body {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  grid-template-rows: var(--topnav-h) 1fr;
  grid-template-areas:
    "sidebar topnav"
    "sidebar main";
  height: 100dvh;
}

body.sidebar-collapsed {
  grid-template-columns: var(--sidebar-w-collapsed) 1fr;
}

/* ===== Sidebar ===== */
aside {
  grid-area: sidebar;
  background: var(--surface-white);
  border-right: 1px solid var(--outline-dim);
  display: flex;
  flex-direction: column;
  padding: var(--space-md);
  gap: var(--space-sm);
  overflow: hidden;
  z-index: 40;
  transition: width 0.2s ease, padding 0.2s ease;
}

aside > .collapse-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--on-surface-dim);
  padding: var(--space-xs);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  width: 2rem;
  height: 2rem;
}

aside > .collapse-btn:hover {
  background: var(--surface-highest);
  color: var(--on-surface);
}

aside > .cta {
  width: 100%;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  background: var(--primary);
  color: var(--on-primary);
  border: none;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: opacity var(--transition);
}

aside > .cta:hover {
  opacity: 0.9;
}

aside > nav {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

aside > nav > a {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  color: var(--on-surface-dim);
  transition: all var(--transition);
}

aside > nav > a:hover {
  background: var(--surface-low);
  color: var(--on-surface);
}

aside > nav > a.active {
  background: var(--primary-container);
  color: var(--primary);
  font-weight: 700;
}

body.sidebar-collapsed aside {
  width: var(--sidebar-w-collapsed);
  padding: var(--space-xs);
  align-items: center;
}

body.sidebar-collapsed aside > .cta {
  width: 2.5rem;
  height: 2.5rem;
  padding: 0;
  border-radius: 50%;
}

body.sidebar-collapsed aside > .cta span:not(.material-symbols-outlined) {
  display: none;
}

body.sidebar-collapsed aside > nav > a {
  justify-content: center;
  padding: var(--space-sm);
}

body.sidebar-collapsed aside > nav > a span:not(.material-symbols-outlined) {
  display: none;
}

/* ===== Topnav ===== */
.topnav {
  grid-area: topnav;
  border-bottom: 1px solid var(--outline-dim);
  background: var(--surface);
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  padding: 0 var(--space-lg);
  flex-shrink: 0;
  position: sticky;
  top: 0;
  z-index: 30;
}

.topnav > h1 {
  margin-right: auto;
}

.topnav > .search {
  position: relative;
  width: 15rem;
}

.topnav > .search input {
  height: 2rem;
  padding-left: 2rem;
  font-size: 0.875rem;
}

.topnav > .search .material-symbols-outlined {
  position: absolute;
  left: var(--space-sm);
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.25rem;
  color: var(--on-surface-dim);
  pointer-events: none;
}

/* ===== Main ===== */
main {
  grid-area: main;
  overflow-y: auto;
}

.main-content {
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  min-height: 0;
  flex: 1;
}

/* ===== Responsive ===== */
@media (max-width: 64em) {
  .topnav > .search {
    width: 10rem;
  }
}

@media (max-width: 48em) {
  aside {
    width: var(--sidebar-w-collapsed);
    padding: var(--space-xs);
    align-items: center;
  }

  aside > .cta {
    width: 2.5rem;
    height: 2.5rem;
    padding: 0;
    border-radius: 50%;
  }

  aside > .cta span:not(.material-symbols-outlined) {
    display: none;
  }

  aside > nav > a {
    justify-content: center;
    padding: var(--space-sm);
  }

  aside > nav > a span:not(.material-symbols-outlined) {
    display: none;
  }

  body.sidebar-collapsed aside {
    width: 0;
    padding: 0;
    overflow: hidden;
    border-right: none;
  }

  body.sidebar-collapsed {
    grid-template-columns: 0 1fr;
  }

  .topnav {
    padding: 0 var(--space-sm);
  }

  .topnav > .search {
    display: none;
  }

  .main-content {
    padding: var(--space-sm);
  }
}