/* Shared site chrome — header / nav / theme / lang
   Served from /css/site-chrome.css (main site nginx root).
   Expects theme tokens: --fg --muted --line --accent --bg-soft --menu-bg --header-bg --font-body
*/

.site-header {
  position: relative;
  z-index: 200;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem clamp(1.25rem, 4vw, 3rem);
  border-bottom: 1px solid var(--line);
  background: var(--header-bg);
  backdrop-filter: blur(10px);
  animation: site-chrome-fade-down 0.7s ease both;
}

.header-end {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  justify-self: end;
  flex-shrink: 0;
}

.theme-toggle {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.1rem;
  height: 2.1rem;
  padding: 0;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg-soft, var(--input-bg));
  color: var(--fg);
  cursor: pointer;
  font-family: var(--font-body);
  flex-shrink: 0;
  overflow: hidden;
}

.theme-toggle:hover {
  border-color: color-mix(in srgb, var(--accent) 45%, transparent);
  color: var(--accent);
}

.theme-toggle svg {
  position: absolute;
  inset: 0;
  margin: auto;
  width: 1.05rem;
  height: 1.05rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.75;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition:
    opacity 0.4s ease,
    transform 0.45s cubic-bezier(0.34, 1.4, 0.64, 1);
}

[data-theme="dark"] .theme-toggle .icon-sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="dark"] .theme-toggle .icon-moon {
  opacity: 0;
  transform: rotate(-70deg) scale(0.4);
  pointer-events: none;
}

[data-theme="light"] .theme-toggle .icon-moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="light"] .theme-toggle .icon-sun {
  opacity: 0;
  transform: rotate(70deg) scale(0.4);
  pointer-events: none;
}

.logo {
  display: grid;
  place-items: center;
  width: 2.5rem;
  height: 2.5rem;
  flex-shrink: 0;
  transition: opacity 0.2s ease;
}

.logo:hover {
  opacity: 0.75;
}

.logo img {
  display: block;
  width: 100%;
  height: 100%;
  transition: filter 0.45s ease;
}

[data-theme="light"] .logo img {
  filter: invert(1);
}

.nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: clamp(0.85rem, 2.5vw, 2rem);
}

.nav a,
.nav-dropdown > summary {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--muted);
  transition: color 0.2s ease;
}

.nav a:hover,
.nav-dropdown > summary:hover,
.nav-dropdown[open] > summary,
.nav-dropdown > summary[aria-current="page"] {
  color: var(--fg);
}

.nav > a[aria-current="page"] {
  color: var(--fg);
  box-shadow: inset 0 -2px 0 var(--accent);
}

.nav-dropdown > summary[aria-current="page"] {
  color: var(--muted);
  box-shadow: none;
}

.nav-dropdown {
  position: relative;
}

.nav-dropdown > summary {
  list-style: none;
  cursor: pointer;
  user-select: none;
  border-radius: 0.35rem;
  outline: none !important;
  box-shadow: none !important;
  -webkit-tap-highlight-color: transparent;
  color: var(--muted);
}

.nav-dropdown > summary::-webkit-details-marker {
  display: none;
}

.nav-dropdown > summary:focus,
.nav-dropdown > summary:focus-visible,
.nav-dropdown > summary:active {
  outline: none !important;
  box-shadow: none !important;
  color: var(--fg);
}

.nav-dropdown > summary::after {
  content: "";
  display: inline-block;
  margin-left: 0.35rem;
  border-left: 3.5px solid transparent;
  border-right: 3.5px solid transparent;
  border-top: 4.5px solid currentColor;
  vertical-align: middle;
  opacity: 0.7;
  transition: transform 0.2s ease;
}

.nav-dropdown[open] > summary::after {
  transform: rotate(180deg);
}

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 0.65rem);
  left: auto;
  right: 0;
  transform: none;
  min-width: 13.5rem;
  padding: 0.4rem;
  border: 1px solid var(--line);
  border-radius: 0.75rem;
  background: var(--menu-bg);
  backdrop-filter: blur(12px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.18);
  z-index: 300;
  display: grid;
  gap: 0.15rem;
  animation: site-chrome-dropdown-in 0.2s ease both;
}

.nav-dropdown-menu a {
  display: block;
  padding: 0.65rem 0.8rem;
  border-radius: 0.5rem;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--muted);
  white-space: nowrap;
  box-shadow: none !important;
  text-decoration: none !important;
  outline: none;
}

.nav-dropdown-menu a:hover,
.nav-dropdown-menu a:focus-visible {
  color: var(--fg);
  background: color-mix(in srgb, var(--fg) 6%, transparent);
}

.nav-dropdown-menu a[aria-current="page"] {
  color: var(--accent);
  background: color-mix(in srgb, var(--fg) 6%, transparent);
  box-shadow: none !important;
  text-decoration: none !important;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  height: 2.1rem;
  padding: 0.15rem;
  gap: 0.1rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg-soft, var(--input-bg));
  flex-shrink: 0;
}

.lang-switch .lang-sep {
  display: none;
}

.lang-switch a,
.lang-switch .lang-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.9rem;
  height: 100%;
  padding: 0 0.55rem;
  border: 0;
  border-radius: 999px;
  background: transparent;
  font-family: inherit;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--muted);
  cursor: pointer;
  transition:
    color 0.25s ease,
    background-color 0.25s ease;
}

.lang-switch a:hover,
.lang-switch .lang-btn:hover {
  color: var(--fg);
}

.lang-switch a[aria-current="true"],
.lang-switch .lang-btn[aria-current="true"] {
  color: var(--fg);
  background: color-mix(in srgb, var(--accent) 22%, transparent);
  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--accent) 35%, transparent);
}

@keyframes site-chrome-fade-down {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes site-chrome-dropdown-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 560px) {
  .site-header {
    gap: 0.5rem;
    padding-inline: 1rem;
  }

  .nav {
    gap: 0.55rem;
  }

  .nav a,
  .nav-dropdown > summary {
    font-size: 0.72rem;
  }

  .nav-dropdown-menu {
    left: auto;
    right: 0;
    transform: none;
    min-width: 11.5rem;
  }

  .nav-dropdown-menu a {
    font-size: 0.8rem;
    white-space: normal;
  }

  .lang-switch {
    height: 1.9rem;
  }

  .lang-switch a,
  .lang-switch .lang-btn {
    min-width: 1.7rem;
    padding: 0 0.45rem;
    font-size: 0.62rem;
  }

  .theme-toggle {
    width: 1.9rem;
    height: 1.9rem;
  }

  .theme-toggle svg {
    width: 0.95rem;
    height: 0.95rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .site-header,
  .nav-dropdown-menu {
    animation: none !important;
  }
}