.site-header {
  align-items: center;
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  backdrop-filter: blur(18px) saturate(160%);
  background: var(--header-bg);
  display: flex;
  gap: 24px;
  justify-content: space-between;
  padding: 14px clamp(20px, 4vw, 48px);
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--color-line);
}

.site-logo {
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 700;
}

.site-nav {
  align-items: center;
  display: flex;
  gap: 28px;
  margin-left: auto;
  white-space: nowrap;
}

.nav-zh {
  color: var(--color-muted);
  display: block;
  font-size: 14px;
  font-weight: 600;
  height: 22px;
  overflow: hidden;
  position: relative;
  transition: color 180ms ease;
  width: 80px;
}

.nav-zh span {
  display: block;
  height: 100%;
  transition: transform 280ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.nav-zh::before {
  color: inherit;
  content: attr(data-en);
  height: 100%;
  left: 0;
  position: absolute;
  top: 0;
  transform: translateY(100%);
  transition: transform 280ms cubic-bezier(0.2, 0.8, 0.2, 1);
  width: 100%;
}

.nav-zh:hover span {
  transform: translateY(-100%);
}

.nav-zh:hover::before {
  transform: translateY(0);
}

.nav-zh:hover {
  color: var(--color-text);
}

.nav-zh[aria-current="page"] {
  color: var(--color-text);
}

.site-nav a:hover {
  color: var(--color-text);
}

.nav-theme-toggle {
  display: none;
}

.theme-toggle {
  align-items: center;
  background: var(--color-panel);
  border: 1px solid var(--color-line);
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  height: 40px;
  justify-content: center;
  width: 40px;
  transition: background 200ms ease, border-color 200ms ease;
}

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

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  color: var(--color-text);
  display: none;
  transition: opacity 200ms ease, transform 200ms ease;
}

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

.menu-toggle {
  display: none;
  position: fixed;
  right: clamp(20px, 4vw, 48px);
  top: 14px;
  background: none;
  border: 1px solid var(--color-line);
  border-radius: 50%;
  cursor: pointer;
  height: 40px;
  padding: 8px;
  width: 40px;
  z-index: 100;
}

.menu-toggle svg {
  color: var(--color-text);
}

.menu-toggle .icon-hamburger {
  display: block;
}

.menu-toggle .icon-close {
  display: none;
}

.page-shell {
  margin: 0 auto;
  max-width: var(--max-content);
  padding: 96px clamp(20px, 4vw, 48px);
  width: 100%;
}

.site-footer {
  align-items: center;
  border-top: 1px solid var(--color-line);
  color: var(--color-muted-strong);
  display: flex;
  font-size: 14px;
  justify-content: space-between;
  margin: 48px auto 0;
  max-width: var(--max-content);
  padding: 28px clamp(20px, 4vw, 48px) 40px;
  background: transparent;
}

@media (max-width: 720px) {
  .site-header {
    align-items: flex-start;
    -webkit-backdrop-filter: blur(16px) saturate(160%);
    backdrop-filter: blur(16px) saturate(160%);
    flex-wrap: wrap;
    gap: 12px;
    padding: 10px clamp(18px, 5vw, 24px);
  }

  .site-logo {
    font-size: 21px;
    line-height: 40px;
  }

  .menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    right: clamp(18px, 5vw, 24px);
    top: 10px;
  }

  .menu-toggle svg {
    color: var(--color-text);
  }

  html.menu-open .menu-toggle .icon-hamburger,
  html:not(.menu-open) .menu-toggle .icon-close {
    display: none;
  }

  html:not(.menu-open) .menu-toggle .icon-hamburger,
  html.menu-open .menu-toggle .icon-close {
    display: block;
  }

  .site-nav {
    align-items: flex-end;
    align-self: flex-end;
    flex-basis: 100%;
    max-height: 0;
    overflow: hidden;
    flex-direction: column;
    gap: 16px;
    width: 100%;
    padding: 0;
    border-top: 1px solid transparent;
    margin-left: auto;
    margin-top: 0;
    opacity: 0;
    pointer-events: none;
    transform: translateX(18px) scaleX(0.96);
    transform-origin: right top;
    transition: max-height 300ms ease, padding 300ms ease, border-color 300ms ease,
      margin-top 300ms ease, opacity 220ms ease,
      transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
  }

  .site-nav.open {
    display: flex;
    align-items: flex-end;
    flex-direction: column;
    max-height: 400px;
    padding: 18px 0 12px;
    border-top-color: var(--color-line);
    margin-top: 12px;
    opacity: 1;
    pointer-events: auto;
    transform: translateX(0) scaleX(1);
  }

  .nav-zh {
    width: min(220px, calc(100vw - 40px));
    height: auto;
    font-size: 18px;
    display: block;
    overflow: visible;
    color: var(--color-text);
    text-align: right;
  }

  .nav-zh span {
    display: block;
    height: auto;
    transform: none;
    text-align: right;
  }

  .nav-zh::before {
    display: none;
  }

  .nav-zh:hover span {
    transform: none;
  }

  .nav-zh:hover::before {
    transform: none;
  }

  .nav-theme-toggle {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 0 0;
    border-top: 1px solid var(--color-line);
    margin-top: 8px;
    width: min(220px, calc(100vw - 40px));
    justify-content: flex-end;
  }

  .nav-theme-toggle button {
    background: var(--color-panel);
    border: 1px solid var(--color-line);
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 40px;
    width: 40px;
  }

  .nav-theme-toggle .icon-sun,
  .nav-theme-toggle .icon-moon {
    color: var(--color-text);
    display: none;
    margin: 0 auto;
  }

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

  .theme-toggle {
    display: none;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    gap: 16px;
  }
}