:root {
    --primary: #60bbd1;
    --secondary: #6d3406;
    --on-primary: #111111;
    --on-secondary: #ffffff;
    --bg: #ffffff;
    --surface: #f5f7fa;
    --light: #eef1f6;
    --dark: #1a1a1a;
    --muted: #5b6472;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    background-color: var(--bg);
    color: var(--dark);
    line-height: 1.6;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--dark);
    font-weight: 700;
}

p {
    color: var(--muted);
}

.header-nav {
    background-color: var(--bg);
    border-bottom: 1px solid var(--light);
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    z-index: 1000;
}

.logo {
    max-height: 40px;
}

.logo-link {
    display: flex;
    align-items: center;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: auto;
    max-width: 100%;
    padding: 14px 28px;
    margin: 8px 0;
    gap: 8px;
    border: none;
    border-radius: 10px;
    font-weight: 600;
    font-size: 16px;
    line-height: 1.2;
    text-align: center;
    text-decoration: none;
    white-space: nowrap;
    box-sizing: border-box;
    cursor: pointer;
    transition: filter 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
    min-height: 44px; /* Minimum tap target height */
}

.btn-cta {
    background: var(--primary);
    color: var(--on-primary) !important;
    box-shadow: 0 6px 16px rgba(0,0,0,0.15);
}

.btn-secondary {
    background: var(--secondary);
    color: var(--on-secondary) !important;
}

.btn-cta:hover, .btn-secondary:hover {
    filter: brightness(0.92);
    box-shadow: 0 8px 20px rgba(0,0,0,0.20);
}

@media (max-width: 575.98px) {
    .btn-lg {
        display: block;
        width: 100%;
    }
    .btn-group-vertical > .btn.btn-lg + .btn.btn-lg {
        margin-top: 1rem; /* Adjust vertical margin for stacked buttons */
    }
}

.hero {
    padding-top: 70px;
    padding-bottom: 70px;
    background-color: var(--surface);
}

.book-cover {
    border-radius: 12px;
    box-shadow: 0 12px 24px rgba(0,0,0,0.15);
    max-width: 400px;
    margin: 0 auto;
}

.benefits, .whats-inside, .product-intro, .author-section, .pricing, .final-cta {
    padding-top: 70px;
    padding-bottom: 70px;
}

.benefits .card, .chapter-item.card, .author-card, .pricing-card {
    background-color: var(--bg);
    border: 1px solid var(--light);
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.benefits .card:hover, .chapter-item.card:hover, .pricing-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 18px rgba(0,0,0,0.10);
}

.benefit-card .card-title {
    color: var(--primary);
}

.chapter-title {
    color: var(--dark);
}

.chapter-blurb {
    color: var(--muted);
}

.checkmark-list li {
    position: relative;
    padding-left: 28px;
    margin-bottom: 10px;
    color: var(--dark);
}

.checkmark-list li::before {
    content: "\2713"; /* Checkmark character */
    position: absolute;
    left: 0;
    top: 0;
    color: var(--primary);
    font-weight: bold;
}

.author-section {
    background-color: var(--surface);
}

.author-card {
    max-width: 600px;
    text-align: center;
}

.avatar-fallback {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background-color: var(--light);
    color: var(--dark);
    font-size: 32px;
    font-weight: 600;
    line-height: 1;
    margin-bottom: 15px;
}

.pricing-card {
    max-width: 400px;
    text-align: center;
    background-color: var(--surface);
}

.price-display {
    font-size: 3rem;
    font-weight: bold;
    color: var(--dark);
    margin-bottom: 15px;
}

.footer-section {
    background-color: var(--dark);
    color: #ffffff;
    padding-top: 30px;
    padding-bottom: 30px;
}

.footer-section p {
    color: #ffffff;
    margin-bottom: 0;
}

/* Responsive adjustments */
@media (max-width: 767.98px) {
    .hero .display-4 {
        font-size: 2.5rem;
    }
    .book-cover {
        max-width: 300px;
    }
    .hero .text-lg-start {
        text-align: center !important;
    }
    .hero .justify-content-lg-start {
        justify-content: center !important;
    }
    .product-intro .row {
        flex-direction: column-reverse;
    }
    .product-intro img {
        margin-bottom: 30px;
    }
}

@media (max-width: 575.98px) {
    .hero .display-4 {
        font-size: 2rem;
    }
    .benefits, .whats-inside, .product-intro, .author-section, .pricing, .final-cta {
        padding-top: 40px;
        padding-bottom: 40px;
    }
    .logo {
        max-height: 35px;
    }
}