.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
  background: var(--bg);
}

.app-sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  border-right: 1px solid var(--border);
  background: var(--surface-raised);
  padding: var(--space-5) var(--space-4);
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--text);
  font-size: 1.12rem;
  font-weight: 800;
  text-decoration: none;
}
.brand-lockup:hover { color: var(--primary); }
.brand-mark { width: 36px; height: 36px; display: block; }
.brand-name { white-space: nowrap; }

.app-navigation { margin-top: var(--space-6); }
.nav-section + .nav-section { margin-top: var(--space-5); }
.nav-section-label {
  margin: 0 0 var(--space-2);
  padding: 0 var(--space-3);
  color: var(--text-muted);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.nav-list { display: grid; gap: var(--space-1); list-style: none; margin: 0; padding: 0; }
.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-height: 44px;
  border-radius: var(--radius-md);
  color: var(--text-muted);
  padding: 0.58rem 0.7rem;
  font-weight: 650;
  text-decoration: none;
}
.nav-link:hover { background: var(--primary-soft); color: var(--primary); }
.nav-link.is-active { background: var(--primary-soft); color: var(--primary); }
.nav-link-prepared { cursor: default; opacity: 0.72; }
.nav-link-prepared:hover { background: transparent; color: var(--text-muted); }
.nav-icon { width: 21px; height: 21px; flex: 0 0 auto; }
.nav-text { min-width: 0; flex: 1; }

.app-frame { min-width: 0; }
.app-topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  min-height: var(--topbar-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  backdrop-filter: blur(10px);
  padding: var(--space-3) var(--space-6);
}
.topbar-title { min-width: 0; color: var(--text); font-weight: 750; }
.topbar-actions { display: flex; align-items: center; justify-content: flex-end; gap: var(--space-4); flex-wrap: wrap; }
.topbar-actions a { color: var(--text-muted); font-weight: 650; text-decoration: none; }
.topbar-actions a:hover { color: var(--primary); }
.user-chip { color: var(--text); font-weight: 700; }

.app-main {
  width: min(calc(100% - 2rem), var(--content-max));
  margin: 0 auto;
  padding: var(--space-8) 0 var(--space-10);
}
.page-header { margin-bottom: var(--space-6); }

.public-shell { min-height: 100vh; background: var(--bg); }
.public-topbar {
  min-height: var(--topbar-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  border-bottom: 1px solid var(--border);
  background: var(--surface-raised);
  padding: var(--space-3) max(var(--space-4), calc((100vw - var(--content-max)) / 2));
}
.public-actions { display: flex; align-items: center; gap: var(--space-4); }
.public-actions a { color: var(--text-muted); font-weight: 650; text-decoration: none; }
.public-main {
  width: min(calc(100% - 2rem), var(--content-max));
  margin: 0 auto;
  padding: var(--space-8) 0 var(--space-10);
}

.topbar-leading { display: flex; align-items: center; gap: var(--space-3); min-width: 0; }
.sidebar-toggle {
  display: none;
  align-items: center;
  gap: var(--space-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-raised);
  color: var(--text-muted);
  padding: 0.45rem 0.65rem;
  font: inherit;
  font-weight: 650;
  cursor: pointer;
}
.sidebar-toggle:hover { color: var(--primary); border-color: color-mix(in srgb, var(--primary) 35%, var(--border)); }
.control-icon { width: 20px; height: 20px; flex: 0 0 auto; }
.mobile-navigation { display: none; }

@media (max-width: 1100px) {
  .sidebar-toggle { display: inline-flex; }
  .app-shell.sidebar-collapsed { grid-template-columns: var(--sidebar-rail-width) minmax(0, 1fr); }
  .app-shell.sidebar-collapsed .app-sidebar { padding-inline: var(--space-3); }
  .app-shell.sidebar-collapsed .brand-lockup { width: 100%; justify-content: center; }
  .app-shell.sidebar-collapsed .brand-name,
  .app-shell.sidebar-collapsed .nav-section-label,
  .app-shell.sidebar-collapsed .nav-text,
  .app-shell.sidebar-collapsed .badge-prepared { display: none; }
  .app-shell.sidebar-collapsed .nav-link { justify-content: center; padding-inline: 0.55rem; }
  .app-shell.sidebar-collapsed .nav-icon { width: 23px; height: 23px; }
}

@media (max-width: 760px) {
  body { overflow-x: hidden; }
  .app-shell { display: block; }
  .app-sidebar { display: none; }
  .sidebar-toggle { display: none; }
  .mobile-navigation { display: block; position: relative; }
  .mobile-navigation > summary {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    list-style: none;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface-raised);
    color: var(--text);
    padding: 0.48rem 0.68rem;
    font-weight: 700;
    cursor: pointer;
  }
  .mobile-navigation > summary::-webkit-details-marker { display: none; }
  .mobile-drawer {
    position: fixed;
    z-index: 60;
    top: var(--topbar-height);
    left: 0;
    width: min(88vw, 330px);
    height: calc(100vh - var(--topbar-height));
    overflow-y: auto;
    border-right: 1px solid var(--border);
    background: var(--surface-raised);
    box-shadow: var(--shadow);
    padding: var(--space-5) var(--space-4) var(--space-8);
    transition: transform 160ms ease;
  }
  .mobile-brand { padding: 0 var(--space-2) var(--space-4); border-bottom: 1px solid var(--border); }
  .app-topbar { min-height: var(--topbar-height); padding-inline: var(--space-3); }
  .topbar-title { display: none; }
  .topbar-actions { gap: var(--space-3); font-size: 0.92rem; }
  .topbar-actions .user-chip,
  .topbar-actions a:first-of-type { display: none; }
  .app-main { width: min(calc(100% - 1.25rem), var(--content-max)); padding-top: var(--space-6); }
  .public-topbar { padding-inline: var(--space-3); }
  .public-main { width: min(calc(100% - 1.25rem), var(--content-max)); padding-top: var(--space-6); }
}

@media (prefers-reduced-motion: reduce) {
  .app-sidebar,
  .mobile-drawer { transition: none !important; }
}

.theme-menu { position: relative; }
.theme-menu > summary {
  list-style: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-raised);
  color: var(--text-muted);
  padding: 0.42rem 0.62rem;
  font-weight: 650;
  cursor: pointer;
}
.theme-menu > summary::-webkit-details-marker { display: none; }
.theme-menu[open] > summary {
  color: var(--primary);
  border-color: color-mix(in srgb, var(--primary) 35%, var(--border));
}
.theme-options {
  position: absolute;
  z-index: 80;
  top: calc(100% + var(--space-2));
  right: 0;
  min-width: 170px;
  display: grid;
  gap: var(--space-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface-raised);
  box-shadow: var(--shadow);
  padding: var(--space-2);
}
.theme-options form { margin: 0; }
.theme-options .button { width: 100%; justify-content: flex-start; }

@media (max-width: 760px) {
  .theme-menu-prefix { display: none; }
}

.brand-mark-stack { width: 36px; height: 36px; display: grid; }
.brand-mark-stack .brand-mark { grid-area: 1 / 1; }
.brand-mark-dark { display: none; }
[data-theme-preference="dark"] .brand-mark-light { display: none; }
[data-theme-preference="dark"] .brand-mark-dark { display: block; }
@media (prefers-color-scheme: dark) {
  [data-theme-preference="system"] .brand-mark-light { display: none; }
  [data-theme-preference="system"] .brand-mark-dark { display: block; }
}