/* ===== RESET & BASE ===== */
*, *::before, *::after {
margin: 0;
padding: 0;
box-sizing: border-box;
}

:root {
--color-bg: #fafaf9;
--color-bg-dark: #1a1a2e;
--color-text: #1a1a1a;
--color-text-muted: #6b6b6b;
--color-text-light: #f0f0f0;
--color-accent: #2563eb;
--color-accent-hover: #1d4ed8;
--color-border: #e5e5e5;
--color-card: #fff;

--font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
--font-display: 'Playfair Display', Georgia, serif;

--space-xs: 0.5rem;
--space-sm: 1rem;
--space-md: 1.5rem;
--space-lg: 3rem;
--space-xl: 6rem;
--space-2xl: 10rem;

--max-width: 1200px;
--transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
scroll-behavior: smooth;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
}

body {
font-family: var(--font-sans);
font-size: 1rem;
line-height: 1.7;
color: var(--color-text);
background: var(--color-bg);
overflow-x: hidden;
}

a {
color: inherit;
text-decoration: none;
}

img {
max-width: 100%;
display: block;
}

/* ===== UTILITIES ===== */
.container {
max-width: var(--max-width);
margin: 0 auto;
padding: 0 var(--space-md);
}

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

.section-dark {
background: var(--color-bg-dark);
color: var(--color-text-light);
}

.section-label {
display: inline-block;
font-size: 0.75rem;
font-weight: 600;
text-transform: uppercase;
letter-spacing: 0.15em;
color: var(--color-accent);
margin-bottom: var(--space-sm);
}

.section-title {
font-family: var(--font-display);
font-size: clamp(2rem, 5vw, 3.25rem);
font-weight: 700;
line-height: 1.15;
margin-bottom: var(--space-lg);
}

/* ===== BUTTONS ===== */
.btn {
display: inline-flex;
align-items: center;
padding: 0.85rem 2rem;
font-size: 0.9rem;
font-weight: 600;
border-radius: 100px;
transition: all var(--transition);
cursor: pointer;
border: none;
font-family: var(--font-sans);
}

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

.btn-primary:hover {
background: var(--color-accent);
transform: translateY(-2px);
box-shadow: 0 8px 30px rgba(37, 99, 235, 0.25);
}

/* ===== HERO ===== */
.hero {
min-height: 100vh;
display: flex;
flex-direction: column;
align-items: center;
justify-content: flex-start;
padding: var(--space-xl) var(--space-md) var(--space-lg);
max-width: var(--max-width);
margin: 0 auto;
position: relative;
text-align: center;
}

.hero-content {
max-width: 700px;
}

.hero-badge {
display: inline-block;
font-size: 0.8rem;
font-weight: 600;
letter-spacing: 0.08em;
color: var(--color-accent);
margin-bottom: var(--space-md);
padding: 0.4rem 1rem;
border: 1px solid var(--color-accent);
border-radius: 100px;
opacity: 0;
transform: translateY(20px);
animation: fadeUp 0.8s 0.2s forwards;
}

.hero-title {
font-family: var(--font-display);
font-size: clamp(2.5rem, 7vw, 5rem);
font-weight: 700;
line-height: 1.08;
letter-spacing: -0.02em;
margin-bottom: var(--space-md);
opacity: 0;
transform: translateY(20px);
animation: fadeUp 0.8s 0.4s forwards;
}

.hero-accent {
color: var(--color-accent);
}

.hero-sub {
font-size: 1.15rem;
color: var(--color-text-muted);
max-width: 540px;
line-height: 1.7;
margin: 0 auto var(--space-lg);
opacity: 0;
transform: translateY(20px);
animation: fadeUp 0.8s 0.6s forwards;
}

.hero-note {
font-size: 0.8rem;
color: var(--color-text-muted);
margin-top: var(--space-sm);
opacity: 0;
animation: fadeIn 1s 1.2s forwards;
}

.hero-scroll {
position: absolute;
bottom: var(--space-lg);
left: 50%;
transform: translateX(-50%);
opacity: 0;
animation: fadeIn 1s 1.4s forwards;
}

.hero-scroll-line {
width: 1px;
height: 60px;
background: linear-gradient(to bottom, var(--color-text), transparent);
animation: scrollPulse 2s ease-in-out infinite;
}

/* ===== EMAIL FORM ===== */
.email-form {
display: flex;
gap: 0.75rem;
max-width: 480px;
margin: 0 auto;
opacity: 0;
transform: translateY(20px);
animation: fadeUp 0.8s 0.8s forwards;
}

.email-form input[type="email"] {
flex: 1;
padding: 0.85rem 1.25rem;
border: 1.5px solid var(--color-border);
border-radius: 100px;
background: var(--color-card);
color: var(--color-text);
font-size: 0.9rem;
font-family: var(--font-sans);
outline: none;
transition: border-color var(--transition);
}

.email-form input[type="email"]::placeholder {
color: #aaa;
}

.email-form input[type="email"]:focus {
border-color: var(--color-accent);
}

/* Dark section form override */
.section-dark .email-form input[type="email"] {
background: rgba(255, 255, 255, 0.08);
border-color: rgba(255, 255, 255, 0.15);
color: var(--color-text-light);
}

.section-dark .email-form input[type="email"]::placeholder {
color: rgba(255, 255, 255, 0.4);
}

.section-dark .email-form input[type="email"]:focus {
border-color: var(--color-accent);
background: rgba(255, 255, 255, 0.12);
}

.section-dark .email-form .btn-primary {
background: var(--color-accent);
color: #fff;
}

.section-dark .email-form .btn-primary:hover {
background: var(--color-accent-hover);
}

/* ===== CHAPTERS ===== */
.chapters-grid {
display: grid;
grid-template-columns: repeat(2, 1fr);
gap: var(--space-sm);
}

.chapter-card {
background: var(--color-card);
border: 1px solid var(--color-border);
border-radius: 20px;
padding: var(--space-lg);
transition: all var(--transition);
}

.chapter-card:hover {
border-color: var(--color-accent);
transform: translateY(-4px);
box-shadow: 0 12px 40px rgba(0, 0, 0, 0.06);
}

.chapter-card-wide {
grid-column: 1 / -1;
}

.chapter-icon {
width: 48px;
height: 48px;
display: flex;
align-items: center;
justify-content: center;
color: var(--color-accent);
margin-bottom: var(--space-sm);
}

.chapter-card h3 {
font-size: 1.15rem;
font-weight: 600;
margin-bottom: 0.25rem;
}

.chapter-card p {
color: var(--color-text-muted);
font-size: 0.95rem;
line-height: 1.6;
}

/* ===== ABOUT ===== */
.about-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: var(--space-xl);
align-items: start;
}

.about-text p {
color: rgba(255, 255, 255, 0.7);
margin-bottom: var(--space-sm);
line-height: 1.8;
}

.about-text em {
color: var(--color-text-light);
font-style: italic;
}

.about-sidebar {
margin-top: 3.5rem;
}

.about-stats {
display: grid;
grid-template-columns: 1fr 1fr;
gap: var(--space-sm);
}

.stat-card {
background: rgba(255, 255, 255, 0.06);
border: 1px solid rgba(255, 255, 255, 0.1);
border-radius: 16px;
padding: var(--space-md);
transition: all var(--transition);
}

.stat-card:hover {
background: rgba(255, 255, 255, 0.1);
border-color: rgba(255, 255, 255, 0.2);
transform: translateY(-4px);
}

.stat-number {
font-family: var(--font-display);
font-size: 1.75rem;
font-weight: 700;
margin-bottom: 0.25rem;
color: var(--color-text-light);
}

.stat-label {
font-size: 0.8rem;
color: rgba(255, 255, 255, 0.5);
font-weight: 500;
}

/* ===== AUTHOR ===== */
.author-container {
text-align: center;
max-width: 680px;
}

.author-photo {
width: 128px;
height: 128px;
border-radius: 50%;
object-fit: cover;
margin: 0 auto var(--space-sm);
border: 3px solid var(--color-card);
box-shadow: 0 10px 30px rgba(0, 0, 0, 0.12);
}

.author-name {
font-family: var(--font-display);
font-size: 1.5rem;
font-weight: 700;
color: var(--color-text);
margin-bottom: 0.2rem;
}

.author-title {
font-size: 0.85rem;
font-weight: 600;
letter-spacing: 0.04em;
color: var(--color-accent);
margin-bottom: var(--space-md);
}

.author-desc {
color: var(--color-text-muted);
font-size: 1.1rem;
line-height: 1.8;
margin-bottom: var(--space-lg);
}

.author-links {
display: flex;
justify-content: center;
gap: var(--space-sm);
flex-wrap: wrap;
}

.social-link {
display: inline-flex;
align-items: center;
gap: 0.5rem;
padding: 0.75rem 1.5rem;
border: 1px solid var(--color-border);
border-radius: 100px;
font-size: 0.875rem;
font-weight: 500;
transition: all var(--transition);
}

.social-link:hover {
border-color: var(--color-accent);
color: var(--color-accent);
transform: translateY(-2px);
box-shadow: 0 8px 30px rgba(37, 99, 235, 0.1);
}

.social-link svg {
width: 18px;
height: 18px;
}

/* ===== CTA ===== */
.cta-container {
text-align: center;
max-width: 640px;
}

.cta-desc {
color: rgba(255, 255, 255, 0.65);
font-size: 1.1rem;
margin-bottom: var(--space-lg);
}

.cta-container .email-form {
opacity: 1;
transform: none;
animation: none;
}

/* ===== FOOTER ===== */
.footer {
padding: var(--space-md) 0;
border-top: 1px solid var(--color-border);
}

.footer-inner {
display: flex;
justify-content: space-between;
align-items: center;
}

.footer-left {
font-size: 0.85rem;
color: var(--color-text-muted);
}

.footer-right {
display: flex;
gap: var(--space-md);
}

.footer-right a {
font-size: 0.85rem;
color: var(--color-text-muted);
transition: color var(--transition);
}

.footer-right a:hover {
color: var(--color-text);
}

/* ===== ANIMATIONS ===== */
@keyframes fadeUp {
to {
opacity: 1;
transform: translateY(0);
}
}

@keyframes fadeIn {
to { opacity: 1; }
}

@keyframes scrollPulse {
0%, 100% { opacity: 1; transform: scaleY(1); }
50% { opacity: 0.4; transform: scaleY(0.6); }
}

/* Scroll reveal */
.reveal {
opacity: 0;
transform: translateY(30px);
transition: opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1), transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
.section {
padding: var(--space-lg) 0;
}

.hero {
padding: 7rem var(--space-md) var(--space-lg);
min-height: auto;
}

.hero-title {
font-size: clamp(2rem, 10vw, 3.5rem);
}

.hero-sub {
font-size: 1rem;
}

.email-form {
flex-direction: column;
max-width: 100%;
}

.email-form .btn {
justify-content: center;
width: 100%;
}

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

.chapter-card-wide {
grid-column: auto;
}

.about-grid {
grid-template-columns: 1fr;
gap: var(--space-lg);
}

.about-sidebar {
margin-top: 0;
}

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

.about-text p {
font-size: 0.95rem;
}

.author-desc {
font-size: 1rem;
}

.author-links {
flex-direction: column;
align-items: center;
}

.cta-desc {
font-size: 1rem;
}

.footer-inner {
flex-direction: column;
gap: var(--space-sm);
text-align: center;
}

.hero-scroll { display: none; }
}

@media (max-width: 480px) {
.hero {
padding: 6rem var(--space-sm) var(--space-md);
}

.hero-title {
font-size: clamp(1.75rem, 10vw, 2.5rem);
}

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

.section-title {
font-size: clamp(1.4rem, 6vw, 2rem);
margin-bottom: var(--space-md);
}

.container {
padding: 0 var(--space-sm);
}

.chapter-card {
padding: var(--space-md);
}

.stat-card {
padding: var(--space-sm);
}

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

@media (pointer: coarse) {
.social-link {
min-height: 48px;
}

.btn {
min-height: 48px;
}
}

/* ===== HERO TAGLINE & CTA (Student Founder update) ===== */
.hero-tagline {
font-family: var(--font-display);
font-size: clamp(1.1rem, 2.5vw, 1.5rem);
font-weight: 700;
color: var(--color-text);
margin-bottom: 0.75rem;
opacity: 0;
transform: translateY(20px);
animation: fadeUp 0.8s 0.5s forwards;
}

.hero-cover {
opacity: 0;
transform: translateY(20px);
animation: fadeUp 0.8s 0.65s forwards;
margin: 0 auto var(--space-lg);
}

.hero-cover img {
width: 170px;
height: auto;
margin: 0 auto;
border-radius: 6px;
box-shadow: 0 20px 50px rgba(26, 26, 46, 0.25), 0 4px 12px rgba(26, 26, 46, 0.12);
transition: transform var(--transition);
}

.hero-cover img:hover {
transform: translateY(-4px);
}

.hero-ctas {
opacity: 0;
transform: translateY(20px);
animation: fadeUp 0.8s 0.7s forwards;
margin-bottom: var(--space-sm);
}

.btn-secondary {
background: transparent;
color: var(--color-text);
border: 1.5px solid var(--color-border);
}

.btn-secondary:hover {
border-color: var(--color-accent);
color: var(--color-accent);
transform: translateY(-2px);
}

/* ===== ARGUMENT SECTION ===== */
.argument-container {
max-width: 720px;
text-align: center;
}

.argument-container .section-title {
margin-bottom: var(--space-md);
}

.argument-container p {
font-size: 1.15rem;
color: var(--color-text-muted);
line-height: 1.8;
}

/* ===== PROLOGUE PAGE ===== */
.prologue-page {
padding: var(--space-2xl) var(--space-md) var(--space-xl);
max-width: 720px;
margin: 0 auto;
}

.prologue-back {
display: inline-block;
font-size: 0.85rem;
font-weight: 600;
color: var(--color-text-muted);
margin-bottom: var(--space-lg);
transition: color var(--transition);
}

.prologue-back:hover {
color: var(--color-accent);
}

.prologue-page h1 {
font-family: var(--font-display);
font-size: clamp(2rem, 5vw, 3rem);
line-height: 1.15;
margin: 1rem 0 1.5rem;
}

.prologue-part {
font-size: 0.8rem;
font-weight: 600;
text-transform: uppercase;
letter-spacing: 0.15em;
color: var(--color-accent);
margin-top: var(--space-lg);
margin-bottom: 0.5rem;
}

.prologue-part-note {
font-style: italic;
color: var(--color-text-muted);
margin-bottom: var(--space-lg);
line-height: 1.7;
}

.prologue-page .epigraph {
font-style: italic;
color: var(--color-text-muted);
border-left: 3px solid var(--color-accent);
padding-left: 1.25rem;
margin: var(--space-lg) 0;
font-size: 1.05rem;
}

.prologue-page h2 {
font-family: var(--font-display);
font-size: 1.4rem;
margin: var(--space-lg) 0 1rem;
}

.prologue-page p {
margin-bottom: 1.25rem;
line-height: 1.8;
color: var(--color-text);
}

.prologue-cta {
margin-top: var(--space-xl);
padding-top: var(--space-lg);
border-top: 1px solid var(--color-border);
text-align: center;
}

.prologue-cta .section-title {
margin-bottom: 0.75rem;
}

.prologue-cta p {
color: var(--color-text-muted);
margin-bottom: var(--space-sm);
}

.prologue-cta .email-form {
opacity: 1;
transform: none;
animation: none;
margin: 0 auto;
}

@media (max-width: 480px) {
.prologue-page {
padding: 6rem var(--space-sm) var(--space-md);
}

.hero-cover img {
width: 140px;
}
}