.app-shell {
  display: grid;
  min-height: 100vh;
  grid-template-columns: var(--rail-width) minmax(0, 1fr);
  grid-template-rows: var(--topbar-height) minmax(0, 1fr);
}

.app-rail {
  position: sticky;
  z-index: var(--z-sticky);
  top: 0;
  grid-row: 1 / -1;
  min-height: 100vh;
  border-right: 1px solid var(--color-line);
  background: var(--color-bg);
}

.brand {
  display: flex;
  min-height: var(--topbar-height);
  align-items: center;
  justify-content: center;
  border-bottom: 1px solid var(--color-line);
  color: var(--color-primary);
  font-size: var(--text-sm);
  font-weight: 750;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.rail-nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3) var(--space-2);
}

.rail-link {
  display: grid;
  min-height: 4rem;
  place-items: center;
  gap: var(--space-1);
  border-radius: var(--radius-md);
  color: var(--color-ink-soft);
  font-size: var(--text-2xs);
  line-height: 1.1;
  text-align: center;
  text-decoration: none;
  transition: background var(--duration-fast) var(--ease-out), color var(--duration-fast) var(--ease-out);
}

.rail-link:hover {
  background: var(--color-surface-strong);
  color: var(--color-ink);
}

.rail-link[aria-current="page"] {
  background: var(--color-primary-soft);
  color: var(--color-primary);
  font-weight: 700;
}

.rail-link[aria-disabled="true"] {
  color: var(--color-ink-muted);
  opacity: 0.58;
}

.rail-link .icon {
  width: 1.4rem;
  height: 1.4rem;
}

.app-topbar {
  position: sticky;
  z-index: var(--z-sticky);
  top: 0;
  display: flex;
  min-width: 0;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  border-bottom: 1px solid var(--color-line);
  background: color-mix(in oklch, var(--color-bg) 96%, transparent);
  padding: 0 var(--space-6);
}

.topbar-context,
.topbar-actions {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: var(--space-3);
}

.topbar-title {
  overflow: hidden;
  margin: 0;
  font-size: var(--text-lg);
  text-overflow: ellipsis;
  white-space: nowrap;
}

.app-main {
  min-width: 0;
  background: var(--color-bg);
}

.view {
  width: 100%;
  max-width: 112rem;
  margin: 0 auto;
  padding: var(--space-6);
}

.view-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-6);
  margin-bottom: var(--space-6);
}

.view-header p {
  margin-bottom: 0;
  color: var(--color-ink-soft);
}

.view-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: var(--space-2);
}

.split-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(16rem, 22rem);
  gap: var(--space-6);
  align-items: start;
}

.detail-layout {
  display: grid;
  grid-template-columns: minmax(15rem, 0.34fr) minmax(0, 1fr) minmax(15rem, 0.3fr);
  min-height: calc(100vh - var(--topbar-height));
}

.detail-pane {
  min-width: 0;
  border-right: 1px solid var(--color-line);
  padding: var(--space-5);
}

.detail-pane:last-child {
  border-right: 0;
}

@media (max-width: 74rem) {
  .split-layout,
  .detail-layout {
    grid-template-columns: 1fr;
  }

  .detail-pane {
    border-right: 0;
    border-bottom: 1px solid var(--color-line);
  }
}

@media (max-width: 58rem) {
  :root {
    --topbar-height: 4rem;
  }

  .app-shell {
    grid-template-columns: 1fr;
    grid-template-rows: var(--topbar-height) minmax(0, 1fr) 4.5rem;
  }

  .app-rail {
    position: fixed;
    inset: auto 0 0;
    grid-row: auto;
    min-height: auto;
    border-top: 1px solid var(--color-line);
    border-right: 0;
  }

  .brand {
    display: none;
  }

  .rail-nav {
    display: grid;
    width: 100%;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0;
    padding: var(--space-1) var(--space-2);
  }

  .rail-link {
    min-width: 0;
    min-height: 3.75rem;
    font-size: var(--text-sm);
  }

  .rail-link:nth-child(n + 6) {
    display: none;
  }

  .app-topbar {
    grid-column: 1;
    min-width: 0;
    overflow: hidden;
    padding: 0 var(--space-4);
  }

  .topbar-context {
    min-width: 0;
    flex: 1 1 auto;
    overflow: hidden;
  }

  .topbar-context > div,
  .topbar-context .muted {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .topbar-actions {
    flex: 0 0 auto;
  }

  .topbar-actions > .status {
    display: none;
  }

  .topbar-actions .button {
    width: var(--control-height);
    padding: 0;
    font-size: 0;
  }

  .topbar-actions .button .icon {
    width: 1.15rem;
    height: 1.15rem;
  }

  .app-main {
    grid-column: 1;
    padding-bottom: 4.75rem;
  }

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

  .view-header {
    flex-direction: column;
    gap: var(--space-4);
  }

  .view-actions {
    width: 100%;
    justify-content: flex-start;
  }
}