/* ═══════════════════════════════════════════════════════════════════
   Layout — app shell, sidebar, topbar, view.
   ═══════════════════════════════════════════════════════════════════ */

.app-shell {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  min-height: 100vh;
  background: var(--surface-sunken);
  transition: grid-template-columns var(--dur-base) var(--ease-out);
}
.app-shell.sidebar-collapsed {
  grid-template-columns: 64px 1fr;
}

.sidebar {
  background: var(--surface-sunken);
  border-right: 1px solid var(--border-subtle);
  padding: var(--s-3) 0 var(--s-4);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  overflow-x: visible;
  display: flex;
  flex-direction: column;
  gap: 2px;
  transition: width var(--dur-base) var(--ease-out);
}
.sidebar-collapsed .sidebar .nav-item span,
.sidebar-collapsed .sidebar .sidebar-brand span,
.sidebar-collapsed .sidebar .nav-group-title {
  display: none;
}
.sidebar-collapsed .sidebar .nav-item {
  justify-content: center;
  padding: 10px 0;
  margin: 1px 6px;
}
.sidebar-collapsed .sidebar .sidebar-brand {
  justify-content: center;
  padding: 10px 0 var(--s-3);
}
.sidebar-toggle {
  align-self: flex-end;
  margin: 0 8px 4px auto;
  width: 28px;
  height: 28px;
  border-radius: 6px;
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--dur-fast) var(--ease-out), transform var(--dur-base) var(--ease-out);
  padding: 0;
  min-height: auto;
  flex-shrink: 0;
}
.sidebar-toggle:hover {
  background: var(--surface-hover);
  color: var(--text-primary);
}
.sidebar-collapsed .sidebar-toggle {
  align-self: center;
  margin: 0 0 4px;
}
.sidebar-collapsed .sidebar-toggle svg {
  transform: rotate(180deg);
}
@media (max-width: 768px) {
  .sidebar-toggle { display: none; }
}
.sidebar-toggle:hover {
  background: var(--surface-hover);
  color: var(--text-primary);
}
.sidebar-collapsed .sidebar-toggle svg {
  transform: rotate(180deg);
}
.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 20px var(--s-4);
  font-family: var(--font-display);
  font-weight: var(--fw-bold);
  font-size: var(--fs-md);
  color: var(--text-primary);
  letter-spacing: var(--tracking-tight);
}
.sidebar-brand-logo {
  width: 28px; height: 28px;
  border-radius: var(--radius-sm);
  background: var(--brand-500);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: var(--fw-bold);
  font-size: 15px;
}
.sidebar-foot {
  margin-top: auto;
  padding: var(--s-3) var(--s-3) 0;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.main {
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--surface-sunken);
}

.topbar {
  background: var(--surface-sunken);
  border-bottom: 1px solid var(--border-subtle);
  padding: 10px var(--s-5);
  display: flex;
  align-items: center;
  gap: var(--s-3);
  position: sticky;
  top: 0;
  z-index: 50;
  min-height: var(--topbar-h);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  background: color-mix(in srgb, var(--surface-sunken) 85%, transparent);
}

.topbar-search {
  display: flex;
  align-items: center;
  gap: 6px;
  flex: 1;
  max-width: 420px;
  padding: 6px 12px;
  background: var(--surface-raised);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: var(--fs-sm);
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out);
  min-height: 34px;
}
.topbar-search:hover { border-color: var(--border-default); background: var(--surface-raised); }
.topbar-search-hint { margin-left: auto; display: flex; gap: 4px; }

.view {
  flex: 1;
  padding: var(--s-6) var(--s-5);
  min-width: 0;
  max-width: var(--view-max);
  width: 100%;
  margin: 0 auto;
  animation: bm-fade-in var(--dur-base) var(--ease-out);
}

.view-head { display: flex; justify-content: space-between; align-items: flex-start; gap: var(--s-4); flex-wrap: wrap; margin-bottom: var(--s-5); }
.view-title { font-size: var(--fs-2xl); font-weight: var(--fw-bold); letter-spacing: var(--tracking-tight); color: var(--text-primary); margin: 0; }
.view-sub { font-size: var(--fs-sm); color: var(--text-secondary); margin-top: 4px; }
.view-actions { display: flex; gap: var(--s-2); align-items: center; flex-wrap: wrap; }

/* Mobile */
@media (max-width: 768px) {
  .app-shell { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed;
    left: -100%;
    width: min(280px, 85vw);
    transition: left var(--dur-base) var(--ease-out);
    z-index: 100;
    box-shadow: var(--shadow-xl);
    background: var(--surface-raised);
  }
  .sidebar.open { left: 0; }
  .view { padding: var(--s-4); }
  .view-title { font-size: var(--fs-xl); }
}

.sidebar-backdrop {
  display: none;
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.3);
  backdrop-filter: blur(2px);
  z-index: 99;
  animation: bm-fade-in var(--dur-fast) var(--ease-out);
}
.sidebar-backdrop.open { display: block; }