.app-shell {
  display: flex;
  min-height: 100vh;
  background: var(--bg-secondary);
}

.sidebar {
  width: 248px;
  flex-shrink: 0;
  background: var(--bg-card);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  padding: max(20px, env(safe-area-inset-top)) 14px max(20px, env(safe-area-inset-bottom));
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 12px;

    padding: 16px 12px 24px;

    font-family: var(--font-display);
    color: var(--text-primary);
}

.brand-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    
}
.brand-icon img {
    width: 55px;
    height: 55px;
    object-fit: contain;
    display: block;
}
.brand-name {
    font-size: 1.4rem;
    font-weight: 700;
    line-height: 1;
    color: var(--text-primary);
}
.sidebar-nav { display: flex; flex-direction: column; gap: 3px; }

.nav-link {
  display: flex;
  align-items: center;
  min-height: 42px;
  gap: 10px;
  padding: 9px 11px;
  border-radius: 8px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.87rem;
  transition: background var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
}

.nav-link:hover { background: var(--bg-secondary); color: var(--text-primary); }
.nav-link:active { transform: translateX(1px); }
.nav-link.active { background: rgba(227, 93, 69, 0.16); color: var(--text-primary); }
.nav-link.active { background: color-mix(in srgb, var(--accent) 18%, transparent); }
.nav-link.active .nav-icon { filter: saturate(1.35); }
.nav-icon { width: 22px; text-align: center; font-size: 1rem; }

.main-column { flex: 1; display: flex; flex-direction: column; min-width: 0; }

.topbar {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 64px;
  padding: max(10px, env(safe-area-inset-top)) max(20px, env(safe-area-inset-right)) 10px max(20px, env(safe-area-inset-left));
  border-bottom: 1px solid var(--border-color);
  background: color-mix(in srgb, var(--bg-card) 88%, transparent);
  backdrop-filter: blur(14px);
  position: sticky;
  top: 0;
  z-index: 20;
}

.topbar-spacer { flex: 1; }
.topbar-user { max-width: 150px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; color: var(--text-secondary); font-size: 0.8rem; }
.icon-btn.mobile-menu-btn { display: none; border-radius: 8px; }
.sidebar-backdrop { display: none; }

.page-content {
  flex: 1;
  width: 100%;
  max-width: 1480px;
  margin: 0 auto;
  padding: clamp(20px, 3vw, 36px);
  overflow-y: auto;
}

.page-header { margin-bottom: 24px; }
.page-header h1 { margin: 0 0 5px; color: var(--text-primary); font-size: clamp(1.55rem, 3vw, 2rem); }
.page-subtitle { color: var(--text-secondary); margin: 0; font-size: 0.9rem; }

.placeholder-content {
  background: var(--bg-card);
  border: 1px dashed var(--border-color);
  border-radius: 10px;
  padding: 48px 24px;
  text-align: center;
  color: var(--text-secondary);
}

@media (max-width: 860px) {
  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 50;
    width: min(82vw, 290px);
    padding-top: max(20px, env(safe-area-inset-top));
    transform: translateX(-102%);
    box-shadow: 18px 0 50px rgba(0, 0, 0, 0.2);
    transition: transform 180ms ease;
  }

  body.menu-open .sidebar { transform: translateX(0); }
  .sidebar-backdrop { display: block; position: fixed; inset: 0; z-index: 40; background: rgba(0, 0, 0, 0.45); opacity: 0; pointer-events: none; transition: opacity 180ms ease; }
  body.menu-open .sidebar-backdrop { opacity: 1; pointer-events: auto; }
  .icon-btn.mobile-menu-btn { display: inline-flex; }
  .topbar { padding-left: max(12px, env(safe-area-inset-left)); }
}

@media (max-width: 560px) {
  .topbar { min-height: 58px; padding-right: max(12px, env(safe-area-inset-right)); }
  .topbar-user { display: none; }
  .topbar .btn-secondary-sm { padding: 8px 10px; }
  .page-content { padding: 20px 14px max(28px, env(safe-area-inset-bottom)); }
  .page-header { margin-bottom: 18px; }
}