/* Alta Resources -- application shell: reset, layout, navigation, header.
 * Restrained by intent: no gradients, no heavy shadows, one accent.
 */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--alta-surface-sunken);
  color: var(--alta-text);
  font-family: var(--alta-font);
  font-size: var(--alta-text-base);
  line-height: var(--alta-leading-normal);
}

h1, h2, h3, h4 {
  margin: 0;
  font-weight: var(--alta-weight-strong);
  line-height: var(--alta-leading-tight);
}

a {
  color: var(--alta-accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

:focus-visible {
  outline: 2px solid var(--alta-border-focus);
  outline-offset: 2px;
  border-radius: var(--alta-radius-sm);
}

/* Keyboard users land here first. */
.alta-skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  padding: var(--alta-space-2) var(--alta-space-4);
  background: var(--alta-surface-raised);
  border: 1px solid var(--alta-border-strong);
  border-radius: var(--alta-radius);
}

.alta-skip-link:focus {
  left: var(--alta-space-3);
  top: var(--alta-space-3);
}

/* ---- shell frame ------------------------------------------------------- */

.alta-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: var(--alta-nav-width) 1fr;
  grid-template-rows: var(--alta-header-height) 1fr;
  grid-template-areas:
    "brand  header"
    "nav    main";
}

.alta-brand {
  grid-area: brand;
  display: flex;
  align-items: center;
  gap: var(--alta-space-2);
  padding: 0 var(--alta-space-4);
  background: var(--alta-surface);
  border-right: 1px solid var(--alta-border);
  border-bottom: 1px solid var(--alta-border);
  font-weight: var(--alta-weight-strong);
  letter-spacing: 0.01em;
  color: var(--alta-text);
}

.alta-header {
  grid-area: header;
  display: flex;
  align-items: center;
  gap: var(--alta-space-4);
  padding: 0 var(--alta-space-5);
  background: var(--alta-surface);
  border-bottom: 1px solid var(--alta-border);
}

.alta-nav {
  grid-area: nav;
  padding: var(--alta-space-4) var(--alta-space-2);
  background: var(--alta-surface);
  border-right: 1px solid var(--alta-border);
  overflow-y: auto;
}

.alta-main {
  grid-area: main;
  padding: var(--alta-space-5);
  overflow-x: hidden;
}

.alta-main > * {
  max-width: var(--alta-content-max);
}

/* ---- navigation -------------------------------------------------------- */

.alta-nav-group + .alta-nav-group {
  margin-top: var(--alta-space-5);
  padding-top: var(--alta-space-4);
  border-top: 1px solid var(--alta-border);
}

.alta-nav-group__label {
  padding: 0 var(--alta-space-3);
  margin-bottom: var(--alta-space-2);
  font-size: var(--alta-text-xs);
  font-weight: var(--alta-weight-strong);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--alta-text-faint);
}

.alta-nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.alta-nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--alta-space-2);
  padding: var(--alta-space-2) var(--alta-space-3);
  border-radius: var(--alta-radius);
  color: var(--alta-text);
  font-weight: var(--alta-weight-medium);
}

.alta-nav-link:hover {
  background: var(--alta-surface-hover);
  text-decoration: none;
}

.alta-nav-link[aria-current="page"] {
  background: var(--alta-surface-selected);
  color: var(--alta-accent);
}

/* An item whose route the host application has not supplied yet. Inert and
 * visibly so -- never a link that goes nowhere. */
.alta-nav-link--pending {
  color: var(--alta-text-faint);
  cursor: default;
}

.alta-nav-count {
  min-width: 1.5rem;
  padding: 0 var(--alta-space-2);
  border-radius: var(--alta-radius-pill);
  background: var(--alta-surface-hover);
  color: var(--alta-text-muted);
  font-size: var(--alta-text-xs);
  font-weight: var(--alta-weight-strong);
  text-align: center;
}

/* ---- top search shell -------------------------------------------------- */

.alta-search {
  flex: 1 1 auto;
  max-width: 30rem;
  position: relative;
}

.alta-search__field {
  width: 100%;
  padding: var(--alta-space-2) var(--alta-space-3);
  background: var(--alta-surface-sunken);
  border: 1px solid var(--alta-border);
  border-radius: var(--alta-radius);
  color: var(--alta-text);
  font: inherit;
}

.alta-search__field::placeholder {
  color: var(--alta-text-faint);
}

.alta-search__field:disabled {
  cursor: not-allowed;
  opacity: 0.7;
}

.alta-viewer {
  display: flex;
  align-items: center;
  gap: var(--alta-space-2);
  margin-left: auto;
  color: var(--alta-text-muted);
  font-size: var(--alta-text-sm);
}

.alta-search__suggestions {
  position: absolute;
  top: calc(100% + var(--alta-space-1));
  left: 0;
  right: 0;
  z-index: 1000;
  max-height: 24rem;
  overflow-y: auto;
  background: var(--alta-surface);
  border: 1px solid var(--alta-border);
  border-radius: var(--alta-radius);
}
.alta-search__suggestions:empty { display: none; }
.alta-search__count, .alta-search__group-label, .alta-search__empty {
  padding: var(--alta-space-2) var(--alta-space-3);
  color: var(--alta-text-muted);
  font-size: var(--alta-text-sm);
}
.alta-search__option {
  display: grid;
  gap: var(--alta-space-1);
  padding: var(--alta-space-2) var(--alta-space-3);
  color: var(--alta-text);
}
.alta-search__option:hover, .alta-search__option[aria-selected="true"] {
  background: var(--alta-surface-hover);
  text-decoration: none;
}
.alta-search__secondary { color: var(--alta-text-muted); font-size: var(--alta-text-sm); }

.alta-add-menu { position: relative; }
.alta-add-menu summary { list-style: none; cursor: pointer; }
.alta-add-menu summary::-webkit-details-marker { display: none; }
.alta-add-menu__items {
  position: absolute;
  right: 0;
  z-index: 1001;
  min-width: 10rem;
  padding: var(--alta-space-2);
  background: var(--alta-surface);
  border: 1px solid var(--alta-border);
  border-radius: var(--alta-radius);
}
.alta-add-menu__items a { display: block; padding: var(--alta-space-2); }

/* ---- responsive -------------------------------------------------------- */

.alta-nav-toggle {
  display: none;
  align-items: center;
  gap: var(--alta-space-2);
  padding: var(--alta-space-2) var(--alta-space-3);
  background: transparent;
  border: 1px solid var(--alta-border);
  border-radius: var(--alta-radius);
  color: var(--alta-text);
  font: inherit;
  cursor: pointer;
}

@media (max-width: 48rem) {
  .alta-shell {
    grid-template-columns: 1fr;
    grid-template-rows: var(--alta-header-height) auto 1fr;
    grid-template-areas:
      "header"
      "nav"
      "main";
  }

  /* The brand collapses into the header row on narrow viewports. */
  .alta-brand {
    display: none;
  }

  .alta-nav-toggle {
    display: inline-flex;
  }

  .alta-nav {
    border-right: none;
    border-bottom: 1px solid var(--alta-border);
  }

  .alta-nav[data-alta-nav-open="false"] {
    display: none;
  }

  .alta-nav-group + .alta-nav-group {
    margin-top: var(--alta-space-4);
  }

  .alta-main {
    padding: var(--alta-space-4);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}