/* =========================================================
   HEADER / NAV  (mobile-first, then enhanced for desktop)
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11, 10, 26, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.site-logo {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.3rem;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 6px;
}
.site-logo span {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* search: full width row under header on mobile, inline on desktop */
.site-search {
  order: 3;
  flex: 1 1 100%;
  padding: 0 0 var(--gap-sm);
}
.site-search input {
  width: 100%;
  height: 42px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: var(--bg-panel);
  color: var(--text-main);
  padding: 0 14px;
  font-size: 0.95rem;
}
.site-search input::placeholder { color: var(--text-dim); }
.site-search input:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.25);
}

/* hamburger button - mobile only */
.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 26px;
  height: 20px;
  background: none;
  border: none;
  padding: 0;
}
.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--text-main);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(9px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }

/* primary nav: off-canvas drawer on mobile */
.primary-nav {
  position: fixed;
  inset: 64px 0 0 0;
  background: var(--bg-deep);
  padding: var(--gap-md);
  transform: translateX(100%);
  transition: transform 0.28s ease;
  overflow-y: auto;
}
.primary-nav.is-open { transform: translateX(0); }

.primary-nav ul { display: flex; flex-direction: column; gap: 2px; }
.primary-nav a {
  display: block;
  padding: 14px 4px;
  font-size: 1.05rem;
  border-bottom: 1px solid var(--line);
}
.primary-nav a:hover,
.primary-nav a:focus-visible { color: var(--accent); }

/* =========================================================
   DESKTOP OVERRIDES  (≥ 900px)
   ========================================================= */
@media (min-width: 900px) {
  .nav-toggle { display: none; }

  .site-header .container {
    flex-wrap: nowrap;
    gap: var(--gap-md);
  }

  .site-search {
    order: 2;
    flex: 1 1 auto;
    max-width: 360px;
    padding: 0;
  }

  .primary-nav {
    position: static;
    order: 3;
    inset: auto;
    background: none;
    padding: 0;
    transform: none;
    overflow: visible;
    width: auto;
  }
  .primary-nav ul { flex-direction: row; gap: var(--gap-md); }
  .primary-nav a { padding: 8px 2px; border-bottom: 2px solid transparent; font-size: 0.95rem; }
  .primary-nav a:hover,
  .primary-nav a:focus-visible { border-color: var(--accent); }
}