/* ============================================================
   PhysicsNP — Glass UI Design System
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800;900&family=DM+Serif+Display:ital@0;1&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --bg-primary:     #f0f4ff;
  --bg-secondary:   #e8eeff;
  --bg-tertiary:    #ffffff;
  --glass-bg:       rgba(255,255,255,0.55);
  --glass-bg2:      rgba(255,255,255,0.35);
  --glass-border:   rgba(255,255,255,0.7);
  --glass-shadow:   0 8px 32px rgba(99,102,241,0.12);
  --glass-blur:     blur(20px);

  --text-primary:   #0f172a;
  --text-secondary: #475569;
  --text-muted:     #94a3b8;

  --accent-1:       #6366f1;   /* indigo */
  --accent-2:       #0ea5e9;   /* sky */
  --accent-3:       #8b5cf6;   /* violet */
  --accent-glow:    rgba(99,102,241,0.3);

  --success:        #10b981;
  --warning:        #f59e0b;
  --danger:         #ef4444;

  --mesh-1: radial-gradient(ellipse 80% 60% at 20% 10%, rgba(99,102,241,0.18) 0%, transparent 60%);
  --mesh-2: radial-gradient(ellipse 60% 80% at 80% 80%, rgba(14,165,233,0.15) 0%, transparent 60%);
  --mesh-3: radial-gradient(ellipse 50% 50% at 50% 50%, rgba(139,92,246,0.1) 0%, transparent 70%);

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;

  --nav-h: 70px;
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
}

[data-theme="dark"] {
  --bg-primary:     #080c1a;
  --bg-secondary:   #0d1226;
  --bg-tertiary:    #111827;
  --glass-bg:       rgba(15,23,42,0.65);
  --glass-bg2:      rgba(15,23,42,0.45);
  --glass-border:   rgba(99,102,241,0.2);
  --glass-shadow:   0 8px 32px rgba(0,0,0,0.4);

  --text-primary:   #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted:     #475569;

  --accent-glow:    rgba(99,102,241,0.4);

  --mesh-1: radial-gradient(ellipse 80% 60% at 20% 10%, rgba(99,102,241,0.25) 0%, transparent 60%);
  --mesh-2: radial-gradient(ellipse 60% 80% at 80% 80%, rgba(14,165,233,0.2) 0%, transparent 60%);
  --mesh-3: radial-gradient(ellipse 50% 50% at 50% 50%, rgba(139,92,246,0.15) 0%, transparent 70%);
}

/* ─── Reset & Base ─────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Outfit', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  transition: background 0.4s, color 0.4s;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: var(--mesh-1), var(--mesh-2), var(--mesh-3);
  pointer-events: none;
  z-index: 0;
}

/* ─── Glass Components ─────────────────────────────────────── */
.glass {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}

.usermenu {
  background: #048207;
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}


.glass-dark {
  background: var(--glass-bg2);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
}

/* ─── Typography ───────────────────────────────────────────── */
h1, h2, h3, h4, h5 { font-weight: 700; line-height: 1.2; }

.display-font { font-family: 'DM Serif Display', serif; }
.mono { font-family: 'JetBrains Mono', monospace; }

/* ─── Navigation ───────────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 100;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: 0 4px 24px rgba(0,0,0,0.08);
  transition: var(--transition);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.nav-logo-icon {
  width: auto; height: 38px;
  display: flex; align-items: center; justify-content: center;
}

.nav-logo-text {
  font-size: 1.25rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-weight: 500;
  font-size: 0.9rem;
  transition: var(--transition);
}

.nav-links a:hover, .nav-links a.active {
  color: var(--accent-1);
  background: rgba(99,102,241,0.1);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.btn-theme {
  width: 40px; height: 40px;
  border-radius: 50%;
  border: 1px solid var(--glass-border);
  background: var(--glass-bg2);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
  color: var(--text-secondary);
  transition: var(--transition);
}

.btn-theme:hover {
  background: rgba(99,102,241,0.15);
  color: var(--accent-1);
  transform: rotate(15deg);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 5px;
}

.hamburger span {
  display: block;
  width: 24px; height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ─── Buttons ──────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0.65rem 1.5rem;
  border-radius: var(--radius-sm);
  font-family: 'Outfit', sans-serif;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  color: #fff;
  box-shadow: 0 4px 16px var(--accent-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--accent-glow);
}

.btn-secondary {
  background: var(--glass-bg);
  color: var(--text-primary);
  border: 1px solid var(--glass-border);
  backdrop-filter: var(--glass-blur);
}

.btn-secondary:hover {
  background: rgba(99,102,241,0.1);
  border-color: var(--accent-1);
  color: var(--accent-1);
}

.btn-outline {
  background: transparent;
  color: var(--accent-1);
  border: 1.5px solid var(--accent-1);
}

.btn-outline:hover {
  background: var(--accent-1);
  color: #fff;
}

.btn-sm { padding: 0.4rem 1rem; font-size: 0.8rem; }
.btn-lg { padding: 0.85rem 2rem; font-size: 1rem; }
.btn-icon { width: 38px; height: 38px; padding: 0; justify-content: center; border-radius: 10px; }

/* ─── Cards ────────────────────────────────────────────────── */
.card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--glass-shadow);
  transition: var(--transition);
  overflow: hidden;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(99,102,241,0.18);
  border-color: rgba(99,102,241,0.3);
}

.card-header {
  padding: 1.5rem;
  border-bottom: 1px solid var(--glass-border);
}

.card-body { padding: 1.5rem; }
.card-footer {
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--glass-border);
  background: var(--glass-bg2);
}

/* ─── Course Card ──────────────────────────────────────────── */
.course-card {
  position: relative;
  overflow: hidden;
}

.course-card-banner {
  height: 160px;
  position: relative;
  overflow: hidden;
}

.course-card-banner img {
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.course-card:hover .course-card-banner img {
  transform: scale(1.05);
}

.course-card-banner-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, transparent 40%, rgba(0,0,0,0.5));
}

.course-card-badges {
  position: absolute;
  top: 12px; left: 12px;
  display: flex; gap: 6px;
}

.badge {
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.3px;
}

.badge-level { background: rgba(99,102,241,0.85); color: #fff; }
.badge-board { background: rgba(14,165,233,0.85); color: #fff; }
.badge-new    { background: rgba(16,185,129,0.85); color: #fff; }

.course-card-content { padding: 1.25rem; }

.course-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
  line-height: 1.3;
}

.course-card-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.course-card-progress { margin-bottom: 1rem; }

.progress-bar {
  height: 5px;
  background: var(--glass-bg2);
  border-radius: 10px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-1), var(--accent-2));
  border-radius: 10px;
  transition: width 0.8s ease;
}

/* ─── Forms ────────────────────────────────────────────────── */
.form-group { margin-bottom: 1.25rem; }

.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  letter-spacing: 0.3px;
}

.form-control {
  width: 100%;
  padding: 0.7rem 1rem;
  background: var(--glass-bg2);
  border: 1.5px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: 'Outfit', sans-serif;
  font-size: 0.9rem;
  transition: var(--transition);
  outline: none;
}

.form-control:focus {
  border-color: var(--accent-1);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.15);
  background: var(--glass-bg);
}

.form-control::placeholder { color: var(--text-muted); }

select.form-control { cursor: pointer; appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 1rem center; padding-right: 2.5rem; }

/* ─── Sections & Layout ────────────────────────────────────── */
.page-wrap {
  min-height: 100vh;
  padding-top: var(--nav-h);
  position: relative;
  z-index: 1;
}

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section { padding: 5rem 0; }
.section-sm { padding: 3rem 0; }

.section-title {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -1px;
  margin-bottom: 0.75rem;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
  line-height: 1.7;
}

.gradient-text {
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ─── Hero ─────────────────────────────────────────────────── */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: calc(var(--nav-h) + 2rem) 0 4rem;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: rgba(99,102,241,0.1);
  border: 1px solid rgba(99,102,241,0.25);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-1);
  margin-bottom: 1.25rem;
  letter-spacing: 0.5px;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 900;
  letter-spacing: -2px;
  line-height: 1.08;
  margin-bottom: 1.25rem;
}

.hero-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 500px;
  line-height: 1.75;
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 3rem;
}

.hero-stats {
  display: flex;
  gap: 2.5rem;
}

.hero-stat-value {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--accent-1);
  letter-spacing: -1px;
}

.hero-stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

.hero-visual {
  position: relative;
}

.hero-card-stack {
  position: relative;
  height: 420px;
}

.floating-card {
  position: absolute;
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  animation: float linear infinite;
}

@keyframes float {
  0%   { transform: translateY(0px) rotate(var(--rot,0deg)); }
  50%  { transform: translateY(-12px) rotate(var(--rot,0deg)); }
  100% { transform: translateY(0px) rotate(var(--rot,0deg)); }
}

.fc-main {
  top: 60px; left: 20px;
  width: 300px;
  --rot: -2deg;
  animation-duration: 6s;
}

.fc-formula {
  top: 20px; right: 10px;
  width: 200px;
  --rot: 3deg;
  animation-duration: 7s;
  animation-delay: -2s;
}

.fc-progress {
  bottom: 30px; right: 30px;
  width: 220px;
  --rot: -1deg;
  animation-duration: 5.5s;
  animation-delay: -1s;
}

.orbit-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px dashed rgba(99,102,241,0.2);
  animation: spin linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

.atom-dot {
  position: absolute;
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--accent-1);
  box-shadow: 0 0 10px var(--accent-1);
}

/* ─── Feature Cards ────────────────────────────────────────── */
.feature-icon {
  width: 50px; height: 50px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, rgba(99,102,241,0.15), rgba(139,92,246,0.15));
  border: 1px solid rgba(99,102,241,0.2);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 1rem;
}

/* ─── Grid Layouts ─────────────────────────────────────────── */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }
.grid-auto { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px,1fr)); gap: 1.5rem; }

/* ─── Tabs ─────────────────────────────────────────────────── */
.tabs {
  display: flex;
  gap: 0.25rem;
  background: var(--glass-bg2);
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--glass-border);
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.tab-btn {
  padding: 0.55rem 1.25rem;
  border-radius: calc(var(--radius-md) - 4px);
  border: none;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  font-family: 'Outfit', sans-serif;
  font-weight: 600;
  font-size: 0.875rem;
  transition: var(--transition);
}

.tab-btn.active, .tab-btn:hover {
  background: var(--glass-bg);
  color: var(--accent-1);
  box-shadow: var(--glass-shadow);
}

.tab-content { display: none; }
.tab-content.active { display: block; }

/* ─── Search Bar ───────────────────────────────────────────── */
.search-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--glass-bg);
  border: 1.5px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: 0.6rem 1rem;
  backdrop-filter: var(--glass-blur);
  transition: var(--transition);
}

.search-bar:focus-within {
  border-color: var(--accent-1);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.15);
}

.search-bar input {
  border: none;
  outline: none;
  background: transparent;
  color: var(--text-primary);
  font-family: 'Outfit', sans-serif;
  font-size: 0.9rem;
  flex: 1;
  min-width: 0;
}

.search-bar input::placeholder { color: var(--text-muted); }

/* ─── Filter Chips ─────────────────────────────────────────── */
.filter-chips {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.chip {
  padding: 0.4rem 1rem;
  border-radius: 20px;
  border: 1.5px solid var(--glass-border);
  background: var(--glass-bg2);
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.chip:hover, .chip.active {
  border-color: var(--accent-1);
  background: rgba(99,102,241,0.1);
  color: var(--accent-1);
}

/* ─── Admin Sidebar ────────────────────────────────────────── */
.admin-layout {
  display: flex;
  min-height: 100vh;
  padding-top: var(--nav-h);
}

.sidebar {
  width: 260px;
  min-height: calc(100vh - var(--nav-h));
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border-right: 1px solid var(--glass-border);
  padding: 1.5rem 1rem;
  position: sticky;
  top: var(--nav-h);
  height: calc(100vh - var(--nav-h));
  overflow-y: auto;
  flex-shrink: 0;
}

.sidebar-title {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin: 1.25rem 0 0.5rem 0.75rem;
}

.sidebar-nav { list-style: none; }

.sidebar-nav li a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0.65rem 0.75rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.9rem;
  transition: var(--transition);
}

.sidebar-nav li a:hover, .sidebar-nav li a.active {
  background: rgba(99,102,241,0.12);
  color: var(--accent-1);
}

.sidebar-nav li a .nav-icon { font-size: 1.1rem; width: 20px; text-align: center; }

.admin-main {
  flex: 1;
  padding: 2rem;
  overflow-x: hidden;
}

/* ─── Data Table ───────────────────────────────────────────── */
.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--glass-border);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

thead th {
  background: var(--glass-bg2);
  padding: 0.85rem 1rem;
  text-align: left;
  font-weight: 700;
  color: var(--text-secondary);
  font-size: 0.78rem;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  border-bottom: 1px solid var(--glass-border);
  white-space: nowrap;
}

tbody td {
  padding: 0.85rem 1rem;
  border-bottom: 1px solid rgba(99,102,241,0.06);
  color: var(--text-primary);
  vertical-align: middle;
}

tbody tr:last-child td { border-bottom: none; }

tbody tr:hover td { background: rgba(99,102,241,0.04); }

/* ─── Alerts & Toasts ──────────────────────────────────────── */
.alert {
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 1rem;
}

.alert-success { background: rgba(16,185,129,0.12); border: 1px solid rgba(16,185,129,0.3); color: var(--success); }
.alert-danger  { background: rgba(239,68,68,0.12);  border: 1px solid rgba(239,68,68,0.3);  color: var(--danger); }
.alert-info    { background: rgba(14,165,233,0.12); border: 1px solid rgba(14,165,233,0.3); color: var(--accent-2); }

/* ─── Toast ────────────────────────────────────────────────── */
#toast-container {
  position: fixed;
  bottom: 2rem; right: 2rem;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.toast {
  min-width: 280px;
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: 0 8px 32px rgba(0,0,0,0.15);
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 500;
  font-size: 0.875rem;
  animation: slideUp 0.3s ease;
}

@keyframes slideUp {
  from { transform: translateY(20px); opacity: 0; }
  to   { transform: translateY(0);    opacity: 1; }
}

/* ─── Modal ────────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  backdrop-filter: blur(4px);
  z-index: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
}

.modal-overlay.open {
  opacity: 1;
  pointer-events: all;
}

.modal {
  background: var(--bg-tertiary);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: 2rem;
  max-width: 580px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  transform: scale(0.95);
  transition: transform 0.3s;
  box-shadow: 0 24px 80px rgba(0,0,0,0.2);
}

.modal-overlay.open .modal { transform: scale(1); }

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.modal-title { font-size: 1.25rem; font-weight: 800; }

.modal-close {
  width: 32px; height: 32px;
  border-radius: 8px;
  border: 1px solid var(--glass-border);
  background: var(--glass-bg2);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  color: var(--text-secondary);
  font-size: 1rem;
  transition: var(--transition);
}

.modal-close:hover { color: var(--danger); background: rgba(239,68,68,0.1); }

/* ─── Question Paper Card ──────────────────────────────────── */
.qp-card {
  position: relative;
  overflow: hidden;
}

.qp-card-header {
  padding: 1.25rem;
  background: linear-gradient(135deg, rgba(99,102,241,0.08), rgba(14,165,233,0.08));
  border-bottom: 1px solid var(--glass-border);
}

.qp-year-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px; height: 52px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  color: #fff;
  font-weight: 800;
  font-size: 0.8rem;
  text-align: center;
  line-height: 1.2;
  box-shadow: 0 4px 12px var(--accent-glow);
  flex-shrink: 0;
}

.qp-img-preview {
  width: 100%;
  height: 180px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: transform 0.3s;
}

.qp-img-preview:hover { transform: scale(1.02); }

/* ─── Image Lightbox ───────────────────────────────────────── */
#lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.92);
  z-index: 9000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

#lightbox.open { display: flex; }

#lightbox img {
  max-width: 90vw;
  max-height: 90vh;
  border-radius: var(--radius-md);
  box-shadow: 0 24px 80px rgba(0,0,0,0.5);
}

#lightbox-close {
  position: absolute;
  top: 1.5rem; right: 1.5rem;
  width: 44px; height: 44px;
  border-radius: 50%;
  background: rgba(255,255,255,0.15);
  border: none;
  cursor: pointer;
  color: #fff;
  font-size: 1.25rem;
  display: flex; align-items: center; justify-content: center;
}

/* ─── Rich Text Editor area ────────────────────────────────── */
.ql-container { border-radius: 0 0 var(--radius-sm) var(--radius-sm) !important; }
.ql-toolbar { border-radius: var(--radius-sm) var(--radius-sm) 0 0 !important; background: var(--glass-bg2); border-color: var(--glass-border) !important; }
.ql-container { border-color: var(--glass-border) !important; background: var(--glass-bg); min-height: 180px; }

/* ─── Footer ───────────────────────────────────────────────── */
footer {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border-top: 1px solid var(--glass-border);
  padding: 3rem 0 1.5rem;
  position: relative;
  z-index: 1;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2.5rem;
}

.footer-links { list-style: none; }
.footer-links li { margin-bottom: 0.6rem; }
.footer-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.875rem;
  transition: color 0.2s;
}
.footer-links a:hover { color: var(--accent-1); }

.footer-bottom {
  border-top: 1px solid var(--glass-border);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* ─── Utilities ────────────────────────────────────────────── */
.text-center { text-align: center; }
.text-right  { text-align: right; }
.flex        { display: flex; }
.items-center{ align-items: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.w-full { width: 100%; }
.rounded { border-radius: var(--radius-md); }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.divider {
  height: 1px;
  background: var(--glass-border);
  margin: 1.5rem 0;
}

.avatar {
  width: 36px; height: 36px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--glass-border);
}

/* ─── Skeletons ────────────────────────────────────────────── */
.skeleton {
  background: linear-gradient(90deg, var(--glass-bg2) 25%, var(--glass-border) 50%, var(--glass-bg2) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-sm);
}

@keyframes shimmer {
  from { background-position: 200% 0; }
  to   { background-position: -200% 0; }
}

/* ─── Page Header Band ─────────────────────────────────────── */
.page-header {
  padding: 3rem 0 2rem;
  position: relative;
}

.page-header::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--glass-border), transparent);
}

/* ─── Responsive ───────────────────────────────────────────── */
@media (max-width: 1024px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-visual { display: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 2rem; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root { --nav-h: 60px; }
  .nav-links { display: none; }
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .sidebar { display: none; }
  .admin-layout { flex-direction: column; }
  .section { padding: 3rem 0; }
  .hero-title { letter-spacing: -1px; }
  .hero-stats { gap: 1.5rem; }
  .tabs { overflow-x: auto; flex-wrap: nowrap; }
  .container { padding: 0 1rem; }
}

@media (max-width: 480px) {
  .grid-4 { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; }
  .btn-lg { width: 100%; justify-content: center; }
}

/* ─── Page Transitions ─────────────────────────────────────── */
/* body opacity fade handled by JS; this ensures no FOUC */
body {
  opacity: 0;
}

/* ─── Navbar scroll elevation ──────────────────────────────── */
.navbar {
  transition: box-shadow 0.3s ease, background 0.4s;
}


/* ─── Card hover lift ──────────────────────────────────────── */
.card {
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1),
              box-shadow 0.25s cubic-bezier(0.4, 0, 0.2, 1),
              border-color 0.25s ease;
  will-change: transform;
}

/* ─── Button press effect ──────────────────────────────────── */
.btn:active {
  transform: scale(0.97);
}

/* ─── Smooth modal backdrop ────────────────────────────────── */
.modal-overlay {
  transition: opacity 0.22s ease;
}
.modal {
  transition: transform 0.22s cubic-bezier(0.34, 1.56, 0.64, 1),
              opacity 0.22s ease;
}

/* ─── Toast slide-up ───────────────────────────────────────── */
.toast {
  animation: toastSlideUp 0.3s cubic-bezier(0.34, 1.56, 0.64, 1) both;
}
@keyframes toastSlideUp {
  from { transform: translateY(16px); opacity: 0; }
  to   { transform: translateY(0);    opacity: 1; }
}

/* ─── Chip hover ───────────────────────────────────────────── */
.chip {
  transition: all 0.18s ease;
}

/* ─── Form focus glow ──────────────────────────────────────── */
.form-control {
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

/* ─── Sidebar nav item ─────────────────────────────────────── */
.sidebar-nav li a {
  transition: background 0.18s ease, color 0.18s ease;
}

/* ─── Skip nav link for accessibility ─────────────────────── */
.skip-nav {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--accent-1);
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  font-weight: 700;
  font-size: 0.875rem;
  text-decoration: none;
  z-index: 9999;
  transition: top 0.2s;
}
.skip-nav:focus { top: 0; }


/* ─── Progress bar animation ───────────────────────────────── */
.progress-fill {
  transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ─── Sticky topbar in course-view ─────────────────────────── */
.cv-topbar {
  transition: box-shadow 0.25s ease;
}

/* ─── Video embed fade-in ──────────────────────────────────── */
.video-wrap iframe {
  animation: fadeIn 0.4s ease both;
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ─── Paper page image ─────────────────────────────────────── */
.paper-page {
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

/* ─── QP card hover ────────────────────────────────────────── */
.qp-card .qp-img-preview {
  transition: transform 0.35s ease;
}
.qp-card:hover .qp-img-preview {
  transform: scale(1.02);
}

/* ═══════════════════════════════════════════════════════════
   STUDENT PAGE MOBILE POLISH
   ══════════════════════════════════════════════════════════= */

/* ── Bottom navigation bar for mobile students ─────────────── */
.mobile-bottom-nav {
  display: none;
  position: fixed;
  bottom: 0; left: 0; right: 0;
  z-index: 90;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-top: 1px solid var(--glass-border);
  padding: .5rem 0 env(safe-area-inset-bottom, .5rem);
  box-shadow: 0 -4px 24px rgba(0,0,0,.08);
}

.mobile-bottom-nav ul {
  list-style: none;
  display: flex;
  justify-content: space-around;
  margin: 0;
  padding: 0;
}

.mobile-bottom-nav a {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  text-decoration: none;
  color: var(--text-secondary);
  font-size: .62rem;
  font-weight: 600;
  padding: .35rem .5rem;
  border-radius: var(--radius-sm);
  transition: color .2s;
  letter-spacing: .3px;
  min-width: 52px;
}

.mobile-bottom-nav a .nav-icon-mob {
  font-size: 1.3rem;
  line-height: 1;
}

.mobile-bottom-nav a.active,
.mobile-bottom-nav a:hover {
  color: var(--accent-1);
}

/* Spacer so content doesn't hide behind bottom nav */
.mobile-bottom-spacer { display: none; height: 72px; }

@media (max-width: 768px) {
  .mobile-bottom-nav    { display: block; }
  .mobile-bottom-spacer { display: block; }
  /* Push page content above bottom nav */
  .page-wrap { padding-bottom: 72px; }
  .cv-root   { padding-bottom: 72px; }
}