:root {
  --yt-canvas: #f7f7f8;
  --yt-ink: #202123;
  --yt-secondary: #6b7280;
  --yt-tertiary: rgba(32, 33, 35, .52);
  --yt-brand: #4f46e5;
  --yt-brand-hover: #4338ca;
  --yt-brand-active: #3730a3;
  --yt-brand-soft: rgba(79, 70, 229, .10);
  --yt-brand-focus: rgba(79, 70, 229, .18);
  --yt-hairline: rgba(32, 33, 35, .12);
  --yt-glass: rgba(255, 255, 255, .68);
  --yt-glass-strong: rgba(255, 255, 255, .82);
  --yt-radius-control: 14px;
  --yt-radius-card: 28px;
  --yt-radius-shell: 22px;
  --yt-shadow-float: 0 20px 60px rgba(31, 35, 48, .10), inset 0 1px 0 rgba(255, 255, 255, .72);
}

html { background: var(--yt-canvas); }

body.home-page,
body.models-page {
  color: var(--yt-ink);
  background:
    radial-gradient(circle at 12% 4%, rgba(224, 231, 255, .72), transparent 32rem),
    radial-gradient(circle at 86% 16%, rgba(199, 210, 254, .48), transparent 34rem),
    radial-gradient(circle at 56% 72%, rgba(238, 242, 255, .56), transparent 38rem),
    var(--yt-canvas);
  font-family: var(--yt-font);
}

body.home-page::before,
body.models-page::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(255,255,255,.7), rgba(255,255,255,.18) 36%, rgba(245,245,247,.72));
}

/* The same floating navigation material is shared by the homepage and model page. */
.home-page .main-nav,
.models-page .site-header {
  position: fixed;
  top: max(18px, env(safe-area-inset-top));
  left: 50%;
  z-index: 1000;
  width: min(1280px, calc(100% - 40px));
  padding: 0;
  transform: translateX(-50%);
  border: 1px solid rgba(255, 255, 255, .78);
  border-radius: var(--yt-radius-shell);
  background: var(--yt-glass);
  box-shadow: var(--yt-shadow-float);
  -webkit-backdrop-filter: blur(28px) saturate(180%);
  backdrop-filter: blur(28px) saturate(180%);
  overflow: visible;
}

.home-page .main-nav::before,
.models-page .site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  border-radius: inherit;
  pointer-events: none;
  background: linear-gradient(120deg, rgba(255,255,255,.56), rgba(255,255,255,.08) 48%, rgba(255,255,255,.3));
}

.home-page .main-nav.scrolled { background: rgba(255, 255, 255, .78); }
.home-page .main-nav > .container { max-width: none; }
.models-page .site-header.shell { margin: 0; }
.models-page .site-header .nav {
  min-height: 64px;
  padding: 9px 12px 9px 20px;
  border: 0;
  border-radius: inherit;
  background: transparent;
  box-shadow: none;
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
}
.models-page .model-language-toggle {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 7px;
  padding: 0 10px;
  border: 0;
  border-radius: 12px;
  color: rgba(29,29,31,.72);
  background: transparent;
  cursor: pointer;
  font: inherit;
  font-size: 14px;
  font-weight: 600;
}
.models-page .model-language-toggle:hover { color: var(--yt-ink); background: rgba(255,255,255,.64); }
.models-page .model-language-toggle svg { width: 15px; height: 15px; fill: none; stroke: currentColor; stroke-width: 1.7; }
.models-page .button.primary.compact { box-shadow: 0 8px 22px rgba(79, 70, 229, .22); }

.home-page .logo-container,
.models-page .brand { color: var(--yt-ink); font-weight: 700; }
.home-page .nav-item,
.models-page .nav-links { color: rgba(29,29,31,.76); }
.home-page .nav-item:hover,
.models-page .nav-links a:hover { color: var(--yt-ink); background: rgba(255,255,255,.7); }

.home-page .hero-section,
.models-page .hero {
  min-height: auto;
  padding-top: clamp(150px, 17vw, 238px);
}

.home-page .hero-section { padding-bottom: 108px; }
.home-page .main-title,
.models-page h1 {
  color: var(--yt-ink);
  font-size: clamp(48px, 6.3vw, 84px);
  font-weight: 720;
  letter-spacing: -.055em;
  line-height: 1.02;
}

.home-page .main-subtitle,
.models-page .hero-copy { color: var(--yt-secondary); }
.home-page .model-mark,
.models-page .model-badge { color: rgba(29,29,31,.8); }
.home-page .model-mark .ai-model-icon,
.models-page .model-badge img,
.models-page .model-logo { background: transparent !important; border: 0 !important; box-shadow: none !important; }

.home-page .search-input {
  min-height: 64px;
  border-color: rgba(255,255,255,.84);
  background: rgba(255,255,255,.76);
  box-shadow: 0 18px 46px rgba(31,35,48,.10), inset 0 1px 0 #fff;
  -webkit-backdrop-filter: blur(24px) saturate(170%);
  backdrop-filter: blur(24px) saturate(170%);
}
.home-page .search-input:focus { border-color: rgba(79, 70, 229, .44); box-shadow: 0 20px 52px rgba(31,35,48,.13), 0 0 0 4px var(--yt-brand-focus); }
.home-page .secondary-button,
.models-page .button.secondary { border-color: rgba(255,255,255,.76); background: rgba(255,255,255,.64); box-shadow: 0 10px 30px rgba(31,35,48,.07), inset 0 1px 0 rgba(255,255,255,.8); }
.home-page .secondary-button.primary-cta,
.models-page .button.primary {
  color: #fff;
  border-color: transparent;
  background: var(--yt-brand);
  box-shadow: 0 12px 28px rgba(79, 70, 229, .24);
}
.home-page .secondary-button.primary-cta:hover,
.models-page .button.primary:hover {
  color: #fff;
  border-color: transparent;
  background: var(--yt-brand-hover);
  box-shadow: 0 16px 34px rgba(79, 70, 229, .30);
}
.home-page .secondary-button.primary-cta:active,
.models-page .button.primary:active { background: var(--yt-brand-active); }
.home-page .secondary-button.primary-cta:focus-visible,
.models-page .button.primary:focus-visible {
  outline: 3px solid var(--yt-brand-focus);
  outline-offset: 3px;
}

.home-page .fluid-background { opacity: .42; }
.home-page .light-streaks,
.home-page .floating-particles { opacity: .12; }
.home-page .section-container { padding: clamp(78px, 9vw, 132px) 20px; }
.home-page .section-title,
.models-page h2 { color: var(--yt-ink); font-weight: 700; letter-spacing: -.045em; }
.home-page .feature-card,
.home-page .professional-content-card,
.models-page .capability-card,
.models-page .model-panel,
.models-page .route-item {
  border-color: rgba(255,255,255,.78);
  background: rgba(255,255,255,.60);
  box-shadow: 0 22px 64px rgba(31,35,48,.08), inset 0 1px 0 rgba(255,255,255,.78);
  -webkit-backdrop-filter: blur(24px) saturate(165%);
  backdrop-filter: blur(24px) saturate(165%);
}
.home-page .feature-card:hover { transform: translateY(-4px); box-shadow: 0 26px 70px rgba(31,35,48,.11); }

/* Homepage idea-to-delivery section: product story first, SEO information second. */
.journey-section { overflow: hidden; }
.journey-heading { max-width: 760px; margin: 0 auto 44px; text-align: center; }
.journey-heading .section-title { margin-bottom: 16px; }
.journey-intro { color: var(--yt-secondary); font-size: 18px; line-height: 1.65; }
.journey-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.journey-card {
  min-height: 280px;
  padding: 30px;
  text-align: left;
  border: 1px solid rgba(255,255,255,.82);
  border-radius: var(--yt-radius-card);
  background: rgba(255,255,255,.62);
  box-shadow: 0 22px 64px rgba(31,35,48,.08), inset 0 1px 0 rgba(255,255,255,.78);
  -webkit-backdrop-filter: blur(24px) saturate(165%);
  backdrop-filter: blur(24px) saturate(165%);
}
.journey-icon { display: grid; width: 48px; height: 48px; margin-bottom: 44px; place-items: center; border-radius: 15px; color: var(--yt-brand); background: var(--yt-brand-soft); font-size: 19px; }
.journey-card h3 { margin-bottom: 10px; color: var(--yt-ink); font-size: 22px; letter-spacing: -.025em; }
.journey-card p { margin: 0; color: var(--yt-secondary); line-height: 1.7; }
.journey-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-top: 24px; }
.journey-links a { display: inline-flex; min-height: 44px; align-items: center; gap: 8px; padding: 0 16px; border: 1px solid var(--yt-hairline); border-radius: 999px; color: var(--yt-brand); background: rgba(255,255,255,.48); font-size: 14px; font-weight: 600; }
.journey-links a:hover { background: rgba(255,255,255,.8); }
.journey-faq { max-width: 900px; margin: 92px auto 0; text-align: left; }
.journey-faq > h3 { margin-bottom: 20px; text-align: center; font-size: clamp(30px, 4vw, 44px); letter-spacing: -.04em; }
.journey-faq details { border-top: 1px solid var(--yt-hairline); }
.journey-faq details:last-child { border-bottom: 1px solid var(--yt-hairline); }
.journey-faq summary { display: flex; min-height: 72px; align-items: center; justify-content: space-between; gap: 20px; color: var(--yt-ink); cursor: pointer; list-style: none; font-size: 17px; font-weight: 650; }
.journey-faq summary::-webkit-details-marker { display: none; }
.journey-faq summary::after { content: "+"; color: var(--yt-tertiary); font-size: 24px; font-weight: 400; transition: transform .22s ease; }
.journey-faq details[open] summary::after { transform: rotate(45deg); }
.journey-faq details p { max-width: 760px; margin: -4px 0 24px; color: var(--yt-secondary); line-height: 1.75; }

/* Model page shares the same rhythm, material, typography and shell. */
.models-page .capability-card .index { color: var(--yt-brand); }
.models-page .gradient-text { color: var(--yt-ink); background: none; -webkit-text-fill-color: currentColor; }
.models-page .capability-card h3 { margin-top: 34px; }
.models-page .model-panel { border-radius: var(--yt-radius-card); }
.models-page .tag { border-color: var(--yt-hairline); background: rgba(255,255,255,.52); }
.models-page .route-number { background: var(--yt-ink); }
.models-page .final-cta { background: linear-gradient(130deg, #202123, #312e81 62%, #4f46e5); box-shadow: 0 28px 80px rgba(49,46,129,.24); }
.models-page .final-cta h2 { color: #fff; }

@media (max-width: 900px) {
  .journey-grid { grid-template-columns: 1fr; }
  .journey-card { min-height: 0; }
  .journey-icon { margin-bottom: 30px; }
}

@media (max-width: 768px) {
  .home-page .main-nav,
  .models-page .site-header { top: max(8px, env(safe-area-inset-top)); width: calc(100% - 24px); border-radius: 18px; }
  .home-page .hero-section,
  .models-page .hero { padding-top: 126px; }
  .home-page .main-title,
  .models-page h1 { font-size: clamp(42px, 13vw, 62px); }
  .home-page .section-container { padding: 72px 12px; }
  .journey-heading { margin-bottom: 30px; }
  .journey-card { padding: 24px; border-radius: 24px; }
  .journey-faq { margin-top: 68px; }
  .journey-faq summary { min-height: 66px; font-size: 16px; }
}

@media (prefers-reduced-motion: reduce) {
  .journey-faq summary::after { transition: none; }
}