/* ============================================================
   LAYOUT.CSS — app shell: sidebar, topbar, routed content area
   ============================================================ */

#app-shell {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-rows: var(--topbar-height) 1fr;
  grid-template-areas:
    "sidebar topbar"
    "sidebar main";
  height: 100vh;
  width: 100%;
  transition: grid-template-columns var(--dur-base) var(--ease-in-out);
}

#app-shell.sidebar-collapsed {
  grid-template-columns: var(--sidebar-collapsed) 1fr;
}

/* ---- Sidebar ---- */

#sidebar {
  grid-area: sidebar;
  background: var(--bg-panel);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  z-index: 20;
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  height: var(--topbar-height);
  padding: 0 var(--sp-4);
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

.sidebar-brand-mark {
  width: 30px; height: 30px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-ccna));
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--on-accent);
  flex-shrink: 0;
}

.sidebar-brand-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-sm);
  white-space: nowrap;
  overflow: hidden;
}
.sidebar-brand-text small {
  display: block;
  font-weight: 500;
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

#app-shell.sidebar-collapsed .sidebar-brand-text,
#app-shell.sidebar-collapsed .nav-label,
#app-shell.sidebar-collapsed .nav-section-title,
#app-shell.sidebar-collapsed .sidebar-footer-text {
  display: none;
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: var(--sp-3) var(--sp-2);
}

.nav-section-title {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-disabled);
  padding: var(--sp-4) var(--sp-3) var(--sp-2);
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  width: 100%;
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: var(--fs-sm);
  font-weight: 500;
  margin-bottom: 2px;
  position: relative;
  transition: background var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}
.nav-item:hover { background: var(--bg-panel-raised); color: var(--text-primary); }
.nav-item.active { background: var(--accent-primary-dim); color: var(--accent-primary); }
.nav-item.active::before {
  content: '';
  position: absolute;
  left: -8px; top: 50%; transform: translateY(-50%);
  width: 3px; height: 60%;
  background: var(--accent-primary);
  border-radius: var(--radius-pill);
}

.nav-item-icon {
  width: 18px; height: 18px;
  flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
}

.nav-item-xp {
  margin-left: auto;
  font-size: 0.65rem;
  font-family: var(--font-mono);
  color: var(--text-disabled);
}

.sidebar-footer {
  border-top: 1px solid var(--border-subtle);
  padding: var(--sp-3);
  flex-shrink: 0;
}

.sidebar-collapse-btn {
  width: 100%;
  display: flex; align-items: center; gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-size: var(--fs-xs);
}
.sidebar-collapse-btn:hover { background: var(--bg-panel-raised); color: var(--text-primary); }

/* ---- Topbar ---- */

#topbar {
  grid-area: topbar;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--sp-5);
  border-bottom: 1px solid var(--border-subtle);
  background: var(--overlay-soft);
  backdrop-filter: blur(8px);
  z-index: 10;
}

.topbar-breadcrumb {
  font-size: var(--fs-sm);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}
.topbar-breadcrumb strong { color: var(--text-primary); font-weight: 600; }

.topbar-right {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
}

.xp-pill {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  background: var(--bg-inset);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-pill);
  padding: var(--sp-1) var(--sp-4) var(--sp-1) var(--sp-2);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
}

.streak-flame {
  font-size: var(--fs-sm);
}

/* ---- Main content ---- */

#main-content {
  grid-area: main;
  overflow-y: auto;
  position: relative;
}

.view {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: var(--sp-6) var(--sp-6) var(--sp-8);
  animation: view-enter var(--dur-slow) var(--ease-out);
}

.view-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: var(--sp-6);
  gap: var(--sp-4);
  flex-wrap: wrap;
}

.view-eyebrow {
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: var(--sp-1);
}

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-5); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--sp-5); }
.grid-auto { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: var(--sp-5); }

.stack { display: flex; flex-direction: column; gap: var(--sp-4); }
.row { display: flex; align-items: center; gap: var(--sp-3); }
.row-between { display: flex; align-items: center; justify-content: space-between; }