.app-shell {
  display: grid;
  grid-template-columns: var(--sidebar) 1fr;
  min-height: 100vh;
}
.sidebar {
  background: var(--navy);
  color: var(--on-navy);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}
.sidebar__brand {
  display: flex;
  gap: 0.75rem;
  align-items: center;
  padding: 1.25rem;
  color: inherit;
  text-decoration: none;
}
.sidebar__logo { width: 2.2rem; height: 2.2rem; }
.sidebar__title { font-size: 1.15rem; }
.sidebar__subtitle { font-size: 0.72rem; color: var(--on-navy-muted); }
.sidebar__nav { flex: 1; padding: 0.5rem 0.5rem 1rem; overflow: auto; }
.sidebar__foot { padding: 1rem; font-size: 0.72rem; color: var(--on-navy-muted); }
.nav-link {
  display: block;
  color: inherit;
  text-decoration: none;
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius);
  font-size: 0.92rem;
  margin-bottom: 0.15rem;
}
.nav-link.is-active, .nav-link:hover { background: rgba(255,255,255,0.08); }
.main, .app-main { display: flex; flex-direction: column; min-width: 0; }
.sidebar__brand { display: block; padding: 1.25rem; }
.sidebar__brand .brand-mark { color: var(--on-navy); text-decoration: none; display: block; }
.sidebar__tag { margin: 0.35rem 0 0; font-size: 0.75rem; color: var(--on-navy-muted); }
.nav-link { display: flex; gap: 0.5rem; align-items: center; }
.nav-link--inline { display: inline; padding: 0; }
.topbar__menu { display: none; }
.topbar {
  height: var(--topbar);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0 1rem;
  border-bottom: 1px solid var(--line);
  background: var(--elev);
  position: sticky;
  top: 0;
  z-index: 5;
}
.topbar__title { flex: 1; font-size: 1.15rem; margin: 0; font-family: var(--font-display); }
.topbar__actions { display: flex; gap: 0.5rem; align-items: center; }
.content { flex: 1; }
.bottom-nav { display: none; }
#btn-menu { display: none; }

@media (max-width: 860px) {
  .app-shell { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    width: min(17rem, 86vw);
    transform: translateX(-105%);
    z-index: var(--z-sidebar);
    transition: transform 180ms ease;
  }
  .app-shell.nav-open .sidebar { transform: none; }
  #btn-menu, .topbar__menu { display: inline-flex; }
  .bottom-nav {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    position: fixed;
    left: 0; right: 0; bottom: 0;
    background: var(--elev);
    border-top: 1px solid var(--line);
    height: var(--bottom-nav);
    z-index: 15;
    align-items: center;
    text-align: center;
  }
  .bottom-nav a {
    color: var(--text);
    text-decoration: none;
    font-size: 0.7rem;
    padding: 0.4rem;
  }
  .bottom-nav a.is-active { color: var(--accent); font-weight: 700; }
}