/* ===== DESIGN TOKENS ===== */
:root {
  /* Colors — Material Design 3 Expressive */
  --color-primary: #1a73e8;
  --color-primary-hover: #1557b0;
  --color-primary-light: rgba(26, 115, 232, 0.08);
  --color-primary-subtle: rgba(26, 115, 232, 0.12);

  --color-surface: #fefefe;
  --color-surface-dim: #f3f4f6;
  --color-surface-container: #ffffff;
  --color-on-surface: #1f2937;
  --color-on-surface-dim: #6b7280;
  --color-on-surface-faint: #9ca3af;
  --color-outline: #e5e7eb;
  --color-outline-subtle: #f0f0f0;

  --color-code-bg: #1e1e2e;
  --color-code-text: #cdd6f4;

  /* Typography */
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'Cascadia Code', 'Fira Code', monospace;

  /* Shapes — M3 Expressive */
  --radius-xs: 8px;
  --radius-sm: 12px;
  --radius-md: 16px;
  --radius-lg: 28px;
  --radius-full: 9999px;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;

  /* Motion */
  --ease-expressive: cubic-bezier(0.2, 0, 0, 1);
  --duration-short: 200ms;
  --duration-medium: 350ms;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.1), 0 4px 12px rgba(0,0,0,0.05);

  /* Layout */
  --nav-height: 64px;
  --container-max: 1200px;
}

/* ===== DARK MODE ===== */
[data-theme="dark"] {
  --color-primary: #8ab4f8;
  --color-primary-hover: #aecbfa;
  --color-primary-light: rgba(138, 180, 248, 0.1);
  --color-primary-subtle: rgba(138, 180, 248, 0.15);

  --color-surface: #111827;
  --color-surface-dim: #1f2937;
  --color-surface-container: #1a2332;
  --color-on-surface: #f3f4f6;
  --color-on-surface-dim: #9ca3af;
  --color-on-surface-faint: #6b7280;
  --color-outline: #374151;
  --color-outline-subtle: #1f2937;

  --color-code-bg: #0d1117;
  --color-code-text: #c9d1d9;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.4);
}

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

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-on-surface);
  background: var(--color-surface);
  transition: background var(--duration-medium) var(--ease-expressive),
              color var(--duration-medium) var(--ease-expressive);
}

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

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

button {
  font: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

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

.section {
  padding: var(--space-4xl) 0;
}

.section__title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.025em;
  text-align: center;
  margin-bottom: var(--space-md);
}

.section__subtitle {
  font-size: clamp(1rem, 2vw, 1.125rem);
  color: var(--color-on-surface-dim);
  text-align: center;
  max-width: 640px;
  margin: 0 auto var(--space-2xl);
  line-height: 1.7;
}

/* ===== NAVIGATION ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 100;
  background: rgba(254, 254, 254, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-outline);
  transition: background var(--duration-medium) var(--ease-expressive),
              border-color var(--duration-medium) var(--ease-expressive);
}

[data-theme="dark"] .nav {
  background: rgba(17, 24, 39, 0.85);
}

.nav__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--color-primary);
  font-weight: 700;
  font-size: 1.125rem;
  flex-shrink: 0;
}

.nav__logo-icon {
  color: var(--color-primary);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav__link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-on-surface-dim);
  transition: color var(--duration-short) var(--ease-expressive);
  white-space: nowrap;
}

.nav__link:hover {
  color: var(--color-primary);
}

.nav__theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-on-surface-dim);
  transition: background var(--duration-short) var(--ease-expressive),
              color var(--duration-short) var(--ease-expressive);
}

.nav__theme-toggle:hover {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

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

/* Hamburger */
.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 32px;
  height: 32px;
  justify-content: center;
  align-items: center;
  z-index: 110;
}

.nav__hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-on-surface);
  border-radius: 2px;
  transition: all var(--duration-short) var(--ease-expressive);
}

.nav__hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.nav__hamburger.active span:nth-child(2) {
  opacity: 0;
}
.nav__hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== HERO ===== */
.hero {
  padding-top: calc(var(--nav-height) + var(--space-3xl));
  padding-bottom: var(--space-4xl);
  overflow: hidden;
}

.hero__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
}

.hero__title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  background: linear-gradient(135deg, var(--color-primary) 0%, #6c5ce7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-theme="dark"] .hero__title {
  background: linear-gradient(135deg, #8ab4f8 0%, #bb86fc 100%);
  -webkit-background-clip: text;
  background-clip: text;
}

.hero__subtitle {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-weight: 600;
  color: var(--color-on-surface);
  margin-top: var(--space-md);
  letter-spacing: -0.015em;
}

.hero__platforms {
  font-size: 0.95rem;
  color: var(--color-on-surface-dim);
  margin-top: var(--space-sm);
  font-weight: 500;
}

.hero__actions {
  display: flex;
  gap: var(--space-md);
  margin-top: var(--space-xl);
  flex-wrap: wrap;
}

.hero__model {
  position: relative;
  width: 100%;
  aspect-ratio: 1;
  max-width: 500px;
  min-height: 400px;
  justify-self: center;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: radial-gradient(ellipse at 50% 40%,
    rgba(26, 115, 232, 0.1) 0%,
    rgba(108, 92, 231, 0.06) 40%,
    var(--color-surface-dim) 80%);
  box-shadow: var(--shadow-lg);
}

[data-theme="dark"] .hero__model {
  background: radial-gradient(ellipse at 50% 40%,
    rgba(138, 180, 248, 0.1) 0%,
    rgba(187, 134, 252, 0.06) 40%,
    var(--color-surface-dim) 80%);
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 14px 28px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--duration-short) var(--ease-expressive);
  white-space: nowrap;
}

.btn--primary {
  background: var(--color-primary);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(26, 115, 232, 0.3);
}

.btn--primary:hover {
  background: var(--color-primary-hover);
  box-shadow: 0 4px 16px rgba(26, 115, 232, 0.4);
  transform: translateY(-1px);
}

[data-theme="dark"] .btn--primary {
  color: #111827;
}

.btn--outline {
  border: 1.5px solid var(--color-outline);
  color: var(--color-on-surface);
  background: var(--color-surface-container);
}

.btn--outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-light);
  transform: translateY(-1px);
}

/* ===== TABS ===== */
.tabs__nav {
  display: flex;
  gap: var(--space-xs);
  padding: var(--space-xs);
  background: var(--color-surface-dim);
  border-radius: var(--radius-sm);
  width: fit-content;
  margin: 0 auto var(--space-lg);
  overflow-x: auto;
}

.tabs__btn {
  padding: 10px 20px;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius-xs);
  color: var(--color-on-surface-dim);
  transition: all var(--duration-short) var(--ease-expressive);
  white-space: nowrap;
}

.tabs__btn:hover {
  color: var(--color-on-surface);
}

.tabs__btn--active {
  background: var(--color-surface-container);
  color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.tabs__panel {
  display: none;
}

.tabs__panel--active {
  display: block;
}

/* ===== CODE BLOCKS ===== */
.code-block {
  background: var(--color-code-bg);
  color: var(--color-code-text);
  padding: var(--space-lg);
  border-radius: var(--radius-sm);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.7;
  box-shadow: var(--shadow-md);
  max-width: 720px;
  margin: 0 auto;
}

.code-block--compact {
  padding: var(--space-md) var(--space-lg);
  max-width: 480px;
  text-align: center;
  margin: var(--space-lg) auto;
}

/* Syntax colors */
.kw { color: #cba6f7; }
.fn { color: #89b4fa; }
.str { color: #a6e3a1; }
.num { color: #fab387; }
.cm { color: #6c7086; }

/* ===== CODE SECTION ===== */
.code-section {
  background: var(--color-surface-dim);
}

/* ===== FEATURES ===== */
.features__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-lg);
}

.card {
  background: var(--color-surface-container);
  border: 1px solid var(--color-outline);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: all var(--duration-medium) var(--ease-expressive);
}

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-subtle);
  transform: translateY(-2px);
}

.card__icon {
  margin-bottom: var(--space-md);
}

.card__title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.card__text {
  color: var(--color-on-surface-dim);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ===== INSTALL ===== */
.install {
  background: var(--color-surface-dim);
}

/* ===== SAMPLES ===== */
.samples__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-md);
}

.sample-card {
  display: block;
  background: var(--color-surface-container);
  border: 1px solid var(--color-outline);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: all var(--duration-medium) var(--ease-expressive);
}

.sample-card:hover {
  border-color: var(--color-primary-subtle);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.sample-card__badge {
  display: inline-block;
  padding: 4px 12px;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: var(--color-primary-subtle);
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.sample-card__badge--ar {
  background: rgba(124, 58, 237, 0.12);
  color: #7c3aed;
}
[data-theme="dark"] .sample-card__badge--ar {
  background: rgba(167, 139, 250, 0.15);
  color: #a78bfa;
}

.sample-card__badge--demo {
  background: rgba(234, 88, 12, 0.12);
  color: #ea580c;
}
[data-theme="dark"] .sample-card__badge--demo {
  background: rgba(251, 146, 60, 0.15);
  color: #fb923c;
}

.sample-card__badge--ios {
  background: rgba(0, 0, 0, 0.08);
  color: #374151;
}
[data-theme="dark"] .sample-card__badge--ios {
  background: rgba(255, 255, 255, 0.1);
  color: #d1d5db;
}

.sample-card__badge--tv {
  background: rgba(16, 185, 129, 0.12);
  color: #059669;
}
[data-theme="dark"] .sample-card__badge--tv {
  background: rgba(52, 211, 153, 0.15);
  color: #34d399;
}

.sample-card__badge--web {
  background: rgba(245, 158, 11, 0.12);
  color: #d97706;
}
[data-theme="dark"] .sample-card__badge--web {
  background: rgba(251, 191, 36, 0.15);
  color: #fbbf24;
}

.sample-card__title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--space-xs);
}

.sample-card__text {
  color: var(--color-on-surface-dim);
  font-size: 0.85rem;
}

/* ===== AI SECTION ===== */
.ai-section {
  background: var(--color-surface-dim);
}

.ai-section__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
}

.ai-section__badge {
  display: inline-block;
  padding: 6px 16px;
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, rgba(26,115,232,0.15), rgba(108,92,231,0.15));
  color: var(--color-primary);
  margin-bottom: var(--space-md);
  letter-spacing: 0.02em;
}

.ai-section__content .section__title {
  text-align: left;
}

.ai-section__content .section__subtitle {
  text-align: left;
  margin-left: 0;
}

.ai-section__hint {
  font-size: 0.85rem;
  color: var(--color-on-surface-faint);
  text-align: center;
}

.ai-section__graphic {
  display: flex;
  justify-content: center;
}

.ai-section__terminal {
  background: var(--color-code-bg);
  border-radius: var(--radius-sm);
  overflow: hidden;
  width: 100%;
  max-width: 460px;
  box-shadow: var(--shadow-lg);
}

.ai-section__terminal-dots {
  display: flex;
  gap: 6px;
  padding: 12px 16px;
  background: rgba(255,255,255,0.05);
}

.ai-section__terminal-dots span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.ai-section__terminal-dots span:nth-child(1) { background: #ff5f57; }
.ai-section__terminal-dots span:nth-child(2) { background: #febc2e; }
.ai-section__terminal-dots span:nth-child(3) { background: #28c840; }

.ai-section__terminal-body {
  padding: var(--space-lg);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-code-text);
  line-height: 2;
}

.ai-section__terminal-dim {
  opacity: 0.5;
}

/* ===== COMMUNITY ===== */
.community__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-lg);
  max-width: 640px;
  margin: 0 auto;
}

.community-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--space-md);
  padding: var(--space-2xl) var(--space-lg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-outline);
  background: var(--color-surface-container);
  transition: all var(--duration-medium) var(--ease-expressive);
}

.community-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.community-card--discord {
  color: #5865f2;
}
.community-card--discord:hover {
  border-color: rgba(88, 101, 242, 0.3);
  background: rgba(88, 101, 242, 0.04);
}

.community-card--github {
  color: var(--color-on-surface);
}
.community-card--github:hover {
  border-color: var(--color-primary-subtle);
  background: var(--color-primary-light);
}

.community-card h3 {
  font-size: 1.125rem;
  font-weight: 700;
}

.community-card p {
  color: var(--color-on-surface-dim);
  font-size: 0.9rem;
}

/* ===== FOOTER ===== */
.footer {
  padding: var(--space-2xl) 0;
  border-top: 1px solid var(--color-outline);
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer__brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--color-on-surface-dim);
}

.footer__links {
  display: flex;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

.footer__links a {
  font-size: 0.85rem;
  color: var(--color-on-surface-dim);
  transition: color var(--duration-short);
}

.footer__links a:hover {
  color: var(--color-primary);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .nav__hamburger {
    display: flex;
  }

  .nav__links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    flex-direction: column;
    background: var(--color-surface);
    padding: calc(var(--nav-height) + var(--space-lg)) var(--space-xl) var(--space-xl);
    box-shadow: var(--shadow-lg);
    transition: right var(--duration-medium) var(--ease-expressive);
    gap: var(--space-lg);
    z-index: 105;
  }

  .nav__links.open {
    right: 0;
  }

  .nav__link {
    font-size: 1rem;
  }

  .hero__container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--space-2xl);
  }

  .hero__actions {
    justify-content: center;
  }

  .hero__model {
    max-width: 360px;
    min-height: 300px;
    aspect-ratio: 1;
  }

  .ai-section__inner {
    grid-template-columns: 1fr;
  }

  .ai-section__content .section__title,
  .ai-section__content .section__subtitle {
    text-align: center;
  }

  .ai-section__content .section__subtitle {
    margin: 0 auto var(--space-lg);
  }

  .footer__inner {
    flex-direction: column;
    text-align: center;
  }

  .footer__links {
    justify-content: center;
  }

  .tabs__nav {
    width: 100%;
    overflow-x: auto;
    justify-content: flex-start;
  }
}

@media (max-width: 480px) {
  .hero__title {
    font-size: 2.25rem;
  }

  .btn {
    padding: 12px 20px;
    font-size: 0.9rem;
  }

  .code-block {
    font-size: 0.78rem;
    padding: var(--space-md);
  }

  .section {
    padding: var(--space-3xl) 0;
  }

  .hero__model {
    max-width: 300px;
    min-height: 260px;
  }
}

/* ===== MOBILE OVERLAY ===== */
.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  z-index: 101;
}

.nav-overlay.active {
  display: block;
}