.bgt-shell {
  display: flex;
  min-height: 100dvh;
}

.bgt-shell__sidebar {
  display: none;
  flex-direction: column;
  width: 240px;
  flex-shrink: 0;
  /* Dark navy to match BuildGenius Ed's sidebar - deliberately not the
     shared canvas/surface tokens, same reasoning as Ed's own .sidebar
     rule (those tokens are used everywhere else, cards included). */
  border-right: 1px solid var(--bgt-color-sidebar-border);
  background: var(--bgt-color-sidebar-bg);
  color: var(--bgt-color-sidebar-text);
  padding: calc(var(--bgt-spacing-base) * 4);
  gap: calc(var(--bgt-spacing-base) * 2);
}

.bgt-shell__brand {
  font-weight: 700;
  font-size: 1.125rem;
  margin: 0 0 calc(var(--bgt-spacing-base) * 4) 0;
  color: var(--bgt-color-sidebar-text-strong);
  padding-bottom: calc(var(--bgt-spacing-base) * 3);
  border-bottom: 1px solid var(--bgt-color-sidebar-border);
}

.bgt-shell__nav-link {
  display: flex;
  align-items: center;
  min-height: var(--bgt-control-height-default);
  padding: 0 calc(var(--bgt-spacing-base) * 3);
  border-radius: var(--bgt-radius-small);
  color: var(--bgt-color-sidebar-text);
  text-decoration: none;
  font-weight: 500;
}

.bgt-shell__nav-link:hover {
  background: var(--bgt-color-sidebar-hover-bg);
  color: var(--bgt-color-sidebar-text-strong);
}

.bgt-shell__nav-link[aria-current="page"] {
  background: var(--bgt-color-sidebar-hover-bg);
  color: #ffffff;
  font-weight: 700;
  box-shadow: inset 4px 0 0 var(--bgt-color-accent);
}

.bgt-shell__main {
  flex: 1;
  min-width: 0;
  max-width: var(--bgt-content-max-width);
  padding: calc(var(--bgt-spacing-base) * 6);
  padding-bottom: calc(var(--bgt-spacing-base) * 20); /* room for the mobile bottom nav */
}

.bgt-shell__bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-around;
  background: var(--bgt-color-surface);
  border-top: 1px solid var(--bgt-color-border);
  padding-bottom: env(safe-area-inset-bottom);
}

.bgt-shell__bottom-nav-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  flex: 1;
  min-height: var(--bgt-control-height-default);
  padding: calc(var(--bgt-spacing-base) * 2) 0;
  color: var(--bgt-color-secondary-text);
  text-decoration: none;
  font-size: 0.75rem;
}

.bgt-shell__bottom-nav-link[aria-current="page"] {
  color: var(--bgt-color-accent);
  font-weight: 700;
}

/* Section 4.8: "persistent sidebar on desktop/tablet and a five-item
   bottom navigation on small screens". */
@media (min-width: 768px) {
  .bgt-shell__sidebar {
    display: flex;
  }
  .bgt-shell__bottom-nav {
    display: none;
  }
  .bgt-shell__main {
    padding-bottom: calc(var(--bgt-spacing-base) * 6);
  }
}

.bgt-centered-message {
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem;
}

.bgt-sign-in {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--bgt-spacing-base);
  padding: calc(var(--bgt-spacing-base) * 6);
  text-align: center;
}

.bgt-sign-in__button {
  min-height: var(--bgt-control-height-default);
  padding: 0 1.5rem;
  border: 1px solid var(--bgt-color-border);
  background: var(--bgt-color-surface);
  border-radius: var(--bgt-radius-medium);
  font-weight: 600;
}