/* CSS Variables */
:root {
  --background: #FAFAFA;
  --foreground: #09090B;
  --secondary: #71717A;
  --accent: #EA580C;
  --accent-hover: #C2410C;
  --accent-light: rgba(234, 88, 12, 0.08);
  --border: #E4E4E7;
  --white: #FFFFFF;
  --surface: #F4F4F5;
  --font-body: 'Noto Sans SC', 'Space Grotesk', sans-serif;
  --font-heading: 'Archivo', 'Noto Sans SC', sans-serif;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --radius: 16px;
  --radius-lg: 24px;
  --transition: 0.2s ease;
}

/* Dark Mode */
[data-theme="dark"] {
  --background: #09090B;
  --foreground: #FAFAFA;
  --secondary: #A1A1AA;
  --accent: #F97316;
  --accent-hover: #FB923C;
  --accent-light: rgba(249, 115, 22, 0.12);
  --border: #27272A;
  --white: #18181B;
  --surface: #1C1C1E;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
}

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

html {
  scroll-behavior: smooth;
  overflow-x: hidden;
}

body {
  font-family: var(--font-body);
  background-color: var(--background);
  color: var(--foreground);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  width: 100%;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
}

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

code {
  background: var(--accent-light);
  color: var(--accent);
  padding: 0.15em 0.4em;
  border-radius: 6px;
  font-size: 0.9em;
  font-family: 'Space Grotesk', monospace;
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  background: rgba(250, 250, 250, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

[data-theme="dark"] .navbar {
  background: rgba(9, 9, 11, 0.8);
}

.nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

@media (min-width: 640px) {
  .nav-container { padding: 0 1.5rem; }
}

@media (min-width: 1024px) {
  .nav-container { padding: 0 2rem; }
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.nav-logo {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  background: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  flex-shrink: 0;
}

.nav-title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.025em;
}

.nav-links {
  display: none;
  align-items: center;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .nav-links { display: flex; }
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--secondary);
  transition: color var(--transition);
}

.nav-link:hover {
  color: var(--accent);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: transparent;
  cursor: pointer;
  transition: all var(--transition);
  color: var(--foreground);
}

.theme-toggle:hover {
  background: var(--border);
}

.theme-toggle .icon {
  width: 18px;
  height: 18px;
  color: var(--foreground);
}

.theme-toggle .moon-icon {
  display: none;
}

[data-theme="dark"] .theme-toggle .sun-icon {
  display: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
  display: block;
}

/* Hero Section */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 4rem;
  overflow: hidden;
  background: linear-gradient(135deg, #FFF7ED 0%, #FFEDD5 30%, #FED7AA 60%, #FDBA74 100%);
}

[data-theme="dark"] .hero {
  background: linear-gradient(135deg, #1C1917 0%, #292524 30%, #44403C 60%, #57534E 100%);
}

.hero-particles {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  pointer-events: none;
}

.particle {
  position: absolute;
  background: var(--accent);
  border-radius: 50%;
  opacity: 0.2;
  pointer-events: none;
  animation: float-particle var(--duration) linear infinite;
}

@keyframes float-particle {
  0% { transform: translateY(100vh) translateX(0); opacity: 0; }
  10% { opacity: 0.2; }
  90% { opacity: 0.2; }
  100% { transform: translateY(-10vh) translateX(var(--drift)); opacity: 0; }
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(to bottom, rgba(250, 250, 250, 0.3), rgba(250, 250, 250, 0.9));
  z-index: 1;
}

[data-theme="dark"] .hero::before {
  background: linear-gradient(to bottom, rgba(9, 9, 11, 0.2), rgba(9, 9, 11, 0.9));
}

.hero-container {
  position: relative;
  z-index: 2;
  max-width: 1280px;
  width: 100%;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 4rem;
}

.hero-content {
  flex: 1.5;
  max-width: 52rem;
  animation: fadeInUp 0.6s ease-out;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  letter-spacing: -0.03em;
}

@media (min-width: 640px) {
  .hero-title { font-size: 5rem; }
}

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

.hero-description {
  font-size: 1.25rem;
  color: var(--secondary);
  line-height: 1.8;
  margin-bottom: 2.5rem;
  max-width: 42rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

/* 3D Cube Visual */
.hero-visual {
  flex: 0.8;
  display: flex;
  justify-content: center;
  align-items: center;
  animation: fadeInRight 0.8s ease-out;
}

.cube-scene {
  width: 200px;
  height: 200px;
  perspective: 600px;
}

@media (min-width: 640px) {
  .cube-scene { width: 260px; height: 260px; }
}

.cube {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  animation: rotate-cube 12s linear infinite;
}

@keyframes rotate-cube {
  0% { transform: rotateX(-20deg) rotateY(0deg); }
  100% { transform: rotateX(-20deg) rotateY(360deg); }
}

.cube-face {
  position: absolute;
  width: 200px;
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 700;
  border: 2px solid rgba(234, 88, 12, 0.3);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: var(--foreground);
}

@media (min-width: 640px) {
  .cube-face { width: 260px; height: 260px; font-size: 2.5rem; }
}

[data-theme="dark"] .cube-face {
  background: rgba(255, 255, 255, 0.05);
  border-color: rgba(249, 115, 22, 0.3);
}

.cube-face.front  { transform: rotateY(0deg) translateZ(100px); }
.cube-face.back   { transform: rotateY(180deg) translateZ(100px); }
.cube-face.right  { transform: rotateY(90deg) translateZ(100px); }
.cube-face.left   { transform: rotateY(-90deg) translateZ(100px); }
.cube-face.top    { transform: rotateX(90deg) translateZ(100px); }
.cube-face.bottom { transform: rotateX(-90deg) translateZ(100px); }

@media (min-width: 640px) {
  .cube-face.front  { transform: rotateY(0deg) translateZ(130px); }
  .cube-face.back   { transform: rotateY(180deg) translateZ(130px); }
  .cube-face.right  { transform: rotateY(90deg) translateZ(130px); }
  .cube-face.left   { transform: rotateY(-90deg) translateZ(130px); }
  .cube-face.top    { transform: rotateX(90deg) translateZ(130px); }
  .cube-face.bottom { transform: rotateX(-90deg) translateZ(130px); }
}

@keyframes fadeInRight {
  from { opacity: 0; transform: translateX(40px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 1024px) {
  .hero-container {
    flex-direction: column;
    text-align: center;
    gap: 2rem;
  }
  .hero-visual { display: none; }
  .hero-content { margin-left: 0; }
  .hero-actions { justify-content: center; }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  border-radius: 9999px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
}

.btn .icon {
  width: 18px;
  height: 18px;
}

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

.btn-primary:hover {
  background: var(--accent-hover);
  box-shadow: 0 10px 15px -3px rgba(234, 88, 12, 0.3);
  transform: translateY(-1px);
}

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

.btn-secondary:hover {
  background: rgba(9, 9, 11, 0.05);
  box-shadow: var(--shadow-md);
}

[data-theme="dark"] .btn-secondary:hover {
  background: rgba(255, 255, 255, 0.05);
}

/* Section Layout */
.section-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1rem;
}

@media (min-width: 640px) {
  .section-inner { padding: 0 1.5rem; }
}

@media (min-width: 1024px) {
  .section-inner { padding: 0 2rem; }
}

.section-header {
  margin-bottom: 3rem;
}

.section-header.center {
  text-align: center;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

.section-subtitle {
  color: var(--secondary);
  font-size: 1.1rem;
}

/* Tools Section */
.tools {
  padding: 5rem 0;
  background: var(--white);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

/* Simulators Section */
.simulators {
  padding: 5rem 0;
}

/* Docs Section */
.docs {
  padding: 5rem 0;
  background: var(--white);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

/* Cards Grid */
.cards-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

@media (min-width: 768px) {
  .cards-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .cards-grid { grid-template-columns: repeat(3, 1fr); }
}

/* Card */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: all 0.3s ease;
  overflow: hidden;
  cursor: pointer;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.card:hover::before {
  transform: scaleX(1);
}

.card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-xl);
  transform: translateY(-4px);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  flex-shrink: 0;
}

.card-icon svg {
  width: 24px;
  height: 24px;
}

.card-icon.blue {
  background: rgba(37, 99, 235, 0.1);
  color: #2563EB;
}

[data-theme="dark"] .card-icon.blue {
  background: rgba(59, 130, 246, 0.15);
  color: #60A5FA;
}

.card-icon.green {
  background: rgba(22, 163, 74, 0.1);
  color: #16A34A;
}

[data-theme="dark"] .card-icon.green {
  background: rgba(34, 197, 94, 0.15);
  color: #4ADE80;
}

.card-icon.orange {
  background: rgba(234, 88, 12, 0.1);
  color: #EA580C;
}

[data-theme="dark"] .card-icon.orange {
  background: rgba(249, 115, 22, 0.15);
  color: #FB923C;
}

.card-icon.purple {
  background: rgba(168, 85, 247, 0.1);
  color: #9333EA;
}

[data-theme="dark"] .card-icon.purple {
  background: rgba(192, 132, 252, 0.15);
  color: #C084FC;
}

.card-icon.red {
  background: rgba(239, 68, 68, 0.1);
  color: #DC2626;
}

[data-theme="dark"] .card-icon.red {
  background: rgba(248, 113, 113, 0.15);
  color: #F87171;
}

.card-icon.teal {
  background: rgba(13, 148, 136, 0.1);
  color: #0D9488;
}

[data-theme="dark"] .card-icon.teal {
  background: rgba(45, 212, 191, 0.15);
  color: #2DD4BF;
}

.card-body {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.card-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  transition: color var(--transition);
}

.card:hover .card-title {
  color: var(--accent);
}

.card-desc {
  color: var(--secondary);
  font-size: 0.875rem;
  line-height: 1.6;
  flex: 1;
  margin-bottom: 0.75rem;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.125rem 0.5rem;
  background: var(--accent-light);
  color: var(--accent);
  font-size: 0.7rem;
  font-weight: 500;
  border-radius: 9999px;
}

.card-arrow {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  width: 18px;
  height: 18px;
  color: var(--secondary);
  transition: all var(--transition);
  opacity: 0;
  transform: translate(-4px, 4px);
}

.card:hover .card-arrow {
  opacity: 1;
  color: var(--accent);
  transform: translate(0, 0);
}

.flag-img {
  display: inline-block;
  width: 20px;
  height: 14px;
  object-fit: cover;
  border-radius: 2px;
  vertical-align: middle;
  margin-left: 0.3em;
  box-shadow: 0 0 0 1px rgba(0,0,0,0.1);
}

.tag .flag-img {
  width: 14px;
  height: 10px;
  margin-left: 0;
  margin-right: 0.25em;
  vertical-align: middle;
}

/* Edition Groups */
.edition-group {
  margin-bottom: 3rem;
}

.edition-group:last-child {
  margin-bottom: 0;
}

.edition-title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--foreground);
}

.edition-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.8rem;
  font-weight: 600;
  color: #fff;
}

.edition-badge.advanced {
  background: linear-gradient(135deg, #16A34A, #22C55E);
}

.edition-badge.normal {
  background: linear-gradient(135deg, #EA580C, #F97316);
}

.edition-badge.dual {
  background: linear-gradient(135deg, #0D9488, #14B8A6);
}

/* Language Switcher */
.lang-switcher {
  position: relative;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--foreground);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.lang-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.lang-btn svg {
  width: 14px;
  height: 14px;
  transition: transform 0.2s;
}

.lang-dropdown.show .lang-btn svg {
  transform: rotate(180deg);
}

.lang-dropdown {
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  min-width: 140px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all 0.2s;
  z-index: 100;
  overflow: hidden;
}

.lang-dropdown.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-option {
  padding: 0.5rem 0.75rem;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.15s;
  color: var(--secondary);
}

.lang-option:hover {
  background: var(--accent);
  color: #fff;
}

.lang-option.active {
  font-weight: 600;
  color: var(--accent);
}

.lang-option.active:hover {
  color: #fff;
}

/* Back to Top Button */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--foreground);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s;
  z-index: 40;
  box-shadow: var(--shadow-lg);
}

.back-to-top:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  transform: translateY(-2px);
}

.back-to-top.show {
  opacity: 1;
  visibility: visible;
}

.back-to-top svg {
  width: 24px;
  height: 24px;
}

@media (max-width: 640px) {
  .back-to-top {
    bottom: 1.5rem;
    right: 1.5rem;
    width: 40px;
    height: 40px;
  }
  .back-to-top svg {
    width: 20px;
    height: 20px;
  }
}

/* Footer */
.footer {
  padding: 5rem 1rem;
  border-top: 1px solid var(--border);
}

.footer-content {
  max-width: 1280px;
  margin: 0 auto;
  text-align: center;
}

.footer-logo {
  width: 64px;
  height: 64px;
  margin: 0 auto 1.5rem;
  border-radius: 16px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  background: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
}

.footer-title {
  font-size: 1.875rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.footer-quote {
  color: var(--secondary);
  font-style: italic;
  max-width: 28rem;
  margin: 0 auto 2rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 2rem;
  margin-bottom: 3rem;
}

.footer-links a {
  color: var(--secondary);
  font-weight: 500;
  transition: color var(--transition);
}

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

.footer-copyright {
  font-size: 0.875rem;
  color: #9CA3AF;
}

/* Scroll Animation */
.animate-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}

.animate-in.visible {
  opacity: 1;
  transform: translateY(0);
}