/* ==========================================================================
   caruit Shell-Layout (v2) — Grid und Regionen. Nutzt nur Tokens.
   Region-Korrespondenz (Bild 2/3):
     sidebar        = sec_left  (nav_account + nav_subject + nav_system)
     topbar         = sec_top_middle (search) + sec_top_right (info)
     header-band    = sec_header_middle
     main-section   = sec_middle
     side-right     = sec_right (tutor_logo + side_info_right)
   ========================================================================== */

*, *::before, *::after { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-normal);
  color: var(--text);
  background: var(--page-bg);
  -webkit-font-smoothing: antialiased;
}

/* Shell-Grundgerüst: Sidebar fix | Rest variabel, volle Höhe */
.shell {
  display: grid;
  grid-template-columns: var(--w-sidebar) 1fr;
  min-height: 100vh;
}

/* --- Sidebar (sec_left) --------------------------------------------------- */
.sidebar {
  background: var(--nav-bg);
  color: var(--nav-text);
  display: flex;
  flex-direction: column;
  padding: var(--space-5) var(--space-3);
  gap: var(--space-6);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.sidebar__logo {
  /* Logo-Asset: grau auf dunkel (Sidebar). Auf weißen Flächen dunkelblaue Variante. */
  font-weight: var(--fw-bold);
  font-size: var(--fs-xl);
  color: var(--nav-text-strong);
  letter-spacing: 0.02em;
  padding: 0 var(--space-3) var(--space-2);
}

.nav-group + .nav-group { margin-top: var(--space-4); }

/* --- Hauptbereich rechts der Sidebar ------------------------------------- */
.main-wrap {
  display: grid;
  grid-template-rows: var(--h-topbar) auto 1fr;
  min-width: 0;            /* erlaubt Schrumpfen der Tabelle statt Overflow */
}

/* --- Topbar (search + info), mit oranger Zierleiste darunter -------------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: 0 var(--space-6);
  background: var(--surface);
  border-bottom: 2px solid var(--topline);   /* die Zierleiste */
}

/* --- Header-Band (sec_header_middle) ------------------------------------- */
.header-band {
  padding: var(--space-6) var(--space-6) var(--space-3);
}

.header-band__title {
  margin: 0;
  font-size: var(--fs-2xl);
  font-weight: var(--fw-bold);
  color: var(--text);
}

.header-band__subtitle {
  margin: var(--space-1) 0 0;
  color: var(--text-muted);
  font-size: var(--fs-sm);
}

/* --- Mittel + Rechts: Inhaltsbereich ------------------------------------- */
.content-row {
  display: grid;
  grid-template-columns: 1fr var(--w-side-right);
  gap: var(--space-6);
  padding: 0 var(--space-6) var(--space-8);
  align-items: start;
  min-width: 0;
}

.main-section { min-width: 0; }

.side-right {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  position: sticky;
  top: calc(var(--h-topbar) + var(--space-6));
}

/* --- Responsiv: rechtes Panel unter die Mitte, dann Sidebar schmaler ------ */
@media (max-width: 1100px) {
  .content-row { grid-template-columns: 1fr; }
  .side-right { position: static; flex-direction: row; flex-wrap: wrap; }
}

@media (max-width: 820px) {
  .shell { grid-template-columns: 64px 1fr; }
  .sidebar { padding: var(--space-4) var(--space-2); }
  .sidebar__logo { font-size: var(--fs-md); text-align: center; padding: 0 0 var(--space-2); }
  /* Icon-only-Kollaps der Nav-Labels folgt in einer späteren Etappe. */
}

/* --- Quality-Floor -------------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}