/**
 * MX Bookshop — Stylesheet
 * @description Styles for the MX book-sale website — CogNovaMX Ltd
 * @version 1.0
 * @author Tom Cranstoun
 * @mx:status active
 * @mx:contentType stylesheet
 */

/* ── Reset ── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ── Custom properties ── */
:root {
  --mx-blue-deep: #0a1628;
  --mx-blue-dark: #0d2137;
  --mx-blue-mid: #1a3a5c;
  --mx-blue-accent: #2d7dd2;
  --mx-blue-light: #5ba4e6;
  --mx-gold: #d4a843;
  --mx-white: #ffffff;
  --mx-off-white: #f0f4f8;
  --mx-text: #e8edf2;
  --mx-text-muted: #8a9bb5;
  --mx-green-free: #2ecc71;
  --mx-font-heading: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --mx-font-body: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --mx-max-width: 1200px;
  --mx-section-padding: 5rem 2rem;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--mx-font-body);
  color: var(--mx-text);
  background-color: var(--mx-blue-deep);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--mx-blue-light);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover,
a:focus-visible {
  color: var(--mx-gold);
}

a:focus-visible {
  outline: 2px solid var(--mx-gold);
  outline-offset: 2px;
}

/* ── Skip link ── */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  background: var(--mx-gold);
  color: var(--mx-blue-deep);
  padding: 0.5rem 1rem;
  border-radius: 0 0 4px 4px;
  z-index: 1000;
  font-weight: 600;
}

.skip-link:focus {
  top: 0;
}

/* ── Header ── */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 22, 40, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(45, 125, 210, 0.15);
  padding: 0.75rem 2rem;
}

.header-inner {
  max-width: var(--mx-max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-logo img {
  height: 36px;
  width: auto;
}

.header-nav {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.header-nav a {
  color: var(--mx-text);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.5rem 0;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.header-nav a:hover,
.header-nav a:focus-visible {
  color: var(--mx-gold);
  border-bottom-color: var(--mx-gold);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--mx-text);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
}

/* ── Hero section ── */
.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 8rem 2rem 4rem;
}

.hero-backdrop {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-backdrop img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-backdrop::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(10, 22, 40, 0.6) 0%,
    rgba(10, 22, 40, 0.8) 60%,
    rgba(10, 22, 40, 1) 100%
  );
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: var(--mx-max-width);
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-text {
  max-width: 600px;
}

.hero-title-graphic {
  max-width: 480px;
  margin-bottom: 1.5rem;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--mx-text-muted);
  margin-bottom: 2rem;
  line-height: 1.8;
}

.hero-books {
  display: flex;
  justify-content: center;
  align-items: flex-end;
  gap: 1.5rem;
  position: relative;
}

.hero-book-item {
  position: relative;
  transition: transform 0.3s ease;
}

.hero-book-item:hover {
  transform: translateY(-8px);
}

.hero-book-item img {
  height: 380px;
  width: auto;
  border-radius: 4px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.free-badge {
  position: absolute;
  top: -20px;
  right: -20px;
  width: 80px;
  height: 80px;
  z-index: 2;
  animation: pulse-badge 2s ease-in-out infinite;
}

@keyframes pulse-badge {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.08); }
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  border: none;
  border-radius: 4px;
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

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

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--mx-blue-light);
  color: var(--mx-white);
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(45, 125, 210, 0.3);
}

.btn-secondary {
  background: transparent;
  color: var(--mx-text);
  border: 2px solid var(--mx-blue-accent);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  background: var(--mx-blue-accent);
  color: var(--mx-white);
}

.btn-free {
  background: var(--mx-green-free);
  color: var(--mx-blue-deep);
}

.btn-free:hover,
.btn-free:focus-visible {
  background: #27ae60;
  color: var(--mx-blue-deep);
  transform: translateY(-1px);
}

.btn-gold {
  background: var(--mx-gold);
  color: var(--mx-blue-deep);
}

.btn-gold:hover,
.btn-gold:focus-visible {
  background: #c49a3a;
  color: var(--mx-blue-deep);
  transform: translateY(-1px);
}

.mx-explanation-cta {
  margin-top: 1.5rem;
}

.author-cta {
  margin-top: 1rem;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 2rem;
}

/* ── Sections ── */
.section {
  padding: var(--mx-section-padding);
}

.section-inner {
  max-width: var(--mx-max-width);
  margin: 0 auto;
}

.section-dark {
  background: var(--mx-blue-dark);
}

.section-deep {
  background: var(--mx-blue-deep);
}

.section-mid {
  background: linear-gradient(180deg, var(--mx-blue-dark) 0%, var(--mx-blue-deep) 100%);
}

.section-title {
  font-family: var(--mx-font-heading);
  font-size: 2.25rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 1.5rem;
  color: var(--mx-white);
}

.section-subtitle {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 3rem;
  font-size: 1.125rem;
  color: var(--mx-text-muted);
  line-height: 1.8;
}

/* ── Proposition section ── */
.proposition-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.proposition-card {
  background: rgba(26, 58, 92, 0.3);
  border: 1px solid rgba(45, 125, 210, 0.15);
  border-radius: 8px;
  padding: 2rem;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.proposition-card:hover {
  border-color: var(--mx-blue-accent);
  transform: translateY(-2px);
}

.proposition-card h3 {
  font-size: 1.25rem;
  color: var(--mx-white);
  margin-bottom: 0.75rem;
}

.proposition-card p {
  color: var(--mx-text-muted);
  font-size: 0.9375rem;
}

/* ── Books section ── */
.books-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2.5rem;
  margin-top: 2rem;
}

.book-card {
  background: rgba(26, 58, 92, 0.25);
  border: 1px solid rgba(45, 125, 210, 0.15);
  border-radius: 12px;
  padding: 2rem;
  text-align: center;
  transition: border-color 0.3s ease, transform 0.3s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.book-card:hover {
  border-color: var(--mx-blue-accent);
  transform: translateY(-4px);
}

.book-card-image {
  position: relative;
  margin-bottom: 1.5rem;
}

.book-card-image img {
  height: 280px;
  width: auto;
  border-radius: 4px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}

.book-card-badge {
  position: absolute;
  top: -12px;
  right: -12px;
  width: 60px;
  height: 60px;
}

.book-card h3 {
  font-size: 1.5rem;
  color: var(--mx-white);
  margin-bottom: 0.5rem;
}

.book-card .book-tagline {
  color: var(--mx-text-muted);
  font-size: 0.9375rem;
  margin-bottom: 1rem;
  min-height: 3rem;
}

.book-card .book-price {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--mx-gold);
  margin-bottom: 1.25rem;
}

.book-card .book-price.free {
  color: var(--mx-green-free);
}

/* ── What is MX section ── */
.mx-explanation {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.mx-explanation-text h3 {
  font-size: 1.5rem;
  color: var(--mx-white);
  margin-bottom: 1rem;
}

.mx-explanation-text p {
  color: var(--mx-text-muted);
  margin-bottom: 1rem;
  font-size: 1rem;
}

.mx-explanation-visual {
  display: flex;
  justify-content: center;
}

.mx-explanation-visual img {
  max-height: 400px;
  border-radius: 8px;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
}

/* ── Author section ── */
.author-grid {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 3rem;
  align-items: start;
}

.author-photo {
  border-radius: 8px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
  width: 100%;
}

.author-bio h3 {
  font-size: 1.5rem;
  color: var(--mx-white);
  margin-bottom: 1rem;
}

.author-bio p {
  color: var(--mx-text-muted);
  margin-bottom: 1rem;
  font-size: 1rem;
}

/* ── Footer ── */
.site-footer {
  background: var(--mx-blue-deep);
  border-top: 1px solid rgba(45, 125, 210, 0.15);
  padding: 3rem 2rem 2rem;
}

.footer-inner {
  max-width: var(--mx-max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
}

.footer-brand p {
  color: var(--mx-text-muted);
  font-size: 0.875rem;
  margin-top: 0.5rem;
}

.footer-links h4,
.footer-contact h4 {
  color: var(--mx-white);
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
}

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

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: var(--mx-text-muted);
  font-size: 0.875rem;
}

.footer-links a:hover {
  color: var(--mx-gold);
}

.footer-contact p,
.footer-contact a {
  color: var(--mx-text-muted);
  font-size: 0.875rem;
  display: block;
  margin-bottom: 0.25rem;
}

.footer-bottom {
  max-width: var(--mx-max-width);
  margin: 2rem auto 0;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(45, 125, 210, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8125rem;
  color: var(--mx-text-muted);
}

/* ── Responsive ── */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-text {
    max-width: 100%;
  }

  .hero-title-graphic {
    margin: 0 auto 1.5rem;
  }

  .hero-cta {
    justify-content: center;
  }

  .hero-books {
    justify-content: center;
  }

  .hero-book-item img {
    height: 280px;
  }

  .books-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }

  .mx-explanation {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .author-grid {
    grid-template-columns: 200px 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }
}

@media (max-width: 768px) {
  :root {
    --mx-section-padding: 3rem 1.25rem;
  }

  .header-nav {
    display: none;
  }

  .header-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(10, 22, 40, 0.98);
    padding: 1rem 2rem;
    gap: 0;
    border-bottom: 1px solid rgba(45, 125, 210, 0.15);
  }

  .header-nav.open a {
    padding: 0.75rem 0;
    border-bottom: 1px solid rgba(45, 125, 210, 0.08);
  }

  .mobile-menu-btn {
    display: block;
  }

  .hero {
    min-height: auto;
    padding: 7rem 1.25rem 3rem;
  }

  .hero-book-item img {
    height: 200px;
  }

  .free-badge {
    width: 50px;
    height: 50px;
    top: -10px;
    right: -10px;
  }

  .section-title {
    font-size: 1.75rem;
  }

  .books-grid {
    grid-template-columns: 1fr;
    max-width: 340px;
    margin: 2rem auto 0;
  }

  .book-card-image img {
    height: 220px;
  }

  .author-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .author-photo {
    max-width: 200px;
    margin: 0 auto;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 0.5rem;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero-books {
    flex-direction: column;
    align-items: center;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

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

/* ── Print ── */
@media print {
  .site-header,
  .skip-link,
  .mobile-menu-btn {
    display: none;
  }

  body {
    background: white;
    color: #1a1a1a;
  }

  .hero-backdrop::after {
    display: none;
  }

  a {
    color: #1a1a1a;
  }

  a[href]::after {
    content: ' (' attr(href) ')';
    font-size: 0.8em;
    color: #666;
  }
}