.app-shell {
  display: grid;
  grid-template-columns: 20% minmax(0, 1fr);
  min-height: 100dvh;
  background: var(--color-background);
  color: var(--color-text-primary);
  transition: grid-template-columns 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.app-shell.sidebar-collapsed {
  grid-template-columns: 56px minmax(0, 1fr);
}

.app-sidebar {
  min-width: 0;
  border-right: 1px solid var(--color-border);
  background: var(--color-surface-1);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

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

@media (max-width: 900px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .app-shell.sidebar-collapsed {
    grid-template-columns: 1fr;
  }

  .app-sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    width: min(86vw, 280px);
    z-index: 40;
  }

  .app-sidebar.collapsed {
    width: 0;
  }
}