.app-shell {
  display: grid;
  grid-template-rows:
    var(--header-height) var(--context-height)
    minmax(0, 1fr);
  height: 100vh;
  height: 100dvh;
  min-height: 0;
  overflow: hidden;
}

.global-header {
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 0 24px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}

.brand-group,
.header-actions,
.subject-title-row,
.subject-status-group {
  display: flex;
  align-items: center;
}

.brand-group {
  min-width: 0;
  gap: 12px;
}

.brand-mark {
  display: grid;
  flex: 0 0 auto;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 12px;
  overflow: hidden;
  background: transparent;
  color: var(--accent-contrast);
  font-weight: 800;
}

.brand-icon {
  display: block;
  width: 100%;
  height: 100%;
}

.brand-title {
  font-size: 1.05rem;
}

.header-actions {
  gap: 10px;
}

.subject-context {
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px 24px;
  border-bottom: 1px solid var(--line);
  background: var(--surface-soft);
}

.subject-copy {
  min-width: 0;
  flex: 1;
}

.subject-title-row {
  justify-content: space-between;
  gap: 24px;
  margin-top: 10px;
}

.subject-title-copy {
  min-width: 0;
}

.subject-title-row h2 {
  overflow: hidden;
  font-size: clamp(1.25rem, 2vw, 1.7rem);
  text-overflow: ellipsis;
  white-space: nowrap;
}

.subject-status-group {
  flex: 0 0 auto;
  gap: 12px;
}

.workspace {
  display: grid;
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
  min-height: 0;
  overflow: hidden;
  transition: grid-template-columns var(--transition-normal);
}

.app-shell.sidebar-collapsed .workspace {
  grid-template-columns: 0 minmax(0, 1fr);
}

.sidebar {
  z-index: 20;
  display: flex;
  min-width: 0;
  min-height: 0;
  flex-direction: column;
  overflow: hidden;
  border-right: 1px solid var(--line);
  background: var(--surface);
  opacity: 1;
  transform: translateX(0);
  transition:
    opacity var(--transition-fast),
    transform var(--transition-normal);
}

.app-shell.sidebar-collapsed .sidebar {
  pointer-events: none;
  opacity: 0;
  transform: translateX(-100%);
}

.subject-nav {
  display: grid;
  gap: 6px;
  padding: 16px 12px;
}

.sidebar-footer {
  margin-top: auto;
  padding: 16px 24px 20px;
  border-top: 1px solid var(--line);
  font-size: 0.82rem;
}

.content-panel {
  min-width: 0;
  min-height: 0;
  overflow-x: hidden;
  overflow-y: auto;
  padding: var(--content-padding);
  overscroll-behavior: contain;
  scrollbar-gutter: stable;
}

.content-inner {
  width: min(100%, var(--content-max-width));
  margin: 0 auto;
}

.section-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 20px;
}

.section-header h2 {
  margin: 4px 0 6px;
  font-size: 1.55rem;
}

.section-description {
  max-width: 760px;
  color: var(--text-soft);
}

.foundation-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  gap: 16px;
}

.foundation-list {
  display: grid;
  gap: 10px;
  margin-top: 14px;
  list-style: none;
}

.foundation-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.foundation-list li::before {
  content: "✓";
  flex: 0 0 auto;
  color: var(--success);
  font-weight: 800;
}

.settings-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.mobile-drawer {
  position: fixed;
  z-index: 130;
  inset: 0 auto 0 0;
  display: flex;
  width: min(86vw, 320px);
  flex-direction: column;
  overflow-y: auto;
  border-right: 1px solid var(--line);
  background: var(--surface);
  box-shadow: var(--shadow-md);
  transform: translateX(-105%);
  transition: transform var(--transition-normal);
}

.mobile-drawer.open {
  transform: translateX(0);
}

.drawer-backdrop {
  position: fixed;
  z-index: 120;
  inset: 0;
  background: var(--surface-overlay);
  backdrop-filter: blur(2px);
}

.drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 16px;
  border-bottom: 1px solid var(--line);
}

body.drawer-open {
  overflow: hidden;
}

.toast-region {
  position: fixed;
  z-index: 300;
  right: 18px;
  bottom: 18px;
  display: grid;
  width: min(360px, calc(100vw - 36px));
  gap: 10px;
  pointer-events: none;
}

.foundation-wide {
  grid-column: 1 / -1;
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-bottom: 18px;
}


.app-shell.missing-context-mode {
  grid-template-rows: var(--header-height) minmax(0, 1fr);
}

.missing-context-mode .global-header {
  justify-content: center;
}

.missing-context-mode .navigation-toggle,
.missing-context-mode .header-actions,
.missing-context-mode .subject-context,
.missing-context-mode .sidebar {
  display: none;
}

.missing-context-mode .workspace,
.missing-context-mode.sidebar-collapsed .workspace {
  grid-template-columns: minmax(0, 1fr);
}

.missing-context-mode .content-panel {
  display: grid;
  place-items: center;
  padding-block: clamp(28px, 7vh, 72px);
}