/* ============================================================
   VINAYAK TUITION CLASSES — Global Design System
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600;700;800;900&family=Inter:wght@300;400;500;600&display=swap');

/* ─── CSS Variables ─── */
:root {
  --primary: #007BFF;
  --primary-dark: #0056b3;
  --primary-light: #e8f4ff;
  --secondary: #28A745;
  --secondary-dark: #1e7e34;
  --secondary-light: #d4edda;
  --warning: #FFC107;
  --danger: #DC3545;
  --info: #17A2B8;
  --dark: #1a1a2e;
  --dark-card: #16213e;
  --dark-border: #0f3460;
  --gray: #6c757d;
  --light-gray: #f8f9fa;
  --border: #dee2e6;
  --text-primary: #2d3748;
  --text-secondary: #718096;
  --white: #ffffff;
  --shadow: 0 4px 20px rgba(0,123,255,0.12);
  --shadow-lg: 0 10px 40px rgba(0,123,255,0.18);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 20px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-heading: 'Poppins', sans-serif;
  --font-body: 'Inter', sans-serif;
}

/* Dark Mode */
[data-theme="dark"] {
  --white: #1a1a2e;
  --light-gray: #16213e;
  --border: #0f3460;
  --text-primary: #e2e8f0;
  --text-secondary: #a0aec0;
  --shadow: 0 4px 20px rgba(0,0,0,0.4);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.5);
  --primary-light: #0f3460;
  --secondary-light: #1a3a2a;
}

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

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

body {
  font-family: var(--font-body);
  color: var(--text-primary);
  background: var(--white);
  line-height: 1.7;
  transition: background 0.3s, color 0.3s;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.3;
}

a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-dark); }
img { max-width: 100%; display: block; }
ul { list-style: none; }

/* ─── Layout ─── */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 80px 0; }
.section-sm { padding: 50px 0; }
.row { display: flex; flex-wrap: wrap; gap: 24px; }
.col-2 { flex: 1 1 calc(50% - 12px); min-width: 280px; }
.col-3 { flex: 1 1 calc(33.33% - 16px); min-width: 240px; }
.col-4 { flex: 1 1 calc(25% - 18px); min-width: 200px; }

/* ─── Navigation ─── */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0,123,255,0.1);
  padding: 0 20px;
  transition: var(--transition);
}
[data-theme="dark"] .navbar {
  background: rgba(26,26,46,0.95);
  border-bottom-color: rgba(0,123,255,0.2);
}
.navbar-inner {
  max-width: 1200px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  height: 70px;
}
.nav-logo { display: flex; align-items: center; gap: 12px; }
.nav-logo-icon {
  width: 42px; height: 42px; border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; color: white; font-family: var(--font-heading); font-weight: 800;
}
.nav-logo-text { font-family: var(--font-heading); font-weight: 800; font-size: 1.1rem; color: var(--text-primary); line-height: 1.2; }
.nav-logo-text span { color: var(--primary); font-size: 0.7rem; font-weight: 500; letter-spacing: 1px; text-transform: uppercase; display: block; }

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-link {
  padding: 8px 14px; border-radius: var(--radius-sm);
  color: var(--text-secondary); font-weight: 500; font-size: 0.9rem;
  transition: var(--transition);
}
.nav-link:hover, .nav-link.active { color: var(--primary); background: var(--primary-light); }

.nav-actions { display: flex; align-items: center; gap: 10px; }
.btn-sm { padding: 8px 18px; font-size: 0.85rem; border-radius: var(--radius-sm); }

.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 5px; background: none; border: none; }
.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; justify-content: center;
  padding: 12px 28px; border-radius: var(--radius-sm); font-size: 0.95rem;
  font-weight: 600; font-family: var(--font-body); cursor: pointer;
  border: 2px solid transparent; transition: var(--transition);
  white-space: nowrap; text-decoration: none;
}
.btn-primary { background: var(--primary); color: white; border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-dark); color: white; border-color: var(--primary-dark); transform: translateY(-2px); box-shadow: 0 8px 25px rgba(0,123,255,0.4); }
.btn-secondary { background: var(--secondary); color: white; border-color: var(--secondary); }
.btn-secondary:hover { background: var(--secondary-dark); color: white; border-color: var(--secondary-dark); transform: translateY(-2px); box-shadow: 0 8px 25px rgba(40,167,69,0.4); }
.btn-outline { background: transparent; color: var(--primary); border-color: var(--primary); }
.btn-outline:hover { background: var(--primary); color: white; transform: translateY(-2px); }
.btn-danger { background: var(--danger); color: white; border-color: var(--danger); }
.btn-danger:hover { background: #bd2130; color: white; }
.btn-warning { background: var(--warning); color: #333; border-color: var(--warning); }
.btn-light { background: var(--light-gray); color: var(--text-primary); border-color: var(--border); }
.btn-light:hover { background: var(--border); color: var(--text-primary); }
.btn-ghost { background: transparent; color: var(--text-secondary); border-color: transparent; }
.btn-ghost:hover { color: var(--primary); background: var(--primary-light); }
.btn-block { width: 100%; }
.btn:disabled { opacity: 0.6; cursor: not-allowed; transform: none !important; }

/* ─── Cards ─── */
.card {
  background: var(--white); border-radius: var(--radius);
  box-shadow: var(--shadow); border: 1px solid rgba(0,123,255,0.08);
  overflow: hidden; transition: var(--transition);
}
.card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.card-body { padding: 24px; }
.card-header { padding: 20px 24px; border-bottom: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; }
.card-footer { padding: 16px 24px; border-top: 1px solid var(--border); background: var(--light-gray); }
[data-theme="dark"] .card { background: var(--dark-card); border-color: var(--dark-border); }
[data-theme="dark"] .card-footer { background: #1a1a2e; }

/* ─── Section Titles ─── */
.section-title { text-align: center; margin-bottom: 50px; }
.section-title h2 { font-size: 2.2rem; margin-bottom: 12px; }
.section-title h2 span { color: var(--primary); }
.section-title p { color: var(--text-secondary); font-size: 1.05rem; max-width: 560px; margin: 0 auto; }
.section-tag {
  display: inline-block; padding: 6px 18px; border-radius: 50px;
  background: var(--primary-light); color: var(--primary);
  font-size: 0.8rem; font-weight: 600; letter-spacing: 2px; text-transform: uppercase;
  margin-bottom: 12px; font-family: var(--font-heading);
}

/* ─── Badges ─── */
.badge {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 4px 12px; border-radius: 50px; font-size: 0.75rem; font-weight: 600;
}
.badge-primary { background: var(--primary-light); color: var(--primary); }
.badge-success { background: var(--secondary-light); color: var(--secondary-dark); }
.badge-danger { background: #fde8ea; color: var(--danger); }
.badge-warning { background: #fff8e1; color: #856404; }
.badge-info { background: #d1ecf1; color: #0c5460; }

/* ─── Forms ─── */
.form-group { margin-bottom: 20px; }
.form-label { display: block; font-weight: 600; margin-bottom: 8px; font-size: 0.9rem; color: var(--text-primary); }
.form-control {
  width: 100%; padding: 12px 16px; border-radius: var(--radius-sm);
  border: 2px solid var(--border); background: var(--white);
  color: var(--text-primary); font-family: var(--font-body); font-size: 0.95rem;
  transition: var(--transition); outline: none;
}
.form-control:focus { border-color: var(--primary); box-shadow: 0 0 0 4px rgba(0,123,255,0.1); }
.form-control::placeholder { color: var(--text-secondary); }
[data-theme="dark"] .form-control { background: var(--dark-card); border-color: var(--dark-border); }
select.form-control { cursor: pointer; }
textarea.form-control { resize: vertical; min-height: 110px; }

/* ─── Tables ─── */
.table-wrapper { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border); }
table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
table th { padding: 14px 16px; background: var(--primary); color: white; font-weight: 600; text-align: left; white-space: nowrap; font-family: var(--font-heading); }
table td { padding: 14px 16px; border-bottom: 1px solid var(--border); vertical-align: middle; }
table tr:last-child td { border-bottom: none; }
table tr:hover td { background: var(--primary-light); }
[data-theme="dark"] table td { border-bottom-color: var(--dark-border); }
[data-theme="dark"] table tr:hover td { background: rgba(0,123,255,0.08); }

/* ─── Tabs ─── */
.tabs { display: flex; gap: 4px; border-bottom: 2px solid var(--border); margin-bottom: 28px; overflow-x: auto; }
.tab-btn {
  padding: 12px 20px; border: none; background: none; cursor: pointer;
  font-family: var(--font-body); font-size: 0.9rem; font-weight: 600;
  color: var(--text-secondary); border-bottom: 3px solid transparent;
  margin-bottom: -2px; white-space: nowrap; transition: var(--transition);
}
.tab-btn:hover { color: var(--primary); }
.tab-btn.active { color: var(--primary); border-bottom-color: var(--primary); }
.tab-pane { display: none; }
.tab-pane.active { display: block; animation: fadeIn 0.3s ease; }

/* ─── Stats Strip ─── */
.stats-strip {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  padding: 50px 20px; border-radius: var(--radius-lg); margin: 40px 0;
  color: white; text-align: center;
}
.stat-item { padding: 10px; }
.stat-number { font-family: var(--font-heading); font-size: 3rem; font-weight: 800; line-height: 1; }
.stat-label { font-size: 0.9rem; opacity: 0.85; margin-top: 6px; font-weight: 500; }

/* ─── Subject Cards ─── */
.subject-card {
  background: var(--white); border-radius: var(--radius);
  box-shadow: var(--shadow); border: 1px solid rgba(0,123,255,0.08);
  overflow: hidden; transition: var(--transition);
  position: relative;
}
.subject-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); }
.subject-card-icon {
  width: 100%; padding: 30px; text-align: center;
  font-size: 3rem; display: flex; align-items: center; justify-content: center;
}
.subject-card-body { padding: 0 24px 24px; }
.subject-card-body h3 { font-size: 1.1rem; margin-bottom: 8px; }
.subject-card-body p { color: var(--text-secondary); font-size: 0.875rem; margin-bottom: 16px; }
.subject-meta { display: flex; gap: 12px; flex-wrap: wrap; }
.subject-meta span { display: flex; align-items: center; gap: 4px; font-size: 0.8rem; color: var(--text-secondary); }

/* ─── Hero ─── */
.hero {
  min-height: 100vh; display: flex; align-items: center; justify-content: center;
  position: relative; overflow: hidden; padding: 120px 20px 80px;
  background: linear-gradient(135deg, #f0f7ff 0%, #e8f4ff 50%, #f0fff4 100%);
}
[data-theme="dark"] .hero { background: linear-gradient(135deg, #0f1729 0%, #1a1a2e 50%, #0d1f15 100%); }
.hero-content { max-width: 700px; }
.hero-tag { background: linear-gradient(135deg, var(--primary-light), var(--secondary-light)); }
.hero h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); margin-bottom: 20px; }
.hero h1 .highlight { color: var(--primary); }
.hero p { font-size: 1.15rem; color: var(--text-secondary); margin-bottom: 32px; max-width: 550px; }
.hero-btns { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-visual { position: relative; }
.hero-card-float {
  background: var(--white); border-radius: var(--radius); box-shadow: var(--shadow-lg);
  padding: 20px 24px; border: 1px solid rgba(0,123,255,0.1);
  animation: float 4s ease-in-out infinite;
}
[data-theme="dark"] .hero-card-float { background: var(--dark-card); }

/* ─── Attendance Calendar ─── */
.att-calendar { display: grid; grid-template-columns: repeat(7, 1fr); gap: 4px; }
.att-day {
  width: 32px; height: 32px; border-radius: 6px; display: flex; align-items: center; justify-content: center;
  font-size: 0.75rem; font-weight: 600; cursor: default;
}
.att-day.present { background: var(--secondary-light); color: var(--secondary-dark); }
.att-day.absent { background: #fde8ea; color: var(--danger); }
.att-day.late { background: #fff3cd; color: #856404; }
.att-day.empty { opacity: 0; }
.att-day.future { background: var(--light-gray); color: var(--text-secondary); }

/* ─── Progress Bar ─── */
.progress-bar-wrap { background: var(--border); border-radius: 50px; height: 10px; overflow: hidden; }
.progress-bar-fill { height: 100%; border-radius: 50px; transition: width 1s ease; }
.progress-bar-fill.green { background: linear-gradient(90deg, var(--secondary), #20c997); }
.progress-bar-fill.blue { background: linear-gradient(90deg, var(--primary), #17a2b8); }
.progress-bar-fill.red { background: linear-gradient(90deg, var(--danger), #fd7e14); }
.progress-bar-fill.yellow { background: linear-gradient(90deg, var(--warning), #ffc107); }

/* ─── KPI Cards ─── */
.kpi-card {
  background: var(--white); border-radius: var(--radius); box-shadow: var(--shadow);
  border: 1px solid rgba(0,123,255,0.08); padding: 24px; display: flex; gap: 16px; align-items: flex-start;
  transition: var(--transition);
}
.kpi-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
[data-theme="dark"] .kpi-card { background: var(--dark-card); border-color: var(--dark-border); }
.kpi-icon {
  width: 52px; height: 52px; border-radius: 12px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center; font-size: 1.5rem;
}
.kpi-icon.blue { background: var(--primary-light); }
.kpi-icon.green { background: var(--secondary-light); }
.kpi-icon.yellow { background: #fff8e1; }
.kpi-icon.red { background: #fde8ea; }
.kpi-info p { font-size: 0.8rem; color: var(--text-secondary); font-weight: 600; text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 4px; }
.kpi-info h3 { font-size: 1.8rem; color: var(--text-primary); }
.kpi-info span { font-size: 0.8rem; color: var(--secondary); font-weight: 600; }

/* ─── Sidebar Layout ─── */
.app-layout { display: flex; min-height: 100vh; padding-top: 70px; }
.sidebar {
  width: 260px; background: var(--white); border-right: 1px solid var(--border);
  position: fixed; left: 0; top: 70px; bottom: 0; overflow-y: auto; padding: 20px 0;
  transition: var(--transition); z-index: 100;
}
[data-theme="dark"] .sidebar { background: var(--dark-card); border-right-color: var(--dark-border); }
.sidebar-brand { padding: 0 20px 20px; border-bottom: 1px solid var(--border); margin-bottom: 10px; text-align: center; }
.sidebar-brand p { font-size: 0.75rem; color: var(--text-secondary); }
.sidebar-section { padding: 10px 12px 6px; font-size: 0.7rem; font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; color: var(--text-secondary); }
.sidebar-link {
  display: flex; align-items: center; gap: 12px; padding: 12px 20px;
  color: var(--text-secondary); font-weight: 500; font-size: 0.9rem;
  border-radius: var(--radius-sm); margin: 2px 8px; transition: var(--transition);
}
.sidebar-link:hover, .sidebar-link.active { color: var(--primary); background: var(--primary-light); }
.sidebar-link .icon { font-size: 1.1rem; width: 22px; text-align: center; }

.main-content { flex: 1; margin-left: 260px; padding: 30px; min-height: calc(100vh - 70px); }

/* ─── Testimonials ─── */
.testimonial-card {
  background: var(--white); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 28px; border: 1px solid rgba(0,123,255,0.08); position: relative;
}
[data-theme="dark"] .testimonial-card { background: var(--dark-card); border-color: var(--dark-border); }
.testimonial-card::before {
  content: '"'; position: absolute; top: 12px; left: 20px;
  font-size: 5rem; color: var(--primary); opacity: 0.15; line-height: 1;
  font-family: Georgia, serif;
}
.testimonial-stars { color: #FFC107; margin-bottom: 12px; }
.testimonial-text { color: var(--text-secondary); margin-bottom: 16px; font-style: italic; }
.testimonial-author { display: flex; align-items: center; gap: 12px; }
.testimonial-avatar {
  width: 44px; height: 44px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex; align-items: center; justify-content: center; color: white; font-weight: 700;
}
.testimonial-author-info strong { display: block; font-family: var(--font-heading); font-size: 0.9rem; }
.testimonial-author-info span { color: var(--text-secondary); font-size: 0.8rem; }

/* ─── Alert Boxes ─── */
.alert {
  padding: 16px 20px; border-radius: var(--radius-sm); border-left: 4px solid;
  margin-bottom: 12px; display: flex; gap: 12px; align-items: flex-start; font-size: 0.9rem;
}
.alert-warning { background: #fff8e1; border-color: var(--warning); color: #856404; }
.alert-danger { background: #fde8ea; border-color: var(--danger); color: #721c24; }
.alert-success { background: var(--secondary-light); border-color: var(--secondary); color: var(--secondary-dark); }
.alert-info { background: #d1ecf1; border-color: var(--info); color: #0c5460; }

/* ─── Modal ─── */
.modal-overlay {
  position: fixed; inset: 0; background: rgba(0,0,0,0.5);
  display: flex; align-items: center; justify-content: center;
  z-index: 9999; opacity: 0; pointer-events: none; transition: opacity 0.3s;
  backdrop-filter: blur(4px);
}
.modal-overlay.open { opacity: 1; pointer-events: all; }
.modal {
  background: var(--white); border-radius: var(--radius-lg); width: 90%; max-width: 540px;
  max-height: 90vh; overflow-y: auto; box-shadow: 0 25px 60px rgba(0,0,0,0.3);
  transform: scale(0.9); transition: transform 0.3s; padding: 32px;
}
[data-theme="dark"] .modal { background: var(--dark-card); }
.modal-overlay.open .modal { transform: scale(1); }
.modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 24px; }
.modal-close { background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--text-secondary); padding: 4px; border-radius: 6px; }
.modal-close:hover { color: var(--danger); background: #fde8ea; }

/* ─── Toast ─── */
#toast-container { position: fixed; top: 90px; right: 20px; z-index: 10000; display: flex; flex-direction: column; gap: 10px; }
.toast {
  background: var(--white); border-radius: var(--radius-sm); box-shadow: 0 8px 32px rgba(0,0,0,0.2);
  padding: 14px 20px; min-width: 280px; border-left: 4px solid;
  display: flex; align-items: center; gap: 12px; animation: slideInRight 0.3s ease;
  font-weight: 500; font-size: 0.9rem;
}
[data-theme="dark"] .toast { background: var(--dark-card); }
.toast-success { border-color: var(--secondary); }
.toast-error { border-color: var(--danger); }
.toast-info { border-color: var(--primary); }
.toast-warning { border-color: var(--warning); }

/* ─── Animations ─── */
@keyframes fadeIn { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: translateY(0); } }
@keyframes slideInRight { from { opacity: 0; transform: translateX(40px); } to { opacity: 1; transform: translateX(0); } }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-12px); } }
@keyframes pulse { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.05); } }
@keyframes countUp { from { opacity: 0; transform: scale(0.5); } to { opacity: 1; transform: scale(1); } }
@keyframes shimmer { 0% { background-position: -200% 0; } 100% { background-position: 200% 0; } }

.fade-in { animation: fadeIn 0.6s ease forwards; opacity: 0; }
.fade-in-d1 { animation-delay: 0.1s; }
.fade-in-d2 { animation-delay: 0.2s; }
.fade-in-d3 { animation-delay: 0.3s; }
.fade-in-d4 { animation-delay: 0.4s; }

/* ─── Chip / Tag ─── */
.chip { display: inline-block; padding: 4px 12px; border-radius: 50px; font-size: 0.75rem; font-weight: 600; }
.chip-blue { background: var(--primary-light); color: var(--primary); }
.chip-green { background: var(--secondary-light); color: var(--secondary-dark); }

/* ─── Divider ─── */
.divider { height: 1px; background: var(--border); margin: 24px 0; }

/* ─── WhatsApp Float ─── */
.whatsapp-float {
  position: fixed; bottom: 28px; right: 28px; z-index: 999;
  background: #25D366; color: white; width: 56px; height: 56px;
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem; box-shadow: 0 8px 25px rgba(37,211,102,0.5);
  animation: pulse 2.5s infinite;
}
.whatsapp-float:hover { background: #22c55e; color: white; transform: scale(1.1); animation: none; }

/* ─── Footer ─── */
.footer {
  background: var(--dark); color: rgba(255,255,255,0.75); padding: 60px 20px 24px;
  font-size: 0.9rem;
}
.footer h4 { color: white; font-family: var(--font-heading); margin-bottom: 16px; font-size: 1rem; }
.footer p { line-height: 1.8; }
.footer a { color: rgba(255,255,255,0.65); transition: var(--transition); }
.footer a:hover { color: var(--primary); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); margin-top: 40px; padding-top: 24px; display: flex; align-items: center; justify-content: space-between; flex-wrap: gap; gap: 12px; }
.footer-logo-text { font-family: var(--font-heading); font-weight: 800; color: white; }

/* ─── Responsive ─── */
@media (max-width: 992px) {
  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); }
  .main-content { margin-left: 0; }
  .sidebar-overlay { display: block; }
}
@media (max-width: 768px) {
  .nav-links { display: none; position: absolute; top: 70px; left: 0; right: 0; background: var(--white); flex-direction: column; padding: 20px; border-bottom: 1px solid var(--border); z-index: 999; }
  [data-theme="dark"] .nav-links { background: var(--dark-card); }
  .nav-links.open { display: flex; }
  .hamburger { display: flex; }
  .section { padding: 60px 0; }
  .hero h1 { font-size: 2rem; }
  .section-title h2 { font-size: 1.8rem; }
  .kpi-card { flex-direction: column; gap: 12px; }
  .main-content { padding: 20px 16px; }
  .stats-strip { margin: 20px 0; }
  .stat-number { font-size: 2.2rem; }
  .modal { padding: 24px 20px; }
}
@media (max-width: 480px) {
  .btn { padding: 10px 20px; font-size: 0.875rem; }
  .hero-btns { flex-direction: column; }
  .row { flex-direction: column; }
  .col-2, .col-3, .col-4 { flex: 1 1 100%; min-width: 0; }
}

/* ─── Utility ─── */
.text-center { text-align: center; }
.text-primary-clr { color: var(--primary); }
.text-success { color: var(--secondary); }
.text-danger { color: var(--danger); }
.text-warning { color: var(--warning); }
.text-muted { color: var(--text-secondary); }
.fw-bold { font-weight: 700; }
.fw-600 { font-weight: 600; }
.mb-0 { margin-bottom: 0; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }
.mb-32 { margin-bottom: 32px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.d-flex { display: flex; }
.align-items-center { align-items: center; }
.justify-content-between { justify-content: space-between; }
.gap-8 { gap: 8px; }
.gap-12 { gap: 12px; }
.gap-16 { gap: 16px; }
.gap-24 { gap: 24px; }
.w-100 { width: 100%; }
.overflow-x-auto { overflow-x: auto; }
.position-relative { position: relative; }

/* ─── Scrollbar ─── */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--light-gray); }
::-webkit-scrollbar-thumb { background: rgba(0,123,255,0.3); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--primary); }

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

/* ─── Grade chip ─── */
.grade-A { color: var(--secondary-dark); background: var(--secondary-light); }
.grade-B { color: var(--primary); background: var(--primary-light); }
.grade-C { color: #856404; background: #fff8e1; }
.grade-D { color: var(--danger); background: #fde8ea; }

/* ─── Sidebar overlay (mobile) ─── */
.sidebar-overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 99; }