/* =========================================================
   ARB KHAO — header.css (site header, every page)
   Markup: _dev/partials/header.html
   ========================================================= */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  color: var(--white);
  transition: background .5s var(--ease), color .5s var(--ease), transform .5s var(--ease);
}
.site-header__inner { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; height: 76px; border-bottom: 1px solid var(--line-light); }
.site-header.is-solid { background: rgba(251, 250, 247, .94); color: var(--ink); backdrop-filter: blur(10px); }
.site-header.is-solid .site-header__inner { border-bottom-color: var(--line); }
.site-header.is-hidden { transform: translateY(-100%); }

/* logo */
.brand { display: inline-flex; align-items: center; gap: 12px; justify-self: start; }
.brand__mark { width: 46px; height: 46px; flex: none; padding: 1px; border-radius: 50%; background: var(--cream-2); box-shadow: 0 4px 18px rgba(20, 24, 18, .18); }
.brand__mark img { width: 100%; height: 100%; }
.brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name { font-size: 16px; font-weight: 500; letter-spacing: .26em; }
.brand__sub { font-size: 8.5px; font-weight: 400; letter-spacing: .34em; text-transform: uppercase; opacity: .75; margin-top: 3px; }

/* page links */
.main-nav { display: flex; align-items: center; gap: clamp(18px, 2.6vw, 44px); }
.main-nav a { position: relative; padding: 6px 0; font-size: 14px; font-weight: 400; letter-spacing: .02em; opacity: .85; transition: opacity .3s; }
html[lang="en"] .main-nav a { font-size: var(--fs-label); font-weight: 500; letter-spacing: .12em; text-transform: uppercase; }
.main-nav a::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 1px; background: currentColor; transform: scaleX(0); transform-origin: right; transition: transform .5s var(--ease); }
.main-nav a:hover, .main-nav a[aria-current="page"] { opacity: 1; }
.main-nav a:hover::after, .main-nav a[aria-current="page"]::after { transform: scaleX(1); transform-origin: left; }

/* language + book */
.header-actions { justify-self: end; display: flex; align-items: center; gap: clamp(14px, 2.4vw, 40px); }
.header-actions a { opacity: .9; transition: opacity .3s; }
.header-actions a:hover { opacity: 1; }
.lang-switch { display: inline-flex; gap: 2px; align-items: center; }
.lang-switch a { padding: 4px 6px; opacity: .7; }
.lang-switch a[aria-current="true"] { opacity: 1; }
.lang-switch span { opacity: .4; }

/* hamburger button (shown ≤767px) */
.nav-toggle { display: none; }

/* ≤991px: page links move to a second row */
@media (max-width: 991px) {
  .site-header__inner { grid-template-columns: 1fr auto; height: auto; }
  .brand { height: 58px; }
  .main-nav { grid-column: 1 / -1; grid-row: 2; justify-content: space-between; gap: 12px; height: 44px; border-top: 1px solid var(--line-light); }
  .site-header.is-solid .main-nav { border-top-color: var(--line); }
  .main-nav a { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; min-width: 44px; padding: 0; font-size: 13px; white-space: nowrap; }
  .main-nav a::after { bottom: 9px; }
  html[lang="en"] .main-nav a { font-size: var(--fs-label-sm); letter-spacing: .08em; }
  .lang-switch a { display: inline-flex; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; padding: 0; }
}

/* ≤767px: hamburger menu */
@media (max-width: 767px) {
  .site-header__inner { height: 64px; }
  .brand { height: auto; min-height: 44px; }
  .header-actions { gap: 4px; }
  .nav-toggle {
    display: inline-grid; place-items: center;
    width: 44px; height: 44px; margin-right: -10px;
    background: none; border: 0; color: inherit; cursor: pointer;
  }
  .nav-toggle__icon, .nav-toggle__icon::before, .nav-toggle__icon::after {
    display: block; width: 22px; height: 1.5px; background: currentColor; border-radius: 2px;
    transition: transform .35s var(--ease), opacity .2s;
  }
  .nav-toggle__icon { position: relative; }
  .nav-toggle__icon::before, .nav-toggle__icon::after { content: ""; position: absolute; left: 0; }
  .nav-toggle__icon::before { top: -7px; }
  .nav-toggle__icon::after { top: 7px; }
  .is-menu-open .nav-toggle__icon { background: transparent; }
  .is-menu-open .nav-toggle__icon::before { transform: translateY(7px) rotate(45deg); }
  .is-menu-open .nav-toggle__icon::after { transform: translateY(-7px) rotate(-45deg); }

  .main-nav {
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0; height: auto;
    padding: 4px var(--gutter) 20px;
    max-height: calc(100svh - 64px); overflow-y: auto;
    background: rgba(251, 250, 247, .98); color: var(--ink);
    border-top: 1px solid var(--line);
    box-shadow: 0 18px 40px rgba(20, 24, 18, .14);
    visibility: hidden; opacity: 0; transform: translateY(-8px);
    transition: opacity .3s var(--ease), transform .3s var(--ease), visibility .3s;
  }
  .site-header.is-solid .main-nav { border-top-color: var(--line); }
  .is-menu-open .main-nav { visibility: visible; opacity: 1; transform: none; }
  .main-nav a { min-height: 52px; font-size: 17px; border-bottom: 1px solid var(--line); opacity: 1; }
  html[lang="en"] .main-nav a { font-size: 13px; letter-spacing: .12em; }
  .main-nav a::after { display: none; }
  .main-nav a[aria-current="page"] { color: var(--brown); font-weight: 500; }

  /* header turns solid while the menu is open */
  .site-header.is-menu-open { background: rgba(251, 250, 247, .98); color: var(--ink); }
  .site-header.is-menu-open .site-header__inner { border-bottom-color: var(--line); }
}

@media (max-width: 575px) {
  .brand { gap: 10px; }
  .brand__name { font-size: 13px; letter-spacing: .24em; }
  .brand__mark { width: 38px; height: 38px; }
  .brand__sub { font-size: 8px; letter-spacing: .26em; }
}