.app-layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-rows: var(--topbar-height) 1fr;
  grid-template-areas:
    "sidebar topbar"
    "sidebar main";
  min-height: 100vh;
}

.sidebar {
  grid-area: sidebar;
  background: var(--bg-sidebar);
  color: var(--text-inverse);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  z-index: 100;
  overflow-y: auto;
  transition: var(--transition);
}

.sidebar-header {
  padding: 1.25rem 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.sidebar-logo {
  width: 36px;
  height: 36px;
  background: var(--accent);
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: var(--font-size-lg);
}

.sidebar-brand {
  font-size: var(--font-size-lg);
  font-weight: 700;
  letter-spacing: 0.5px;
}

.sidebar-section {
  padding: 1rem 0 0.25rem;
}

.sidebar-section-title {
  font-size: var(--font-size-xs);
  text-transform: uppercase;
  letter-spacing: 1px;
  color: rgba(255,255,255,0.5);
  padding: 0 1rem;
  margin-bottom: 0.5rem;
}

.sidebar-nav {
  list-style: none;
}

.sidebar-nav li a {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 1rem;
  color: rgba(255,255,255,0.8);
  transition: var(--transition);
  border-left: 3px solid transparent;
}

.sidebar-nav li a:hover,
.sidebar-nav li a.active {
  background: rgba(255,255,255,0.1);
  color: #fff;
  text-decoration: none;
}

.sidebar-nav li a.active {
  border-left-color: var(--accent);
}

.sidebar-nav li a .icon {
  width: 20px;
  text-align: center;
  font-size: var(--font-size-lg);
}

.sidebar-submenu {
  list-style: none;
  padding-left: 2.5rem;
  display: none;
}

.sidebar-submenu.open {
  display: block;
}

.sidebar-submenu li a {
  padding: 0.4rem 1rem;
  font-size: var(--font-size-sm);
}

.topbar {
  grid-area: topbar;
  background: var(--bg-topbar);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  position: fixed;
  top: 0;
  left: var(--sidebar-width);
  right: 0;
  height: var(--topbar-height);
  z-index: 90;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.topbar-indicator {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.75rem;
  background: var(--success-light);
  border-radius: var(--border-radius);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--success);
}

.topbar-user {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
}

.topbar-user-avatar {
  width: 32px;
  height: 32px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: var(--font-size-sm);
}

.main-content {
  grid-area: main;
  padding: calc(var(--topbar-height) + 1.5rem) 1.5rem 1.5rem;
  margin-left: var(--sidebar-width);
  min-height: calc(100vh - var(--topbar-height));
}

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
}

.page-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--text-primary);
}

.page-title .icon {
  color: var(--primary);
}

.btn-group {
  display: flex;
  gap: 0.5rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

@media (max-width: 768px) {
  .app-layout {
    grid-template-columns: 1fr;
    grid-template-areas:
      "topbar"
      "main";
  }

  .sidebar {
    transform: translateX(-100%);
  }

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

  .topbar {
    left: 0;
  }

  .main-content {
    margin-left: 0;
    padding: calc(var(--topbar-height) + 1rem) 1rem 1rem;
  }

  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}