:root {
  --detail-header-bg: oklch(1 0 0 / 0.96);
  --detail-ink: oklch(0.17 0.026 160);
  --detail-muted: oklch(0.42 0.028 160);
  --detail-green: oklch(0.36 0.135 145);
  --detail-accent: oklch(0.24 0.07 160);
  --detail-line: oklch(0.88 0.014 150 / 0.92);
  --detail-inline: clamp(20px, 5vw, 72px);
  --detail-header-offset: 94px;
}

body.product-detail-page {
  padding-top: var(--detail-header-offset);
}

.product-site-header,
.product-site-header * {
  box-sizing: border-box;
}

.product-site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 40;
  font-family: Arial, "Microsoft YaHei", sans-serif;
  line-height: 1.2;
}

.product-site-header a {
  color: inherit;
  text-decoration: none;
}

.product-site-header .header-inner {
  display: grid;
  grid-template-columns: minmax(180px, 240px) 1fr auto;
  align-items: center;
  gap: 30px;
  width: 100%;
  padding: 14px var(--detail-inline);
  border-bottom: 1px solid var(--detail-line);
  background: var(--detail-header-bg);
  box-shadow: 0 14px 30px oklch(0.17 0.026 160 / 0.08);
  backdrop-filter: blur(16px);
}

.product-site-header .brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
  min-width: 0;
}

.product-site-header .brand-logo {
  display: block;
  width: clamp(172px, 14vw, 220px);
  max-height: 50px;
  object-fit: contain;
}

.product-site-header .brand-meta {
  color: var(--detail-muted);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.16em;
  opacity: 0.86;
}

.product-site-header .site-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(10px, 1.5vw, 22px);
  min-width: 0;
}

.product-site-header .site-nav-item {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 46px;
}

.product-site-header .site-nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 40px;
  padding: 0 4px;
  border-radius: 6px;
  color: var(--detail-muted);
  font-size: 14px;
  font-weight: 700;
  white-space: nowrap;
  transition: color 180ms ease, transform 180ms ease;
}

.product-site-header .site-nav-link::before {
  position: absolute;
  inset: 4px -10px;
  border-radius: inherit;
  background: oklch(0.955 0.034 145 / 0.9);
  content: "";
  opacity: 0;
  transition: opacity 180ms ease;
}

.product-site-header .site-nav-link::after {
  position: absolute;
  right: 4px;
  bottom: 4px;
  left: 4px;
  height: 2px;
  border-radius: 999px;
  background: var(--detail-green);
  content: "";
  opacity: 0;
  transform: scaleX(0.35);
  transition: opacity 180ms ease, transform 180ms ease;
}

.product-site-header .site-nav-link > span {
  position: relative;
  z-index: 1;
}

.product-site-header .site-nav-link:hover,
.product-site-header .site-nav-item:focus-within .site-nav-link,
.product-site-header .site-nav-link.is-active {
  color: var(--detail-green);
  transform: translateY(-1px);
}

.product-site-header .site-nav-link:hover::before,
.product-site-header .site-nav-item:focus-within .site-nav-link::before,
.product-site-header .site-nav-link.is-active::before,
.product-site-header .site-nav-link:hover::after,
.product-site-header .site-nav-item:focus-within .site-nav-link::after,
.product-site-header .site-nav-link.is-active::after {
  opacity: 1;
  transform: scaleX(1);
}

.product-site-header .nav-caret {
  width: 7px;
  height: 7px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: translateY(-2px) rotate(45deg);
  opacity: 0.64;
}

.product-site-header .site-nav-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  left: 50%;
  display: grid;
  min-width: 180px;
  padding: 10px;
  border: 1px solid var(--detail-line);
  border-radius: 12px;
  background: oklch(1 0 0 / 0.98);
  box-shadow: 0 18px 42px oklch(0.17 0.026 160 / 0.14);
  opacity: 0;
  pointer-events: none;
  transform: translate3d(-50%, 8px, 0) scale(0.98);
  visibility: hidden;
  transition: opacity 180ms ease, transform 220ms cubic-bezier(0.16, 1, 0.3, 1);
}

.product-site-header .site-nav-dropdown::before {
  position: absolute;
  top: -12px;
  right: 0;
  left: 0;
  height: 12px;
  content: "";
}

.product-site-header .site-nav-item:hover .site-nav-dropdown,
.product-site-header .site-nav-item:focus-within .site-nav-dropdown {
  opacity: 1;
  pointer-events: auto;
  transform: translate3d(-50%, 0, 0) scale(1);
  visibility: visible;
}

.product-site-header .site-nav-item:last-child .site-nav-dropdown {
  right: 0;
  left: auto;
  transform: translate3d(0, 8px, 0) scale(0.98);
}

.product-site-header .site-nav-item:last-child:hover .site-nav-dropdown,
.product-site-header .site-nav-item:last-child:focus-within .site-nav-dropdown {
  transform: translate3d(0, 0, 0) scale(1);
}

.product-site-header .site-nav-dropdown__link {
  display: flex;
  align-items: center;
  min-height: 38px;
  padding: 0 12px;
  border-radius: 8px;
  color: oklch(0.31 0.028 160);
  font-size: 13px;
  font-weight: 800;
  white-space: nowrap;
}

.product-site-header .site-nav-dropdown__link:hover,
.product-site-header .site-nav-dropdown__link:focus-visible {
  background: oklch(0.955 0.034 145 / 0.9);
  color: var(--detail-green);
}

.product-site-header .header-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 14px;
}

.product-site-header .language-switcher {
  position: relative;
  display: inline-flex;
  color: var(--detail-muted);
  font-size: 12px;
  font-weight: 800;
  white-space: nowrap;
}

.product-site-header .language-switcher__trigger {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 38px;
  padding: 0 12px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: inherit;
  font: inherit;
  cursor: pointer;
}

.product-site-header .language-switcher__menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  display: grid;
  min-width: 132px;
  padding: 8px;
  border: 1px solid var(--detail-line);
  border-radius: 8px;
  background: oklch(1 0 0 / 0.98);
  box-shadow: 0 12px 28px oklch(0.16 0.026 160 / 0.12);
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 180ms ease, transform 180ms ease;
}

.product-site-header .language-switcher:hover .language-switcher__menu,
.product-site-header .language-switcher:focus-within .language-switcher__menu {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.product-site-header .language-switcher__link {
  display: flex;
  align-items: center;
  min-height: 34px;
  padding: 0 10px;
  border-radius: 6px;
}

.product-site-header .language-switcher__link:hover,
.product-site-header .language-switcher__link:focus-visible,
.product-site-header .language-switcher__link.is-active {
  background: oklch(0.96 0.024 145);
  color: var(--detail-green);
}

.product-site-header .quote-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 999px;
  background: var(--detail-accent);
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  box-shadow: 0 7px 16px oklch(0.24 0.07 160 / 0.15);
  transition: transform 180ms ease;
}

.product-site-header .quote-link:hover,
.product-site-header .quote-link:focus-visible {
  transform: translateY(-2px);
}

.product-detail-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 22px;
  margin-top: 36px;
  padding: 18px 0 24px;
  border-top: 1px solid var(--detail-line);
  color: oklch(0.42 0.016 245);
  font-size: 13px;
  line-height: 1.6;
  text-align: center;
}

@media (max-width: 1040px) {
  :root { --detail-header-offset: 158px; }
  .product-site-header .header-inner { grid-template-columns: 1fr auto; align-items: start; }
  .product-site-header .site-nav { grid-column: 1 / -1; justify-content: flex-start; flex-wrap: wrap; }
}

@media (max-width: 700px) {
  :root { --detail-header-offset: 240px; }
  .product-site-header .header-inner { grid-template-columns: 1fr; gap: 14px; }
  .product-site-header .header-actions { justify-content: flex-start; }
  .product-site-header .site-nav { flex-wrap: nowrap; overflow-x: auto; padding: 4px 0; }
  .product-site-header .brand-logo { width: 172px; }
  .product-detail-footer { justify-content: flex-start; text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  .product-site-header *,
  .product-site-header *::before,
  .product-site-header *::after { transition-duration: 0.01ms !important; }
}