.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.85);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--c-border-soft);
}
.site-header__inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--c-primary-700);
  font-weight: 700;
  font-size: 1.02rem;
  letter-spacing: -0.01em;
  min-width: 0;
  transition: transform var(--dur-fast) var(--ease);
}
.brand:hover { transform: translateY(-1px); color: var(--c-primary); }
.brand__logo { width: 36px; height: 36px; filter: drop-shadow(0 2px 4px rgba(31,79,122,0.18)); }
.brand__name {
  display: inline-flex;
  flex-direction: column;
  line-height: 1.1;
}
.brand__name strong { font-weight: 700; }
.brand__name small {
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--c-text-soft);
  letter-spacing: 0.02em;
}

/* Nav */
.nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.nav__list {
  list-style: none;
  display: flex;
  gap: 0.25rem;
  padding: 0;
  margin: 0;
}
.nav__link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 0.85rem;
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--c-text-muted);
  font-weight: 600;
  font-size: 0.93rem;
  transition: background var(--dur-fast) var(--ease),
              color var(--dur-fast) var(--ease),
              transform var(--dur-fast) var(--ease);
}
.nav__link:hover {
  background: var(--c-surface-2);
  color: var(--c-primary);
  transform: translateY(-1px);
}
.nav__link[aria-current="page"],
.nav__link.is-active {
  background: linear-gradient(180deg, rgba(31,79,122,0.10), rgba(42,138,166,0.08));
  color: var(--c-primary-700);
  box-shadow: inset 0 -2px 0 var(--c-accent);
}
.nav__icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

/* Mobile nav */
.nav__toggle {
  display: none;
  margin-left: auto;
  background: transparent;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 0.4rem 0.5rem;
  color: var(--c-primary-700);
}
.nav__toggle svg { width: 22px; height: 22px; display: block; }

@media (max-width: 820px) {
  .nav__toggle { display: inline-flex; }
  .nav {
    position: absolute;
    top: var(--header-h);
    right: 0;
    left: 0;
    background: var(--c-surface);
    border-bottom: 1px solid var(--c-border-soft);
    padding: 0.5rem var(--gutter) 1rem;
    box-shadow: var(--shadow-md);
    display: none;
  }
  .nav.is-open { display: block; }
  .nav__list { flex-direction: column; gap: 0.15rem; }
  .nav__link { width: 100%; }
  .brand__name small { display: none; }
  .brand__name { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
}