/* The Human Need — site header (see components/site-header.tsx)
   Fixed, scroll-aware header used across all pages. On the home page it overlays
   the hero (transparent → glass on scroll); on other pages it is solid. Tokens
   come from /styles/tokens.css. */

:root {
  --header-h: 76px;
  --header-h-scrolled: 60px;
  --header-z: 100;
}

.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: var(--header-z);
  height: var(--header-h);
  display: flex;
  align-items: center;
  border-bottom: 1px solid transparent;
  background: transparent;
  transition: height var(--dur) var(--ease), background-color var(--dur) var(--ease),
    border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease), backdrop-filter var(--dur) var(--ease);
}

.site-header__inner {
  width: min(var(--max), calc(100% - 2 * var(--gutter)));
  margin: 0 auto;
  /* Left lockup: logo + nav cluster together on the left, CTA pushed to the far
     right. The tight logo↔nav grouping is what stops the bar reading as empty. */
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
}

.site-header__logo {
  display: block;
  width: 108px;
  height: auto;
  transition: width var(--dur) var(--ease);
}

.site-header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  /* Editorial nav: small-caps display serif with open tracking reads as a
     considered masthead label, not a bare utility link, at a compact size. */
  font-family: var(--font-display);
  font-variant: small-caps;
  font-size: var(--text-sm);
  letter-spacing: 0.09em;
  line-height: 1;
}

.site-header__nav a {
  position: relative;
  padding-bottom: 2px;
  color: var(--ink);
  transition: color var(--dur-fast) var(--ease);
}

.site-header__nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur) var(--ease);
}

.site-header__nav a:hover::after,
.site-header__nav a:focus-visible::after {
  transform: scaleX(1);
}

/* Current page: clay accent + a persistent underline so it reads as "you are
   here" even at rest, distinct from the ink-coloured hover underline. */
.site-header__nav a.is-active {
  color: var(--clay-ink);
}

.site-header__nav a.is-active::after {
  transform: scaleX(1);
  background: var(--clay);
}

.site-header__nav a:focus-visible {
  outline: 2px solid var(--sage);
  outline-offset: 4px;
  border-radius: 2px;
}

.site-header__tools {
  margin-left: auto;
  flex: 0 0 auto;
}

.site-header__cta {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  padding: 0.5rem 1rem 0.5rem 1.1rem;
  border: 1px solid var(--clay);
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--clay-ink);
  font-family: var(--font-thai);
  font-size: var(--text-sm);
  line-height: 1;
  white-space: nowrap;
  transition: background-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease),
    transform var(--dur-fast) var(--ease);
}

.site-header__cta:hover {
  background: var(--clay);
  color: var(--on-sage);
  transform: translateY(-1px);
}

.site-header__cta:active {
  transform: translateY(1px);
}

.site-header__cta:focus-visible {
  outline: 2px solid var(--clay);
  outline-offset: 3px;
}

/* Hamburger */
.site-header__burger {
  display: none;
  width: 44px;
  height: 44px;
  margin-left: auto;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.site-header__burger span {
  display: block;
  width: 22px;
  height: 2px;
  border-radius: 2px;
  background: var(--ink);
  transition: transform var(--dur) var(--ease), opacity var(--dur-fast) var(--ease);
}

.site-header__burger:focus-visible {
  outline: 2px solid var(--sage);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

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

.site-header.is-open .site-header__burger span:nth-child(2) {
  opacity: 0;
}

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

/* Scrolled / solid backgrounds (glass) */
.site-header.is-scrolled,
.site-header.is-solid {
  height: var(--header-h-scrolled);
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom-color: var(--line);
}

.site-header.is-scrolled {
  box-shadow: 0 8px 28px -22px rgba(30, 27, 23, 0.55);
}

.site-header.is-scrolled .site-header__logo,
.site-header.is-solid .site-header__logo {
  width: 88px;
}

/* An overlay header that is also open needs a readable backdrop */
.site-header.is-overlay.is-open {
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

/* Spacer pushes solid-header pages' content below the fixed header */
.site-header__spacer {
  height: var(--header-h);
}

/* ---- Mobile menu panel ---- */
.site-menu {
  position: fixed;
  top: var(--header-h);
  left: 0;
  right: 0;
  z-index: calc(var(--header-z) - 1);
  padding: var(--space-4) var(--gutter) var(--space-6);
  background: color-mix(in srgb, var(--paper) 96%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
  transform: translateY(-12px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease), visibility 0s linear var(--dur);
}

.site-menu.is-open {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease), visibility 0s;
}

.site-menu__nav {
  display: flex;
  flex-direction: column;
}

.site-menu__nav a {
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  font-family: var(--font-display);
  font-size: var(--text-xl);
}

.site-menu__nav a.is-active {
  color: var(--clay-ink);
  font-style: italic;
}

.site-menu__nav a:focus-visible {
  outline: 2px solid var(--sage);
  outline-offset: 2px;
}

.site-menu__cta {
  margin-top: var(--space-5);
  border-bottom: 0 !important;
  color: var(--clay-ink) !important;
  font-family: var(--font-thai) !important;
  font-size: var(--text-base) !important;
}

.site-menu__scrim {
  position: fixed;
  inset: 0;
  z-index: calc(var(--header-z) - 2);
  border: 0;
  padding: 0;
  background: rgba(30, 27, 23, 0.28);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity var(--dur) var(--ease), visibility 0s linear var(--dur);
}

.site-menu__scrim.is-open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transition: opacity var(--dur) var(--ease), visibility 0s;
}

/* ---- Responsive ---- */
@media (max-width: 860px) {
  :root {
    --header-h: 64px;
    --header-h-scrolled: 56px;
  }

  /* On mobile the overlay (home) header is not transparent — give it the same
     glass background as the solid header from the top. */
  .site-header.is-overlay {
    background: color-mix(in srgb, var(--paper) 82%, transparent);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom-color: var(--line);
  }

  .site-header__nav,
  .site-header__tools {
    display: none;
  }

  .site-header__burger {
    display: flex;
  }

  .site-header__logo {
    width: 92px;
  }

  .site-header.is-scrolled .site-header__logo,
  .site-header.is-solid .site-header__logo {
    width: 80px;
  }
}

@media (min-width: 861px) {
  .site-menu,
  .site-menu__scrim {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .site-header,
  .site-header__logo,
  .site-header__nav a::after,
  .site-header__burger span,
  .site-header__cta,
  .site-menu,
  .site-menu__scrim {
    transition: none;
  }
}