primary {
        font-size: 1rem;
        padding: 1rem 1.5rem;
    }
}

@media (max-width: 480px) {
    .main-headline {
        font-size: 1.75rem;
    }
    
    .hero {
        padding: 4rem 0;
    }
}