/* ==========================================================================
   Amit Classes by Amit Sir — Design System & Stylesheet
   Modern, accessible Vanilla CSS design system
   ========================================================================== */

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

:root {
  /* Core Brand Colors */
  --color-midnight: #10182B;
  --color-midnight-surface: #162035;
  --color-midnight-card: #1D2A45;
  --color-midnight-border: #28395D;
  --color-electric-blue: #2563EB;
  --color-electric-blue-hover: #1D4ED8;
  --color-electric-blue-light: #EFF6FF;
  --color-electric-blue-glow: rgba(37, 99, 235, 0.25);
  --color-amber: #F59E0B;
  --color-amber-light: #FEF3C7;
  --color-amber-dark: #B45309;
  
  /* Neutral Surfaces & Texts */
  --color-soft-bg: #F5F7FB;
  --color-white: #FFFFFF;
  --color-slate-50: #F8FAFC;
  --color-slate-100: #F1F5F9;
  --color-slate-200: #E2E8F0;
  --color-slate-300: #CBD5E1;
  --color-slate-400: #94A3B8;
  --color-slate-500: #64748B;
  --color-slate-600: #475569;
  --color-slate-700: #334155;
  --color-slate-800: #1E293B;
  --color-slate-900: #0F172A;

  /* Feedback Colors */
  --color-success: #10B981;
  --color-success-bg: #ECFDF5;
  --color-danger: #EF4444;
  --color-danger-bg: #FEF2F2;
  --color-warning: #F59E0B;
  --color-warning-bg: #FFFBEB;

  /* Typography */
  --font-heading: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Shadows */
  --shadow-xs: 0 1px 2px 0 rgba(16, 24, 43, 0.05);
  --shadow-sm: 0 1px 3px 0 rgba(16, 24, 43, 0.08), 0 1px 2px -1px rgba(16, 24, 43, 0.08);
  --shadow-md: 0 4px 6px -1px rgba(16, 24, 43, 0.08), 0 2px 4px -2px rgba(16, 24, 43, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(16, 24, 43, 0.08), 0 4px 6px -4px rgba(16, 24, 43, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(16, 24, 43, 0.1), 0 8px 10px -6px rgba(16, 24, 43, 0.06);
  --shadow-glow: 0 0 25px var(--color-electric-blue-glow);

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 350ms cubic-bezier(0.16, 1, 0.3, 1);
}

/* ================= CSS RESET & BASE ================= */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  background-color: var(--color-soft-bg);
  color: var(--color-slate-800);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--color-slate-900);
  font-weight: 700;
  line-height: 1.25;
}

h1 { font-size: clamp(2rem, 4vw + 1rem, 3.25rem); font-weight: 800; letter-spacing: -0.03em; }
h2 { font-size: clamp(1.6rem, 2.5vw + 0.5rem, 2.25rem); letter-spacing: -0.02em; }
h3 { font-size: 1.35rem; font-weight: 700; }
h4 { font-size: 1.15rem; font-weight: 600; }

p {
  margin-bottom: 1rem;
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--color-electric-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-electric-blue-hover);
}

img, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

/* Accessible Focus States */
:focus-visible {
  outline: 2px solid var(--color-electric-blue);
  outline-offset: 3px;
}

/* Skip to Content Link */
.skip-link {
  position: absolute;
  top: -999px;
  left: 1rem;
  background: var(--color-electric-blue);
  color: var(--color-white);
  padding: 0.75rem 1.25rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  z-index: 1000;
}

.skip-link:focus {
  top: 1rem;
}

/* Container */
.container {
  width: 100%;
  max-width: 1240px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}

/* ================= HEADER & NAVIGATION ================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-slate-200);
  transition: all var(--transition-base);
}

.site-header.scrolled {
  box-shadow: var(--shadow-sm);
  background: rgba(255, 255, 255, 0.98);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.75rem;
  gap: 1.5rem;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  flex-shrink: 0;
}

.brand-icon-wrap {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, #1E3A8A, #2563EB);
  padding: 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.2);
}

.brand-icon-wrap img {
  width: 100%;
  height: 100%;
  border-radius: var(--radius-full);
  object-fit: cover;
}

.brand-title {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.15rem;
  color: var(--color-slate-900);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.brand-name span {
  color: var(--color-electric-blue);
}

.brand-sub {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--color-slate-500);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.nav-links {
  display: none;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

@media (min-width: 900px) {
  .nav-links {
    display: flex;
  }
}

.nav-link {
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--color-slate-600);
  padding: 0.5rem 0.25rem;
  position: relative;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-electric-blue);
}

.nav-link.active {
  color: var(--color-electric-blue);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-electric-blue);
  border-radius: var(--radius-full);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.mobile-menu-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.6rem;
  height: 2.6rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-slate-200);
  background: var(--color-white);
  color: var(--color-slate-700);
}

@media (min-width: 900px) {
  .mobile-menu-btn {
    display: none;
  }
}

/* Mobile Drawer */
.mobile-drawer {
  position: fixed;
  inset: 0;
  z-index: 100;
  background: rgba(16, 24, 43, 0.6);
  backdrop-filter: blur(4px);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.mobile-drawer.open {
  opacity: 1;
  visibility: visible;
}

.drawer-panel {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 82%;
  max-width: 340px;
  background: var(--color-white);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transform: translateX(100%);
  transition: transform var(--transition-smooth);
  box-shadow: var(--shadow-xl);
}

.mobile-drawer.open .drawer-panel {
  transform: translateX(0);
}

.drawer-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--color-slate-200);
  margin-bottom: 1.5rem;
}

.drawer-close {
  width: 2.4rem;
  height: 2.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--color-slate-500);
}

.drawer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.drawer-link {
  display: block;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-slate-700);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.drawer-link:hover, .drawer-link.active {
  background: var(--color-electric-blue-light);
  color: var(--color-electric-blue);
}

/* ================= BUTTONS ================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.35rem;
  font-size: 0.92rem;
  font-weight: 700;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-electric-blue);
  color: var(--color-white);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

.btn-primary:hover {
  background: var(--color-electric-blue-hover);
  color: var(--color-white);
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.35);
}

.btn-secondary {
  background: var(--color-white);
  color: var(--color-slate-800);
  border: 1px solid var(--color-slate-300);
}

.btn-secondary:hover {
  background: var(--color-slate-50);
  color: var(--color-slate-900);
  border-color: var(--color-slate-400);
}

.btn-dark {
  background: var(--color-midnight-surface);
  color: var(--color-white);
  border: 1px solid var(--color-midnight-border);
}

.btn-dark:hover {
  background: var(--color-midnight-card);
  color: var(--color-white);
}

.btn-amber {
  background: var(--color-amber);
  color: var(--color-white);
  box-shadow: 0 4px 12px rgba(245, 158, 11, 0.25);
}

.btn-amber:hover {
  background: #D97706;
  color: var(--color-white);
  transform: translateY(-1px);
}

.btn-sm {
  padding: 0.45rem 0.85rem;
  font-size: 0.82rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 0.95rem 1.85rem;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

.btn-block {
  width: 100%;
}

/* ================= DARK HERO SECTION ================= */
.hero-dark {
  background: linear-gradient(175deg, #090E1A 0%, #10182B 50%, #15223D 100%);
  color: var(--color-white);
  position: relative;
  overflow: hidden;
  padding: 4.5rem 0 5.5rem;
  border-bottom: 1px solid var(--color-midnight-border);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  align-items: center;
}

@media (min-width: 992px) {
  .hero-grid {
    grid-template-columns: 1.15fr 0.85fr;
  }
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  background: rgba(37, 99, 235, 0.15);
  border: 1px solid rgba(37, 99, 235, 0.35);
  border-radius: var(--radius-full);
  color: #93C5FD;
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1.25rem;
}

.hero-title {
  color: var(--color-white);
  margin-bottom: 1.25rem;
}

.hero-title .highlight {
  color: #60A5FA;
  background: linear-gradient(135deg, #60A5FA 0%, #93C5FD 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.12rem;
  color: #CBD5E1;
  max-width: 580px;
  line-height: 1.7;
  margin-bottom: 2rem;
}

.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  margin-bottom: 2.5rem;
}

.hero-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 1.25rem;
  padding-top: 1.75rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.hero-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}

.hero-feature-icon {
  width: 2rem;
  height: 2rem;
  border-radius: var(--radius-sm);
  background: rgba(37, 99, 235, 0.2);
  color: #60A5FA;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 0.15rem;
}

.hero-feature-text strong {
  display: block;
  font-size: 0.95rem;
  color: var(--color-white);
}

.hero-feature-text span {
  font-size: 0.8rem;
  color: #94A3B8;
}

/* Physics Graphic Card */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.physics-visual-card {
  position: relative;
  width: 100%;
  max-width: 440px;
  background: var(--color-midnight-surface);
  border: 1px solid var(--color-midnight-border);
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  overflow: hidden;
}

.physics-visual-card img {
  border-radius: var(--radius-lg);
  width: 100%;
  aspect-ratio: 16/10;
  object-fit: cover;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

/* Floating Physics Formula Badges */
.formula-chip {
  position: absolute;
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  background: rgba(16, 24, 43, 0.92);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(37, 99, 235, 0.4);
  padding: 0.6rem 0.95rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  animation: float 4s ease-in-out infinite;
}

.formula-chip-1 {
  top: -10px;
  left: -12px;
}

.formula-chip-2 {
  bottom: -15px;
  right: -10px;
  animation-delay: 2s;
  border-color: rgba(245, 158, 11, 0.4);
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.formula-symbol {
  width: 1.85rem;
  height: 1.85rem;
  border-radius: var(--radius-sm);
  background: var(--color-electric-blue);
  color: var(--color-white);
  font-family: var(--font-mono);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
}

.formula-chip-2 .formula-symbol {
  background: var(--color-amber);
}

.formula-details strong {
  display: block;
  font-size: 0.82rem;
  font-family: var(--font-mono);
  color: var(--color-white);
}

.formula-details span {
  font-size: 0.68rem;
  color: #94A3B8;
  font-weight: 500;
}

/* ================= SECTION COMMON ================= */
.section {
  padding: 4.5rem 0;
}

.section-light {
  background: var(--color-white);
}

.section-soft {
  background: var(--color-soft-bg);
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 3rem;
}

.section-tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--color-electric-blue);
  background: var(--color-electric-blue-light);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

.section-title {
  margin-bottom: 0.85rem;
}

.section-subtitle {
  color: var(--color-slate-600);
  font-size: 1.05rem;
  line-height: 1.6;
}

/* ================= NOTE CARDS & GRID ================= */
.notes-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.75rem;
}

@media (min-width: 640px) {
  .notes-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .notes-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.note-card {
  background: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-lg);
  padding: 1.6rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-xs);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.note-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--color-electric-blue);
  opacity: 0.8;
  transition: height var(--transition-fast);
}

.note-card.class-jee::before {
  background: var(--color-amber);
}

.note-card.class-foundation::before {
  background: var(--color-success);
}

.note-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-slate-300);
}

.note-card:hover::before {
  height: 5px;
}

.note-card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.85rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.65rem;
  font-size: 0.72rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.badge-blue {
  background: var(--color-electric-blue-light);
  color: var(--color-electric-blue);
  border: 1px solid rgba(37, 99, 235, 0.2);
}

.badge-amber {
  background: var(--color-amber-light);
  color: var(--color-amber-dark);
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.badge-green {
  background: var(--color-success-bg);
  color: var(--color-success);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-gray {
  background: var(--color-slate-100);
  color: var(--color-slate-600);
  border: 1px solid var(--color-slate-200);
}

.note-date {
  font-size: 0.75rem;
  color: var(--color-slate-400);
  font-weight: 500;
}

.note-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-slate-900);
  margin-bottom: 0.5rem;
  line-height: 1.35;
}

.note-title a {
  color: inherit;
  text-decoration: none;
}

.note-title a:hover {
  color: var(--color-electric-blue);
}

.note-topic {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--color-slate-500);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.note-desc {
  font-size: 0.88rem;
  color: var(--color-slate-600);
  line-height: 1.55;
  margin-bottom: 1.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.note-card-footer {
  padding-top: 1rem;
  border-top: 1px solid var(--color-slate-100);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.note-file-info {
  font-size: 0.75rem;
  color: var(--color-slate-400);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.note-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* ================= FILTER TOOLBAR ================= */
.filter-toolbar {
  background: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-xs);
}

.filter-search-row {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 1rem;
}

@media (min-width: 768px) {
  .filter-search-row {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.search-input-wrap {
  position: relative;
  flex: 1;
  max-width: 460px;
}

.search-input-wrap svg {
  position: absolute;
  left: 0.95rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-slate-400);
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: 0.75rem 1rem 0.75rem 2.6rem;
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  background: var(--color-slate-50);
  transition: all var(--transition-fast);
}

.search-input:focus {
  background: var(--color-white);
  border-color: var(--color-electric-blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
  outline: none;
}

.filter-status-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.notes-count-pill {
  font-size: 0.8rem;
  font-weight: 700;
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-full);
  background: var(--color-electric-blue-light);
  color: var(--color-electric-blue);
}

.filter-selects-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.85rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-slate-100);
}

@media (min-width: 640px) {
  .filter-selects-row {
    grid-template-columns: repeat(3, 1fr);
  }
}

.filter-group label {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-slate-500);
  text-transform: uppercase;
  margin-bottom: 0.35rem;
}

.filter-select {
  width: 100%;
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-md);
  background: var(--color-white);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-slate-700);
  transition: border-color var(--transition-fast);
}

.filter-select:focus {
  border-color: var(--color-electric-blue);
  outline: none;
}

/* ================= COURSES / CLASSES CARDS ================= */
.courses-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

@media (min-width: 768px) {
  .courses-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1100px) {
  .courses-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.course-card {
  background: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-xl);
  padding: 1.85rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-xs);
  transition: all var(--transition-base);
  position: relative;
}

.course-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-slate-300);
}

.course-level-badge {
  display: inline-flex;
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 800;
  background: var(--color-slate-100);
  color: var(--color-slate-700);
  margin-bottom: 1.25rem;
  width: fit-content;
}

.course-name {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--color-slate-900);
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.course-desc {
  font-size: 0.92rem;
  color: var(--color-slate-600);
  line-height: 1.6;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.course-meta {
  padding-top: 1rem;
  border-top: 1px solid var(--color-slate-100);
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
}

.course-notes-count {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-slate-500);
}

/* ================= TEACHER / ABOUT SECTION ================= */
.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3.5rem;
  align-items: center;
}

@media (min-width: 992px) {
  .about-grid {
    grid-template-columns: 0.85fr 1.15fr;
  }
}

.about-photo-card {
  position: relative;
  text-align: center;
}

.about-avatar-wrap {
  width: 280px;
  height: 280px;
  margin: 0 auto;
  border-radius: var(--radius-full);
  padding: 8px;
  background: linear-gradient(135deg, #10182B 0%, #2563EB 50%, #F59E0B 100%);
  box-shadow: var(--shadow-xl);
}

@media (min-width: 640px) {
  .about-avatar-wrap {
    width: 320px;
    height: 320px;
  }
}

.about-avatar-wrap img {
  width: 100%;
  height: 100%;
  border-radius: var(--radius-full);
  object-fit: cover;
  border: 4px solid var(--color-white);
}

.about-badge-float {
  position: absolute;
  bottom: 0;
  right: 10%;
  background: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-lg);
  padding: 0.75rem 1.25rem;
  box-shadow: var(--shadow-lg);
  text-align: left;
}

.about-badge-float strong {
  display: block;
  font-size: 0.95rem;
  color: var(--color-slate-900);
}

.about-badge-float span {
  font-size: 0.75rem;
  color: var(--color-slate-500);
}

.pillars-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  margin: 1.75rem 0;
}

.pillar-item {
  background: var(--color-slate-50);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-md);
  padding: 1.25rem;
}

.pillar-item h4 {
  font-size: 1rem;
  color: var(--color-slate-900);
  margin-bottom: 0.35rem;
}

.pillar-item p {
  font-size: 0.85rem;
  color: var(--color-slate-600);
  line-height: 1.5;
}

.unverified-notice {
  background: var(--color-amber-light);
  border: 1px solid rgba(245, 158, 11, 0.4);
  border-radius: var(--radius-md);
  padding: 0.85rem 1.15rem;
  font-size: 0.82rem;
  color: var(--color-amber-dark);
  margin-top: 1.5rem;
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
}

/* ================= CONTACT & ENQUIRY ================= */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
}

@media (min-width: 992px) {
  .contact-grid {
    grid-template-columns: 0.8fr 1.2fr;
  }
}

.contact-info-card {
  background: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: var(--shadow-xs);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.contact-detail-row {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.contact-detail-icon {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-md);
  background: var(--color-electric-blue-light);
  color: var(--color-electric-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-detail-text h4 {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--color-slate-400);
  text-transform: uppercase;
  margin-bottom: 0.2rem;
}

.contact-detail-text p, .contact-detail-text a {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-slate-900);
  text-decoration: none;
}

.contact-form-card {
  background: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-xl);
  padding: 2.25rem;
  box-shadow: var(--shadow-md);
}

.form-group {
  margin-bottom: 1.35rem;
}

.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-slate-700);
  margin-bottom: 0.4rem;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-md);
  font-size: 0.92rem;
  background: var(--color-slate-50);
  transition: all var(--transition-fast);
}

.form-control:focus {
  background: var(--color-white);
  border-color: var(--color-electric-blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
  outline: none;
}

textarea.form-control {
  resize: vertical;
  min-height: 110px;
}

/* Honeypot field - visually hidden from genuine human users */
.hp-field {
  position: absolute;
  left: -9999px;
  top: -9999px;
  opacity: 0;
  pointer-events: none;
}

/* ================= MODAL & PDF PREVIEW ================= */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(16, 24, 43, 0.75);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.25rem;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-dialog {
  background: var(--color-white);
  border-radius: var(--radius-xl);
  width: 100%;
  max-width: 900px;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  transform: scale(0.96);
  transition: transform var(--transition-smooth);
}

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

.modal-header {
  padding: 1.25rem 1.75rem;
  border-bottom: 1px solid var(--color-slate-200);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--color-slate-50);
}

.modal-body {
  padding: 1.5rem;
  overflow-y: auto;
  flex: 1;
}

.pdf-preview-frame {
  width: 100%;
  height: 65vh;
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-md);
}

/* ================= TOAST NOTIFICATIONS ================= */
#toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  background: var(--color-slate-900);
  color: var(--color-white);
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  min-width: 280px;
  max-width: 420px;
  animation: toastIn 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.toast.toast-success {
  border-left: 4px solid var(--color-success);
}

.toast.toast-error {
  border-left: 4px solid var(--color-danger);
}

@keyframes toastIn {
  from { transform: translateY(1rem); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* ================= FOOTER ================= */
.site-footer {
  background: var(--color-midnight);
  color: #94A3B8;
  padding: 4rem 0 2rem;
  border-top: 1px solid var(--color-midnight-border);
  margin-top: auto;
}

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

@media (min-width: 640px) {
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
  }
}

.footer-col h4 {
  color: var(--color-white);
  font-size: 0.95rem;
  margin-bottom: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  color: #94A3B8;
  text-decoration: none;
  font-size: 0.9rem;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-white);
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  font-size: 0.82rem;
  color: #64748B;
  text-align: center;
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

/* ================= ADMIN DASHBOARD SPECIFIC ================= */
.admin-layout {
  display: flex !important;
  flex-direction: row !important;
  min-height: 100vh;
  width: 100%;
  background: #F1F5F9;
  position: relative;
  align-items: stretch;
}

#admin-dashboard-section[style*="display: none"] {
  display: none !important;
}

.admin-sidebar {
  width: 260px;
  min-width: 260px;
  max-width: 260px;
  background: var(--color-midnight);
  color: #CBD5E1;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 1.5rem 1rem;
  flex-shrink: 0;
  border-right: 1px solid var(--color-midnight-border);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  z-index: 40;
}

.admin-main {
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 100vh;
  background: #F1F5F9;
}

.admin-topbar {
  height: 4.5rem;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-slate-200);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  position: sticky;
  top: 0;
  z-index: 30;
  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.03);
}

.admin-content {
  padding: 2rem;
  flex: 1;
}

@media (max-width: 900px) {
  .admin-layout {
    flex-direction: column !important;
  }
  .admin-sidebar {
    width: 100%;
    min-width: 100%;
    max-width: 100%;
    height: auto;
    position: relative;
  }
  .admin-topbar {
    padding: 0 1rem;
  }
  .admin-content {
    padding: 1rem;
  }
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-xs);
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.stat-icon {
  width: 3.25rem;
  height: 3.25rem;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.stat-val {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--color-slate-900);
  line-height: 1.1;
}

.stat-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-slate-500);
  text-transform: uppercase;
}

.admin-table-card {
  background: var(--color-white);
  border: 1px solid var(--color-slate-200);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xs);
  overflow: hidden;
}

.table-responsive {
  width: 100%;
  overflow-x: auto;
}

.admin-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.88rem;
}

.admin-table th {
  background: var(--color-slate-50);
  padding: 0.95rem 1.25rem;
  font-weight: 700;
  color: var(--color-slate-600);
  border-bottom: 1px solid var(--color-slate-200);
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.04em;
}

.admin-table td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--color-slate-100);
  vertical-align: middle;
}

.admin-table tr:hover td {
  background: var(--color-slate-50);
}

.file-dropzone {
  border: 2px dashed var(--color-slate-300);
  border-radius: var(--radius-lg);
  padding: 2.5rem 1.5rem;
  text-align: center;
  background: var(--color-slate-50);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.file-dropzone:hover, .file-dropzone.dragover {
  border-color: var(--color-electric-blue);
  background: var(--color-electric-blue-light);
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}