.app-shell {
  display: grid;
  grid-template-columns: 224px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: 28px 14px;
  background-color: light-dark(rgba(255, 255, 255, 0.65), rgba(11, 15, 27, 0.6));
  border-right: 1px solid light-dark(rgba(15, 23, 42, 0.06), rgba(255, 255, 255, 0.06));
  backdrop-filter: var(--backdrop-blur);
  display: flex;
  flex-direction: column;
  z-index: 10;
}

.nav-backdrop {
  display: none;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 32px;
}

.brand strong {
  display: block;
  font-size: 16px;
  font-weight: 800;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.brand span {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: 11px;
  font-weight: 500;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-md);
  color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  font-weight: 900;
  font-size: 16px;
  letter-spacing: -0.03em;
  box-shadow: 0 8px 16px var(--primary-glow);
}

.brand-mark.large {
  width: 60px;
  height: 60px;
  margin-bottom: 20px;
  font-size: 22px;
  border-radius: var(--radius-lg);
}

nav {
  display: grid;
  grid-auto-rows: 42px;
  align-content: start;
  gap: 6px;
  overflow-y: auto;
  flex: 1;
}

/* Custom Scrollbar for Sidebar nav if it overflows */
nav::-webkit-scrollbar {
  width: 4px;
}
nav::-webkit-scrollbar-thumb {
  background: rgba(0,0,0,0.05);
  border-radius: 4px;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  height: 42px;
  min-height: 42px;
  flex-shrink: 0;
  padding: 0 12px;
  border-radius: var(--radius-md);
  color: var(--muted);
  font-size: 14px;
  font-weight: 600;
  border: 1px solid transparent;
  transition: var(--transition);
}

.nav-link svg {
  width: 18px;
  height: 18px;
  opacity: 0.75;
  transition: var(--transition-fast);
}

.nav-link:hover {
  color: var(--ink);
  background: light-dark(rgba(15, 23, 42, 0.04), rgba(255, 255, 255, 0.04));
  transform: translateX(4px);
}

.nav-link:hover svg {
  opacity: 1;
  color: var(--primary);
}

.nav-link.active {
  color: light-dark(var(--primary), #fff);
  background: light-dark(rgba(99, 102, 241, 0.08), rgba(255, 255, 255, 0.06));
  border-color: light-dark(rgba(99, 102, 241, 0.12), rgba(255, 255, 255, 0.08));
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.01), inset 0 1px 0 rgba(255, 255, 255, 0.05);
  font-weight: 700;
}

.nav-link.active svg {
  opacity: 1;
  color: var(--primary);
}

.nav-link.sub-item {
  padding-left: 24px;
  font-size: 13px;
  opacity: 0.9;
}

.main {
  min-width: 0;
  padding: 36px 40px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.topbar h1 {
  margin: 0;
  font-size: 24px;
  font-weight: 800;
  color: var(--ink);
}

.topbar p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 13px;
  font-weight: 500;
}

.topbar .ghost-btn {
  transition: var(--transition);
}

.topbar .ghost-btn:hover {
  color: var(--rose);
  border-color: light-dark(rgba(244, 63, 94, 0.2), rgba(251, 113, 133, 0.2));
  background: light-dark(rgba(244, 63, 94, 0.04), rgba(251, 113, 133, 0.04));
}

.mobile-nav-toggle {
  display: none;
}

.mobile-nav-toggle svg {
  width: 18px;
  height: 18px;
}