.shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  min-height: 100dvh;
}

.main {
  min-width: 0;
  display: flex;
  flex-direction: column;
}

/* Sidebar */
.sidebar {
  position: fixed;
  inset-block: 0;
  inset-inline-start: 0;
  z-index: var(--z-sidebar);
  width: min(var(--sidebar-w), 86vw);
  display: flex;
  flex-direction: column;
  background: var(--sidebar-bg);
  color: var(--sidebar-text);
  border-inline-end: 1px solid var(--sidebar-border);
  translate: calc(-100% * var(--dir)) 0;
  visibility: hidden;
  transition: translate var(--dur-base) var(--ease), visibility 0s linear var(--dur-base);
}

:root[data-nav="open"] .sidebar {
  translate: 0 0;
  visibility: visible;
  transition-delay: 0s;
}

.sidebar :focus-visible {
  outline-color: var(--brand);
}

.sidebar__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  height: var(--topbar-h);
  padding-inline: var(--space-4);
  flex: none;
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-width: 0;
  color: #fff;
  text-decoration: none;
  font-weight: var(--weight-bold);
  font-size: var(--text-lg);
}
.brand img {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-md);
  flex: none;
}
.brand__name {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar__nav {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-3);
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.nav-group__title {
  padding: 0 var(--space-3) var(--space-2);
  color: var(--sidebar-muted);
  font-size: var(--text-xs);
  font-weight: var(--weight-bold);
}

.nav-group ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav__link,
.sidebar__collapse {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  width: 100%;
  min-height: var(--target-min);
  padding: var(--space-2) var(--space-3);
  background: none;
  border: 0;
  border-radius: var(--radius-md);
  color: var(--sidebar-text);
  font-size: var(--text-base);
  text-align: start;
  text-decoration: none;
  transition: background-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
.nav__link:hover,
.sidebar__collapse:hover {
  background: var(--sidebar-hover);
  color: #fff;
}
.nav__link:active,
.sidebar__collapse:active {
  background: var(--sidebar-active);
}

.nav__link[aria-current="page"] {
  background: var(--sidebar-active);
  color: #fff;
  font-weight: var(--weight-bold);
}
.nav__link[aria-current="page"] .icon {
  color: var(--brand);
}
.nav__link[aria-current="page"]::before {
  content: "";
  position: absolute;
  inset-block: var(--space-2);
  inset-inline-start: calc(-1 * var(--space-3));
  width: 3px;
  background: var(--brand);
  border-start-end-radius: 3px;
  border-end-end-radius: 3px;
}

.sidebar__foot {
  flex: none;
  display: none;
  padding: var(--space-3);
  border-block-start: 1px solid var(--sidebar-hover);
}

/* Top bar */
.topbar {
  position: sticky;
  inset-block-start: 0;
  z-index: var(--z-sticky);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  height: var(--topbar-h);
  padding-inline: var(--gutter);
  background: var(--surface);
  border-block-end: 1px solid var(--border);
}

.topbar__spacer {
  flex: 1;
}

.topbar__tools {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.crumbs {
  display: flex;
  align-items: center;
  min-width: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: var(--text-sm);
  color: var(--text-muted);
}
.crumbs li {
  display: flex;
  align-items: center;
  min-width: 0;
}
.crumbs li + li::before {
  content: "/";
  padding-inline: var(--space-2);
  color: var(--text-subtle);
}
.crumbs a {
  color: var(--text-muted);
  text-decoration: none;
  white-space: nowrap;
}
.crumbs a:hover {
  color: var(--text);
  text-decoration: underline;
}
.crumbs [aria-current="page"] {
  color: var(--text);
  font-weight: var(--weight-bold);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.scrim {
  position: fixed;
  inset: 0;
  z-index: var(--z-scrim);
  background: var(--scrim);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur-base) var(--ease), visibility 0s linear var(--dur-base);
}
:root[data-nav="open"] .scrim {
  opacity: 1;
  visibility: visible;
  transition-delay: 0s;
}

/* Page */
.page {
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding: var(--space-6) var(--gutter) var(--space-12);
}

.page--narrow {
  max-width: 52rem;
  margin-inline: 0;
}

.page-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-4);
  margin-block-end: var(--space-6);
}
.page-head__text {
  flex: 1 1 20rem;
  min-width: 0;
}
.page-head h1 {
  overflow-wrap: anywhere;
}
.page-head p {
  margin-block-start: var(--space-2);
  max-width: 68ch;
  color: var(--text-muted);
}
.page-head__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.split {
  display: grid;
  gap: var(--space-6);
  align-items: start;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-block-start: var(--space-6);
  font-size: var(--text-sm);
}

@media (min-width: 64em) {
  .shell {
    grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
    transition: grid-template-columns var(--dur-base) var(--ease);
  }

  :root[data-sidebar="collapsed"] .shell {
    grid-template-columns: var(--sidebar-w-collapsed) minmax(0, 1fr);
  }

  .sidebar {
    position: sticky;
    inset-block-start: 0;
    height: 100dvh;
    width: auto;
    translate: none;
    visibility: visible;
    transition: none;
  }

  .sidebar__foot {
    display: block;
  }

  .icon-btn.only-mobile,
  .scrim {
    display: none;
  }

  .split--aside {
    grid-template-columns: minmax(0, 1fr) 22rem;
  }

  /* Collapsed icon rail */
  :root[data-sidebar="collapsed"] .brand__name,
  :root[data-sidebar="collapsed"] .nav__label,
  :root[data-sidebar="collapsed"] .nav-group__title,
  :root[data-sidebar="collapsed"] .sidebar__collapse .nav__label {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
    white-space: nowrap;
  }

  :root[data-sidebar="collapsed"] .sidebar__head {
    justify-content: center;
    padding-inline: 0;
  }

  :root[data-sidebar="collapsed"] .nav-group + .nav-group {
    padding-block-start: var(--space-4);
    border-block-start: 1px solid var(--sidebar-hover);
  }

  :root[data-sidebar="collapsed"] .nav__link,
  :root[data-sidebar="collapsed"] .sidebar__collapse {
    justify-content: center;
    padding-inline: 0;
  }

  :root[data-sidebar="collapsed"] .sidebar__collapse .icon {
    transform: scaleX(-1);
  }
  :root[data-sidebar="collapsed"][dir="rtl"] .sidebar__collapse .icon {
    transform: none;
  }

  [dir="rtl"] .sidebar__collapse .icon {
    transform: scaleX(-1);
  }
}

@media (max-width: 39.99em) {
  .crumbs li:not(:last-child) {
    display: none;
  }
  .crumbs li:last-child::before {
    content: none;
  }
}

/* Tooltip (shared element, positioned by script) */
.tooltip {
  position: fixed;
  z-index: var(--z-menu);
  max-width: 16rem;
  padding: var(--space-1) var(--space-3);
  background: #000;
  color: #fff;
  border: 1px solid #2d3028;
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  line-height: var(--lh-snug);
  pointer-events: none;
  box-shadow: var(--shadow-pop);
}

.sidebar .icon-btn {
  color: var(--sidebar-text);
}
.sidebar .icon-btn:hover {
  background: var(--sidebar-hover);
  color: #fff;
}

.sidebar .brand {
  font-size: var(--text-md);
}