/* ========================================
   Fonts Import
   ======================================== */
@import url("https://fonts.googleapis.com/css2?family=Fraunces:wght@600;700&family=Plus+Jakarta+Sans:wght@400;500;600&display=swap");

/* ========================================
   CSS Variables
   Vietnamese-inspired color palette with 7 rainbow colors
   ======================================== */
:root {
  /* Base colors */
  --bg: #fff6ec;
  --card: #ffffff;
  --ink: #1f1a18;
  --muted: #5e4f49;
  --line: rgba(31, 26, 24, 0.12);
  --shadow: 0 24px 60px rgba(31, 26, 24, 0.12);

  /* Seven rainbow colors */
  --red: #e64a3b;
  --orange: #ff8b2c;
  --sun: #ffd24a;
  --green: #4dbb6b;
  --teal: #36b4a7;
  --blue: #3a7bd5;
  --pink: #ff6f91;

  /* Layout constants */
  --radius: 20px;
  --max: 1100px;
  --rainbow: linear-gradient(90deg, var(--red), var(--orange), var(--sun), var(--green), var(--teal), var(--blue), var(--pink));
}

/* ========================================
   Global Reset & Base Styles
   ======================================== */
* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  font-family: "Plus Jakarta Sans", "Segoe UI", sans-serif;
  color: var(--ink);
  /* Radial gradient background with Vietnamese warm tones */
  background:
    radial-gradient(900px 600px at 10% -10%, rgba(255, 210, 74, 0.25), transparent 60%),
    radial-gradient(700px 600px at 100% 0%, rgba(54, 180, 167, 0.18), transparent 55%),
    var(--bg);
  line-height: 1.7;
}

h1, h2 {
  font-family: "Fraunces", "Times New Roman", serif;
  letter-spacing: 0.2px;
}

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

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

/* ========================================
   Header & Navigation
   ======================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  background: rgba(255, 246, 236, 0.85);
  border-bottom: 1px solid var(--line);
}

.header-content {
  max-width: var(--max);
  margin: 0 auto;
  padding: 16px 24px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 16px;
  align-items: center;
}

/* Brand logo and title */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
}

.brand-logo {
  width: 44px;
  height: 44px;
  object-fit: contain;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-weight: 700;
  font-size: 18px;
}

.brand-tag {
  font-size: 12px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.18em;
}

/* Navigation links */
.nav-links {
  display: flex;
  justify-content: center;
  gap: 20px;
  font-weight: 500;
  color: var(--muted);
}

.nav-links a {
  padding: 8px 10px;
  border-radius: 999px;
  transition: color 0.2s ease, background 0.2s ease;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--ink);
  background: rgba(255, 139, 44, 0.16);
}

/* ========================================
   Main Content Layout
   ======================================== */
main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 40px 24px 80px;
  display: flex;
  flex-direction: column;
  gap: 48px;
}

/* ========================================
   Hero Section (Homepage)
   ======================================== */
.hero {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
  align-items: center;
}

.hero-text h1 {
  font-size: clamp(32px, 4vw, 48px);
  margin: 0 0 12px;
}

.hero-lede {
  color: var(--muted);
  margin: 0 0 20px;
}

/* Small uppercase label */
.eyebrow {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.3em;
  color: var(--muted);
  margin-bottom: 12px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 22px;
}

/* Button styles */
.btn-primary,
.btn-ghost {
  padding: 12px 20px;
  border-radius: 999px;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-primary {
  background: var(--red);
  color: #fff;
  box-shadow: 0 12px 24px rgba(230, 74, 59, 0.25);
}

.btn-ghost {
  border: 1px solid var(--line);
  color: var(--ink);
  background: rgba(255, 255, 255, 0.7);
}

.btn-primary:hover,
.btn-ghost:hover {
  transform: translateY(-1px);
}

/* Seven-color rainbow decorative bar */
.rainbow-bar {
  height: 6px;
  border-radius: 999px;
  background: var(--rainbow);
  box-shadow: 0 10px 20px rgba(58, 123, 213, 0.2);
}

/* Hero media (logo display on right side) */
.hero-media {
  display: grid;
  gap: 18px;
  align-items: center;
}

.logo-card-large {
  display: flex;
  justify-content: center;
  align-items: center;
}

.logo-card-large img {
  width: 100%;
  max-width: 420px;
  height: auto;
  object-fit: contain;
}

/* ========================================
   Feature Grid (Homepage highlights)
   ======================================== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.feature-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 139, 44, 0.15);
}

.feature-card h2 {
  margin: 0 0 8px;
  font-size: 20px;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
}

/* ========================================
   Privacy Policy Section
   ======================================== */
.policy {
  display: grid;
  gap: 24px;
}

.section-title h1 {
  margin: 0 0 6px;
}

.updated {
  margin: 0;
  color: var(--muted);
}

.policy-content {
  display: grid;
  gap: 18px;
}

/* Individual policy cards */
.policy-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
}

.policy-card h2 {
  margin: 0 0 10px;
  font-size: 20px;
}

.policy-card p,
.policy-card ul {
  margin: 0 0 12px;
  color: var(--muted);
}

.policy-card ul {
  padding-left: 20px;
}

.policy-card strong {
  color: var(--ink);
}

/* ========================================
   Footer
   ======================================== */
.site-footer {
  background: #1f1a18;
  color: #f7efe8;
}

.footer-content {
  max-width: var(--max);
  margin: 0 auto;
  padding: 32px 24px 40px;
  display: grid;
  gap: 16px;
}

.footer-content h2 {
  margin: 0 0 6px;
  font-size: 22px;
}

.footer-content p {
  margin: 0;
  color: rgba(247, 239, 232, 0.7);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-weight: 500;
}

.footer-note {
  font-size: 13px;
}

/* ========================================
   Animations
   ======================================== */
@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Elements that animate on page load */
.hero-text,
.hero-media,
.feature-card,
.policy-card {
  animation: rise 0.8s ease both;
}

.hero-media {
  animation-delay: 0.1s;
}

.feature-card:nth-child(2) {
  animation-delay: 0.12s;
}

.feature-card:nth-child(3) {
  animation-delay: 0.2s;
}

/* ========================================
   Documentation Page Styles
   ======================================== */
/* Page header for documentation page */
.page-header {
  margin-bottom: 40px;
  padding-bottom: 32px;
  border-bottom: 2px solid var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 32px;
}

.page-header-content {
  flex: 1;
}

.page-header h1 {
  margin: 0 0 8px;
  font-size: clamp(32px, 4vw, 48px);
}

.page-lede {
  margin: 0;
  color: var(--muted);
  font-size: 18px;
}

/* Documentation section cards */
.documentation-section {
  background: var(--card);
  border-radius: var(--radius);
  padding: 32px;
  margin-bottom: 24px;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  animation: rise 0.8s ease both;
}

/* Section headers within documentation cards */
.section-header {
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid rgba(255, 139, 44, 0.2);
}

.section-header h2 {
  margin: 0 0 6px;
  font-size: 26px;
  color: var(--ink);
}

.section-tag {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.2em;
}

/* Content area within documentation sections */
.section-content {
  color: var(--muted);
  line-height: 1.8;
}

.section-content h3 {
  color: var(--ink);
  margin: 20px 0 10px;
}

.section-content ul,
.section-content ol {
  margin: 12px 0;
  padding-left: 24px;
}

.section-content li {
  margin: 6px 0;
  color: var(--muted);
}

/* Introduction section (special styling) */
.intro-section {
  background: linear-gradient(135deg, rgba(255, 210, 74, 0.12), rgba(54, 180, 167, 0.12));
  border: 1px solid rgba(255, 139, 44, 0.25);
}

.intro-content {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 32px;
  align-items: center;
}

.intro-logo {
  display: flex;
  justify-content: center;
  align-items: center;
}

.intro-logo img {
  width: 140px;
  height: auto;
  object-fit: contain;
}

.intro-text p {
  margin: 0 0 16px;
  color: var(--muted);
}

.intro-text p:last-child {
  margin-bottom: 0;
}

/* Limitations section (special styling at bottom) */
.limitations-section {
  background: linear-gradient(135deg, rgba(255, 139, 44, 0.08), rgba(58, 123, 213, 0.08));
  border: 1px solid rgba(255, 139, 44, 0.2);
  margin-top: 40px;
}

/* ========================================
   Image Gallery (Art Design Section)
   ======================================== */
.asset-breakdown {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 20px;
  margin: 20px 0;
}

.asset-category {
  background: rgba(255, 139, 44, 0.08);
  border: 1px solid rgba(255, 139, 44, 0.2);
  border-radius: 12px;
  padding: 16px;
}

.asset-category h4 {
  margin: 0 0 12px;
  color: var(--ink);
  font-size: 14px;
  font-weight: 600;
}

.asset-category p {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* Image gallery viewer */
.image-gallery {
  margin: 32px 0;
  padding: 24px;
  background: rgba(255, 246, 236, 0.5);
  border-radius: 16px;
  border: 1px solid var(--line);
}

/* Gallery grid layout */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 16px;
}

/* Gallery card */
.gallery-card {
  position: relative;
  aspect-ratio: 1;
  border-radius: 12px;
  overflow: hidden;
  background: var(--card);
  box-shadow: 0 10px 30px rgba(31, 26, 24, 0.15);
  cursor: pointer;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.gallery-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 16px 48px rgba(31, 26, 24, 0.25);
}

/* Card image wrapper */
.gallery-card-image {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  background: var(--card);
}

.gallery-card-image img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

/* Card overlay (shows on hover) */
.gallery-card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(230, 74, 59, 0.95), rgba(255, 139, 44, 0.95));
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 16px;
  text-align: center;
  opacity: 0;
  transition: opacity 0.3s ease;
}

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

.gallery-card-overlay h4 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
}

.gallery-card-overlay .card-type {
  margin: 0 0 4px;
  font-size: 12px;
  color: rgba(255, 255, 255, 0.9);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.gallery-card-overlay .card-size {
  margin: 0;
  font-size: 11px;
  color: rgba(255, 255, 255, 0.8);
}

/* Blocker showcase */
.blocker-showcase {
  display: flex;
  justify-content: center;
  margin: 32px 0;
  padding: 24px;
  background: rgba(255, 210, 74, 0.08);
  border-radius: 16px;
  border: 1px solid rgba(255, 210, 74, 0.2);
}

.blocker-tile {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  text-align: center;
}

/* Gameplay showcase */
.gameplay-showcase {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  margin: 24px 0;
  padding: 20px;
  background: rgba(34, 197, 94, 0.04);
  border-radius: 12px;
  border: 1px solid rgba(34, 197, 94, 0.12);
}

.gameplay-featured {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  text-align: center;
  padding: 16px;
  background: white;
  border-radius: 10px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
  width: 100%;
  max-width: 380px;
}

.gameplay-featured img {
  width: 100%;
  height: auto;
  object-fit: contain;
  border-radius: 8px;
}

.gameplay-surround {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 20px;
  width: 100%;
  max-width: 1100px;
}

.gameplay-element {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  text-align: center;
  padding: 12px;
  background: white;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  transition: transform 0.22s ease;
}

.gameplay-element:hover {
  transform: translateY(-6px);
}

.gameplay-element img {
  width: 100%;
  height: 100px;
  object-fit: contain;
  border-radius: 6px;
}

.blocker-tile img {
  max-width: 200px;
  max-height: 200px;
  width: auto;
  height: auto;
  object-fit: contain;
  padding: 12px;
  background: var(--card);
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(31, 26, 24, 0.12);
}

.blocker-tile p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

/* Architecture diagrams */
.architecture-diagrams {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  padding: 16px 0;
  margin: 24px 0;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}

.architecture-diagrams img {
  max-width: 300px;
  height: auto;
  border-radius: 8px;
  box-shadow: var(--shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  cursor: pointer;
  flex-shrink: 0;
}

.architecture-diagrams img:hover {
  transform: scale(1.1);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
}

/* Code blocks for architecture */
pre {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 14px;
  line-height: 1.4;
  margin: 16px 0;
}

code {
  background: rgba(0, 0, 0, 0.05);
  padding: 2px 4px;
  border-radius: 3px;
  font-family: 'Courier New', monospace;
  font-size: 0.9em;
}

/* Surprise details */
.surprise {
  display: inline;
  margin: 0 4px;
}

.trigger {
  color: var(--accent);
  font-weight: bold;
  text-decoration: underline;
  text-decoration-style: dotted;
  cursor: pointer;
  transition: color 0.3s;
}

.trigger:hover {
  color: var(--accent-hover, #ff6b6b);
}

.hidden-content {
  font-style: italic;
  margin-left: 4px;
}

/* Documentation logo showcase */
.documentation-logo-showcase {
  display: flex;
  justify-content: center;
  margin: 24px 0;
  padding: 24px;
  background: rgba(58, 123, 213, 0.08);
  border-radius: 16px;
  border: 1px solid rgba(58, 123, 213, 0.2);
}

.documentation-logo {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  text-align: center;
}

.documentation-logo img {
  max-width: 160px;
  max-height: 160px;
  width: auto;
  height: auto;
  object-fit: contain;
  padding: 16px;
  background: var(--card);
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(31, 26, 24, 0.12);
}

.documentation-logo p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

/* Documentation stack grid */
.documentation-stack-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 16px;
  margin: 24px 0;
}

.documentation-item {
  background: rgba(77, 187, 107, 0.08);
  border: 1px solid rgba(77, 187, 107, 0.2);
  border-radius: 12px;
  padding: 16px;
  text-align: center;
}

.documentation-item h4 {
  margin: 0 0 8px;
  color: var(--ink);
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.documentation-item p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

/* ========================================
   Accessibility - Reduce Motion
   ======================================== */
@media (prefers-reduced-motion: reduce) {
  * {
    animation: none !important;
    transition: none !important;
  }
}

/* ========================================
   Responsive Design - Tablet (900px and below)
   ======================================== */
@media (max-width: 900px) {
  .header-content {
    grid-template-columns: 1fr;
    justify-items: start;
  }

  .nav-links {
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  /* Gallery responsive - 4-5 columns on tablet */
  .gallery-grid {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  }
}

/* ========================================
   Responsive Design - Mobile (600px and below)
   ======================================== */
@media (max-width: 600px) {
  main {
    padding: 28px 18px 60px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: flex-start;
  }

  /* Introduction section mobile layout */
  .intro-content {
    grid-template-columns: 1fr;
    gap: 20px;
    text-align: center;
  }

  .intro-text {
    text-align: left;
  }

  .intro-logo img {
    width: 100px;
  }

  /* Gallery responsive - 3 columns on mobile */
  .gallery-grid {
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 12px;
  }

  .gallery-card {
    aspect-ratio: 1;
  }

  .gallery-card-overlay h4 {
    font-size: 14px;
  }

  .gallery-card-overlay .card-type {
    font-size: 10px;
  }

  .gallery-card-overlay .card-size {
    font-size: 9px;
  }
}

/* ========================================
   Animation Table Styles
   ======================================== */
.animation-table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  font-size: 16px;
  background-color: #fff;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
  overflow: hidden;
}

.animation-table th,
.animation-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid #e0e0e0;
}

.animation-table th {
  background-color: #f8f9fa;
  font-weight: 600;
  color: #333;
}

.animation-table td {
  color: #555;
}

.animation-table tr:last-child td {
  border-bottom: none;
}

.animation-table tr:hover {
  background-color: #f8f9fa;
}

/* ========================================
   Animation GIFs Grid
   ======================================== */
.animation-gifs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
  margin: 20px 0;
}

.animation-gif-card {
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.animation-gif-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.animation-gif-image {
  width: 100%;
  height: 200px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #f8f9fa;
}

.animation-gif-image img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

.animation-gif-overlay {
  padding: 16px;
  text-align: center;
}

.animation-gif-overlay h4 {
  margin: 0 0 8px 0;
  font-size: 18px;
  font-weight: 600;
  color: #333;
}

.gif-description {
  margin: 0;
  font-size: 14px;
  color: #666;
  line-height: 1.4;
}

/* ========================================
   Table to GIFs Arrow
   ======================================== */
.table-to-gifs-arrow {
  text-align: center;
  margin: 15px 0 10px 0;
}

.table-to-gifs-arrow span {
  font-size: 36px;
  color: #007acc;
  display: block;
  margin-bottom: 8px;
  animation: bounce 2s infinite;
}

.table-to-gifs-arrow p {
  margin: 0;
  font-size: 16px;
  color: #666;
  font-style: italic;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-10px);
  }
  60% {
    transform: translateY(-5px);
  }
}

/* ========================================
   Animation Note
   ======================================== */
.animation-note {
  margin: 20px 0 0 0;
  padding: 16px;
  background-color: #f8f9fa;
  border-left: 4px solid #007acc;
  border-radius: 4px;
  font-style: italic;
  color: #555;
  line-height: 1.5;
}

/* Audio player styles */
.audio-player {
  margin-top: 18px;
  padding: 14px;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.audio-player .audio-controls {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 10px;
}
.audio-player .btn {
  background: #007acc;
  color: #fff;
  border: none;
  padding: 8px 12px;
  border-radius: 6px;
  cursor: pointer;
}
.audio-player .btn:hover { opacity: 0.95; }
.audio-player .audio-note {
  margin: 8px 0 0 0;
  color: #666;
  font-size: 13px;
}

/* Collapsible sections styling */
.collapsible-header {
  display: flex;
  align-items: center;
  gap: 12px;
}

.section-toggle {
  appearance: none;
  background: transparent;
  border: none;
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  color: var(--red);
  padding: 6px;
  border-radius: 6px;
}

.section-toggle:hover {
  background: rgba(230,74,59,0.06);
}

.documentation-section.collapsed .section-header h2,
.documentation-section.collapsed .section-header .section-tag {
  opacity: 0.9;
}

.documentation-section .section-content {
  transition: max-height 280ms ease, opacity 200ms linear;
}

.documentation-section.collapsed .section-content {
  opacity: 0;
}