/* Page structure: container, section themes, header, footer */

.container {
  width: 100%;
  max-width: calc(var(--container) + 2 * var(--gutter));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: var(--section-y);
  overflow: hidden;
}

.section--white { background: var(--white); }
.section--concrete { background: var(--concrete); }
.section--dark { background: var(--heavy-metal); color: var(--ink-inverse); }

.section__head {
  display: grid;
  gap: 20px;
  max-width: 720px;
  margin-bottom: clamp(44px, 6vw, 72px);
}

.section__head > p:not(.eyebrow) { color: var(--ink-soft); font-size: var(--text-lede); }
.section--dark .section__head > p:not(.eyebrow) { color: var(--ink-inverse-soft); }

/* ---------- header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(242, 242, 242, 0.88);
  -webkit-backdrop-filter: saturate(140%) blur(14px);
  backdrop-filter: saturate(140%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 240ms ease, background 240ms ease;
}
.site-header.is-scrolled { border-bottom-color: var(--rule); background: rgba(242, 242, 242, 0.94); }

.site-header__inner {
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-header__logo { display: block; flex: none; }
.site-header__logo img { height: 38px; width: auto; }

.site-nav { display: flex; align-items: center; gap: clamp(20px, 2.6vw, 40px); }

.site-nav__list { display: flex; align-items: center; gap: clamp(18px, 2.4vw, 36px); }

.site-nav__link {
  font-size: var(--text-label);
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--ink);
  padding-block: 6px;
  background: linear-gradient(currentColor, currentColor) 0 100% / 0 1px no-repeat;
  transition: background-size 320ms var(--ease);
}
.site-nav__link:hover { background-size: 100% 1px; }

.nav-toggle {
  display: none;
  width: 48px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--rule);
  border-radius: 14px / 50%;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
}
.nav-toggle__bars, .nav-toggle__bars::before, .nav-toggle__bars::after {
  display: block;
  width: 18px;
  height: 1.5px;
  margin-inline: auto;
  background: currentColor;
  transition: transform 240ms var(--ease), opacity 160ms ease;
}
.nav-toggle__bars { position: relative; }
.nav-toggle__bars::before, .nav-toggle__bars::after { content: ""; position: absolute; left: 0; }
.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-6px) rotate(-45deg); }

@media (max-width: 959px) {
  :root { --header-h: 72px; }
  .site-header__logo img { height: 32px; }
  .nav-toggle { display: block; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 24px;
    padding: 12px var(--gutter) 32px;
    background: var(--concrete);
    border-bottom: 1px solid var(--rule);
    box-shadow: 0 24px 40px -28px rgba(42, 53, 46, 0.4);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-8px);
    transition: opacity 220ms ease, transform 280ms var(--ease), visibility 0s linear 280ms;
  }
  .site-nav.is-open {
    visibility: visible;
    opacity: 1;
    transform: none;
    transition: opacity 220ms ease, transform 280ms var(--ease);
  }
  .site-nav__list { flex-direction: column; align-items: stretch; gap: 0; }
  .site-nav__link { display: block; padding-block: 16px; border-bottom: 1px solid var(--rule); background: none; }
  .site-nav .btn { align-self: flex-start; }
}

/* ---------- footer ---------- */

.site-footer {
  background: var(--heavy-metal);
  color: var(--ink-inverse-soft);
  font-size: var(--text-small);
}

.site-footer__top {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 32px;
  padding-block: 56px 40px;
  border-top: 1px solid var(--rule-inverse);
}

.site-footer__brand { display: grid; gap: 18px; }
.site-footer__brand img { height: 34px; width: auto; }
.site-footer__tagline {
  font-family: var(--font-highlight);
  font-style: italic;
  font-weight: 300;
  font-size: 1.375rem;
  color: var(--heathered-gray);
}

.site-footer__nav { display: flex; flex-wrap: wrap; gap: 12px 28px; }
.site-footer__nav a {
  font-size: var(--text-label);
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--concrete);
}
.site-footer__nav a:hover { color: var(--heathered-gray); }

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px 32px;
  padding-block: 24px 36px;
  border-top: 1px solid var(--rule-inverse);
  font-size: 0.8125rem;
}