.container {
  width: 100%;
  max-width: var(--content-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-inline: var(--space-lg);
}

/* header and primary navigation */

.site-header {
  background-image: linear-gradient(to right, var(--color-nav-gradient-start), var(--color-nav-gradient-end));
  color: var(--color-text-on-dark);
  flex-shrink: 0;
  position: sticky;
  top: 0;
  z-index: 50;
}

.site-header a:focus-visible,
.site-header button:focus-visible {
  outline-color: white;
}

.site-header__bar {
  max-width: var(--content-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-inline: var(--space-lg);
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  color: var(--color-text-on-dark);
  font-weight: 700;
  font-size: var(--font-size-medium);
  text-decoration: none;
  white-space: nowrap;
}

.site-header__brand-icon {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  flex-shrink: 0;
  background-color: var(--color-surface);
}

.nav-toggle {
  display: block;
  background: none;
  border: 0.125rem solid var(--color-text-on-dark);
  border-radius: var(--radius-small);
  width: 2.75rem;
  height: 2.75rem;
  padding: 0;
  cursor: pointer;
  position: relative;
}

.nav-toggle__icon,
.nav-toggle__icon::before,
.nav-toggle__icon::after {
  position: absolute;
  left: 50%;
  width: 1.4rem;
  height: 0.15rem;
  background-color: var(--color-text-on-dark);
  transform: translateX(-50%);
  transition: transform 0.15s ease-in-out, opacity 0.15s ease-in-out;
}

.nav-toggle__icon {
  top: 50%;
  transform: translate(-50%, -50%);
}

.nav-toggle__icon::before {
  content: "";
  top: -0.45rem;
}

.nav-toggle__icon::after {
  content: "";
  top: 0.45rem;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__icon {
  background-color: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__icon::before {
  top: 0;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__icon::after {
  top: 0;
  transform: rotate(-45deg);
}

/* mobile base state: the nav is a hidden panel toggled open by the
   hamburger button, and its links stack full-width for easy tapping */
.primary-nav {
  display: none;
  width: 100%;
  padding-bottom: var(--space-md);
}

.primary-nav.is-open {
  display: block;
}

.primary-nav__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2xs);
}

.primary-nav__list a,
.primary-nav__list button {
  display: block;
  width: 100%;
  color: var(--color-text-on-dark);
  text-decoration: none;
  font: inherit;
  font-weight: 600;
  font-size: var(--font-size-small);
  padding: var(--space-sm) var(--space-md);
  border: 0;
  border-radius: var(--radius-pill);
  background: none;
  cursor: pointer;
  text-align: left;
  transition: background-color 0.15s ease-in-out, filter 0.15s ease-in-out;
}

.primary-nav__list a:hover,
.primary-nav__list button:hover {
  background-color: var(--color-brand-primary-strong);
  filter: brightness(1.15);
}

.primary-nav__list a[aria-current="page"] {
  background-color: var(--color-brand-primary-dark);
}

.primary-nav__account {
  display: block;
  color: var(--color-text-on-dark);
  font-size: var(--font-size-small);
  padding: var(--space-sm) var(--space-md);
  opacity: 0.85;
}

.primary-nav__divider {
  display: none;
}

.primary-nav__signup {
  background-color: var(--color-surface);
  color: var(--color-brand-primary-strong) !important;
}

.primary-nav__signup:hover {
  background-color: var(--color-surface-muted) !important;
  filter: none !important;
}

.site-header__bar {
  flex-wrap: wrap;
}

/* desktop enhancement: the nav becomes a permanent horizontal bar and
   the hamburger button disappears, since there's room to show it all */
@media (min-width: 56rem) {
  .nav-toggle {
    display: none;
  }

  .primary-nav {
    display: block;
    width: auto;
    padding-bottom: 0;
  }

  .primary-nav__list {
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--space-2xs);
  }

  .primary-nav__list a,
  .primary-nav__list button,
  .primary-nav__account {
    display: inline-block;
    width: auto;
  }

  .primary-nav__divider {
    display: block;
    width: 0.0625rem;
    align-self: stretch;
    background-color: cornflowerblue;
    margin-left: var(--space-2xs);
    margin-right: var(--space-2xs);
  }

  .site-header__bar {
    flex-wrap: nowrap;
  }
}

/* page shell */

.page-main {
  display: block;
  flex: 1 0 auto;
}

.page-header {
  padding-block: var(--space-lg) var(--space-md);
}

.page-header--tight {
  padding-block: var(--space-md) var(--space-md);
}

.page-header__title {
  margin-bottom: var(--space-xs);
}

.page-header__lede {
  color: var(--color-text-muted);
  max-width: 42rem;
  font-size: var(--font-size-medium);
}

.page-header__lede--wide {
  max-width: 60rem;
}

.page-header--center .page-header__lede {
  margin-left: auto;
  margin-right: auto;
}

.page-section {
  padding-block: var(--space-md);
}

.page-section + .page-section {
  padding-top: 0;
}

.page-section:last-of-type {
  padding-bottom: var(--space-lg);
}

/* footer */

.site-footer {
  background-color: var(--color-footer-background);
  color: var(--color-text-on-dark);
  flex-shrink: 0;
  position: sticky;
  bottom: 0;
  z-index: 50;
}

.site-footer__nav {
  max-width: var(--content-max-width);
  margin-left: auto;
  margin-right: auto;
  padding: var(--space-2xs) var(--space-lg);
}

.site-footer__list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-sm) var(--space-lg);
}

.site-footer__list li {
  flex: 1 1 auto;
  text-align: center;
}

.site-footer__list a {
  color: var(--color-text-on-dark);
  text-decoration: none;
  font-weight: 600;
  font-size: var(--font-size-small);
  padding: 0.2rem var(--space-sm);
  border-radius: var(--radius-pill);
  transition: background-color 0.15s ease-in-out, filter 0.15s ease-in-out;
}

.site-footer__list a:hover {
  background-color: var(--color-brand-primary-strong);
  filter: brightness(1.15);
}

.site-footer__list a[aria-current="page"] {
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

.site-footer__copyright {
  background-color: var(--color-footer-background);
  text-align: center;
  font-size: var(--font-size-small);
  margin: 0;
  padding: 0.2rem;
}

/* generic layout helpers reused across pages */

.grid {
  display: grid;
  gap: var(--space-lg);
}

@media (min-width: 56rem) {
  .grid--3 {
    grid-template-columns: repeat(3, 1fr);
  }

  .grid--4 {
    grid-template-columns: repeat(4, 1fr);
  }
}

.stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}