:root {
  /* Design tokens (default: dark theme) */
  --bg: #0e0f1a;
  --bg-alt: #0b0d18;
  --bg-soft: #11162b;
  --panel-bg: #0f1423;
  --panel-bg-2: #101529;
  --border: #1b2240;
  --text: #e2e8f0;
  --text-muted: #9fb1cf;
  --muted-2: #cbd5e1;
  --brand-1: #7b2cff;
  --brand-2: #22d3ee;
  --focus: rgba(123,44,255,0.55);
  --focus-ring: rgba(123,44,255,0.15);
  --hover-bg: #1a2141;
  --active-bg: #222a53;
  --input-bg: #0e1528;
  --table-head-bg: #0c1120;
  --table-row-hover: #121936;
  --on-accent: #0b0b11;
}

[data-theme="light"] {
  --bg: #f8fafc;
  --bg-alt: #ffffff;
  --bg-soft: #ffffff;
  --panel-bg: #ffffff;
  --panel-bg-2: #f1f5f9;
  --border: #dbe2ea;
  --text: #0f172a;
  --text-muted: #475569;
  --muted-2: #334155;
  --brand-1: #7b2cff;
  --brand-2: #06b6d4;
  --focus: rgba(123,44,255,0.55);
  --focus-ring: rgba(123,44,255,0.18);
  --hover-bg: #eef2ff;
  --active-bg: #e0e7ff;
  --input-bg: #ffffff;
  --table-head-bg: #eef2ff;
  --table-row-hover: #f8fafc;
  --on-accent: #0b0b11;
}

body {
  background:
    radial-gradient(900px 400px at 80% -10%, rgba(123,44,255,0.12), rgba(123,44,255,0) 60%),
    radial-gradient(800px 500px at -10% 110%, rgba(34,211,238,0.08), rgba(34,211,238,0) 60%),
    linear-gradient(180deg, var(--bg), var(--bg-alt) 50%, var(--bg));
  color: var(--text);
  /* Subtle animated background: drift and gentle size breathing */
  background-attachment: fixed, fixed, fixed;
  background-size: 900px 400px, 800px 500px, auto;
  background-position: 80% -10%, -10% 110%, center top;
  animation: bg-pan var(--bg-anim-duration, 48s) var(--anim-ease) infinite alternate;
}
.auth-body { background: var(--bg); }
.card { background: var(--panel-bg); color: var(--text); border: 1px solid var(--border); box-shadow: 0 1px 2px rgba(0,0,0,0.06); }
.navbar .navbar-brand { font-weight: 600; }

/* --- Topbar (global navbar) --- */
.topbar {
  position: sticky; top: 0; z-index: 1030;
  background:
    radial-gradient(600px 160px at 100% -20%, rgba(123,44,255,0.10), rgba(123,44,255,0) 60%),
    radial-gradient(500px 180px at -20% 120%, rgba(34,211,238,0.06), rgba(34,211,238,0) 60%),
    linear-gradient(180deg, var(--bg-soft), var(--panel-bg));
  border-bottom: 1px solid var(--border);
  box-shadow: 0 6px 18px rgba(2,6,23,0.35);
  padding: 8px 0;
}
.brand-badge {
  width: 56px; height: 56px; border-radius: 12px;
  background: linear-gradient(135deg, var(--brand-1), var(--brand-2));
  color: var(--on-accent); font-weight: 800; text-decoration: none;
  box-shadow: 0 10px 22px rgba(123,44,255,0.35), 0 0 0 2px rgba(226,232,240,0.05) inset;
}
.brand-badge:hover { filter: brightness(1.05); }
.brand-badge img { display: block; max-width: 100%; max-height: 100%; }
.brand-link { text-decoration: none; color: var(--text); line-height: 1; }
.brand-title { font-weight: 700; font-size: 1.1rem; color: var(--text); }
.brand-initials { font-weight: 800; font-size: 0.95rem; letter-spacing: 0.5px; }
@media (min-width: 992px) {
  .topbar .brand-link { min-width: 220px; }
}
.top-toggler { color: var(--text-muted); border: 1px solid var(--border); background: var(--input-bg); }
.top-toggler:hover { border-color: var(--focus); }
.topnav { gap: 4px; }
.topnav > li { margin-right: 6px; }
.topnav-link {
  display: inline-flex; align-items: center;
  padding: 8px 12px; border-radius: 10px;
  color: var(--text-muted); text-decoration: none;
  border: 1px solid transparent;
}
.topnav-link:hover { color: inherit; background: var(--hover-bg); border-color: var(--border); }
.topnav-link.active {
  background: var(--active-bg);
  color: inherit;
  border-color: var(--border);
  box-shadow: 0 6px 14px rgba(123,44,255,0.18) inset, 0 2px 10px rgba(123,44,255,0.25);
}
.topnav-link:focus-visible { outline: none; box-shadow: 0 0 0 3px var(--focus-ring); }
.topnav-link i { color: var(--text-muted); }
.top-actions .btn { border-radius: 10px; }
.user-chip {
  padding: 6px 10px; border-radius: 10px;
  background: var(--input-bg); color: var(--text);
  border: 1px solid var(--border);
}
.user-chip .role { color: var(--text-muted); }

@media (max-width: 991.98px) {
  #topnav.collapse.show, #topnav.collapsing {
    background: var(--panel-bg); border: 1px solid var(--border); border-radius: 12px; padding: 8px; margin-top: 8px;
  }
  .topnav > li { margin: 4px 0; }
  .topnav-link { display: flex; }
}

/* Readability on dark background */
.form-label { color: var(--text-muted); }
.link-secondary { color: var(--text-muted) !important; }
.text-muted { color: var(--text-muted) !important; }

/* --- Login page (neon / glassmorphism) --- */
.login-page {
  position: relative;
  min-height: 100vh;
  display: grid;
  align-items: center;
}

.login-wrap {
  background: radial-gradient(1200px 600px at 70% -10%, rgba(123,44,255,0.35), rgba(123,44,255,0) 60%),
              radial-gradient(800px 400px at 20% 110%, rgba(34,211,238,0.25), rgba(34,211,238,0) 60%),
              linear-gradient(180deg, var(--bg-alt), var(--bg));
  color: var(--text);
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 10px 40px rgba(0,0,0,0.35);
  min-height: 100vh; /* ensure panel fills viewport height on login */
  display: grid;                /* center inner row */
  place-items: center;          /* vertical + horizontal center */
  padding: 16px;                /* breathing room on small screens */
}

/* Constrain the row width so centering is visible */
.login-wrap > .row {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
}

.login-panel {
  height: 100%;
  backdrop-filter: blur(10px);
  background: linear-gradient(180deg, rgba(226,232,240,0.06), rgba(226,232,240,0.03));
  border-right: 1px solid rgba(226,232,240,0.08);
}
.login-panel .avatar svg { color: var(--brand-2); }

.login-form .input-wrap { position: relative; }
.login-form .input-wrap .icon {
  position: absolute; left: 14px; top: 50%; transform: translateY(-50%);
  color: var(--text-muted); pointer-events: none;
}
.login-form .form-control {
  background: var(--input-bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding-left: 42px;
}
.login-form .form-control:focus {
  background: var(--input-bg);
  outline: none; border-color: var(--focus);
  box-shadow: 0 0 0 0.25rem var(--focus-ring);
}
.text-muted { color: var(--text-muted) !important; }
.btn-neon {
  --c1:#7b2cff; --c2:#22d3ee;
  background: linear-gradient(135deg, var(--c1), var(--c2));
  color: var(--on-accent); font-weight: 600; border: none;
  box-shadow: 0 10px 25px rgba(123,44,255,0.35), 0 0 0 1px rgba(226,232,240,0.08) inset;
}
.btn-neon:hover { filter: brightness(1.05); }
.btn-neon:active { transform: translateY(1px); }

.login-hero { position: relative; color: var(--text); }
.login-hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(1100px 400px at 50% 0%, rgba(123,44,255,0.5), rgba(123,44,255,0) 60%),
    conic-gradient(from 180deg at 50% 20%, rgba(123,44,255,0.7), rgba(217,70,239,0.5), rgba(34,211,238,0.6), rgba(123,44,255,0.7));
  opacity: 0.25; filter: blur(30px);
}
.neon-cap {
  font-size: clamp(36px, 6vw, 72px); font-weight: 800; line-height: 1; color: var(--text);
  text-shadow: 0 0 20px rgba(123,44,255,0.8), 0 0 40px rgba(34,211,238,0.5);
}
.hero-subtext { margin-top: 1rem; max-width: 46ch; color: var(--text-muted); }

@media (max-width: 767.98px) {
  .login-wrap { border-radius: 14px; }
  .login-panel { border-right: none; }
}

/* --- Admin Sidebar Layout --- */
.admin-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: calc(100vh - 56px);
  background: var(--bg);
}
.admin-sidebar {
  background: var(--bg-soft);
  color: var(--text-muted);
  padding: 12px 0;
}
.admin-brand {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px 12px;
  color: var(--text);
  font-weight: 700;
}
.admin-brand .brand-text {
  background: var(--brand-1);
  color: var(--on-accent);
  padding: 4px 8px;
  border-radius: 6px;
  font-size: 18px;
}
.admin-brand .toggle-btn { color: var(--text-muted); border: 1px solid var(--border); }
.admin-menu ul { list-style: none; margin: 0; padding: 8px 8px; }
.admin-menu li { margin: 4px 0; }
.admin-menu a {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 12px;
  color: var(--text-muted); text-decoration: none;
  border-radius: 8px;
}
.admin-menu a:hover { background: var(--hover-bg); color: var(--text); }
.admin-menu li.active > a { background: var(--active-bg); color: var(--text); }
.admin-menu i { font-size: 1.1rem; color: var(--text-muted); }
.admin-menu li.active i { color: var(--brand-2); }
.admin-content { background: transparent; }

/* Admin footer spans full width (sidebar + content) */
.admin-footer { grid-column: 1 / -1; }

@media (max-width: 991.98px) {
  .admin-layout { grid-template-columns: 1fr; }
  .admin-sidebar { position: relative; }
}

/* --- Footer theming --- */
.app-footer {
  background:
    radial-gradient(600px 120px at 100% -20%, rgba(123,44,255,0.10), rgba(123,44,255,0) 60%),
    radial-gradient(500px 140px at -20% 120%, rgba(34,211,238,0.08), rgba(34,211,238,0) 60%),
    linear-gradient(180deg, var(--panel-bg-2), var(--panel-bg));
  border-top: 1px solid var(--border);
  box-shadow: 0 -8px 20px rgba(2,6,23,0.35), 0 1px 0 rgba(123,44,255,0.15) inset;
}
.app-footer .link-secondary { color: var(--muted-2) !important; opacity: 0.95; }
.app-footer .link-secondary:hover { color: var(--text) !important; text-decoration: underline; }
.app-footer .small { letter-spacing: 0.2px; }

/* --- Admin: Groups page --- */
.panel-dark {
  background:
    radial-gradient(600px 200px at 110% -10%, rgba(123,44,255,0.08), rgba(123,44,255,0) 60%),
    radial-gradient(500px 200px at -10% 110%, rgba(34,211,238,0.06), rgba(34,211,238,0) 60%),
    linear-gradient(180deg, var(--panel-bg-2), var(--panel-bg));
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 16px;
  color: var(--text);
}
.panel-dark .panel-actions { gap: 10px; }

.pillbar { display: flex; flex-wrap: wrap; gap: 8px; }
.pill {
  padding: 8px 12px; border-radius: 999px; font-weight: 600; font-size: 14px;
  background: var(--input-bg); color: var(--text); border: 1px solid var(--border);
  transition: background .2s ease, box-shadow .2s ease, transform .2s ease;
}
.pill.active { background: var(--active-bg); color: var(--text); border-color: var(--focus); box-shadow: 0 0 0 3px var(--focus-ring); }
.pill:hover { transform: translateY(-1px); }

.search-dark .form-control {
  background: var(--input-bg); border: 1px solid var(--border); color: var(--text);
}
.search-dark .form-control::placeholder { color: var(--text-muted); }
.search-dark .input-group-text { background: var(--input-bg); color: var(--text-muted); border: 1px solid var(--border); }
/* subtle focus glow around the whole search input group */
.search-dark .input-group:focus-within .form-control,
.search-dark .input-group:focus-within .input-group-text { border-color: var(--focus); }
.search-dark .input-group:focus-within {
  box-shadow: 0 0 0 0.35rem var(--focus-ring);
  border-radius: 14px;
}

.btn-add {
  background: linear-gradient(135deg, var(--brand-1), var(--brand-2));
  color: var(--on-accent); font-weight: 700; border: none; padding: 8px 14px;
}
.btn-add:hover { filter: brightness(1.05); }

.groups-table { overflow-x: auto; border-radius: 10px; }
.groups-table table { width: 100%; border-collapse: separate; border-spacing: 0; }
.groups-table thead th {
  background: var(--table-head-bg); color: var(--text-muted); font-weight: 600; padding: 12px;
  border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 1;
}
.groups-table tbody tr { background: var(--panel-bg); }
.groups-table tbody tr + tr td { border-top: 1px solid var(--border); }
.groups-table td { color: var(--text); padding: 14px 12px; vertical-align: middle; }
.groups-table .muted { color: var(--text-muted); font-size: 12px; }

.chip { display: inline-block; padding: 6px 10px; border-radius: 999px; font-size: 12px; font-weight: 700; }
.chip.status-active { background: rgba(255,159,67,0.18); color: #ffb35b; border: 1px solid rgba(255,159,67,0.25); }
.chip.status-recruit { background: rgba(255,206,86,0.16); color: #ffd470; border: 1px solid rgba(255,206,86,0.24); }
.chip.status-finished { background: rgba(148,163,184,0.16); color: #cbd5e1; border: 1px solid rgba(148,163,184,0.24); }
.chip.status-published { background: rgba(16,185,129,0.16); color: #86efac; border: 1px solid rgba(16,185,129,0.24); }
.chip.status-draft { background: rgba(148,163,184,0.16); color: #cbd5e1; border: 1px solid rgba(148,163,184,0.24); }
.chip.status-archived { background: rgba(2,132,199,0.16); color: #7dd3fc; border: 1px solid rgba(2,132,199,0.24); }
.chip.type-group { background: rgba(59,130,246,0.16); color: #93c5fd; border: 1px solid rgba(59,130,246,0.24); }
.chip.type-intensive { background: rgba(168,85,247,0.16); color: #d8b4fe; border: 1px solid rgba(168,85,247,0.24); }
.chip.type-master { background: rgba(16,185,129,0.16); color: #86efac; border: 1px solid rgba(16,185,129,0.24); }
.chip.format-online { background: rgba(14,165,233,0.16); color: #7dd3fc; border: 1px solid rgba(14,165,233,0.24); }
.chip.format-offline { background: rgba(99,102,241,0.16); color: #c7d2fe; border: 1px solid rgba(99,102,241,0.24); }

.table-title { color: var(--text-muted); }
.col-actions { width: 64px; text-align: right; }
.teacher { color: var(--text); font-weight: 600; }

@media (max-width: 575.98px) {
  .panel-dark { padding: 12px; }
  .pillbar { gap: 6px; }
  .groups-table td, .groups-table th { padding: 10px; }
}

/* --- UI Glow / Elevation Utilities --- */
.card-elev {
  background:
    linear-gradient(180deg, var(--panel-bg-2), var(--panel-bg));
  color: var(--text);
  box-shadow: 0 10px 24px rgba(2,6,23,0.35), 0 2px 6px rgba(0,0,0,0.25), 0 0 0 1px rgba(226,232,240,0.03) inset;
  border: 1px solid var(--border);
  border-radius: 16px;
  transition: box-shadow .2s ease, transform .2s ease;
}
.card-elev:hover {
  box-shadow: 0 20px 46px rgba(2,6,23,0.5), 0 6px 18px rgba(0,0,0,0.3), 0 0 0 3px rgba(123,44,255,0.08);
  transform: translateY(-2px);
}

.btn-glow {
  background: linear-gradient(135deg, #3b82f6, #22d3ee);
  color: var(--on-accent) !important;
  border: 0;
  box-shadow: 0 10px 22px rgba(59,130,246,0.35), 0 0 0 3px rgba(34,211,238,0.15);
  font-weight: 700;
}
.btn-glow:hover { filter: brightness(1.05); box-shadow: 0 14px 28px rgba(59,130,246,0.45), 0 0 0 4px rgba(34,211,238,0.18); }
.btn-glow:active { transform: translateY(1px); }

/* ghost button for subtle outline with glow */
.btn-ghost {
  background: var(--input-bg);
  color: var(--text);
  border: 1px solid var(--border);
  box-shadow: 0 0 0 2px rgba(34,211,238,0.08) inset;
  font-weight: 600;
}
.btn-ghost:hover {
  color: inherit;
  border-color: var(--focus);
  box-shadow: 0 0 0 3px rgba(34,211,238,0.14), 0 8px 20px rgba(34,211,238,0.12);
}

/* Outline buttons — dark-friendly defaults */
.btn-outline-secondary {
  background: var(--input-bg);
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.btn-outline-secondary:hover,
.btn-outline-secondary:focus {
  background: var(--hover-bg);
  color: var(--text);
  border-color: var(--focus);
}

.btn-outline-primary {
  background: var(--input-bg);
  color: #93c5fd;
  border-color: rgba(59,130,246,0.55);
}
.btn-outline-primary:hover,
.btn-outline-primary:focus {
  background: rgba(59,130,246,0.14);
  color: #bfdbfe;
  border-color: rgba(59,130,246,0.75);
}

.btn-outline-success {
  background: var(--input-bg);
  color: #86efac;
  border-color: rgba(34,197,94,0.55);
}
.btn-outline-success:hover,
.btn-outline-success:focus {
  background: rgba(34,197,94,0.14);
  color: #bbf7d0;
  border-color: rgba(34,197,94,0.75);
}

.btn-outline-danger {
  background: var(--input-bg);
  color: #fca5a5;
  border-color: rgba(239,68,68,0.55);
}
.btn-outline-danger:hover,
.btn-outline-danger:focus {
  background: rgba(239,68,68,0.14);
  color: #fecaca;
  border-color: rgba(239,68,68,0.75);
}

.input-glow.form-control,
.input-glow.form-select {
  background: var(--input-bg);
  color: var(--text);
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow: 0 2px 8px rgba(2,6,23,0.25) inset;
}
.input-glow.form-control:focus,
.input-glow.form-select:focus {
  border-color: var(--focus);
  box-shadow: 0 0 0 0.25rem var(--focus-ring), 0 8px 24px rgba(123,44,255,0.25);
}
.input-glow.form-control::placeholder,
.input-glow.form-select::placeholder { color: var(--text-muted); }
.input-glow.form-control:hover,
.input-glow.form-select:hover { border-color: var(--border); }
.input-glow.form-control:disabled,
.input-glow.form-select:disabled,
.input-glow.form-control[readonly],
.input-glow.form-select[readonly] {
  background: var(--input-bg);
  color: var(--text-muted);
  opacity: 0.9;
}
.input-glow.is-invalid {
  border-color: rgba(239,68,68,0.6) !important;
  box-shadow: 0 0 0 0.2rem rgba(239,68,68,0.15), 0 8px 24px rgba(239,68,68,0.15);
}
.input-glow.is-valid {
  border-color: rgba(34,197,94,0.6) !important;
  box-shadow: 0 0 0 0.2rem rgba(34,197,94,0.15), 0 8px 24px rgba(34,197,94,0.15);
}

/* Generic form controls (defaults) */
.form-control,
.form-select {
  background: var(--input-bg);
  color: var(--text);
  border: 1px solid var(--border);
}
.form-control:focus,
.form-select:focus {
  border-color: var(--focus);
  box-shadow: 0 0 0 0.25rem var(--focus-ring);
  background: var(--input-bg);
  color: var(--text);
}
.form-control::placeholder { color: var(--text-muted); }
.input-group-text { background: var(--input-bg); color: var(--text-muted); border: 1px solid var(--border); }

/* dark checkboxes/switches */
.form-check-input {
  background-color: var(--input-bg);
  border: 1px solid var(--border);
}
.form-check-input:focus {
  border-color: var(--focus);
  box-shadow: 0 0 0 0.2rem var(--focus-ring);
}
.form-check-input:checked {
  background-color: var(--brand-1);
  border-color: var(--brand-1);
}

/* Generic table theming */
.table { color: var(--text); border-color: var(--border); }
.table thead th { background: var(--table-head-bg); color: var(--text-muted); border-bottom: 1px solid var(--border); }
.table tbody tr { background: var(--panel-bg); }
/* Override Bootstrap cell backgrounds to remove white cells */
.table > :not(caption) > * > * { background-color: var(--panel-bg); color: var(--text); }
.table tbody tr:hover > * { background-color: var(--table-row-hover); }
.table tbody tr + tr td { border-top: 1px solid var(--border); }

.table-elev {
  background: var(--panel-bg);
  color: var(--text);
  border-radius: 12px;
  box-shadow: 0 8px 22px rgba(2,6,23,0.35);
  padding: 4px;
  border: 1px solid var(--border);
}
.table-elev .table-responsive { overflow: visible; }
@media (max-width: 767.98px) {
  /* keep horizontal scroll on small screens while allowing dropdowns to escape vertically */
  .table-elev .table-responsive { overflow-x: auto; overflow-y: visible; }
}
.table-elev .table { color: var(--text); }
.table-elev .table thead th { background: var(--table-head-bg); color: var(--text-muted); border-bottom: 1px solid var(--border); letter-spacing: 0.2px; }
.table-elev .table tbody tr { background: var(--panel-bg); transition: background .15s ease; }
.table-elev .table > :not(caption) > * > * { background-color: var(--panel-bg); }
.table-elev .table tbody tr:hover > * { background-color: var(--table-row-hover); }
.table-elev .table tbody tr + tr td { border-top: 1px solid var(--border); }

/* Ensure dropdown overlays above table */
.table-elev .dropdown-menu { z-index: 1100; }

/* Course list actions dropdown should always appear above table rows */
#coursesTable .dropdown-menu { z-index: 1200; }

/* table title sorting icon tone */
.table-title i { color: var(--text-muted); opacity: 0.9; }

.modal-glow .modal-content {
  background: var(--panel-bg);
  color: var(--text);
  border-radius: 16px;
  border: 1px solid var(--border);
  box-shadow: 0 20px 60px rgba(2,6,23,0.55), 0 0 0 1px rgba(226,232,240,0.04) inset;
}
.modal-glow .modal-header {
  background:
    linear-gradient(180deg, var(--panel-bg-2), var(--panel-bg));
}
.modal-glow .btn-primary { box-shadow: 0 8px 20px rgba(59,130,246,0.35); }

.tab-glow.nav-tabs .nav-link.active {
  position: relative;
  box-shadow: 0 6px 16px rgba(123,44,255,0.15) inset, 0 2px 12px rgba(123,44,255,0.25);
}

/* Dark-friendly nav tabs (works for both themes via variables) */
.tab-glow.nav-tabs {
  border-bottom: 1px solid var(--border);
}
.tab-glow.nav-tabs .nav-link {
  color: var(--text-muted);
  background: var(--panel-bg-2);
  border: 1px solid var(--border);
  border-bottom-color: transparent;
  margin-bottom: -1px;
  border-top-left-radius: 12px;
  border-top-right-radius: 12px;
}
.tab-glow.nav-tabs .nav-link:hover {
  color: var(--text);
  background: var(--hover-bg);
  border-color: var(--border);
  border-bottom-color: transparent;
}
.tab-glow.nav-tabs .nav-link.active,
.tab-glow.nav-tabs .nav-item.show .nav-link {
  color: var(--text);
  background: var(--panel-bg);
  border-color: var(--border) var(--border) transparent;
}

/* Dark-friendly list groups */
.list-group {
  background: transparent;
  color: var(--text);
  border-radius: 12px;
}
.list-group-item {
  background: var(--panel-bg);
  color: var(--text);
  border-color: var(--border);
}
.list-group-item + .list-group-item {
  border-top-color: var(--border);
}
.list-group-item-action {
  color: var(--text);
}
.list-group-item-action:hover,
.list-group-item-action:focus {
  background: var(--table-row-hover);
  color: var(--text);
}
.list-group-item.active {
  background: var(--active-bg);
  border-color: var(--border);
  color: var(--text);
}
/* flush variant keeps dark borders but removes extra padding/background */
.list-group-flush > .list-group-item {
  border-right: 0;
  border-left: 0;
  background: var(--panel-bg);
}
.list-group-flush > .list-group-item:last-child { border-bottom: 0; }
.list-group-flush > .list-group-item:first-child { border-top: 0; }

/* --- Course page: structure tree --- */
.course-structure .fw-semibold {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  background: var(--panel-bg-2);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.course-structure .fw-semibold i { opacity: 0.95; }
.course-structure i.bi-folder2-open { color: #f59e0b; }
.course-structure i.bi-journal-text { color: #60a5fa; }
.course-structure i.bi-check2-square { color: #86efac; }

/* tree connectors */
.course-structure ul {
  margin-top: 8px;
  margin-bottom: 8px;
  padding-left: 16px; /* compensate for connector arm */
  border-left: 1px dashed var(--border);
}
.course-structure ul > li { position: relative; }
.course-structure ul > li::before {
  content: "";
  position: absolute;
  left: -16px; /* connect to vertical guide */
  top: 12px;
  width: 16px;
  height: 1px;
  background: var(--border);
}

/* links */
.course-structure a { color: var(--text); text-decoration: none; }
.course-structure a:hover { text-decoration: underline; }

/* assignment row & badges */
.course-structure li.small { padding: 2px 0; }
.course-structure .badge {
  background: var(--panel-bg-2) !important;
  color: var(--text-muted);
  border-color: var(--border) !important;
}

/* subtle hover affordance */
.course-structure li:hover > .d-flex > div > a { text-decoration: underline; }

@media (max-width: 575.98px) {
  .course-structure .fw-semibold { padding: 8px; }
  .course-structure ul { padding-left: 14px; }
  .course-structure ul > li::before { left: -14px; width: 14px; }
}

/* --- Admin: Analytics compact mode --- */
.analytics-compact {
  --ac-card-pad-y: 10px;
  --ac-card-pad-x: 12px;
  --ac-font-small: 0.9rem;
}
.analytics-compact .card .card-body { padding: var(--ac-card-pad-y) var(--ac-card-pad-x); }
.analytics-compact .card h6 { font-size: var(--ac-font-small); margin: 0; }
.analytics-compact .form-label { margin-bottom: .25rem; }
.analytics-compact .display-6 { font-size: clamp(1.35rem, 2.8vw, 1.75rem); line-height: 1.1; }
.analytics-compact .small { font-size: 0.85rem; }
.analytics-compact .table { font-size: 0.9rem; }
.analytics-compact .table.table-sm th,
.analytics-compact .table.table-sm td { padding: .3rem .5rem; }
.analytics-compact .card { border-radius: 12px; }
.analytics-compact .row.g-2 { --bs-gutter-x: .5rem; --bs-gutter-y: .5rem; }
.analytics-compact .row.g-2 .mb-3 { margin-bottom: .5rem !important; }

/* --- Aspect ratio overrides --- */
.ratio-16x9 { --bs-aspect-ratio: 45.25%; }

/* --- Student panel utilities --- */
.text-truncate-2 {
  display: -webkit-box;
  line-clamp: 2;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Student panel: filter tabs (module header) */
.filter-tabs .nav-link {
  color: var(--text-muted);
  background: var(--panel-bg-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 12px;
  margin-left: 6px;
}
.filter-tabs .nav-link:hover { color: var(--text); background: var(--hover-bg); border-color: var(--border); }
.filter-tabs .nav-link.active {
  color: var(--text);
  background: var(--active-bg);
  border-color: var(--focus);
  box-shadow: 0 0 0 3px var(--focus-ring);
}

/* Student panel: lesson blocks and assignment circles */
.lesson-block { border-radius: 12px; }
.lesson-block .assign-circles { display: flex; flex-wrap: wrap; gap: 8px; }
.assign-circle {
  position: relative;
  width: 44px; height: 44px; border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  text-decoration: none;
  font-weight: 700;
  border: 1px solid var(--border);
  background: var(--panel-bg-2);
  color: var(--text-muted);
  box-shadow: 0 2px 6px rgba(0,0,0,0.25) inset;
  transition: transform .15s ease, box-shadow .15s ease;
}
.assign-circle:hover { transform: translateY(-1px); box-shadow: 0 4px 12px rgba(0,0,0,0.35) inset; }
.assign-circle.done { background: rgba(34,197,94,0.14); color: #86efac; border-color: rgba(34,197,94,0.45); }
.assign-circle.pending { background: rgba(148,163,184,0.12); color: #cbd5e1; border-color: rgba(148,163,184,0.32); }
.assign-circle span { line-height: 1; }

/* overlay progress text (e.g., 0/1) inside circle */
.assign-progress {
  position: absolute;
  top: -8px; left: 50%; transform: translateX(-50%);
  background: var(--panel-bg-2);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 11px; line-height: 1;
  padding: 2px 6px;
  border-radius: 999px;
}

/* Lesson groups and task links */
.lesson-group { border-radius: 12px; }
.lesson-group .task-list { display: flex; flex-direction: column; gap: 8px; }
.lesson-group .task-link {
  display: flex; align-items: center; gap: 12px;
  text-decoration: none; color: var(--text);
  padding: 8px; border-radius: 10px;
}
.lesson-group .task-link:hover { background: var(--hover-bg); }
.lesson-group .task-title { font-weight: 600; }
.lesson-group .task-title bdi { color: var(--text); }

/* --- Motion System & Animations (global) --- */
html { scroll-behavior: smooth; }

:root {
  --anim-ease: cubic-bezier(.22,.61,.36,1);
  --anim-duration: 600ms;
  --anim-fast: 160ms;
  --anim-medium: 260ms;
  --anim-slow: 400ms;
  --bg-anim-duration: 48s; /* global background animation duration */
}

/* Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto !important; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  [data-animate] { opacity: 1 !important; transform: none !important; }
}

/* Subtle animated background for body */
@keyframes bg-pan {
  0% {
    background-position: 80% -10%, -10% 110%, center top;
    background-size: 900px 400px, 800px 500px, auto;
  }
  50% {
    background-position: 78% -8%, -12% 108%, center top;
    background-size: 920px 410px, 810px 510px, auto;
  }
  100% {
    background-position: 74% -14%, -6% 116%, center top;
    background-size: 940px 420px, 820px 520px, auto;
  }
}

/* Subtle transitions for common interactive elements */
a,
button,
.btn,
.card,
.card-elev,
.list-group-item,
.nav-link,
.pill,
.chip,
.user-chip,
.form-control,
.form-select,
.dropdown-menu,
.modal-content,
.table tbody tr {
  transition: background var(--anim-medium) ease, border-color var(--anim-medium) ease,
              color var(--anim-medium) ease, box-shadow var(--anim-medium) ease,
              transform var(--anim-medium) ease, opacity var(--anim-medium) ease;
}

/* Data-attribute driven scroll-in animations */
[data-animate] {
  opacity: 0;
  transform: translateY(12px);
  will-change: transform, opacity;
}
[data-animate].in {
  opacity: 1;
  transform: none;
  transition: transform var(--anim-duration) var(--anim-ease), opacity var(--anim-duration) var(--anim-ease);
}

/* Variants */
[data-animate="fade"] { transform: none; }
[data-animate="fade-down"] { transform: translateY(-12px); }
[data-animate="fade-left"] { transform: translateX(12px); }
[data-animate="fade-right"] { transform: translateX(-12px); }
[data-animate="scale-in"],
[data-animate="pop"] { transform: scale(.96); transform-origin: center; }

/* Dropdown and modal micro-animations */
.dropdown-menu {
  transform: translateY(6px) scale(.98);
  opacity: 0;
  transform-origin: top right;
}
.dropup .dropdown-menu { transform-origin: bottom right; }
.dropdown-menu.show { transform: none; opacity: 1; }

.modal.fade .modal-dialog {
  transform: translateY(10px) scale(.98);
  transition: transform var(--anim-slow) var(--anim-ease), opacity var(--anim-slow) var(--anim-ease);
}
.modal.show .modal-dialog { transform: none; }

/* Elevation hover tweaks for cards and panels (already present, reinforce) */
.card:hover { transform: translateY(-1px); }

/* --- Hover Animations (subtle) --- */
/* Buttons: gentle lift on hover, exclude special variants already styled */
.btn:not(.btn-link):not(.btn-glow):not(.btn-neon):not(.btn-ghost):hover { transform: translateY(-1px); }
.btn:not(.btn-link):not(.btn-glow):not(.btn-neon):not(.btn-ghost):active { transform: translateY(0); }

/* List-group actionable items: light lift */
.list-group-item-action { transition: transform var(--anim-medium) var(--anim-ease); }
.list-group-item-action:hover { transform: translateY(-1px); }
.list-group-item-action:active { transform: translateY(0); }

/* Chips and user chips: micro lift on hover */
.chip,
.user-chip,
.pill { transition: transform var(--anim-medium) var(--anim-ease), box-shadow var(--anim-medium) var(--anim-ease); }
.chip:hover,
.user-chip:hover { transform: translateY(-1px); }
.chip:active,
.user-chip:active { transform: translateY(0); }

/* Dropdown items: subtle nudge */
.dropdown-menu .dropdown-item { transition: transform var(--anim-fast) var(--anim-ease); }
.dropdown-menu .dropdown-item:hover { transform: translateX(2px); }
.dropdown-menu .dropdown-item:active { transform: translateX(0); }

/* Utility: underline reveal for links on hover (opt-in) */
.link-underline {
  background-image: linear-gradient(currentColor, currentColor);
  background-position: 0 100%;
  background-repeat: no-repeat;
  background-size: 0% 2px;
  transition: background-size var(--anim-fast) var(--anim-ease);
}
.link-underline:hover { background-size: 100% 2px; }
/* --- Knowledge Portal (post-login) --- */
body.portal-enter {
  opacity: 0;
  transform: translateY(8px) scale(0.99);
}

body.portal-enter.portal-enter-active {
  opacity: 1;
  transform: none;
  transition:
    opacity var(--anim-duration) var(--anim-ease),
    transform var(--anim-duration) var(--anim-ease);
}