.site-header {
  position: fixed;
  z-index: 100;
  top: 0;
  right: 0;
  left: 0;
  color: var(--white);
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
  transition:
    color 0.3s ease,
    background 0.3s ease,
    border-color 0.3s ease,
    box-shadow 0.3s ease;
}

.site-header.is-scrolled,
.site-header.menu-active {
  color: var(--ink);
  border-bottom-color: var(--line);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 8px 30px rgba(21, 27, 28, 0.06);
  backdrop-filter: blur(14px);
}

.nav-shell {
  display: flex;
  min-height: 76px;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
}

.brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
}

.brand-logo {
  width: 116px;
  height: auto;
  border-radius: 2px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(16px, 2vw, 30px);
}

.site-nav a {
  position: relative;
  padding-block: 10px;
  font-size: 0.69rem;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-nav a:not(.nav-contact)::after {
  position: absolute;
  right: 0;
  bottom: 4px;
  left: 0;
  height: 2px;
  background: var(--red);
  content: "";
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.25s var(--ease);
}

.site-nav a:hover::after,
.site-nav a.active::after {
  transform: scaleX(1);
  transform-origin: left;
}

.site-nav .nav-contact {
  padding: 11px 16px;
  color: var(--white);
  background: var(--red);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 0;
  background: transparent;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  margin: 6px auto;
  background: currentColor;
  transition:
    transform 0.25s ease,
    opacity 0.25s ease;
}

.menu-active .menu-toggle span:first-child {
  transform: translateY(4px) rotate(45deg);
}

.menu-active .menu-toggle span:last-child {
  transform: translateY(-4px) rotate(-45deg);
}

.section-heading {
  display: grid;
  grid-template-columns: 1.35fr 0.65fr;
  gap: clamp(40px, 8vw, 110px);
  align-items: end;
  margin-bottom: clamp(48px, 7vw, 78px);
}

.section-heading h2 {
  margin-bottom: 0;
}

.section-heading > p {
  max-width: 430px;
  margin-bottom: 6px;
  color: var(--muted);
}

.site-footer {
  color: rgba(255, 255, 255, 0.68);
  background: #111617;
}

.footer-main {
  display: grid;
  grid-template-columns: 1fr 1.45fr;
  gap: 80px;
  padding-block: 76px 64px;
}

.brand-footer {
  padding: 5px;
  background: var(--white);
}

.brand-footer .brand-logo {
  width: 166px;
}

.footer-main > div:first-child p {
  margin: 24px 0 0;
  font-size: 1.15rem;
  line-height: 1.5;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.footer-links strong {
  display: block;
  margin-bottom: 18px;
  color: var(--white);
  font-size: 0.66rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.footer-links a {
  display: block;
  width: fit-content;
  margin-block: 8px;
  font-size: 0.86rem;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--white);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 28px;
  padding-block: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.13);
  font-size: 0.7rem;
  letter-spacing: 0.03em;
}

.back-to-top {
  position: fixed;
  z-index: 90;
  right: 20px;
  bottom: 20px;
  display: grid;
  width: 46px;
  height: 46px;
  color: var(--white);
  border: 0;
  border-radius: 50%;
  background: var(--red);
  box-shadow: 0 10px 24px rgba(229, 43, 53, 0.3);
  opacity: 0;
  pointer-events: none;
  place-items: center;
  transform: translateY(12px);
  transition:
    opacity 0.25s ease,
    transform 0.25s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}