/* ==========================================================================
   Layout: AppShell, Sidebar, Topbar, BottomNav, Page
   Breakpoints: mobil < 768 px · Tablet 768–1279 px (Rail) · Desktop >= 1280 px
   ========================================================================== */

.app {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  min-height: 100vh;
  transition: grid-template-columns var(--dur) var(--ease);
}
:root[data-sidebar="collapsed"] .app { grid-template-columns: var(--sidebar-rail-w) minmax(0, 1fr); }

/* --- Sidebar ----------------------------------------------------------- */

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3);
  background: var(--surface);
  border-right: 1px solid var(--border);
  overflow-x: hidden;
  overflow-y: auto;
}

.sidebar__brand {
  display: flex;
  align-items: center;
  height: 40px;
  padding: 0 var(--space-2);
  margin-bottom: var(--space-4);
}

.nav-group__label {
  padding: var(--space-4) var(--space-3) var(--space-1);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-subtle);
  white-space: nowrap;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  height: 36px;
  padding: 0 var(--space-3);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: var(--text-sm);
  font-weight: 500;
  white-space: nowrap;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}
.nav-item .icon { width: 18px; height: 18px; }
.nav-item:hover { background: var(--surface-raised); color: var(--text); }
.nav-item[aria-current="page"] {
  background: var(--primary-subtle);
  color: var(--primary-text);
  font-weight: 600;
}
.nav-item__count {
  margin-left: auto;
  min-width: 20px;
  padding: 0 6px;
  border-radius: var(--radius-full);
  background: var(--surface-raised);
  color: var(--text-muted);
  font-size: var(--text-xs);
  line-height: 20px;
  text-align: center;
  font-variant-numeric: tabular-nums;
}
.nav-item[aria-current="page"] .nav-item__count { background: var(--surface); color: var(--primary-text); }

.sidebar__footer {
  margin-top: auto;
  padding-top: var(--space-3);
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

/* Eingeklappt (Rail) */
:root[data-sidebar="collapsed"] .sidebar .nav-item__label,
:root[data-sidebar="collapsed"] .sidebar .nav-item__count,
:root[data-sidebar="collapsed"] .sidebar .wordmark__text { display: none; }
:root[data-sidebar="collapsed"] .sidebar .nav-group__label { visibility: hidden; height: 12px; padding: 0; }
:root[data-sidebar="collapsed"] .sidebar .nav-item { justify-content: center; padding: 0; }
:root[data-sidebar="collapsed"] .sidebar .sidebar__brand { justify-content: center; padding: 0; }
.collapse-btn .icon-expand { display: none; }
:root[data-sidebar="collapsed"] .collapse-btn .icon-expand { display: block; }
:root[data-sidebar="collapsed"] .collapse-btn .icon-collapse { display: none; }

/* --- Main / Topbar ---------------------------------------------------- */

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  height: var(--topbar-h);
  padding: 0 var(--space-8);
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: saturate(180%) blur(8px);
  -webkit-backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--border);
}
.topbar__brand { display: none; }
.topbar__spacer { flex: 1; }
.topbar__actions { display: flex; align-items: center; gap: var(--space-1); }
.topbar__divider { width: 1px; height: 24px; background: var(--border); margin: 0 var(--space-2); }

/* --- Page ------------------------------------------------------------- */

.page {
  width: 100%;
  max-width: calc(var(--content-max) + 2 * var(--space-8));
  margin: 0 auto;
  padding: var(--space-8);
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

.page-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}
.page-header__title { font-size: var(--text-display); line-height: 2.25rem; font-weight: 600; letter-spacing: -0.02em; }
.page-header__meta {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-2);
  color: var(--text-muted);
  font-size: var(--text-sm);
}
.page-header__actions { display: flex; gap: var(--space-2); }

/* --- Bottom Navigation (mobil) ---------------------------------------- */

.bottom-nav { display: none; }

/* ======================= Tablet: Rail ================================= */
@media (min-width: 768px) and (max-width: 1279px) {
  .app { grid-template-columns: var(--sidebar-rail-w) minmax(0, 1fr); }
  .sidebar .nav-item__label,
  .sidebar .nav-item__count,
  .sidebar .wordmark__text,
  .sidebar .collapse-btn { display: none; }
  .sidebar .nav-group__label { visibility: hidden; height: 12px; padding: 0; }
  .sidebar .nav-item { justify-content: center; padding: 0; }
  .sidebar .sidebar__brand { justify-content: center; padding: 0; }
  .topbar { padding: 0 var(--space-6); }
  .page { padding: var(--space-6); }
}

/* ======================= Mobil ======================================== */
@media (max-width: 767px) {
  .app,
  :root[data-sidebar="collapsed"] .app { grid-template-columns: minmax(0, 1fr); }
  .sidebar { display: none; }

  .topbar { padding: 0 var(--space-4); gap: var(--space-1); }
  .topbar__brand { display: flex; align-items: center; }
  .topbar__divider { display: none; }

  .page {
    padding: var(--space-5) var(--space-4) calc(var(--bottomnav-h) + var(--space-8));
    gap: var(--space-6);
  }
  .page-header__title { font-size: var(--text-h1); line-height: 2rem; }
  .page-header__actions { display: none; }
  .hide-mobile { display: none !important; }

  .bottom-nav {
    position: fixed;
    inset: auto 0 0 0;
    z-index: 30;
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    height: calc(var(--bottomnav-h) + env(safe-area-inset-bottom));
    padding-bottom: env(safe-area-inset-bottom);
    background: var(--surface);
    border-top: 1px solid var(--border);
  }
  .bottom-nav__item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    min-height: 44px;
    color: var(--text-muted);
    font-size: 11px;
    font-weight: 500;
  }
  .bottom-nav__item .icon { width: 22px; height: 22px; }
  .bottom-nav__item[aria-current="page"] { color: var(--primary-text); font-weight: 600; }
  .bottom-nav__item[aria-current="page"] .icon { stroke-width: 2.4; }
}