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

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: var(--space-3);
  background: var(--color-bg-secondary);
  border-right: 1px solid rgba(55, 53, 47, 0.09);
  transition: width var(--transition-slow), transform var(--transition-slow);
}

.sidebar.is-collapsed {
  width: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  height: 36px;
  padding: 0 var(--space-2);
  font-weight: var(--font-bold);
}

.brand-mark {
  width: 24px;
  height: 24px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-md);
  color: white;
  background: var(--color-primary);
  font-size: var(--text-sm);
}

.nav {
  display: grid;
  gap: var(--space-1);
  margin-top: var(--space-4);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 32px;
  padding: var(--space-2);
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: background var(--transition-base), color var(--transition-base);
}

.nav-link:hover,
.nav-link.is-active {
  background: rgba(255, 255, 255, 0.7);
  color: var(--color-text-primary);
}

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  min-height: 56px;
  padding: 0 var(--space-6);
  background: rgba(255, 255, 255, 0.86);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
}

.page {
  width: min(100%, var(--content-max-width));
  margin: 0 auto;
  padding: var(--space-6);
}

.page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.page-title {
  margin: 0;
  font-size: var(--text-3xl);
  line-height: 40px;
  font-weight: var(--font-bold);
  color: var(--color-text-primary);
}

.page-subtitle {
  margin: var(--space-1) 0 0;
  color: var(--color-text-secondary);
  font-size: var(--text-base);
}

.toolbar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.grid {
  display: grid;
  gap: var(--space-3);
}

.grid.cards {
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
}

.grid.two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

@media (max-width: 768px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    width: min(var(--sidebar-width), 86vw);
    z-index: 20;
    transform: translateX(-100%);
    box-shadow: var(--shadow-lg);
  }

  .sidebar.is-open {
    transform: translateX(0);
  }

  .topbar,
  .page {
    padding-left: var(--space-4);
    padding-right: var(--space-4);
  }

  .page-header,
  .grid.two {
    grid-template-columns: 1fr;
    display: grid;
  }
}