/* ==========================================
   BVDLC Website - Main Stylesheet
   ========================================== */

/* ==========================================
   CSS Variables
   ========================================== */
:root {
    /* Colors */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #0f172a;
    --secondary-light: #1e293b;
    --accent-color: #f59e0b;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-light: #64748b;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-dark: #0f172a;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

/* ==========================================
   Reset & Base Styles
   ========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: var(--font-size-base);
}

body {
    font-family: var(--font-primary);
    color: var(--text-primary);
    line-height: var(--line-height-base);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

.announcement-bar {
    background: linear-gradient(90deg, #2563eb 0%, #7c3aed 100%);
    color: white;
    padding: var(--spacing-xs) 0;
    font-size: 0.95rem;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1001;
}

.announcement-content {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--spacing-sm);
    justify-content: center;
}

.announcement-label {
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-weight: 700;
    font-size: 0.75rem;
}

.announcement-text {
    opacity: 0.9;
}

.announcement-link {
    background: rgba(255, 255, 255, 0.15);
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    color: white;
    font-weight: 600;
}

@media (max-width: 640px) {
    .announcement-content {
        flex-direction: column;
        text-align: center;
    }

    .announcement-link {
        width: 100%;
        text-align: center;
    }
}

/* ==========================================
   Typography
   ========================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: clamp(1.25rem, 2.5vw, 1.5rem); }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-base);
}

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

ul {
    list-style: none;
}

/* ==========================================
   Container & Layout
   ========================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-xl) 0;
}

/* ==========================================
   Navigation
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: background-color var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
}

.nav-brand h2 {
    font-size: 1.5rem;
    margin: 0;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-link {
    font-weight: 500;
    color: var(--text-primary);
    transition: color var(--transition-base);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width var(--transition-base);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    transition: all var(--transition-base);
}

/* ==========================================
   Hero Section
   ========================================== */
.hero {
    margin-top: 70px;
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, #f8fafc 0%, #e0e7ff 100%);
    min-height: 80vh;
    display: flex;
    align-items: center;
}

.hero-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.hero-title {
    margin-bottom: 0;
    line-height: 1.1;
}

.hero-title .highlight {
    color: var(--primary-color);
    position: relative;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 0;
    font-weight: 500;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

.hero-definition {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    color: var(--primary-dark);
    background: linear-gradient(120deg, rgba(59, 130, 246, 0.15), rgba(14, 165, 233, 0.25));
    padding: 0.35rem 0.9rem;
    border-radius: 999px;
    box-shadow: 0 8px 20px rgba(37, 99, 235, 0.12);
}

.hero-definition-acronym {
    background: var(--primary-color);
    color: #ffffff;
    padding: 0.15rem 0.75rem;
    border-radius: 999px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-size: 0.9rem;
    box-shadow: 0 6px 18px rgba(37, 99, 235, 0.25);
}

.hero-definition-label {
    color: var(--primary-dark);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin: var(--spacing-lg) 0;
}

.stat {
    text-align: center;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary-color);
    line-height: 1;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
    font-weight: 500;
}

/* CTA Buttons */
.cta-buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.btn {
    display: inline-block;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
    text-align: center;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: #1f3fb7;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: white;
    border-color: #1f3fb7;
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
}

.btn-large {
    padding: var(--spacing-md) var(--spacing-2xl);
    font-size: 1.125rem;
}

/* Book Mockup */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.book-mockup {
    perspective: 1000px;
}

.book-cover {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-color) 100%);
    color: white;
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    transform: rotateY(-10deg) rotateX(5deg);
    transition: transform var(--transition-slow);
    min-height: 500px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.book-cover:hover {
    transform: rotateY(0deg) rotateX(0deg);
}

.book-cover h3 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
    color: white;
}

.book-cover p {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-md);
    color: rgba(255, 255, 255, 0.9);
}

.book-subtitle {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.8);
    margin-top: auto;
    margin-bottom: var(--spacing-md);
}

.book-authors {
    font-size: 1.125rem;
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
}

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

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.section-title {
    margin-bottom: var(--spacing-md);
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.problem-layout {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
    align-items: start;
}

.problem-context {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 120px;
}

.problem-context h3 {
    margin-bottom: var(--spacing-md);
}

.context-list {
    list-style: none;
    padding: 0;
    margin: 0 0 var(--spacing-lg) 0;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    color: var(--text-secondary);
}

.context-stat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.context-stat {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
}

.context-stat .stat-label {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-secondary);
}

.context-stat .stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    margin: var(--spacing-xs) 0;
}

.context-stat .stat-footnote {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.problem-cta {
    border-top: 1px solid var(--border-color);
    padding-top: var(--spacing-md);
}

.problem-cta .cta-label {
    font-weight: 700;
    color: var(--primary-color);
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 0.15em;
}

.problem-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: var(--spacing-md);
}

.problem-card {
    position: relative;
}

.problem-note {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    border-left: 4px solid var(--primary-color);
    background-color: var(--bg-primary);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
}

@media (max-width: 1024px) {
    .problem-layout {
        grid-template-columns: 1fr;
    }

    .problem-context {
        position: static;
    }
}

.problem-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-md) var(--spacing-lg) var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.problem-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.problem-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.problem-card h3 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-md);
}

.problem-card p {
    color: var(--text-secondary);
    margin-bottom: 0;
}

.insight-box {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-top: var(--spacing-xl);
}

.insight-box h3 {
    color: white;
    margin-bottom: var(--spacing-md);
}

.insight-box p {
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--spacing-md);
}

.insight-box strong {
    color: white;
}

/* ==========================================
   Framework Section
   ========================================== */
.framework-section {
    background-color: var(--bg-primary);
}

.pillars-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.pillar-card {
    background-color: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    transition: all var(--transition-base);
}

.pillar-card:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-lg);
}

.pillar-number {
    display: inline-block;
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.pillar-card h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-xs);
}

.pillar-subtitle {
    font-size: 1rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

/* Phases Timeline */
.phases-section {
    background-color: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-top: var(--spacing-lg);
}

.phases-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.phases-intro {
    text-align: center;
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
}

.phases-timeline {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.phase-group {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
}

.phase-group h4 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
}

.phase-duration {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.phase-item {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
}

.phase-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 40px;
    background-color: var(--primary-color);
    color: white;
    border-radius: var(--radius-md);
    font-weight: 700;
    flex-shrink: 0;
}

.phase-content h5 {
    font-size: 1rem;
    margin-bottom: var(--spacing-xs);
}

.phase-content p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0;
}

.framework-cta {
    text-align: center;
    margin-top: var(--spacing-2xl);
}

.framework-cta p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

/* ==========================================
   Benefits Section
   ========================================== */
.benefits-section {
    background-color: var(--bg-secondary);
}

.audience-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-3xl);
}

.audience-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.audience-card h3 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.audience-card ul {
    list-style: none;
}

.audience-card li {
    padding-left: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
    position: relative;
    color: var(--text-secondary);
}

.audience-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: 700;
}

/* Testimonials */
.testimonials {
    margin-top: var(--spacing-3xl);
}

.testimonials-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

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

.testimonial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.testimonial-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border-top: 4px solid var(--primary-color);
}

.testimonial-quote {
    font-size: 1.125rem;
    font-style: italic;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.testimonial-author {
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.testimonial-result {
    font-weight: 500;
    color: var(--success-color);
}

/* ==========================================
   Contents Section
   ========================================== */
.contents-section {
    background-color: var(--bg-primary);
}

.contents-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.part-card {
    background-color: var(--bg-secondary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
}

.part-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.part-number {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    font-weight: 700;
    font-size: 0.875rem;
    margin-bottom: var(--spacing-md);
}

.part-card h3 {
    margin-bottom: var(--spacing-md);
}

.part-card > p {
    margin-bottom: var(--spacing-md);
}

.part-card ul {
    list-style: none;
}

.part-card li {
    padding-left: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
    position: relative;
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.part-card li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

/* ==========================================
   Authors Section
   ========================================== */
.authors-section {
    background-color: var(--bg-secondary);
}

.authors-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-2xl);
}

.authors-bio h3 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.authors-intro {
    font-size: 1.2rem;
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.authors-credentials {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
    padding: var(--spacing-xl);
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
}

.credential {
    text-align: center;
}

.credential-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-color);
    line-height: 1;
}

.credential-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
}

.authors-expertise {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    height: fit-content;
}

.authors-expertise h4 {
    margin-bottom: var(--spacing-md);
}

.authors-expertise ul {
    list-style: none;
}

.authors-expertise li {
    padding-left: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
    position: relative;
    color: var(--text-secondary);
}

.authors-expertise li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* ==========================================
   CTA Section
   ========================================== */
.cta-section {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-color) 100%);
    color: white;
}

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

.cta-content h2 {
    color: white;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.cta-subtitle {
    font-size: 1.5rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--spacing-2xl);
}

.cta-book-info {
    background-color: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-2xl);
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
}

.book-details {
    text-align: left;
}

.book-details h3 {
    color: white;
    margin-bottom: var(--spacing-sm);
}

.book-details > p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: var(--spacing-lg);
}

.book-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-sm);
}

.feature {
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.9375rem;
}

.cta-actions {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.cta-actions .btn-primary {
    background-color: white;
    color: var(--primary-color);
}

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

.cta-actions .btn-secondary {
    border-color: white;
    color: white;
}

.cta-actions .btn-secondary:hover {
    background-color: white;
    color: var(--primary-color);
}

.cta-note {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.7);
    margin-top: var(--spacing-sm);
}

.urgency-message {
    background-color: rgba(245, 158, 11, 0.2);
    border: 2px solid rgba(245, 158, 11, 0.5);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: left;
    max-width: 800px;
    margin: 0 auto;
}

.urgency-message h4 {
    color: white;
    margin-bottom: var(--spacing-md);
}

.urgency-message p {
    color: rgba(255, 255, 255, 0.9);
}

.urgency-message strong {
    color: white;
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    background-color: var(--bg-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
}

.footer-brand h3 {
    color: white;
    margin-bottom: var(--spacing-xs);
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.6);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.footer-column h4 {
    color: white;
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
}

.footer-column ul {
    list-style: none;
}

.footer-column li {
    margin-bottom: var(--spacing-xs);
}

.footer-column a {
    color: rgba(255, 255, 255, 0.7);
    transition: color var(--transition-base);
}

.footer-column a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.5);
    margin: 0;
}

/* ==========================================
   Responsive Design
   ========================================== */

@media (max-width: 992px) {
    .hero-content {
        grid-template-columns: 1fr;
    }

    .hero-visual {
        order: -1;
    }

    .stats-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .authors-content {
        grid-template-columns: 1fr;
    }

    .cta-book-info {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: left var(--transition-base);
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-lg) 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }

    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }

    .hero {
        padding: var(--spacing-xl) 0;
        min-height: auto;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .cta-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .phases-timeline {
        grid-template-columns: 1fr;
    }

    .book-features {
        grid-template-columns: 1fr;
    }

    .authors-credentials {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        --font-size-base: 14px;
    }

    .section {
        padding: var(--spacing-xl) 0;
    }

    .book-cover {
        padding: var(--spacing-lg);
        min-height: 400px;
    }
}

/* ==========================================
   Animations
   ========================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* Scroll reveal animation */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Prevent flash of invisible content */
html:not(.js-loaded) .reveal {
    opacity: 1;
    transform: none;
}

/* ==========================================
   Framework-Focused Updates
   ========================================== */

/* Framework Visual - Universe Theme */
.framework-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-lg);
    perspective: 1000px;
}

.orbital-diagram {
    position: relative;
    width: 550px;
    height: 550px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: radial-gradient(circle at center, rgba(15, 23, 42, 0.4) 0%, rgba(15, 23, 42, 0.8) 100%);
    border-radius: 50%;
    overflow: visible;
}

/* Universe Background Stars */
.universe-stars {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: 1;
}

.star {
    position: absolute;
    width: 3px;
    height: 3px;
    background: white;
    border-radius: 50%;
    animation: twinkle 3s ease-in-out infinite;
    box-shadow: 0 0 4px rgba(255, 255, 255, 0.8);
}

.star-1 { top: 15%; left: 20%; animation-delay: 0s; }
.star-2 { top: 25%; right: 15%; animation-delay: 0.5s; }
.star-3 { bottom: 20%; left: 25%; animation-delay: 1s; }
.star-4 { bottom: 30%; right: 20%; animation-delay: 1.5s; }
.star-5 { top: 40%; left: 10%; animation-delay: 2s; }
.star-6 { top: 60%; right: 10%; animation-delay: 2.5s; }

/* Context Sun - The Center of the Universe */
.context-sun {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 140px;
    height: 140px;
    z-index: 10;
}

.sun-corona {
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle,
        rgba(251, 191, 36, 0.6) 0%,
        rgba(245, 158, 11, 0.4) 40%,
        rgba(251, 146, 60, 0.2) 70%,
        transparent 100%);
    border-radius: 50%;
    animation: sun-pulse 4s ease-in-out infinite;
    filter: blur(8px);
}

.sun-surface {
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle,
        #fbbf24 0%,
        #f59e0b 50%,
        #ea580c 100%);
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow:
        0 0 40px rgba(251, 191, 36, 0.6),
        0 0 80px rgba(245, 158, 11, 0.4),
        inset 0 0 30px rgba(255, 255, 255, 0.2);
}

.sun-label {
    color: white;
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: 2px;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.sun-subtitle {
    color: rgba(255, 255, 255, 0.95);
    font-size: 0.75rem;
    font-weight: 600;
    margin-top: 4px;
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
}

/* Universe SVG Layer */
.universe-svg {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
    height: 100%;
    z-index: 4;
    pointer-events: none;
}

.orbit-track {
    fill: none;
    stroke: rgba(148, 163, 184, 0.15);
    stroke-width: 1.5;
    stroke-dasharray: 8 8;
}

/* Outcome Beams - Connecting phases back to Context */
.outcome-beam {
    stroke: #10b981;
    stroke-width: 2;
    stroke-opacity: 0;
    stroke-linecap: round;
    transition: stroke-opacity 0.5s ease;
    filter: drop-shadow(0 0 4px rgba(16, 185, 129, 0.6));
}

.outcome-beam.beam-0 { animation: beam-pulse 3s ease-in-out 0s infinite; }
.outcome-beam.beam-1 { animation: beam-pulse 3s ease-in-out 0.5s infinite; }
.outcome-beam.beam-2 { animation: beam-pulse 3s ease-in-out 1s infinite; }
.outcome-beam.beam-3 { animation: beam-pulse 3s ease-in-out 1.5s infinite; }
.outcome-beam.beam-4 { animation: beam-pulse 3s ease-in-out 2s infinite; }
.outcome-beam.beam-5 { animation: beam-pulse 3s ease-in-out 2.5s infinite; }

@keyframes beam-pulse {
    0%, 100% { stroke-opacity: 0.15; }
    50% { stroke-opacity: 0.6; }
}

/* Flow Lines - Dynamic connections between phases */
.flow-line {
    fill: none;
    stroke: rgba(59, 130, 246, 0.3);
    stroke-width: 2;
    stroke-linecap: round;
    animation: flow-dash 20s linear infinite;
}

@keyframes flow-dash {
    0% { stroke-dashoffset: 0; }
    100% { stroke-dashoffset: -100; }
}

/* AI Acceleration Particles - Electric Cyan */
.ai-particle {
    fill: #22d3ee;
    filter: drop-shadow(0 0 8px rgba(34, 211, 238, 0.9));
    opacity: 1;
}

.ai-particle.particle-1 { r: 7; }
.ai-particle.particle-2 { r: 6; }
.ai-particle.particle-3 { r: 8; }
.ai-particle.particle-4 { r: 6.5; }

/* Phase Planets - Orbiting Bodies */
.phase-planets-mask {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    border-radius: 50%;
    overflow: hidden;
    z-index: 8;
}

.phase-planets {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    animation: planets-orbit 60s linear infinite;
    z-index: 8;
}

.phase-planet {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 110px;
    height: 110px;
    margin: -55px 0 0 -55px;
    transform-origin: center;
    transform: rotate(var(--orbit-angle)) translateY(-190px) rotate(calc(-1 * var(--orbit-angle)));
    cursor: pointer;
    transition: all 0.4s ease;
}

/* AI Boost Effect - Speed trails (Electric Cyan) */
.ai-boost {
    position: absolute;
    width: 130px;
    height: 130px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(34, 211, 238, 0.35) 0%, transparent 70%);
    top: -10px;
    left: -10px;
    animation: boost-pulse 2s ease-in-out infinite;
    pointer-events: none;
    z-index: 0;
}

@keyframes boost-pulse {
    0%, 100% {
        transform: scale(0.9);
        opacity: 0.5;
    }
    50% {
        transform: scale(1.2);
        opacity: 0.9;
    }
}

.planet-body {
    width: 110px;
    height: 110px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 10px;
    box-shadow:
        0 0 20px rgba(37, 99, 235, 0.4),
        inset -5px -5px 15px rgba(0, 0, 0, 0.2),
        inset 5px 5px 15px rgba(255, 255, 255, 0.2);
    border: 3px solid rgba(255, 255, 255, 0.3);
    position: relative;
    transition: all 0.3s ease;
    z-index: 1;
    animation: keep-upright 60s linear infinite;
}

.planet-number {
    font-size: 2rem;
    font-weight: 800;
    color: white;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    line-height: 1;
}

.planet-label {
    font-size: 0.6rem;
    font-weight: 700;
    color: white;
    text-align: center;
    line-height: 1.2;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
    max-width: 85px;
    word-wrap: break-word;
}

.phase-planet:hover .planet-body {
    box-shadow:
        0 0 30px rgba(37, 99, 235, 0.6),
        inset -5px -5px 15px rgba(0, 0, 0, 0.3),
        inset 5px 5px 15px rgba(255, 255, 255, 0.3);
}

.phase-planet:hover .planet-body {
    transform: scale(1.15);
}


/* Phase 0 - Special Golden Planet */
.phase-0 .planet-body {
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
    box-shadow:
        0 0 30px rgba(251, 191, 36, 0.6),
        inset -5px -5px 15px rgba(0, 0, 0, 0.2),
        inset 5px 5px 15px rgba(255, 255, 255, 0.3);
}


/* AI Accelerator Badge - Electric Cyan */
.ai-accelerator-badge {
    position: absolute;
    top: -35px;
    right: 10px;
    background: linear-gradient(135deg, #22d3ee 0%, #06b6d4 100%);
    color: var(--secondary-color);
    padding: 8px 18px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    box-shadow: 0 4px 15px rgba(34, 211, 238, 0.5);
    display: flex;
    align-items: center;
    gap: 6px;
    z-index: 15;
    animation: badge-glow 2s ease-in-out infinite;
}

@keyframes badge-glow {
    0%, 100% {
        box-shadow: 0 4px 15px rgba(34, 211, 238, 0.5);
    }
    50% {
        box-shadow: 0 4px 25px rgba(34, 211, 238, 0.8);
    }
}

.ai-icon {
    font-size: 1.1rem;
    animation: spark 1.5s ease-in-out infinite;
}

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

.ai-text {
    font-weight: 700;
}

/* Framework Hint */
.framework-hint {
    position: absolute;
    bottom: -80px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    opacity: 0.7;
    background: rgba(255, 255, 255, 0.95);
    padding: 6px 16px;
    border-radius: 14px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.12);
    pointer-events: none;
    white-space: nowrap;
}

/* Orbital Path */

/* Universe Animations */
@keyframes twinkle {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.3;
        transform: scale(0.8);
    }
}

@keyframes sun-pulse {
    0%, 100% {
        transform: scale(1);
        opacity: 1;
    }
    50% {
        transform: scale(1.15);
        opacity: 0.85;
    }
}

@keyframes planets-orbit {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

@keyframes keep-upright {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(-360deg);
    }
}

/* Problem Solution Link */
.problem-solution {
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 2px solid var(--primary-color);
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.875rem;
}

/* Framework Overview / Big Picture */
.framework-overview {
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.big-picture-container {
    max-width: 1000px;
    margin: 0 auto;
}

.framework-foundation {
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.framework-foundation h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-lg);
}

.foundation-pillars {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

.foundation-pillar {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
}

.pillar-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: var(--spacing-md);
}

.foundation-pillar h4 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.foundation-pillar p {
    font-size: 1rem;
    color: var(--text-secondary);
    margin: 0;
}

.framework-phases-visual {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

.framework-phases-visual h3 {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.phase-intro {
    text-align: center;
    color: var(--text-secondary);
    max-width: 720px;
    margin: 0 auto var(--spacing-xl);
}

.phase-conveyor {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    position: relative;
}

.phase-conveyor::before {
    content: '';
    position: absolute;
    left: 240px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--primary-light), transparent);
    opacity: 0.25;
}

.phase-row {
    display: flex;
    gap: var(--spacing-lg);
    align-items: stretch;
    position: relative;
}

.phase-row::before {
    content: '';
    position: absolute;
    left: 240px;
    top: 50%;
    width: 30px;
    height: 2px;
    background: var(--primary-color);
    opacity: 0.4;
}

.phase-stage-info {
    flex: 0 0 240px;
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.stage-label {
    display: block;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    margin-bottom: var(--spacing-xs);
}

.stage-duration {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.stage-summary {
    margin-top: var(--spacing-sm);
    color: var(--text-secondary);
}

.phase-stage-cards {
    flex: 1;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: var(--spacing-md);
}

.phase-stage-card {
    background-color: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.phase-stage-card .stage-number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.15rem;
    flex-shrink: 0;
}

.phase-stage-card h4 {
    margin-bottom: var(--spacing-xs);
}

.phase-stage-card p {
    margin: 0 0 var(--spacing-sm) 0;
    color: var(--text-secondary);
}

.phase-card-list {
    margin: 0;
    padding-left: 1rem;
    color: var(--text-secondary);
}

.phase-card-list li {
    margin-bottom: 0.35rem;
}

@media (max-width: 1024px) {
    .phase-conveyor::before,
    .phase-row::before {
        display: none;
    }

    .phase-row {
        flex-direction: column;
    }

    .phase-stage-info {
        width: 100%;
    }
}

.phase-loop-note {
    margin-top: var(--spacing-xl);
    text-align: center;
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.phase-loop-note p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

.framework-result {
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--bg-primary);
    border-radius: var(--radius-md);
    text-align: center;
    font-size: 1.125rem;
    max-width: 600px;
}

.framework-result strong {
    color: var(--primary-color);
}

/* Grid auto-wrap handles responsiveness */

/* Three Pillars Deep Dive */
.pillars-deep-dive {
    display: grid;
    gap: var(--spacing-xl);
}

.pillar-deep {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    border-left: 6px solid var(--primary-color);
}

.pillar-header {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
    margin-bottom: var(--spacing-lg);
}

.pillar-number-large {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 80px;
    height: 80px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-size: 3rem;
    font-weight: 800;
    flex-shrink: 0;
}

.pillar-title-group h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-xs);
}

.pillar-tagline {
    font-size: 1.125rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin: 0;
}

.pillar-content {
    display: grid;
    gap: var(--spacing-lg);
}

.pillar-problem,
.pillar-approach,
.pillar-outcome {
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
}

.pillar-problem {
    background-color: #fef3c7;
    border-left: 4px solid var(--warning-color);
}

.pillar-approach {
    background-color: #dbeafe;
    border-left: 4px solid var(--primary-color);
}

.pillar-outcome {
    background-color: #d1fae5;
    border-left: 4px solid var(--success-color);
}

.pillar-problem h4,
.pillar-approach h4,
.pillar-outcome h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
}

.pillar-problem p,
.pillar-approach p,
.pillar-outcome strong {
    color: var(--text-primary);
}

.pillar-approach ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.pillar-approach li {
    padding-left: var(--spacing-lg);
    position: relative;
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

.pillar-approach li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

/* 12 Phases Interactive */
.phases-interactive {
    display: grid;
    gap: var(--spacing-xl);
}

.phase-detail {
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: all var(--transition-base);
}

.phase-detail:hover {
    box-shadow: var(--shadow-xl);
}

.phase-detail-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: var(--spacing-md);
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.phase-num {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 70px;
    height: 70px;
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    font-size: 2rem;
    font-weight: 800;
    backdrop-filter: blur(10px);
}

.phase-detail-header h3 {
    color: white;
    margin-bottom: var(--spacing-xs);
}

.phase-duration {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
    margin: 0;
}

.phase-detail-content {
    padding: var(--spacing-lg);
    display: grid;
    gap: var(--spacing-md);
}

.phase-description p {
    font-size: 1.125rem;
    line-height: 1.7;
}

.phase-artifacts h4,
.phase-outcome h4 {
    font-size: 1.125rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.phase-artifacts ul {
    list-style: disc;
    padding-left: var(--spacing-lg);
}

.phase-artifacts li {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

/* Implementation Patterns */
.implementation-playbooks {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.playbook {
    background-color: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    border-left: 5px solid var(--primary-color);
}

.playbook-header {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-lg);
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.playbook-label {
    display: inline-flex;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    background-color: var(--bg-secondary);
    font-size: 0.85rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--primary-color);
    font-weight: 700;
}

.playbook h3 {
    margin: var(--spacing-xs) 0;
}

.playbook-tagline {
    color: var(--text-secondary);
    margin: 0;
}

.playbook-duration {
    font-weight: 700;
    color: var(--primary-color);
    white-space: nowrap;
}

@media (max-width: 640px) {
    .playbook-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }

    .playbook-duration {
        white-space: normal;
        width: 100%;
    }
}

.playbook-body {
    display: grid;
    gap: var(--spacing-lg);
}

.playbook-meta {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-lg);
}

.meta-block {
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
}

.meta-label {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-light);
    display: block;
    margin-bottom: var(--spacing-xs);
}

.meta-block p {
    margin: 0;
    color: var(--text-secondary);
}

.playbook-timeline {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.timeline-step {
    flex: 1 1 220px;
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
}

.step-phase {
    display: block;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
}

.playbook-benefits {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-sm);
    list-style: none;
    padding: 0;
    margin: 0;
}

.playbook-benefits li::before {
    content: '✓';
    color: var(--success-color);
    margin-right: 0.5rem;
}

.playbook-benefits li {
    display: flex;
    align-items: flex-start;
    color: var(--text-secondary);
}

.implementation-cta {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    text-align: center;
}

.implementation-cta h3 {
    color: white;
    margin-bottom: var(--spacing-sm);
}

.implementation-cta p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
}

/* Roles Section */
.roles-section {
    background-color: var(--bg-secondary);
}

.roles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-md);
    align-items: stretch;
}

@media (min-width: 1200px) {
    .roles-grid {
        grid-template-columns: repeat(3, minmax(280px, 1fr));
        justify-items: stretch;
    }
}

.role-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.role-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.role-card h3 {
    font-size: 1.2rem;
    color: var(--primary-color);
    margin-bottom: 0;
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid rgba(37, 99, 235, 0.2);
}

.role-challenges,
.role-solutions {
    margin-bottom: 0;
}

.role-challenges h4,
.role-solutions h4 {
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.role-challenges ul,
.role-solutions ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.role-challenges li,
.role-solutions li {
    padding-left: var(--spacing-lg);
    position: relative;
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.role-challenges li::before {
    content: '⚠';
    position: absolute;
    left: 0;
    color: var(--warning-color);
}

.role-solutions li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: 700;
}

/* Resources Section */
.resources-section {
    background-color: var(--bg-primary);
}

.book-teaser {
    margin-top: var(--spacing-md);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: rgba(59, 130, 246, 0.08);
    border: 1px solid rgba(59, 130, 246, 0.3);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xs) var(--spacing-md);
}

.teaser-label {
    font-weight: 600;
    color: var(--primary-color);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.75rem;
}

.teaser-link {
    font-weight: 600;
}

.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.resource-card {
    background-color: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition-base);
    border: 2px solid transparent;
}

.resource-card.coming-soon {
    border-color: rgba(37, 99, 235, 0.4);
    position: relative;
}

.resource-card.coming-soon::after {
    content: 'Coming soon';
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--primary-color);
    font-weight: 700;
}

.resource-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.resource-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-xl);
    background-color: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    box-shadow: inset 0 0 0 1px var(--border-color);
}

.resource-icon svg {
    width: 34px;
    height: 34px;
    stroke: var(--primary-color);
    stroke-width: 1.8;
    stroke-linecap: round;
    stroke-linejoin: round;
    fill: none;
}

.resource-card h3 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-md);
}

.resource-card p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.resource-link {
    display: inline-block;
    color: var(--primary-color);
    font-weight: 600;
    transition: all var(--transition-base);
}

.resource-link:hover {
    transform: translateX(5px);
}

.resources-note {
    background-color: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
}

.resources-note p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Contact & Community */
.contact-section {
    background-color: var(--bg-secondary);
    padding-bottom: var(--spacing-2xl);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
    align-items: stretch;
}

.contact-grid.single-card {
    grid-template-columns: minmax(320px, 500px);
    justify-content: center;
}

.contact-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    border-left: 5px solid var(--primary-color);
    height: 100%;
}

.contact-card h3 {
    margin-bottom: var(--spacing-sm);
}


/* Book Notification Section */
.book-notification {
    background: linear-gradient(135deg, #f8fafc 0%, #e0e7ff 100%);
}

.book-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
    max-width: 1100px;
    margin: 0 auto;
}

.book-info h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.book-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

.book-highlights {
    display: grid;
    gap: var(--spacing-lg);
}

.book-highlight {
    padding: var(--spacing-md);
    background-color: var(--bg-primary);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--primary-color);
}

.book-highlight strong {
    display: block;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
    font-size: 1.125rem;
}

.book-highlight p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.book-signup {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
}

.book-signup h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-sm);
    text-align: center;
}

.book-signup > p {
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.email-signup-form {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.email-signup-form input[type="email"] {
    flex: 1;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: all var(--transition-base);
}

.email-signup-form input[type="email"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.email-signup-form button {
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    white-space: nowrap;
}

.form-status {
    font-size: 0.875rem;
    text-align: center;
    min-height: 1.5em;
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    color: var(--text-secondary);
}

.form-status[data-state="success"] {
    color: #15803d;
}

.form-status[data-state="error"] {
    color: #dc2626;
}

.signup-note {
    font-size: 0.75rem;
    color: var(--text-light);
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.book-authors-mini {
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.book-authors-mini p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.book-authors-mini strong {
    color: var(--primary-color);
}

/* Authors Section */
.authors-section {
    background-color: var(--bg-secondary);
}

.authors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.author-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    border-left: 5px solid var(--primary-color);
}

.author-title {
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.author-card ul {
    margin-top: var(--spacing-md);
    padding-left: 1rem;
    color: var(--text-secondary);
}

.author-card li {
    margin-bottom: 0.35rem;
}

/* Footer Updates */
.footer-tagline {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-top: var(--spacing-xs);
}

.footer-mission {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-top: var(--spacing-xs);
}

/* ==========================================
   Responsive Updates
   ========================================== */
@media (max-width: 1024px) {
    .book-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
    
    .foundation-pillars {
        grid-template-columns: 1fr;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .phases-row {
        flex-direction: column;
    }
    
    .phase-box {
        min-width: auto;
    }
    
    .implementation-benefits {
        grid-template-columns: 1fr;
    }
    
    .email-signup-form {
        flex-direction: column;
    }
    
    .email-signup-form button {
        width: 100%;
    }
    
    .pillar-header {
        flex-direction: column;
        text-align: center;
    }
    
    .pillar-number-large {
        margin: 0 auto;
    }
    
    .phase-detail-header {
        flex-direction: column;
        text-align: center;
    }
    
    .phase-num {
        margin: 0 auto;
    }
    
    .diagram-layer {
        flex-direction: column;
    }

    /* Universe Orbital Diagram Responsive */
    .orbital-diagram {
        width: 420px;
        height: 420px;
    }

    .context-sun {
        width: 110px;
        height: 110px;
    }

    .sun-surface {
        width: 110px;
        height: 110px;
    }

    .sun-label {
        font-size: 1rem;
    }

    .sun-subtitle {
        font-size: 0.65rem;
    }

    .universe-svg {
        width: 420px;
        height: 420px;
    }

    .orbit-track {
        r: 140;
    }

    .phase-planet {
        width: 95px;
        height: 95px;
        margin: -47.5px 0 0 -47.5px;
        transform: rotate(var(--orbit-angle)) translateY(-150px) rotate(calc(-1 * var(--orbit-angle)));
    }

    .ai-boost {
        width: 115px;
        height: 115px;
        top: -10px;
        left: -10px;
    }

    .planet-body {
        width: 95px;
        height: 95px;
        gap: 3px;
        padding: 8px;
    }

    .planet-number {
        font-size: 1.6rem;
    }

    .planet-label {
        font-size: 0.55rem;
        max-width: 75px;
    }

    .ai-accelerator-badge {
        font-size: 0.75rem;
        padding: 6px 14px;
        top: -30px;
    }

    .framework-hint {
        font-size: 0.7rem;
        bottom: -50px;
    }
}

@media (max-width: 480px) {
    /* Universe Orbital Diagram Mobile */
    .orbital-diagram {
        width: 340px;
        height: 340px;
    }

    .universe-stars {
        width: 340px;
        height: 340px;
    }

    .star {
        width: 2px;
        height: 2px;
    }

    .context-sun {
        width: 90px;
        height: 90px;
    }

    .sun-corona {
        width: 90px;
        height: 90px;
    }

    .sun-surface {
        width: 90px;
        height: 90px;
    }

    .sun-label {
        font-size: 0.85rem;
    }

    .sun-subtitle {
        font-size: 0.6rem;
    }

    .universe-svg {
        width: 340px;
        height: 340px;
    }

    .orbit-track {
        r: 110;
    }

    .ai-particle.particle-1 { r: 5.5; }
    .ai-particle.particle-2 { r: 4.5; }
    .ai-particle.particle-3 { r: 6; }
    .ai-particle.particle-4 { r: 5; }

    .phase-planet {
        width: 80px;
        height: 80px;
        margin: -40px 0 0 -40px;
        transform: rotate(var(--orbit-angle)) translateY(-120px) rotate(calc(-1 * var(--orbit-angle)));
    }

    .ai-boost {
        width: 100px;
        height: 100px;
        top: -10px;
        left: -10px;
    }

    .planet-body {
        width: 80px;
        height: 80px;
        gap: 2px;
        padding: 6px;
    }

    .planet-number {
        font-size: 1.4rem;
    }

    .planet-label {
        font-size: 0.5rem;
        max-width: 65px;
    }

    .ai-accelerator-badge {
        font-size: 0.7rem;
        padding: 5px 12px;
        top: -28px;
        right: 5px;
    }

    .ai-icon {
        font-size: 0.9rem;
    }

    .framework-hint {
        font-size: 0.65rem;
        bottom: -45px;
        padding: 5px 12px;
    }
}


.contact-card .contact-list p {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.contact-card .contact-list strong {
    display: inline-block;
    min-width: 110px;
}

.contact-card a {
    color: var(--primary-color);
    font-weight: 600;
}