.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid transparent;
  background: rgba(247, 248, 250, 0.88);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  transition: border-color 180ms ease, box-shadow 180ms ease, background-color 180ms ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
  background: rgba(255, 255, 255, 0.94);
  box-shadow: var(--shadow-sm);
}

.site-header__inner {
  position: relative;
  display: grid;
  min-height: var(--header-height);
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 34px;
}

.brand {
  display: inline-flex;
  align-items: center;
  width: 122px;
  height: 62px;
  overflow: hidden;
  border-radius: 8px;
}

.brand img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(18px, 2.5vw, 34px);
}

.site-nav a {
  position: relative;
  padding: 8px 0;
  color: var(--text-soft);
  font-size: 14px;
  font-weight: 650;
  transition: color 180ms ease;
}

.site-nav a::after {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 2px;
  content: "";
  border-radius: 999px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 180ms var(--ease);
}

.site-nav a:hover,
.site-nav a.is-active { color: var(--text); }
.site-nav a:hover::after,
.site-nav a.is-active::after { transform: scaleX(1); }

.site-header__cta { white-space: nowrap; }

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  place-items: center;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 99px;
  background: var(--text);
  transition: transform 180ms var(--ease), opacity 180ms ease;
}

.menu-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.mobile-nav {
  overflow: hidden;
  border-top: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.98);
}

.mobile-nav__links {
  display: grid;
  gap: 2px;
  padding-top: 12px;
  padding-bottom: 18px;
}

.mobile-nav__links > a:not(.button) {
  padding: 14px 2px;
  color: var(--text);
  font-size: 16px;
  font-weight: 700;
  border-bottom: 1px solid var(--line);
}

.mobile-nav__cta { margin-top: 12px; }

@media (max-width: 980px) {
  .site-header__inner { gap: 18px; }
  .site-nav { gap: 18px; }
  .site-header__cta { padding-inline: 14px; font-size: 13px; }
}

@media (max-width: 820px) {
  .site-header__inner { grid-template-columns: auto 1fr auto; }
  .site-nav,
  .site-header__cta { display: none; }
  .menu-toggle { display: grid; justify-self: end; }
}

@media (max-width: 460px) {
  .brand { width: 104px; height: 54px; }
}