/* ========================================
   青色大脑 / CYAN BRAIN - 游戏官网样式
   ======================================== */

/* ---------- CSS Variables ---------- */
:root {
  --primary: #2d2f33;
  --primary-light: #383a3f;
  --primary-dark: #222427;
  --aux1: #d2d3ea;
  --aux2: #54cfe2;
  --aux2-dark: #3ab8cb;
  --aux3: #7589ae;
  --white: #f0f1f8;
  --text: #c8c9d8;
  --text-muted: #8a8b9a;
  --border: rgba(84, 207, 226, 0.15);
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.4);
  --glow: 0 0 20px rgba(84, 207, 226, 0.3);
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.3s ease;
  --font-base: 'Noto Sans SC', sans-serif;
  --font-display: 'Orbitron', sans-serif;
  --header-height: 64px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
  font-size: 16px;
}

body {
  font-family: var(--font-base);
  background-color: var(--primary-dark);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--aux2);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--aux1);
}

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

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--white);
  line-height: 1.3;
}

::selection {
  background: var(--aux2);
  color: var(--primary-dark);
}

/* ---------- Utility ---------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section-title {
  text-align: center;
  margin-bottom: 48px;
}

.section-title h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 12px;
  position: relative;
  display: inline-block;
}

.section-title h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--aux2), var(--aux3));
  border-radius: 2px;
}

.section-title p {
  color: var(--text-muted);
  font-size: 1rem;
  margin-top: 16px;
}

section {
  padding: 80px 0;
}

section:nth-child(even) {
  background: var(--primary);
}

section:nth-child(odd) {
  background: var(--primary-dark);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  font-family: var(--font-base);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0);
  transition: background var(--transition);
}

.btn:active::after {
  background: rgba(255, 255, 255, 0.15);
}

.btn-primary {
  background: linear-gradient(135deg, var(--aux2), var(--aux2-dark));
  color: var(--primary-dark);
  box-shadow: 0 4px 16px rgba(84, 207, 226, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(84, 207, 226, 0.45);
  color: var(--primary-dark);
}

.btn-outline {
  background: transparent;
  color: var(--aux2);
  border: 2px solid var(--aux2);
}

.btn-outline:hover {
  background: var(--aux2);
  color: var(--primary-dark);
  transform: translateY(-2px);
}

/* ---------- Header ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(34, 36, 39, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 1000;
  border-bottom: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

.site-header.scrolled {
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.4);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}

.logo img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.logo span {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--aux2);
  letter-spacing: 1px;
}

/* Nav */
.main-nav ul {
  display: flex;
  align-items: center;
  gap: 4px;
}

.main-nav a {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  color: var(--text);
  font-size: 0.88rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  white-space: nowrap;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--aux2);
  background: rgba(84, 207, 226, 0.08);
}

.main-nav a i {
  font-size: 0.85rem;
  width: 16px;
  text-align: center;
}

.nav-download {
  background: linear-gradient(135deg, var(--aux2), var(--aux2-dark)) !important;
  color: var(--primary-dark) !important;
  font-weight: 600;
}

.nav-download:hover {
  box-shadow: var(--glow);
  color: var(--primary-dark) !important;
}

/* Mobile menu */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--aux2);
  font-size: 1.4rem;
  cursor: pointer;
  padding: 8px;
}

/* ---------- Hero Section ---------- */
.hero {
  padding-top: calc(var(--header-height) + 40px);
  padding-bottom: 50px;
  background: linear-gradient(160deg, var(--primary-dark) 0%, var(--primary) 50%, var(--primary-dark) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(84, 207, 226, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  display: flex;
  align-items: center;
  gap: 48px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.hero-text {
  flex: 1;
  min-width: 0;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(84, 207, 226, 0.1);
  border: 1px solid rgba(84, 207, 226, 0.25);
  border-radius: 20px;
  font-size: 0.82rem;
  color: var(--aux2);
  margin-bottom: 18px;
}

.hero-badge i {
  font-size: 0.75rem;
}

.hero-text h1 {
  font-size: 2.6rem;
  font-weight: 800;
  margin-bottom: 6px;
  background: linear-gradient(135deg, var(--white) 0%, var(--aux2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-text .subtitle {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--aux3);
  letter-spacing: 3px;
  margin-bottom: 16px;
}

.hero-text .description {
  font-size: 0.95rem;
  color: var(--text);
  line-height: 1.8;
  margin-bottom: 20px;
  max-width: 560px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 24px;
}

.hero-meta .meta-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 6px;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.hero-meta .meta-tag i {
  color: var(--aux2);
  font-size: 0.8rem;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}

.hero-tags span {
  padding: 4px 12px;
  background: rgba(84, 207, 226, 0.08);
  border: 1px solid rgba(84, 207, 226, 0.15);
  border-radius: 4px;
  font-size: 0.78rem;
  color: var(--aux2);
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.hero-cover {
  flex-shrink: 0;
  width: 320px;
}

.hero-cover img {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
}

/* ---------- News Section ---------- */
.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
}

.news-card {
  background: var(--primary-light);
  border-radius: var(--radius);
  padding: 28px;
  border: 1px solid var(--border);
  transition: all var(--transition);
}

.news-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: rgba(84, 207, 226, 0.3);
}

.news-card .news-date {
  font-size: 0.8rem;
  color: var(--aux3);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.news-card .news-date i {
  color: var(--aux2);
}

.news-card h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
}

.news-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  line-height: 1.7;
}

.news-card .news-link {
  font-size: 0.85rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.news-card .news-link:hover i {
  transform: translateX(4px);
}

.news-card .news-link i {
  transition: transform var(--transition);
}

/* ---------- Gallery Section ---------- */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 16px;
}

.gallery-item {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--border);
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.gallery-item:hover img {
  transform: scale(1.05);
}

.gallery-item .gallery-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(34, 36, 39, 0.7) 0%, transparent 50%);
  opacity: 0;
  transition: opacity var(--transition);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding: 20px;
}

.gallery-item:hover .gallery-overlay {
  opacity: 1;
}

.gallery-overlay span {
  color: var(--white);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Lightbox */
.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.92);
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 40px;
  cursor: pointer;
}

.lightbox.active {
  display: flex;
}

.lightbox img {
  max-width: 90vw;
  max-height: 85vh;
  object-fit: contain;
  border-radius: var(--radius-sm);
  cursor: default;
}

.lightbox-close {
  position: absolute;
  top: 20px;
  right: 30px;
  color: var(--white);
  font-size: 2rem;
  cursor: pointer;
  transition: color var(--transition);
  background: none;
  border: none;
}

.lightbox-close:hover {
  color: var(--aux2);
}

/* ---------- Reviews Section ---------- */
.reviews-summary {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

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

.reviews-score .score-number {
  font-size: 3.5rem;
  font-weight: 800;
  color: var(--aux2);
  line-height: 1;
}

.reviews-score .score-stars {
  color: #f5a623;
  font-size: 1.1rem;
  margin: 8px 0 4px;
  letter-spacing: 2px;
}

.reviews-score .score-count {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.reviews-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  max-width: 400px;
}

.reviews-tags span {
  padding: 6px 16px;
  background: rgba(84, 207, 226, 0.08);
  border: 1px solid rgba(84, 207, 226, 0.15);
  border-radius: 20px;
  font-size: 0.82rem;
  color: var(--aux2);
}

.reviews-carousel {
  position: relative;
  overflow: hidden;
}

.reviews-track {
  display: flex;
  transition: transform 0.5s ease;
}

.review-card {
  min-width: 100%;
  padding: 0 20px;
}

.review-card-inner {
  background: var(--primary-light);
  border-radius: var(--radius);
  padding: 32px;
  border: 1px solid var(--border);
  max-width: 700px;
  margin: 0 auto;
}

.review-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.review-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--aux2), var(--aux3));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary-dark);
  font-weight: 700;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.review-info .review-name {
  font-weight: 600;
  color: var(--white);
  font-size: 0.95rem;
}

.review-info .review-date {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.review-stars {
  color: #f5a623;
  font-size: 0.85rem;
  margin-bottom: 12px;
}

.review-text {
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--text);
}

.reviews-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 28px;
}

.reviews-controls button {
  background: rgba(84, 207, 226, 0.1);
  border: 1px solid rgba(84, 207, 226, 0.2);
  color: var(--aux2);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.reviews-controls button:hover {
  background: var(--aux2);
  color: var(--primary-dark);
}

.reviews-dots {
  display: flex;
  gap: 8px;
}

.reviews-dots span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--aux3);
  cursor: pointer;
  transition: all var(--transition);
}

.reviews-dots span.active {
  background: var(--aux2);
  width: 24px;
  border-radius: 4px;
}

/* ---------- Version History Section ---------- */
.version-timeline {
  position: relative;
  padding-left: 32px;
}

.version-timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--aux2), var(--aux3), transparent);
}

.version-item {
  position: relative;
  margin-bottom: 36px;
  padding-left: 20px;
}

.version-item::before {
  content: '';
  position: absolute;
  left: -32px;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--primary-dark);
  border: 3px solid var(--aux2);
}

.version-item:first-child::before {
  background: var(--aux2);
  box-shadow: 0 0 12px rgba(84, 207, 226, 0.5);
}

.version-item .version-header {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 10px;
}

.version-item .version-tag {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--aux2);
}

.version-item .version-date {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.version-item .version-size {
  font-size: 0.82rem;
  color: var(--aux3);
  display: flex;
  align-items: center;
  gap: 4px;
}

.version-item .version-body {
  font-size: 0.9rem;
  color: var(--text);
  line-height: 1.8;
  margin-bottom: 12px;
}

.version-item .version-body ul {
  padding-left: 18px;
}

.version-item .version-body li {
  list-style: disc;
  margin-bottom: 4px;
}

.version-item .version-platforms {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.version-item .version-platforms span {
  padding: 3px 10px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 4px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ---------- Guide Section ---------- */
.guide-filters {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}

.guide-filters button {
  padding: 8px 20px;
  border-radius: 20px;
  border: 1px solid rgba(84, 207, 226, 0.2);
  background: transparent;
  color: var(--text-muted);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-base);
}

.guide-filters button:hover,
.guide-filters button.active {
  background: var(--aux2);
  color: var(--primary-dark);
  border-color: var(--aux2);
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.guide-card {
  background: var(--primary-light);
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid var(--border);
  transition: all var(--transition);
}

.guide-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: rgba(84, 207, 226, 0.3);
}

.guide-card .guide-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(84, 207, 226, 0.15), rgba(117, 137, 174, 0.15));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: var(--aux2);
  margin-bottom: 16px;
}

.guide-card h3 {
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.guide-card p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 14px;
  line-height: 1.7;
}

.guide-card .guide-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.78rem;
}

.guide-card .guide-difficulty {
  padding: 3px 10px;
  border-radius: 4px;
  font-weight: 600;
}

.guide-difficulty.easy {
  background: rgba(80, 200, 120, 0.12);
  color: #50c878;
}

.guide-difficulty.medium {
  background: rgba(245, 166, 35, 0.12);
  color: #f5a623;
}

.guide-difficulty.hard {
  background: rgba(235, 87, 87, 0.12);
  color: #eb5757;
}

.guide-card .guide-recommend {
  color: var(--aux3);
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ---------- Chapters Section ---------- */
.chapters-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 20px;
}

.chapter-card {
  background: var(--primary-light);
  border-radius: var(--radius);
  padding: 28px;
  border: 1px solid var(--border);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.chapter-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: rgba(84, 207, 226, 0.3);
}

.chapter-card .chapter-number {
  position: absolute;
  top: -10px;
  right: 16px;
  font-family: var(--font-display);
  font-size: 4rem;
  font-weight: 900;
  color: rgba(84, 207, 226, 0.06);
  line-height: 1;
  pointer-events: none;
}

.chapter-card .chapter-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  background: rgba(84, 207, 226, 0.1);
  border-radius: 4px;
  font-size: 0.75rem;
  color: var(--aux2);
  margin-bottom: 12px;
  font-weight: 600;
}

.chapter-card .chapter-label.side {
  background: rgba(117, 137, 174, 0.15);
  color: var(--aux3);
}

.chapter-card h3 {
  font-size: 1.15rem;
  margin-bottom: 10px;
}

.chapter-card .chapter-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 14px;
  line-height: 1.7;
}

.chapter-card .chapter-info {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 12px;
}

.chapter-card .chapter-info span {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.chapter-card .chapter-info span i {
  color: var(--aux2);
  font-size: 0.75rem;
}

.chapter-card .chapter-mood {
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: var(--text-muted);
  display: inline-block;
}

/* ---------- FAQ Section ---------- */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
  transition: border-color var(--transition);
}

.faq-item:hover {
  border-color: rgba(84, 207, 226, 0.3);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  cursor: pointer;
  background: var(--primary-light);
  transition: background var(--transition);
  gap: 16px;
}

.faq-question:hover {
  background: rgba(84, 207, 226, 0.04);
}

.faq-question h4 {
  font-size: 0.95rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 10px;
}

.faq-question h4 i {
  color: var(--aux2);
  font-size: 0.85rem;
}

.faq-question .faq-toggle {
  color: var(--aux2);
  font-size: 0.85rem;
  transition: transform var(--transition);
  flex-shrink: 0;
}

.faq-item.active .faq-toggle {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}

.faq-item.active .faq-answer {
  max-height: 400px;
}

.faq-answer-inner {
  padding: 0 24px 20px;
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.8;
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--primary-dark);
  border-top: 1px solid var(--border);
  padding: 60px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand .logo {
  margin-bottom: 14px;
}

.footer-brand p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 280px;
}

.footer-col h4 {
  font-size: 0.95rem;
  margin-bottom: 16px;
  color: var(--white);
}

.footer-col ul li {
  margin-bottom: 8px;
}

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

.footer-col ul a:hover {
  color: var(--aux2);
}

.footer-bottom {
  border-top: 1px solid var(--border);
  padding: 20px 0;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ---------- Back to Top ---------- */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 44px;
  height: 44px;
  background: var(--aux2);
  color: var(--primary-dark);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  cursor: pointer;
  border: none;
  box-shadow: 0 4px 16px rgba(84, 207, 226, 0.35);
  opacity: 0;
  transform: translateY(20px);
  transition: all var(--transition);
  z-index: 900;
  pointer-events: none;
}

.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 24px rgba(84, 207, 226, 0.5);
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .hero-content {
    flex-direction: column-reverse;
    text-align: center;
  }

  .hero-cover {
    width: 220px;
  }

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

  .hero-meta,
  .hero-tags {
    justify-content: center;
  }

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

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

@media (max-width: 768px) {
  html {
    font-size: 15px;
  }

  section {
    padding: 56px 0;
  }

  .section-title {
    margin-bottom: 32px;
  }

  .section-title h2 {
    font-size: 1.6rem;
  }

  /* Mobile Nav */
  .menu-toggle {
    display: block;
  }

  .main-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: rgba(34, 36, 39, 0.97);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 16px;
    transform: translateY(-110%);
    transition: transform 0.4s ease;
    border-bottom: 1px solid var(--border);
    z-index: 999;
  }

  .main-nav.open {
    transform: translateY(0);
  }

  .main-nav ul {
    flex-direction: column;
    gap: 4px;
  }

  .main-nav a {
    padding: 12px 16px;
    font-size: 0.95rem;
    border-radius: var(--radius-sm);
  }

  /* Hero */
  .hero {
    padding-top: calc(var(--header-height) + 28px);
    padding-bottom: 36px;
  }

  .hero-text h1 {
    font-size: 1.9rem;
  }

  .hero-cover {
    width: 180px;
  }

  .hero-meta .meta-tag {
    font-size: 0.78rem;
    padding: 4px 10px;
  }

  /* Grids */
  .news-grid {
    grid-template-columns: 1fr;
  }

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

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

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

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .reviews-summary {
    flex-direction: column;
    gap: 20px;
  }

  .reviews-tags {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero-text h1 {
    font-size: 1.6rem;
  }

  .hero-meta .meta-tag {
    font-size: 0.75rem;
  }

  .lightbox {
    padding: 16px;
  }
}