.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-fast), box-shadow var(--dur-fast);
}
.site-header.is-scrolled {
  border-bottom-color: var(--color-line);
  box-shadow: var(--shadow-sm);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding-block: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  flex-shrink: 0;
}
.brand__text {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.1;
  display: flex;
  flex-direction: column;
}
.brand__text-thin {
  font-family: var(--font-body);
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-ink-soft);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  font-size: 0.94rem;
  font-weight: 600;
}
.main-nav a {
  position: relative;
  color: var(--color-ink-soft);
  padding-block: 0.3rem;
  transition: color var(--dur-fast);
}
.main-nav a::after {
  content: "";
  position: absolute;
  left: 0; right: 100%;
  bottom: 0;
  height: 2px;
  background: var(--color-accent);
  transition: right var(--dur-med) var(--ease-out);
}
.main-nav a:hover, .main-nav a.is-active { color: var(--color-ink); }
.main-nav a:hover::after, .main-nav a.is-active::after { right: 0; }

.header-actions { display: flex; align-items: center; gap: var(--space-md); }
.header-actions__phone {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--color-ink);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.5rem;
  height: 2.5rem;
  background: none;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  align-items: center;
}
.nav-toggle span {
  width: 18px; height: 1.5px;
  background: var(--color-ink);
  transition: transform var(--dur-fast), opacity var(--dur-fast);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

.mobile-nav {
  display: none;
  flex-direction: column;
  gap: 0.9rem;
  padding: 1.25rem clamp(1.25rem, 5vw, 3rem) 1.75rem;
  border-top: 1px solid var(--color-line);
  background: var(--color-paper);
}
.mobile-nav.is-open { display: flex; }
.mobile-nav a:not(.btn) { font-weight: 600; padding-block: 0.4rem; }
.mobile-nav .btn { margin-top: 0.4rem; }

@media (max-width: 900px) {
  .main-nav, .header-actions__phone { display: none; }
  .nav-toggle { display: flex; }
}