/* 全站统一顶部导航栏（最后加载，规格锁定） */
:root {
  --nav-h: 64px;
  --nav-font: "Noto Sans SC", system-ui, -apple-system, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  --nav-display: "Space Grotesk", "Noto Sans SC", system-ui, sans-serif;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

header.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h) !important;
  min-height: var(--nav-h) !important;
  max-height: var(--nav-h) !important;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 40px !important;
  box-sizing: border-box;
  background: rgba(255, 255, 255, 0.9);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  backdrop-filter: blur(20px) saturate(160%);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.08);
  transition: background 0.25s ease, box-shadow 0.25s ease, backdrop-filter 0.25s ease;
  overflow: visible;
}

header.navbar > nav {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  min-width: 0;
}

header.navbar .logo {
  flex-shrink: 0;
  text-decoration: none;
  white-space: nowrap;
}

header.navbar .logo-text {
  color: #111;
}

header.navbar .nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  flex-shrink: 0;
  list-style: none;
  margin: 0;
  padding: 0;
}

header.navbar .nav-links a {
  position: relative;
  font-family: var(--nav-font) !important;
  font-size: 15px !important;
  font-weight: 500 !important;
  line-height: 1 !important;
  color: #111;
  white-space: nowrap;
  text-decoration: none;
  transition: opacity 0.2s ease, color 0.2s ease;
}

header.navbar .nav-links a:hover {
  opacity: 0.5;
}

header.navbar .nav-links a.active::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -22px;
  height: 2px;
  background: #111;
  border-radius: 2px;
}

header.navbar .nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-shrink: 0;
}

header.navbar .cta-button {
  background: #111 !important;
  color: #fff !important;
  padding: 8px 18px !important;
  border-radius: 6px;
  font-family: var(--nav-font) !important;
  font-size: 14px !important;
  font-weight: 600 !important;
  line-height: 1 !important;
  white-space: nowrap;
  text-decoration: none;
  transition: opacity 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  border: none;
}

header.navbar .cta-button:hover {
  opacity: 0.75;
}

header.navbar .lang-switch {
  display: inline-flex;
  align-items: center;
  background: #f0f0f0;
  border: 1px solid #ddd;
  border-radius: 20px;
  padding: 2px;
  flex-shrink: 0;
}

header.navbar .lang-switch button {
  font-family: var(--nav-font) !important;
  font-size: 13px !important;
  font-weight: 600 !important;
  line-height: 1 !important;
  padding: 4px 12px !important;
  border-radius: 18px;
  color: #888;
  border: none;
  background: none;
  cursor: pointer;
  transition: all 0.2s ease;
}

header.navbar .lang-switch button.active {
  background: #111 !important;
  color: #fff !important;
}

header.navbar .hamburger {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 22px;
  height: 16px;
  padding: 0;
  border: none;
  background: none;
  cursor: pointer;
  flex-shrink: 0;
}

header.navbar .hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: #111;
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease, background 0.25s ease;
}

header.navbar .hamburger.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

header.navbar .hamburger.open span:nth-child(2) {
  opacity: 0;
}

header.navbar .hamburger.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.mobile-menu {
  position: fixed;
  top: var(--nav-h);
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  backdrop-filter: blur(20px) saturate(160%);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
  transform: translateY(-10px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 999;
}

.mobile-menu.open {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.mobile-menu a {
  display: block;
  padding: 16px 32px;
  font-family: var(--nav-font);
  font-size: 16px;
  font-weight: 500;
  line-height: 1.4;
  color: #111;
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

.mobile-menu a.mobile-cta {
  background: #111;
  color: #fff;
  border-bottom: none;
}

/* 首页首屏：透明导航，滚动后变白底 */
header.navbar.navbar--overlay {
  background: transparent;
  box-shadow: none;
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
}

header.navbar.navbar--overlay .logo-text,
header.navbar.navbar--overlay .nav-links a {
  color: rgba(255, 255, 255, 0.9);
}

header.navbar.navbar--overlay .nav-links a.active::after {
  background: #fff;
}

header.navbar.navbar--overlay .cta-button {
  background: rgba(255, 255, 255, 0.15) !important;
  border: 1px solid rgba(255, 255, 255, 0.3) !important;
  color: #fff !important;
}

header.navbar.navbar--overlay .lang-switch {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.22);
}

header.navbar.navbar--overlay .lang-switch button {
  color: rgba(255, 255, 255, 0.7);
}

header.navbar.navbar--overlay .lang-switch button.active {
  background: rgba(255, 255, 255, 0.2) !important;
  color: #fff !important;
}

header.navbar.navbar--overlay .hamburger span {
  background: #fff;
}

header.navbar.navbar--overlay.scrolled {
  background: rgba(255, 255, 255, 0.9);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  backdrop-filter: blur(20px) saturate(160%);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.08);
}

header.navbar.navbar--overlay.scrolled .logo-text,
header.navbar.navbar--overlay.scrolled .nav-links a {
  color: #111;
}

header.navbar.navbar--overlay.scrolled .nav-links a.active::after {
  background: #111;
}

header.navbar.navbar--overlay.scrolled .cta-button {
  background: #111 !important;
  border: none !important;
  color: #fff !important;
}

header.navbar.navbar--overlay.scrolled .lang-switch {
  background: #f0f0f0;
  border-color: #ddd;
}

header.navbar.navbar--overlay.scrolled .lang-switch button {
  color: #888;
}

header.navbar.navbar--overlay.scrolled .lang-switch button.active {
  background: #111 !important;
  color: #fff !important;
}

header.navbar.navbar--overlay.scrolled .hamburger span {
  background: #111;
}

@media (max-width: 860px) {
  header.navbar {
    padding: 0 20px !important;
  }

  header.navbar > nav,
  header.navbar .nav-links,
  header.navbar .nav-right .cta-button,
  header.navbar .nav-right .lang-switch {
    display: none;
  }

  header.navbar .hamburger {
    display: flex;
  }
}