/* ================================================================
   College Hub — stylesheet
   Dark theme default, light theme via [data-theme="light"]
   ================================================================ */

/* ── Variables ──────────────────────────────────────────────────── */
:root {
  /* dark (default) */
  --bg:          #0d0d0d;
  --bg2:         #141414;
  --surface:     #1a1a1a;
  --surface2:    #222222;
  --border:      #2a2a2a;
  --text:        #e8e8e8;
  --text-muted:  #888;
  --text-faint:  #555;
  --accent:      #7c3aed;
  --accent-glow: rgba(124,58,237,.35);
  --accent-dim:  #4c1d95;
  --success:     #10b981;
  --danger:      #ef4444;
  --warning:     #f59e0b;
  --info:        #3b82f6;
  --radius:      10px;
  --radius-lg:   16px;
  --sidebar-w:   240px;
  --topbar-h:    56px;
  --trans:       .22s ease;
}

[data-theme="light"] {
  --bg:          #f4f4f8;
  --bg2:         #eaeaf0;
  --surface:     #ffffff;
  --surface2:    #f0f0f5;
  --border:      #dde0e8;
  --text:        #111827;
  --text-muted:  #6b7280;
  --text-faint:  #9ca3af;
  --accent:      #6d28d9;
  --accent-glow: rgba(109,40,217,.18);
  --accent-dim:  #ede9fe;
}

/* ── Utility ─────────────────────────────────────────────────────── */
.hidden { display: none !important; }

/* ── Reset ──────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 15px;
  transition: background var(--trans), color var(--trans);
  overflow-x: hidden;
}
a { color: var(--accent); text-decoration: none; transition: opacity var(--trans); }
a:hover { opacity: .8; }
img { max-width: 100%; }

/* ── Scrollbar ──────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg2); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 99px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent); }

/* ================================================================
   LAYOUT
   ================================================================ */

/* ── Sidebar ────────────────────────────────────────────────────── */
#sidebar {
  position: fixed;
  top: 0; left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  z-index: 200;
  transition: width var(--trans);
  overflow: hidden;
}

/* Floating toggle tab on the right edge of sidebar */
#sidebar-toggle {
  position: fixed;
  top: 50%;
  left: var(--sidebar-w);
  transform: translate(-50%, -50%);
  z-index: 201;
  width: 22px;
  height: 48px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: none;
  border-radius: 0 8px 8px 0;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-faint);
  font-size: .7rem;
  transition: left var(--trans), background var(--trans), color var(--trans), box-shadow var(--trans);
  box-shadow: 3px 0 8px rgba(0,0,0,.15);
}
#sidebar-toggle:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  box-shadow: 3px 0 16px var(--accent-glow);
}
#sidebar-toggle .chevron {
  transition: transform var(--trans);
  display: inline-block;
  line-height: 1;
}

/* Collapsed state */
#sidebar.collapsed { width: 64px; }
#sidebar.collapsed + #sidebar-overlay ~ #topbar,
#topbar.sidebar-collapsed { left: 64px; }

#sidebar.collapsed ~ #sidebar-toggle,
#sidebar-toggle.sidebar-collapsed {
  left: 64px;
}
#sidebar.collapsed ~ #sidebar-toggle .chevron,
#sidebar-toggle.sidebar-collapsed .chevron {
  transform: rotate(180deg);
}

#sidebar.collapsed .nav-label,
#sidebar.collapsed .sidebar-logo-text,
#sidebar.collapsed .sidebar-section-label,
#sidebar.collapsed .sidebar-footer-label {
  opacity: 0;
  width: 0;
  overflow: hidden;
}
#sidebar.collapsed .nav-link {
  justify-content: center;
  padding: .7rem 0;
  margin: 0 8px;
  border-radius: var(--radius);
  border-left: none;
}
#sidebar.collapsed .nav-link.active {
  background: var(--accent-glow);
}
#sidebar.collapsed .sidebar-logo {
  justify-content: center;
  padding: 1rem 0;
}
#sidebar.collapsed .sidebar-footer {
  padding: .5rem 8px;
}

/* Logo / header */
.sidebar-logo {
  display: flex;
  align-items: center;
  gap: .7rem;
  padding: 0 1.1rem;
  height: var(--topbar-h);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  overflow: hidden;
}
.sidebar-logo-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
  color: var(--accent);
  line-height: 1;
}
.sidebar-logo-text {
  font-weight: 800;
  font-size: .95rem;
  letter-spacing: .02em;
  white-space: nowrap;
  transition: opacity var(--trans);
  background: linear-gradient(135deg, var(--text) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Nav */
.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: .75rem 0;
  scrollbar-width: none;
}
.sidebar-nav::-webkit-scrollbar { display: none; }

.sidebar-section-label {
  font-size: .65rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--text-faint);
  padding: .85rem 1.1rem .3rem;
  white-space: nowrap;
  transition: opacity var(--trans);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: .6rem 1.1rem;
  color: var(--text-muted);
  font-size: .855rem;
  font-weight: 500;
  white-space: nowrap;
  transition: background var(--trans), color var(--trans), border-color var(--trans);
  border-left: 2px solid transparent;
  margin: 1px 0;
}
.nav-link:hover {
  background: var(--surface2);
  color: var(--text);
  border-left-color: var(--border);
  opacity: 1;
}
.nav-link.active {
  color: var(--accent);
  background: var(--accent-glow);
  border-left-color: var(--accent);
  font-weight: 600;
}
.nav-icon {
  font-size: 1rem;
  flex-shrink: 0;
  width: 20px;
  text-align: center;
}
.nav-label { transition: opacity var(--trans); }

/* Footer */
.sidebar-footer {
  border-top: 1px solid var(--border);
  padding: .6rem .75rem;
  flex-shrink: 0;
}
.sidebar-footer .nav-link {
  border-radius: var(--radius);
  border-left: none;
  font-size: .8rem;
  opacity: .45;
  padding: .5rem .7rem;
}
.sidebar-footer .nav-link:hover { opacity: .75; border-left: none; }

/* ── Top bar ────────────────────────────────────────────────────── */
#topbar {
  position: fixed;
  top: 0;
  left: var(--sidebar-w);
  right: 0;
  height: var(--topbar-h);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: 0 1.25rem;
  z-index: 100;
  transition: left var(--trans);
}
#topbar.sidebar-collapsed { left: 64px; }

/* mobile-only hamburger in topbar */
.topbar-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.25rem;
  cursor: pointer;
  padding: .3rem .5rem;
  border-radius: 6px;
  line-height: 1;
  transition: color var(--trans), background var(--trans);
  flex-shrink: 0;
}
.topbar-toggle:hover { color: var(--text); background: var(--surface2); }
@media (max-width: 767px) { .topbar-toggle { display: flex; align-items: center; } }

.topbar-search {
  display: flex;
  align-items: center;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 99px;
  padding: .3rem .85rem;
  gap: .4rem;
  flex: 1;
  max-width: 400px;
  transition: border-color var(--trans), box-shadow var(--trans);
}
.topbar-search:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}
.topbar-search input {
  background: none;
  border: none;
  outline: none;
  color: var(--text);
  font-size: .875rem;
  width: 100%;
}
.topbar-search input::placeholder { color: var(--text-faint); }
.topbar-search .search-icon { color: var(--text-faint); font-size: .85rem; }

.topbar-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: .5rem;
}

#theme-toggle {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  width: 36px; height: 36px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1rem;
  display: flex; align-items: center; justify-content: center;
  transition: background var(--trans), transform .3s;
}
#theme-toggle:hover { background: var(--accent-glow); transform: rotate(20deg); }

/* ── Main wrap ──────────────────────────────────────────────────── */
#main-wrap {
  margin-left: var(--sidebar-w);
  margin-top: var(--topbar-h);
  min-height: calc(100vh - var(--topbar-h));
  transition: margin-left var(--trans);
  padding: 1.75rem 1.5rem 3rem;
}
#main-wrap.sidebar-collapsed { margin-left: 64px; }

/* sidebar overlay (mobile) */
#sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.55);
  z-index: 199;
  backdrop-filter: blur(2px);
}
#sidebar-overlay.active { display: block; }

/* ── Flash alerts ───────────────────────────────────────────────── */
.flash-wrap { margin-bottom: 1.25rem; }
.alert {
  display: flex;
  align-items: center;
  gap: .6rem;
  padding: .75rem 1rem;
  border-radius: var(--radius);
  font-size: .875rem;
  animation: slideDown .25s ease;
}
.alert-success { background: rgba(16,185,129,.12); color: #6ee7b7; border: 1px solid rgba(16,185,129,.25); }
.alert-danger   { background: rgba(239,68,68,.12);  color: #fca5a5; border: 1px solid rgba(239,68,68,.25); }
.alert-warning  { background: rgba(245,158,11,.12); color: #fcd34d; border: 1px solid rgba(245,158,11,.25); }

[data-theme="light"] .alert-success { color: #065f46; }
[data-theme="light"] .alert-danger  { color: #991b1b; }
[data-theme="light"] .alert-warning { color: #92400e; }

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Page header ────────────────────────────────────────────────── */
.page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 1rem;
}
.page-header h1 {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -.02em;
}
.page-header .subtitle { color: var(--text-muted); font-size: .9rem; margin-top: .15rem; }

/* ── Buttons ────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .45rem .9rem;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  font-size: .85rem;
  font-weight: 600;
  text-decoration: none;
  transition: opacity var(--trans), transform .15s, box-shadow .15s;
  white-space: nowrap;
}
.btn:hover { opacity: .88; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-primary  { background: var(--accent); color: #fff; box-shadow: 0 2px 12px var(--accent-glow); }
.btn-secondary{ background: var(--surface2); color: var(--text); border: 1px solid var(--border); }
.btn-danger   { background: rgba(239,68,68,.15); color: #ef4444; border: 1px solid rgba(239,68,68,.25); }
.btn-outline  { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
.btn-ghost    { background: transparent; color: var(--text-muted); }
.btn-ghost:hover { color: var(--text); background: var(--surface2); }
.btn-sm  { padding: .3rem .65rem; font-size: .78rem; }
.btn-block { width: 100%; justify-content: center; }

/* ── Badges ─────────────────────────────────────────────────────── */
.badge {
  display: inline-flex;
  align-items: center;
  padding: .2rem .55rem;
  border-radius: 99px;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .03em;
  white-space: nowrap;
}
.badge-subject { background: rgba(124,58,237,.15); color: #a78bfa; border: 1px solid rgba(124,58,237,.2); }
.badge-type    { background: rgba(59,130,246,.12);  color: #93c5fd; border: 1px solid rgba(59,130,246,.2); }
.badge-urgent  { background: rgba(239,68,68,.15);  color: #fca5a5; border: 1px solid rgba(239,68,68,.25); animation: pulse 1.5s infinite; }
.badge-success { background: rgba(16,185,129,.12); color: #6ee7b7; border: 1px solid rgba(16,185,129,.2); }

[data-theme="light"] .badge-subject { color: #5b21b6; }
[data-theme="light"] .badge-type    { color: #1d4ed8; }
[data-theme="light"] .badge-urgent  { color: #991b1b; }

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(239,68,68,.4); }
  50%       { box-shadow: 0 0 0 5px rgba(239,68,68,0); }
}

/* ── Cards ──────────────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  transition: border-color var(--trans), box-shadow var(--trans), transform .2s;
}
.card:hover {
  border-color: var(--accent);
  box-shadow: 0 0 0 1px var(--accent-glow), 0 8px 24px rgba(0,0,0,.25);
  transform: translateY(-2px);
}

/* animate-on-scroll */
.anim-card {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .4s ease, transform .4s ease;
}
.anim-card.visible { opacity: 1; transform: translateY(0); }

/* ── Quick nav grid (index) ─────────────────────────────────────── */
.quick-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: .85rem;
  margin-bottom: 2rem;
}
.quick-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .55rem;
  padding: 1.5rem 1rem 1.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  color: var(--text);
  font-weight: 600;
  font-size: .875rem;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--trans), box-shadow var(--trans), transform .2s, background var(--trans);
}
.quick-card:hover {
  border-color: var(--accent);
  background: var(--surface2);
  box-shadow: 0 0 20px var(--accent-glow);
  transform: translateY(-3px);
  opacity: 1;
}
.quick-card .q-icon { font-size: 1.8rem; }

/* ── Filter bar ─────────────────────────────────────────────────── */
.filter-bar {
  display: flex;
  align-items: center;
  gap: .6rem;
  flex-wrap: wrap;
  margin-bottom: 1.25rem;
}
.filter-bar label { font-size: .8rem; color: var(--text-muted); }
.filter-bar select {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: .35rem .75rem;
  border-radius: 99px;
  font-size: .825rem;
  cursor: pointer;
  outline: none;
  transition: border-color var(--trans);
}
.filter-bar select:focus { border-color: var(--accent); }

/* ── Item cards (file listings) ─────────────────────────────────── */
.item-list { display: flex; flex-direction: column; gap: .85rem; }

.item-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.1rem 1.25rem;
  transition: border-color var(--trans), box-shadow var(--trans), transform .2s;
  position: relative;
  overflow: hidden;
}
.item-card::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--accent);
  opacity: 0;
  transition: opacity var(--trans);
}
.item-card:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 20px rgba(0,0,0,.2);
  transform: translateX(3px);
}
.item-card:hover::before { opacity: 1; }

.item-meta { display: flex; align-items: center; gap: .5rem; margin-bottom: .4rem; flex-wrap: wrap; }
.item-date { font-size: .75rem; color: var(--text-faint); margin-left: auto; }
.item-title { font-size: 1rem; font-weight: 600; margin-bottom: .2rem; }
.item-desc  { font-size: .85rem; color: var(--text-muted); margin-bottom: .75rem; line-height: 1.5; }
.item-actions { display: flex; gap: .5rem; flex-wrap: wrap; }

/* ── Events ─────────────────────────────────────────────────────── */
.event-list { display: flex; flex-direction: column; gap: .75rem; }

.event-card {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1rem 1.25rem;
  transition: border-color var(--trans), transform .2s;
  align-items: start;
}
.event-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.event-card.urgent {
  border-color: rgba(239,68,68,.4);
  background: rgba(239,68,68,.04);
}
.event-card.past { opacity: .5; }

.event-date-col {
  text-align: center;
  background: var(--surface2);
  border-radius: 8px;
  padding: .5rem .25rem;
}
.event-day   { font-size: 1.6rem; font-weight: 800; line-height: 1; color: var(--accent); }
.event-month { font-size: .7rem; text-transform: uppercase; letter-spacing: .05em; color: var(--text-muted); margin-top: .1rem; }

.event-title   { font-weight: 600; font-size: .975rem; margin-bottom: .3rem; }
.event-badges  { display: flex; flex-wrap: wrap; gap: .35rem; }
.event-notes   { font-size: .82rem; color: var(--text-muted); margin-top: .35rem; }

.past-toggle {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: .5rem 1rem;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: .85rem;
  margin-top: 1.25rem;
  display: flex;
  align-items: center;
  gap: .5rem;
  transition: background var(--trans), color var(--trans);
}
.past-toggle:hover { background: var(--surface2); color: var(--text); }

/* ── Teachers ───────────────────────────────────────────────────── */
.teacher-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
}
.teacher-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  transition: border-color var(--trans), transform .2s;
}
.teacher-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.teacher-avatar {
  width: 48px; height: 48px;
  background: var(--accent-glow);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem;
  margin-bottom: .75rem;
}
.teacher-name    { font-size: 1rem; font-weight: 700; margin-bottom: .35rem; }
.teacher-subs    { display: flex; flex-wrap: wrap; gap: .3rem; margin-bottom: .5rem; }
.teacher-email   { font-size: .82rem; color: var(--accent); }
.teacher-bio     { font-size: .83rem; color: var(--text-muted); margin-top: .4rem; line-height: 1.55; }

/* ── Search results ─────────────────────────────────────────────── */
.search-section  { margin-bottom: 2rem; }
.search-section h2 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .06em;
  margin-bottom: .75rem;
  padding-bottom: .4rem;
  border-bottom: 1px solid var(--border);
}
.result-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: .85rem 1rem;
  margin-bottom: .6rem;
}
.result-meta { display: flex; gap: .4rem; flex-wrap: wrap; margin-bottom: .3rem; }
.result-title { font-weight: 600; }
.result-desc  { font-size: .83rem; color: var(--text-muted); margin-top: .2rem; }

/* ── PDF Modal ──────────────────────────────────────────────────── */
.modal { position: fixed; inset: 0; z-index: 500; display: flex; align-items: center; justify-content: center; }
.modal.hidden { display: none; }
.modal-bg {
  position: fixed; inset: 0;
  background: rgba(0,0,0,.75);
  backdrop-filter: blur(4px);
}
.modal-box {
  position: relative; z-index: 501;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  width: min(94vw, 940px);
  height: min(90vh, 800px);
  display: flex; flex-direction: column;
  box-shadow: 0 32px 80px rgba(0,0,0,.5);
  animation: popIn .2s ease;
}
@keyframes popIn {
  from { opacity: 0; transform: scale(.96) translateY(12px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}
.modal-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: .85rem 1.1rem;
  border-bottom: 1px solid var(--border);
  font-weight: 600; font-size: .9rem;
}
.modal-close {
  background: var(--surface2); border: none;
  width: 28px; height: 28px; border-radius: 50%;
  cursor: pointer; color: var(--text-muted);
  font-size: 1rem; display: flex; align-items: center; justify-content: center;
  transition: background var(--trans), color var(--trans);
}
.modal-close:hover { background: rgba(239,68,68,.2); color: #ef4444; }
#pdf-frame { flex: 1; border: none; border-radius: 0 0 var(--radius-lg) var(--radius-lg); }

/* ── Section divider ────────────────────────────────────────────── */
.section-title {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin: 1.75rem 0 1rem;
  display: flex;
  align-items: center;
  gap: .5rem;
}
.section-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* ── Stats row (index) ──────────────────────────────────────────── */
.stats-row {
  display: flex;
  gap: .75rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}
.stat-pill {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 99px;
  padding: .35rem .9rem;
  font-size: .8rem;
  color: var(--text-muted);
  display: flex; align-items: center; gap: .4rem;
}
.stat-pill strong { color: var(--text); }

/* ── Empty state ────────────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-muted);
}
.empty-state .empty-icon { font-size: 3rem; margin-bottom: .75rem; opacity: .4; }
.empty-state p { font-size: .9rem; }

/* ================================================================
   ADMIN
   ================================================================ */

.admin-body { background: var(--bg); }

.admin-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--topbar-h);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center;
  padding: 0 1.25rem;
  gap: 1rem;
  z-index: 300;
}
.admin-header .brand { font-weight: 700; font-size: 1rem; }
.admin-header-right  { margin-left: auto; display: flex; align-items: center; gap: .75rem; }

.admin-wrap {
  display: grid;
  grid-template-columns: 220px 1fr;
  min-height: 100vh;
  padding-top: var(--topbar-h);
}
.admin-sidebar {
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 1rem 0;
  position: sticky;
  top: var(--topbar-h);
  height: calc(100vh - var(--topbar-h));
  overflow-y: auto;
}
.admin-sidebar .nav-link { font-size: .85rem; }
.admin-main { padding: 1.75rem 1.5rem 3rem; min-width: 0; }
.admin-main h1 { font-size: 1.5rem; font-weight: 700; margin-bottom: 1.25rem; }
.admin-main h2 { font-size: 1.1rem; font-weight: 700; margin: 1.5rem 0 .75rem; }

/* ── Stat cards (dashboard) ─────────────────────────────────────── */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: .85rem;
  margin-bottom: 2rem;
}
.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.1rem;
  text-align: center;
  transition: border-color var(--trans), transform .2s;
}
.stat-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.stat-num   { font-size: 2rem; font-weight: 800; color: var(--accent); line-height: 1.1; }
.stat-label { font-size: .72rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: .05em; margin-top: .25rem; }

/* ── Form panel ─────────────────────────────────────────────────── */
.form-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  margin-bottom: 1.5rem;
  overflow: hidden;
}
.form-panel summary {
  padding: .9rem 1.1rem;
  cursor: pointer;
  font-weight: 700;
  font-size: .9rem;
  user-select: none;
  list-style: none;
  display: flex; align-items: center; gap: .5rem;
  transition: background var(--trans);
}
.form-panel summary::-webkit-details-marker { display: none; }
.form-panel summary:hover { background: var(--surface2); }
.form-panel summary::before { content: '﹢'; color: var(--accent); font-size: 1.1rem; }
.form-panel[open] summary::before { content: '－'; }

.form-body {
  padding: 1.1rem 1.25rem 1.4rem;
  border-top: 1px solid var(--border);
}
.form-row  { display: flex; gap: 1rem; flex-wrap: wrap; }
.form-group { display: flex; flex-direction: column; gap: .3rem; flex: 1; min-width: 180px; }
.form-group label { font-size: .78rem; font-weight: 600; color: var(--text-muted); text-transform: uppercase; letter-spacing: .04em; }

.form-group input,
.form-group select,
.form-group textarea {
  background: var(--bg2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: .5rem .75rem;
  border-radius: var(--radius);
  font-size: .875rem;
  font-family: inherit;
  width: 100%;
  outline: none;
  transition: border-color var(--trans), box-shadow var(--trans);
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}
.form-group textarea { resize: vertical; min-height: 70px; }
.form-gap { margin-top: 1rem; }

/* ── Admin table ────────────────────────────────────────────────── */
.admin-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  font-size: .855rem;
}
.admin-table th {
  background: var(--surface2);
  text-align: left;
  padding: .7rem 1rem;
  font-size: .72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border);
}
.admin-table td {
  padding: .7rem 1rem;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}
.admin-table tr:last-child td { border-bottom: none; }
.admin-table tbody tr:hover td { background: var(--surface2); }

.actions-cell { display: flex; gap: .4rem; align-items: center; flex-wrap: wrap; }
.actions-cell form { margin: 0; }

/* ── Inline edit popover ────────────────────────────────────────── */
.inline-edit { position: relative; }
.inline-edit summary { list-style: none; }
.inline-edit summary::-webkit-details-marker { display: none; }
.inline-form {
  position: absolute;
  right: 0; top: calc(100% + 6px);
  z-index: 150;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1rem;
  box-shadow: 0 16px 48px rgba(0,0,0,.4);
  min-width: 290px;
  display: flex; flex-direction: column; gap: .5rem;
  animation: popIn .18s ease;
}
.inline-form input,
.inline-form select,
.inline-form textarea {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: .4rem .65rem;
  border-radius: var(--radius);
  font-size: .82rem;
  font-family: inherit;
  width: 100%;
  outline: none;
}
.inline-form input:focus,
.inline-form select:focus,
.inline-form textarea:focus { border-color: var(--accent); }
.inline-form textarea { resize: vertical; min-height: 60px; }

/* ── Checkbox group ─────────────────────────────────────────────── */
.checkbox-group { display: flex; flex-wrap: wrap; gap: .5rem; }
.checkbox-label {
  display: flex; align-items: center; gap: .3rem;
  font-size: .84rem; cursor: pointer;
  background: var(--bg2);
  padding: .25rem .6rem;
  border-radius: 99px;
  border: 1px solid var(--border);
  transition: border-color var(--trans), background var(--trans);
}
.checkbox-label:hover { border-color: var(--accent); }
.checkbox-label input[type=checkbox]:checked + span,
.checkbox-label:has(input:checked) { color: var(--accent); }

/* ── Login page ─────────────────────────────────────────────────── */
.login-body {
  display: flex; align-items: center; justify-content: center;
  min-height: 100vh;
  background: var(--bg);
}
.login-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  width: min(100%, 380px);
  box-shadow: 0 24px 64px rgba(0,0,0,.35);
  animation: popIn .3s ease;
}
.login-card h1 { font-size: 1.4rem; font-weight: 700; margin-bottom: 1.5rem; }
.login-card .form-group { margin-bottom: .85rem; }
.login-card .btn { margin-top: .5rem; }

/* ── Past events toggle ─────────────────────────────────────────── */
.past-section { margin-top: 1.5rem; }
.past-list { margin-top: .75rem; }

/* ================================================================
   RESPONSIVE
   ================================================================ */
@media (max-width: 767px) {
  #sidebar {
    transform: translateX(-100%);
    width: var(--sidebar-w) !important;
  }
  #sidebar.open { transform: translateX(0); box-shadow: 16px 0 48px rgba(0,0,0,.5); }

  #sidebar-toggle { display: none; }

  #topbar { left: 0 !important; }
  #main-wrap { margin-left: 0 !important; }

  .admin-wrap { grid-template-columns: 1fr; }
  .admin-sidebar { display: none; }

  .quick-grid { grid-template-columns: repeat(3, 1fr); }
  .event-card { grid-template-columns: 60px 1fr; }
  .teacher-grid { grid-template-columns: 1fr; }
  .form-row { flex-direction: column; }
  .inline-form { position: static; box-shadow: none; }
}

@media (max-width: 480px) {
  .quick-grid { grid-template-columns: repeat(2, 1fr); }
  .stat-grid  { grid-template-columns: repeat(2, 1fr); }
}