/* ── LAYOUT CSS ── */
/* BUG-042 FIX: grid-template-rows now updates at the tablet breakpoint
   alongside grid-template-columns, preventing a possible invisible gap. */

/* App shell for authenticated pages */
.app-shell {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  grid-template-rows: var(--topnav-h) 1fr;
  min-height: 100vh;
}

/* ── TOPNAV ── */
.topnav {
  grid-column: 1 / -1;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  height: var(--topnav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--sp-5);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.topnav-brand {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  text-decoration: none;
}
.topnav-brand:hover { text-decoration: none; }

.brand-ico {
  width: 36px; height: 36px;
  background: linear-gradient(135deg, var(--brand-primary), #E55A2B);
  border-radius: var(--r);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.2rem;
  box-shadow: 0 4px 12px rgba(255,107,53,.3);
}

.brand-name {
  font-family: var(--font-head);
  font-size: var(--fs-lg);
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.3px;
}
.brand-name span { color: var(--brand-text); }

.topnav-right { display:flex; align-items:center; gap:var(--sp-3); }

.topnav-btn {
  width: 36px; height: 36px;
  border-radius: var(--r-full);
  display: flex; align-items:center; justify-content:center;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-2);
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--t-fast);
  position: relative;
}
.topnav-btn:hover { background:var(--gray-100); color:var(--text); }
[data-theme="dark"] .topnav-btn:hover { background:rgba(255,255,255,.08); }

.user-menu {
  display: flex; align-items: center; gap: var(--sp-2);
  padding: 5px 12px 5px 5px;
  border-radius: var(--r-full);
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  cursor: pointer;
  transition: all var(--t-fast);
}
.user-menu:hover { border-color:var(--blue-600); }
.user-name { font-size:var(--fs-sm); font-weight:600; color:var(--text); }
.user-cls  { font-size:var(--fs-xs); color:var(--text-3); }
.user-menu-caret { font-size:10px; color:var(--text-3); margin-left:2px; }

/* Dropdown (Dashboard / Logout) — replaces the old #globalUserBadge's
   one job (a site-wide one-click Logout) by folding it into this
   existing menu instead of a separate floating element. */
.user-menu-wrap { position:relative; }
.user-menu-dropdown {
  position:absolute; top:calc(100% + 8px); right:0;
  min-width:170px;
  background:var(--bg-card); border:1px solid var(--border);
  border-radius:var(--r-md); box-shadow:var(--shadow-md);
  padding:var(--sp-2);
  display:flex; flex-direction:column; gap:2px;
  opacity:0; visibility:hidden; transform:translateY(-6px);
  transition:opacity var(--t-fast), transform var(--t-fast), visibility var(--t-fast);
  z-index:2500;
}
.user-menu-dropdown.open { opacity:1; visibility:visible; transform:translateY(0); }
.user-menu-item {
  display:flex; align-items:center; gap:var(--sp-2);
  width:100%; border:none; background:transparent; text-align:left;
  padding:var(--sp-2) var(--sp-3); border-radius:var(--r-sm,8px);
  font-size:var(--fs-sm); font-weight:600; color:var(--text);
  font-family:var(--font); cursor:pointer; text-decoration:none;
}
.user-menu-item:hover { background:var(--gray-100); }
[data-theme="dark"] .user-menu-item:hover { background:rgba(255,255,255,.08); }
.user-menu-item.user-menu-logout { color:var(--red-600, #e53e3e); }

/* ── SIDEBAR ── */
.sidebar {
  background: var(--bg-card);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: var(--sp-4) var(--sp-3);
  position: sticky;
  top: var(--topnav-h);
  height: calc(100vh - var(--topnav-h));
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
}
.sidebar::-webkit-scrollbar { width: 3px; }

.sidebar-section-label {
  font-size: var(--fs-xs);
  font-weight: 700;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: .6px;
  padding: var(--sp-3) var(--sp-3) var(--sp-1);
  margin-top: var(--sp-2);
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: 9px 12px;
  border-radius: var(--r);
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--text-2);
  text-decoration: none;
  transition: all var(--t-fast);
  cursor: pointer;
  border: 1px solid transparent;
}
.nav-item:hover {
  background: var(--bg-secondary);
  color: var(--text);
  text-decoration: none;
}
.nav-item.active {
  background: linear-gradient(135deg,rgba(255,107,53,.12),rgba(83,52,131,.08));
  color: var(--brand-text);
  border-color: rgba(255,107,53,.18);
  font-weight: 600;
}
.nav-icon { font-size: 1.05rem; width: 22px; text-align:center; flex-shrink:0; }
.nav-badge {
  margin-left:auto; background:var(--brand-primary); color:white;
  font-size:9px; font-weight:800; padding:1px 6px; border-radius:10px;
}

.sidebar-bottom {
  margin-top: auto;
  padding-top: var(--sp-4);
  border-top: 1px solid var(--border);
}

/* BUG-246 FIX: mobile close button hidden by default, shown via mobile.css */
.mobile-close-btn { display: none; }

/* ── MAIN CONTENT ── */
.main-content {
  overflow-y: auto;
  height: calc(100vh - var(--topnav-h));
  background: var(--bg-secondary);
}

.page-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: var(--sp-6);
}

.page-header {
  margin-bottom: var(--sp-6);
}
.page-title {
  font-family: var(--font-head);
  font-size: var(--fs-2xl);
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.5px;
  line-height: 1.2;
}
.page-subtitle {
  font-size: var(--fs-sm);
  color: var(--text-2);
  margin-top: var(--sp-1);
}

/* ── FULLSCREEN LAYOUT (Teacher, Classroom) ── */
.fullscreen-layout {
  grid-template-columns: 1fr;
  grid-template-rows: var(--topnav-h) 1fr;
}
.fullscreen-layout .sidebar { display: none; }
.fullscreen-layout .main-content { height: calc(100vh - var(--topnav-h)); overflow: hidden; }

/* ── RESPONSIVE ── */
/* BUG-042 FIX: grid-template-rows explicitly re-declared at this
   breakpoint (was previously only grid-template-columns changing,
   which could leave a topnav-height gap on some tablet configurations
   depending on how child elements compute their row placement). */
@media (max-width: 1024px) {
  .app-shell {
    grid-template-columns: 1fr;
    grid-template-rows: var(--topnav-h) 1fr;  /* explicit, was implicit before */
  }
  .sidebar { display: none; }
  .sidebar.mobile-open { display:flex; position:fixed; left:0; top:var(--topnav-h); width:var(--sidebar-w); z-index:200; box-shadow:var(--shadow-lg); }
}
@media (max-width: 768px) {
  .page-container { padding:var(--sp-4); }
}