/* ==========================================================================
   Layout: containers, sections, grids, site header, site footer.
   ========================================================================== */

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

.container--narrow {
  max-width: 900px;
}

.container--prose {
  max-width: var(--container-prose);
  margin-inline: auto;
}

.section {
  padding-block: var(--section-y);
}

.section--tight {
  padding-block: var(--section-y-tight);
}

.section--subtle {
  background: var(--bg-subtle);
  border-block: 1px solid var(--border);
}

.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-8);
}

/* A small label above a section title: sentence case, muted, generous tracking.
   No colour and no rule, so the heading keeps all of the emphasis. */
.section__eyebrow {
  display: block;
  margin: 0 0 var(--space-3);
  font-size: var(--text-xs);
  font-weight: var(--weight-normal);
  letter-spacing: var(--tracking-wide);
  color: var(--text-muted);
}

.section__head--center .section__eyebrow {
  text-align: center;
}

.section__head--center {
  flex-direction: column;
  align-items: center;
  text-align: center;
  max-width: 640px;
  margin-inline: auto;
  margin-bottom: var(--space-10);
}

.section__title {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  text-wrap: balance;
}

.section__subtitle {
  margin-top: var(--space-3);
  color: var(--text-muted);
  font-size: var(--text-base);
  max-width: 62ch;
  text-wrap: pretty;
}

.section__head--center .section__subtitle {
  text-wrap: balance;
}

.section__link {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  white-space: nowrap;
}

/* ------------------------------------------------------------------ grids */
.grid {
  display: grid;
  gap: var(--space-5);
}

.grid--4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.grid--tools {
  grid-template-columns: repeat(auto-fill, minmax(min(258px, 100%), 1fr));
  gap: var(--space-4);
}

.grid--categories {
  grid-template-columns: repeat(auto-fill, minmax(min(230px, 100%), 1fr));
  gap: var(--space-4);
}

.stack {
  display: grid;
  gap: var(--space-6);
}

.cluster {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--space-10);
  align-items: start;
}

/* ==========================================================================
   Site header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}

.site-header.is-scrolled {
  border-bottom-color: var(--border);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  min-height: var(--header-height);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--text);
  font-weight: var(--weight-medium);
  letter-spacing: -0.02em;
  font-size: 0.9375rem;
  flex-shrink: 0;
}

.brand:hover {
  color: var(--text);
  text-decoration: none;
}

/* The logo artwork supplies its own tile, so the mark is just the image:
   28px, rounded to match the system radius, never stretched. */
.brand__mark {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  object-fit: contain;
  display: block;
  flex-shrink: 0;
}

.brand__name {
  white-space: nowrap;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  margin-inline-start: var(--space-2);
}

.site-nav__link {
  position: relative;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 0.875rem;
  font-weight: var(--weight-normal);
  transition: color var(--duration-fast) var(--ease-out);
}

.site-nav__link:hover {
  color: var(--text);
  text-decoration: none;
}

.site-nav__link[aria-current="page"],
.site-nav__link.is-active {
  color: var(--text);
}

.site-nav__link.is-active::after {
  content: "";
  position: absolute;
  left: var(--space-3);
  right: var(--space-3);
  bottom: -1px;
  height: 1px;
  background: var(--accent);
}

.site-header__actions {
  margin-inline-start: auto;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* The site is light only for now. The control stays in the markup so dark mode
   can return without touching every page. */
[data-theme-toggle] {
  display: none !important;
}

/* ---------------------------------------------------------- search trigger */
.search-trigger {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-width: 200px;
  height: 40px;
  padding: 0 0.5rem 0 0.7rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: var(--text-sm);
  transition: border-color var(--duration-fast) var(--ease-out),
    color var(--duration-fast) var(--ease-out);
}

.search-trigger:hover {
  border-color: var(--text-muted);
  color: var(--text);
}

.search-trigger__label {
  flex: 1;
  text-align: left;
}

.search-trigger__kbd {
  font-family: var(--font-sans);
  font-size: var(--text-2xs);
  font-weight: var(--weight-normal);
  color: var(--text-muted);
  background: var(--pill);
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  padding: 0.1rem 0.3rem;
  line-height: 1.5;
}

/* ----------------------------------------------------------- icon buttons */
.icon-button {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  border: 1px solid transparent;
  transition: background-color var(--duration-fast) var(--ease-out),
    color var(--duration-fast) var(--ease-out);
}

.icon-button:hover {
  background: var(--surface-hover);
  color: var(--text);
}

/* Theme toggle: only the icon for the theme you would switch *to* is visible, so
   the button always shows the action rather than the current state. */
.theme-icon {
  display: none;
}

[data-theme="light"] .theme-icon--dark {
  display: block;
}

[data-theme="dark"] .theme-icon--light {
  display: block;
}

.nav-toggle {
  display: none;
}

/* ------------------------------------------------------------ mobile menu */
.mobile-menu {
  position: fixed;
  inset: var(--header-height) 0 0 0;
  z-index: var(--z-overlay);
  background: var(--bg);
  padding: var(--space-5) var(--gutter) var(--space-10);
  overflow-y: auto;
  animation: fade-in var(--duration-fast) var(--ease-out) both;
}

.mobile-menu__nav {
  display: grid;
  gap: var(--space-1);
}

.mobile-menu__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-2);
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-size: var(--text-lg);
  font-weight: var(--weight-normal);
}

.mobile-menu__link:hover {
  color: var(--accent);
  text-decoration: none;
}

.mobile-menu__section {
  margin-top: var(--space-8);
}

.mobile-menu__title {
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-wide);
  color: var(--text-muted);
  margin-bottom: var(--space-3);
}

.mobile-menu__cats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

/* ==========================================================================
   Site footer
   ========================================================================== */
.site-footer {
  margin-top: var(--space-16);
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding-block: var(--space-12) var(--space-8);
}

.site-footer__top {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) repeat(4, minmax(0, 1fr));
  gap: var(--space-8);
}

.site-footer__brand {
  max-width: 34ch;
}

.site-footer__tagline {
  margin-top: var(--space-4);
  color: var(--text-muted);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
}

.site-footer__col {
  min-width: 0;
}

.site-footer__col-title {
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-wide);
  color: var(--text-muted);
  margin-bottom: var(--space-4);
}

.site-footer__links {
  display: grid;
  gap: var(--space-3);
  list-style: none;
  padding: 0;
}

.site-footer__links a {
  color: var(--text-muted);
  font-size: var(--text-sm);
}

.site-footer__links a:hover {
  color: var(--accent);
}

.site-footer__bottom {
  margin-top: var(--space-10);
  padding-top: var(--space-6);
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  color: var(--text-muted);
  font-size: var(--text-sm);
}

.site-footer__social {
  display: flex;
  gap: var(--space-2);
}

/* --------------------------------------------------------------- responsive */
@media (max-width: 1024px) {
  .grid--4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .site-footer__top {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .site-footer__brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 900px) {
  .split {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-8);
  }

  .site-nav,
  .search-trigger {
    display: none;
  }

  .nav-toggle {
    display: grid;
  }
}

/* Five navigation items plus a full search field need more room than a small
   laptop provides. Below this width the search control collapses to its icon
   and the nav tightens, so nothing has to be dropped from the menu. */
@media (min-width: 901px) and (max-width: 1020px) {
  .search-trigger {
    min-width: 0;
    width: 40px;
    padding: 0;
    justify-content: center;
  }

  .search-trigger__label,
  .search-trigger__kbd {
    display: none;
  }

  .site-nav {
    margin-inline-start: var(--space-2);
  }

  .site-nav__link {
    padding-inline: var(--space-2);
  }
}

@media (max-width: 640px) {
  .grid--4 {
    grid-template-columns: minmax(0, 1fr);
  }

  .grid--tools,
  .grid--categories {
    grid-template-columns: minmax(0, 1fr);
  }

  .site-footer__top {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-6);
  }

  .section__head {
    align-items: flex-start;
  }
}

@media (max-width: 420px) {
  .site-footer__top {
    grid-template-columns: minmax(0, 1fr);
  }
}