/* =============================================================================
   TradersVault Academy — Design System
   Electric Blue / Dark Trading Aesthetic
   ============================================================================= */

/* ----------------------------------------------------------------------------
   DESIGN TOKENS
   ---------------------------------------------------------------------------- */
:root {
  /* Type Scale — fluid clamp() */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-3xl:  clamp(2.5rem,   1rem    + 4vw,    5rem);
  --text-hero: clamp(3rem,     0.5rem  + 7vw,    8rem);

  /* Spacing — 4px base */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Border Radius */
  --radius-sm:   0.375rem;
  --radius-md:   0.5rem;
  --radius-lg:   0.75rem;
  --radius-xl:   1rem;
  --radius-2xl:  1.5rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast:        120ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow:        320ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Content Widths */
  --content-narrow:  640px;
  --content-default: 960px;
  --content-wide:    1200px;
  --content-full:    100%;

  /* Sidebar Width */
  --sidebar-width: 280px;
  --nav-height:    64px;

  /* Fonts */
  --font-display: 'Cabinet Grotesk', 'Helvetica Neue', sans-serif;
  --font-body:    'Satoshi', 'Inter', sans-serif;
}

/* DARK MODE — Default */
:root,
[data-theme="dark"] {
  --color-bg:              #0a0f1a;
  --color-surface:         #111827;
  --color-surface-2:       #14202f;
  --color-card:            #1a2236;
  --color-card-hover:      #1e2942;
  --color-border:          #243047;
  --color-border-subtle:   #1a2236;
  --color-divider:         #1e2a3d;

  --color-text:            #E2E8F0;
  --color-text-muted:      #94A3B8;
  --color-text-faint:      #4A5568;
  --color-text-inverse:    #0a0f1a;

  --color-primary:         #3B82F6;
  --color-primary-hover:   #2563EB;
  --color-primary-active:  #1D4ED8;
  --color-primary-subtle:  rgba(59, 130, 246, 0.1);
  --color-primary-glow:    rgba(59, 130, 246, 0.2);

  --color-secondary:       #60A5FA;
  --color-secondary-hover: #3B82F6;

  --color-success:         #22C55E;
  --color-success-hover:   #16A34A;
  --color-success-subtle:  rgba(34, 197, 94, 0.1);

  --color-error:           #EF4444;
  --color-error-hover:     #DC2626;
  --color-error-subtle:    rgba(239, 68, 68, 0.1);

  --color-warning:         #F59E0B;
  --color-warning-hover:   #D97706;
  --color-warning-subtle:  rgba(245, 158, 11, 0.1);

  --color-gold:            #F59E0B;
  --color-gold-subtle:     rgba(245, 158, 11, 0.12);

  --color-purple:          #A855F7;
  --color-purple-subtle:   rgba(168, 85, 247, 0.1);

  --color-green-subtle:    rgba(34, 197, 94, 0.1);

  /* Shadows */
  --shadow-sm:  0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md:  0 4px 16px rgba(0, 0, 0, 0.5);
  --shadow-lg:  0 12px 40px rgba(0, 0, 0, 0.6);
  --shadow-xl:  0 24px 64px rgba(0, 0, 0, 0.7);
  --shadow-glow: 0 0 24px rgba(59, 130, 246, 0.2);

  /* Navbar blur */
  --nav-blur: blur(12px) saturate(1.5);
  --nav-bg:   rgba(10, 15, 26, 0.85);
}

/* LIGHT MODE */
[data-theme="light"] {
  --color-bg:              #F8FAFC;
  --color-surface:         #FFFFFF;
  --color-surface-2:       #F1F5F9;
  --color-card:            #FFFFFF;
  --color-card-hover:      #F8FAFC;
  --color-border:          #E2E8F0;
  --color-border-subtle:   #F1F5F9;
  --color-divider:         #E2E8F0;

  --color-text:            #0F172A;
  --color-text-muted:      #475569;
  --color-text-faint:      #94A3B8;
  --color-text-inverse:    #FFFFFF;

  --color-primary:         #2563EB;
  --color-primary-hover:   #1D4ED8;
  --color-primary-active:  #1E40AF;
  --color-primary-subtle:  rgba(37, 99, 235, 0.08);
  --color-primary-glow:    rgba(37, 99, 235, 0.15);

  --color-secondary:       #3B82F6;
  --color-secondary-hover: #2563EB;

  --color-success:         #16A34A;
  --color-success-hover:   #15803D;
  --color-success-subtle:  rgba(22, 163, 74, 0.08);

  --color-error:           #DC2626;
  --color-error-hover:     #B91C1C;
  --color-error-subtle:    rgba(220, 38, 38, 0.08);

  --color-warning:         #D97706;
  --color-warning-hover:   #B45309;
  --color-warning-subtle:  rgba(217, 119, 6, 0.08);

  --color-gold:            #B45309;
  --color-gold-subtle:     rgba(180, 83, 9, 0.08);

  --color-purple:          #7C3AED;
  --color-purple-subtle:   rgba(124, 58, 237, 0.08);

  --color-green-subtle:    rgba(22, 163, 74, 0.08);

  --shadow-sm:  0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md:  0 4px 16px rgba(15, 23, 42, 0.08);
  --shadow-lg:  0 12px 40px rgba(15, 23, 42, 0.12);
  --shadow-xl:  0 24px 64px rgba(15, 23, 42, 0.16);
  --shadow-glow: 0 0 24px rgba(37, 99, 235, 0.15);

  --nav-blur: blur(12px) saturate(1.5);
  --nav-bg:   rgba(248, 250, 252, 0.9);
}

/* System preference fallback */
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --color-bg:              #F8FAFC;
    --color-surface:         #FFFFFF;
    --color-surface-2:       #F1F5F9;
    --color-card:            #FFFFFF;
    --color-card-hover:      #F8FAFC;
    --color-border:          #E2E8F0;
    --color-border-subtle:   #F1F5F9;
    --color-divider:         #E2E8F0;
    --color-text:            #0F172A;
    --color-text-muted:      #475569;
    --color-text-faint:      #94A3B8;
    --color-text-inverse:    #FFFFFF;
    --color-primary:         #2563EB;
    --color-primary-hover:   #1D4ED8;
    --color-primary-active:  #1E40AF;
    --color-primary-subtle:  rgba(37, 99, 235, 0.08);
    --color-primary-glow:    rgba(37, 99, 235, 0.15);
    --color-success:         #16A34A;
    --color-success-subtle:  rgba(22, 163, 74, 0.08);
    --color-error:           #DC2626;
    --color-error-subtle:    rgba(220, 38, 38, 0.08);
    --color-warning:         #D97706;
    --color-warning-subtle:  rgba(217, 119, 6, 0.08);
    --shadow-sm:  0 1px 2px rgba(15, 23, 42, 0.06);
    --shadow-md:  0 4px 16px rgba(15, 23, 42, 0.08);
    --shadow-lg:  0 12px 40px rgba(15, 23, 42, 0.12);
    --nav-bg:   rgba(248, 250, 252, 0.9);
  }
}

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

html {
  -webkit-text-size-adjust: none;
  text-size-adjust: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + var(--space-4));
}

body {
  min-height: 100dvh;
  line-height: 1.6;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  overflow-x: hidden;
}

img, picture, video, canvas {
  display: block;
  max-width: 100%;
  height: auto;
}

svg { display: block; }

ul[role='list'], ol[role='list'] { list-style: none; }

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

h1, h2, h3, h4, h5, h6 {
  text-wrap: balance;
  line-height: 1.15;
  font-family: var(--font-display);
}

p, li, figcaption {
  text-wrap: pretty;
  max-width: 72ch;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-interactive);
}

a:hover { color: var(--color-primary-hover); }

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

::selection {
  background: var(--color-primary-subtle);
  color: var(--color-text);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

@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;
  }
}

a, button, [role='button'], input, textarea, select {
  transition:
    color var(--transition-interactive),
    background var(--transition-interactive),
    border-color var(--transition-interactive),
    box-shadow var(--transition-interactive),
    opacity var(--transition-interactive);
}

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0;
  margin: -1px; overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border-width: 0;
}

/* ----------------------------------------------------------------------------
   SCROLL PROGRESS BAR (very top of page)
   ---------------------------------------------------------------------------- */
#scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  z-index: 1100;
  transition: width 0.1s linear;
  border-radius: 0 var(--radius-full) var(--radius-full) 0;
}

/* ----------------------------------------------------------------------------
   NAVBAR
   ---------------------------------------------------------------------------- */
.nav {
  position: fixed;
  top: 3px; /* below scroll progress */
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--nav-bg);
  backdrop-filter: var(--nav-blur);
  -webkit-backdrop-filter: var(--nav-blur);
  border-bottom: 1px solid var(--color-border-subtle);
  z-index: 1000;
  transition: background var(--transition-slow), border-color var(--transition-slow);
}

.nav.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-md);
}

.nav-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 100%;
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-text);
  flex-shrink: 0;
}

.nav-logo-icon {
  width: 32px;
  height: 32px;
  color: var(--color-primary);
}

.nav-logo-text {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1;
}

.nav-logo-text span {
  color: var(--color-primary);
}

/* Nav Links */
.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex: 1;
  justify-content: center;
  list-style: none;
}

.nav-link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  transition: color var(--transition-interactive), background var(--transition-interactive);
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--color-text);
  background: var(--color-primary-subtle);
}

.nav-link.active {
  color: var(--color-primary);
  background: var(--color-primary-subtle);
}

/* Nav Right */
.nav-right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  background: transparent;
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition-interactive);
}

.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-primary-subtle);
  border-color: var(--color-primary);
}

/* Theme toggle icon visibility — show sun in dark, moon in light */
[data-theme="dark"] .theme-toggle .icon-moon,
:root:not([data-theme="light"]) .theme-toggle .icon-moon {
  display: none;
}
[data-theme="dark"] .theme-toggle .icon-sun,
:root:not([data-theme="light"]) .theme-toggle .icon-sun {
  display: block;
}
[data-theme="light"] .theme-toggle .icon-sun {
  display: none;
}
[data-theme="light"] .theme-toggle .icon-moon {
  display: block;
}

/* User Avatar */
.user-avatar {
  position: relative;
}

.avatar-btn {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--color-primary), var(--color-purple));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 700;
  color: white;
  cursor: pointer;
  border: 2px solid var(--color-border);
  transition: all var(--transition-interactive);
  font-family: var(--font-display);
}

.avatar-btn:hover {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-subtle);
}

/* Profile Dropdown */
.profile-dropdown {
  position: absolute;
  top: calc(100% + var(--space-2));
  right: 0;
  width: 280px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  padding: var(--space-4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--transition-interactive);
  z-index: 200;
}

.profile-dropdown.open {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-4);
}

.dropdown-avatar {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--color-primary), var(--color-purple));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-base);
  font-weight: 700;
  color: white;
  font-family: var(--font-display);
  flex-shrink: 0;
}

.dropdown-user-name {
  font-weight: 600;
  font-size: var(--text-sm);
  color: var(--color-text);
}

.dropdown-user-email {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: 2px;
}

.dropdown-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.dropdown-stat {
  background: var(--color-card);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  text-align: center;
}

.dropdown-stat-value {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-primary);
  font-family: var(--font-display);
  display: block;
}

.dropdown-stat-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.dropdown-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.dropdown-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  transition: all var(--transition-interactive);
}

.dropdown-link:hover {
  color: var(--color-text);
  background: var(--color-primary-subtle);
}

.dropdown-link.danger:hover {
  color: var(--color-error);
  background: var(--color-error-subtle);
}

/* Hamburger */
.nav-hamburger {
  display: none;
  width: 36px;
  height: 36px;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-interactive);
}

.nav-hamburger:hover {
  background: var(--color-primary-subtle);
  border-color: var(--color-primary);
}

.hamburger-line {
  width: 18px;
  height: 2px;
  background: var(--color-text-muted);
  border-radius: var(--radius-full);
  transition: all var(--transition-interactive);
}

.nav-hamburger.active .hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-hamburger.active .hamburger-line:nth-child(2) {
  opacity: 0;
}
.nav-hamburger.active .hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: calc(var(--nav-height) + 3px);
  left: 0;
  right: 0;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-4) var(--space-6);
  z-index: 999;
  flex-direction: column;
  gap: var(--space-2);
  box-shadow: var(--shadow-lg);
}

.mobile-menu.open { display: flex; }

.mobile-nav-link {
  display: block;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: all var(--transition-interactive);
}

.mobile-nav-link:hover {
  color: var(--color-text);
  background: var(--color-primary-subtle);
}

/* ----------------------------------------------------------------------------
   BUTTONS
   ---------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: all var(--transition-interactive);
  white-space: nowrap;
  font-family: var(--font-body);
}

.btn-primary {
  background: var(--color-primary);
  color: white;
  box-shadow: 0 0 0 0 var(--color-primary-glow);
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  color: white;
  transform: translateY(-1px);
  box-shadow: 0 4px 20px var(--color-primary-glow);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: none;
}

.btn-secondary {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background: var(--color-primary-subtle);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-muted);
  border: none;
}

.btn-ghost:hover {
  color: var(--color-text);
  background: var(--color-primary-subtle);
}

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
  border-radius: var(--radius-lg);
}

.btn-icon {
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: var(--radius-md);
}

/* ----------------------------------------------------------------------------
   HERO SECTION
   ---------------------------------------------------------------------------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: calc(var(--nav-height) + var(--space-16));
  padding-bottom: var(--space-24);
  position: relative;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero-bg-gradient {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, rgba(59, 130, 246, 0.15) 0%, transparent 60%),
    radial-gradient(ellipse 40% 40% at 80% 50%, rgba(168, 85, 247, 0.06) 0%, transparent 50%),
    radial-gradient(ellipse 40% 40% at 10% 70%, rgba(34, 197, 94, 0.04) 0%, transparent 50%);
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--color-border-subtle) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-border-subtle) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 0%, black 0%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 80% 80% at 50% 0%, black 0%, transparent 70%);
  opacity: 0.5;
}

.hero-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: 0 var(--space-6);
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: var(--color-primary-subtle);
  border: 1px solid rgba(59, 130, 246, 0.2);
  color: var(--color-secondary);
  font-size: var(--text-xs);
  font-weight: 600;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-6);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.hero-title {
  font-size: var(--text-3xl);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: var(--space-6);
  color: var(--color-text);
}

.hero-title-gradient {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 50%, var(--color-purple) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto var(--space-10);
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  margin-bottom: var(--space-16);
  flex-wrap: wrap;
}

/* Stats Row */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
  max-width: 700px;
  margin: 0 auto;
}

.hero-stat {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4) var(--space-3);
  position: relative;
  overflow: hidden;
}

.hero-stat::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  opacity: 0.5;
}

.hero-stat-value {
  display: block;
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: var(--space-1);
}

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

/* ----------------------------------------------------------------------------
   SECTION HEADERS
   ---------------------------------------------------------------------------- */
.section {
  padding: clamp(var(--space-16), 8vw, var(--space-32)) 0;
}

.section-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-12);
}

.section-eyebrow {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}

.section-title {
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.section-subtitle {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 580px;
  margin: 0 auto;
}

/* ----------------------------------------------------------------------------
   HOW IT WORKS — 3 Steps
   ---------------------------------------------------------------------------- */
.how-it-works {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-subtle);
  border-bottom: 1px solid var(--color-border-subtle);
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-8);
  position: relative;
}

.steps-grid::before {
  content: '';
  position: absolute;
  top: 28px;
  left: calc(33.33% - var(--space-4));
  right: calc(33.33% - var(--space-4));
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  opacity: 0.3;
  z-index: 0;
}

.step-card {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: var(--space-6);
}

.step-number {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-full);
  background: var(--color-primary-subtle);
  border: 2px solid var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 800;
  color: var(--color-primary);
  margin: 0 auto var(--space-5);
  box-shadow: var(--shadow-glow);
}

.step-title {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.step-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* ----------------------------------------------------------------------------
   COURSE CARDS
   ---------------------------------------------------------------------------- */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-6);
}

.course-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  position: relative;
  overflow: hidden;
  transition: all var(--transition-interactive);
  cursor: pointer;
  text-decoration: none;
  display: flex;
  flex-direction: column;
}

.course-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--card-accent, linear-gradient(90deg, var(--color-primary), var(--color-secondary)));
}

.course-card:hover {
  background: var(--color-card-hover);
  border-color: var(--color-primary);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg), 0 0 0 1px var(--color-primary);
}

.course-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: var(--space-4);
  gap: var(--space-3);
}

.course-card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  flex-shrink: 0;
}

.course-title {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
  line-height: 1.2;
}

.course-description {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.5;
  margin-bottom: var(--space-4);
  flex: 1;
}

.course-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
}

.course-meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

/* Course progress bar */
.course-progress {
  margin-top: auto;
}

.course-progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.course-progress-pct {
  color: var(--color-primary);
  font-weight: 600;
}

.progress-bar {
  height: 4px;
  background: var(--color-border);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  border-radius: var(--radius-full);
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.course-card-footer {
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.lock-icon {
  color: var(--color-text-faint);
  opacity: 0.6;
}

/* ----------------------------------------------------------------------------
   LEVEL BADGES
   ---------------------------------------------------------------------------- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 3px var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.badge-beginner {
  background: var(--color-success-subtle);
  color: var(--color-success);
  border: 1px solid rgba(34, 197, 94, 0.2);
}

.badge-intermediate {
  background: var(--color-primary-subtle);
  color: var(--color-primary);
  border: 1px solid rgba(59, 130, 246, 0.2);
}

.badge-advanced {
  background: var(--color-purple-subtle);
  color: var(--color-purple);
  border: 1px solid rgba(168, 85, 247, 0.2);
}

.badge-j3 {
  background: var(--color-gold-subtle);
  color: var(--color-gold);
  border: 1px solid rgba(245, 158, 11, 0.2);
}

.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background: currentColor;
}

/* ----------------------------------------------------------------------------
   WHAT YOU'LL LEARN — Concept Cards Grid
   ---------------------------------------------------------------------------- */
.concepts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--space-4);
}

.concept-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  transition: all var(--transition-interactive);
}

.concept-card:hover {
  border-color: var(--color-primary);
  background: var(--color-card-hover);
  transform: translateY(-2px);
}

.concept-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background: var(--color-primary-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
  color: var(--color-primary);
}

.concept-name {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.3;
}

/* ----------------------------------------------------------------------------
   LEARNING FEATURES SECTION
   ---------------------------------------------------------------------------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-5);
}

.feature-item {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  transition: all var(--transition-interactive);
}

.feature-item:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.feature-icon-wrap {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  background: var(--color-primary-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-4);
  color: var(--color-primary);
}

.feature-title {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.feature-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* ----------------------------------------------------------------------------
   CTA SECTION
   ---------------------------------------------------------------------------- */
.cta-section {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-subtle);
}

.cta-inner {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
  padding: clamp(var(--space-16), 8vw, var(--space-32)) var(--space-6);
}

.cta-title {
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.cta-subtitle {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
}

/* Continue banner */
.continue-banner {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-primary);
  border-radius: var(--radius-lg);
  padding: var(--space-4) var(--space-5);
  display: flex;
  align-items: center;
  gap: var(--space-4);
  max-width: var(--content-default);
  margin: 0 auto var(--space-16);
  text-decoration: none;
  transition: all var(--transition-interactive);
}

.continue-banner:hover {
  border-left-color: var(--color-primary);
  background: var(--color-card-hover);
  transform: translateX(4px);
}

.continue-banner-text {
  flex: 1;
}

.continue-banner-eyebrow {
  font-size: var(--text-xs);
  color: var(--color-primary);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 2px;
}

.continue-banner-title {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
}

/* ----------------------------------------------------------------------------
   FOOTER
   ---------------------------------------------------------------------------- */
.footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: var(--space-12) 0 var(--space-8);
}

.footer-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-8);
  margin-bottom: var(--space-10);
}

.footer-brand p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-3);
  line-height: 1.6;
  max-width: 280px;
}

.footer-col-title {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-text);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-4);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.footer-links a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition-interactive);
}

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

.footer-bottom {
  border-top: 1px solid var(--color-border-subtle);
  padding-top: var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-copyright {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.footer-social {
  display: flex;
  gap: var(--space-3);
}

.social-link {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: all var(--transition-interactive);
}

.social-link:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background: var(--color-primary-subtle);
}

/* ----------------------------------------------------------------------------
   LOGIN MODAL
   ---------------------------------------------------------------------------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-slow);
}

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

.modal {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  width: 100%;
  max-width: 420px;
  box-shadow: var(--shadow-xl);
  transform: translateY(16px) scale(0.98);
  transition: all var(--transition-slow);
  position: relative;
}

.modal-overlay.open .modal {
  transform: translateY(0) scale(1);
}

.modal-close {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  width: 32px;
  height: 32px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  background: transparent;
  border: none;
  cursor: pointer;
  transition: all var(--transition-interactive);
}

.modal-close:hover {
  color: var(--color-text);
  background: var(--color-primary-subtle);
}

.modal-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}

.modal-title {
  font-size: var(--text-xl);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: var(--space-2);
  letter-spacing: -0.02em;
}

.modal-subtitle {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

.form-group {
  margin-bottom: var(--space-4);
}

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.form-input {
  width: 100%;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-text);
  outline: none;
  transition: border-color var(--transition-interactive), box-shadow var(--transition-interactive);
}

.form-input::placeholder { color: var(--color-text-faint); }

.form-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-subtle);
}

.form-input.error {
  border-color: var(--color-error);
  box-shadow: 0 0 0 3px var(--color-error-subtle);
}

.form-error {
  font-size: var(--text-xs);
  color: var(--color-error);
  margin-top: var(--space-1);
  display: none;
}

.form-error.visible { display: block; }

.modal-submit {
  width: 100%;
  margin-top: var(--space-2);
}

.modal-footer {
  margin-top: var(--space-5);
  text-align: center;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.modal-footer a {
  color: var(--color-primary);
  font-weight: 500;
}

.modal-divider {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin: var(--space-5) 0;
  color: var(--color-text-faint);
  font-size: var(--text-xs);
}

.modal-divider::before,
.modal-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border);
}

.modal-error-msg {
  background: var(--color-error-subtle);
  border: 1px solid rgba(239, 68, 68, 0.2);
  color: var(--color-error);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-sm);
  margin-bottom: var(--space-4);
  display: none;
}

.modal-error-msg.visible { display: block; }

/* ----------------------------------------------------------------------------
   LESSON PAGE LAYOUT
   ---------------------------------------------------------------------------- */
.lesson-layout {
  display: flex;
  min-height: 100vh;
  padding-top: calc(var(--nav-height) + 3px);
}

/* Lesson Sidebar */
.lesson-sidebar {
  position: fixed;
  top: calc(var(--nav-height) + 3px);
  left: 0;
  width: var(--sidebar-width);
  height: calc(100vh - var(--nav-height) - 3px);
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  z-index: 100;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-slow);
}

.lesson-sidebar::-webkit-scrollbar { width: 4px; }
.lesson-sidebar::-webkit-scrollbar-track { background: transparent; }
.lesson-sidebar::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: var(--radius-full);
}

.sidebar-header {
  padding: var(--space-5) var(--space-5) var(--space-4);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  background: var(--color-surface);
  z-index: 10;
}

.sidebar-course-badge {
  margin-bottom: var(--space-2);
}

.sidebar-course-title {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.3;
  margin-bottom: var(--space-3);
}

.sidebar-progress-wrap {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.sidebar-progress-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  display: flex;
  justify-content: space-between;
}

.sidebar-modules {
  padding: var(--space-3) 0;
  flex: 1;
}

.sidebar-module {
  margin-bottom: var(--space-1);
}

.sidebar-module-header {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-5);
  cursor: pointer;
  transition: background var(--transition-interactive);
}

.sidebar-module-header:hover {
  background: var(--color-primary-subtle);
}

.sidebar-module-chevron {
  width: 16px;
  height: 16px;
  color: var(--color-text-faint);
  flex-shrink: 0;
  transition: transform var(--transition-interactive);
  margin-left: auto;
}

.sidebar-module.open .sidebar-module-chevron {
  transform: rotate(180deg);
}

.sidebar-module-name {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  flex: 1;
}

.sidebar-lessons {
  display: none;
}

.sidebar-module.open .sidebar-lessons {
  display: block;
}

.sidebar-lesson-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-4) var(--space-2) var(--space-8);
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  font-weight: 500;
  border-left: 3px solid transparent;
  margin-left: 0;
  transition: all var(--transition-interactive);
  line-height: 1.4;
}

.sidebar-lesson-item:hover {
  color: var(--color-text);
  background: var(--color-primary-subtle);
}

.sidebar-lesson-item.active {
  color: var(--color-primary);
  border-left-color: var(--color-primary);
  background: var(--color-primary-subtle);
  font-weight: 600;
}

.sidebar-lesson-item.completed {
  color: var(--color-success);
}

.lesson-check {
  width: 16px;
  height: 16px;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--color-border);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-interactive);
}

.sidebar-lesson-item.completed .lesson-check {
  background: var(--color-success);
  border-color: var(--color-success);
  color: white;
}

.sidebar-toggle-btn {
  display: none;
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-4);
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: white;
  border: none;
  cursor: pointer;
  z-index: 500;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-interactive);
}

.sidebar-toggle-btn:hover {
  background: var(--color-primary-hover);
  transform: scale(1.05);
}

/* Lesson Content Area */
.lesson-content-wrapper {
  margin-left: var(--sidebar-width);
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.lesson-top-bar {
  position: sticky;
  top: calc(var(--nav-height) + 3px);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  z-index: 50;
  height: 4px;
  padding: 0;
}

.lesson-course-progress {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  border-radius: 0 var(--radius-full) var(--radius-full) 0;
  transition: width 0.4s ease;
}

.lesson-breadcrumb {
  padding: var(--space-4) var(--space-8);
  border-bottom: 1px solid var(--color-border-subtle);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  flex-wrap: wrap;
}

.breadcrumb-sep { color: var(--color-text-faint); opacity: 0.5; }

.breadcrumb-link {
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition-interactive);
}

.breadcrumb-link:hover { color: var(--color-primary); }

.breadcrumb-current { color: var(--color-text); font-weight: 500; }

.lesson-main {
  padding: var(--space-10) var(--space-12);
  max-width: 860px;
  width: 100%;
}

/* Reading time + lesson header */
.lesson-header {
  margin-bottom: var(--space-10);
  padding-bottom: var(--space-8);
  border-bottom: 1px solid var(--color-border-subtle);
}

.lesson-meta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
}

.reading-time {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.lesson-title {
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.lesson-intro {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  line-height: 1.65;
  font-weight: 400;
}

/* Lesson typography */
.lesson-body {
  font-size: var(--text-base);
  color: var(--color-text);
  line-height: 1.75;
}

.lesson-body h2 {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
  margin-top: var(--space-12);
  margin-bottom: var(--space-4);
  letter-spacing: -0.02em;
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-border-subtle);
}

.lesson-body h3 {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
}

.lesson-body p {
  margin-bottom: var(--space-5);
  max-width: 70ch;
}

.lesson-body ul,
.lesson-body ol {
  margin-bottom: var(--space-5);
  padding-left: var(--space-6);
}

.lesson-body li {
  margin-bottom: var(--space-2);
  max-width: 68ch;
}

.lesson-body strong {
  color: var(--color-text);
  font-weight: 700;
}

.lesson-body em { font-style: italic; color: var(--color-text-muted); }

.lesson-body code {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 2px 6px;
  font-size: 0.9em;
  color: var(--color-secondary);
  font-family: 'JetBrains Mono', monospace;
}

/* ----------------------------------------------------------------------------
   CALLOUT BOXES
   ---------------------------------------------------------------------------- */

/* Key Takeaway */
.callout-takeaway {
  background: rgba(59, 130, 246, 0.06);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-left: 3px solid var(--color-primary);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-6);
  margin: var(--space-8) 0;
  display: flex;
  gap: var(--space-4);
}

.callout-icon {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  margin-top: 2px;
  color: var(--color-primary);
}

.callout-content h4 {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.callout-content p,
.callout-content ul,
.callout-content li {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin: 0;
  line-height: 1.65;
}

.callout-content ul { padding-left: var(--space-4); margin-top: var(--space-2); }
.callout-content li { margin-bottom: var(--space-1); }

/* What to Note Down */
.callout-note {
  background: rgba(245, 158, 11, 0.06);
  border: 1px solid rgba(245, 158, 11, 0.2);
  border-left: 3px solid var(--color-warning);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-6);
  margin: var(--space-8) 0;
  display: flex;
  gap: var(--space-4);
}

.callout-note .callout-icon { color: var(--color-warning); }
.callout-note .callout-content h4 { color: var(--color-warning); }

/* Did You Know */
.callout-didyouknow {
  background: rgba(96, 165, 250, 0.05);
  border: 1px solid rgba(96, 165, 250, 0.15);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-6);
  margin: var(--space-8) 0;
  display: flex;
  gap: var(--space-4);
}

.callout-didyouknow .callout-icon { color: var(--color-secondary); }
.callout-didyouknow .callout-content h4 { color: var(--color-secondary); }

/* Practice Exercise */
.practice-box {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  margin: var(--space-8) 0;
  position: relative;
  overflow: hidden;
}

.practice-box::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-success), #4ade80);
}

.practice-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  background: var(--color-success-subtle);
  color: var(--color-success);
  border: 1px solid rgba(34, 197, 94, 0.2);
  font-size: var(--text-xs);
  font-weight: 700;
  padding: 3px var(--space-3);
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-4);
}

.practice-title {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.practice-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.65;
  margin: 0;
}

/* ----------------------------------------------------------------------------
   CHART CONTAINER
   ---------------------------------------------------------------------------- */
.chart-container {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-5);
  margin: var(--space-8) 0;
  overflow: hidden;
}

.chart-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
}

.chart-title {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.chart-img {
  width: 100%;
  border-radius: var(--radius-lg);
}

.chart-caption {
  margin-top: var(--space-3);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-align: center;
  font-style: italic;
  max-width: 100%;
}

/* ----------------------------------------------------------------------------
   QUIZ COMPONENT
   ---------------------------------------------------------------------------- */
.quiz-section {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  margin: var(--space-10) 0;
  position: relative;
  overflow: hidden;
}

.quiz-section::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
}

.quiz-header {
  text-align: center;
  margin-bottom: var(--space-8);
}

.quiz-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: var(--color-primary-subtle);
  color: var(--color-primary);
  border: 1px solid rgba(59, 130, 246, 0.2);
  font-size: var(--text-xs);
  font-weight: 700;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-4);
}

.quiz-title {
  font-size: var(--text-xl);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: var(--space-2);
  letter-spacing: -0.02em;
}

.quiz-subtitle {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* Question */
.quiz-question {
  margin-bottom: var(--space-8);
}

.question-number {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-2);
}

.question-text {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  line-height: 1.4;
}

.answer-options {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.answer-option {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-lg);
  cursor: pointer;
  background: var(--color-surface);
  transition: all var(--transition-interactive);
}

.answer-option:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-subtle);
}

.answer-option.selected {
  border-color: var(--color-primary);
  background: var(--color-primary-subtle);
}

.answer-option.correct {
  border-color: var(--color-success);
  background: var(--color-success-subtle);
  color: var(--color-success);
}

.answer-option.incorrect {
  border-color: var(--color-error);
  background: var(--color-error-subtle);
  color: var(--color-error);
}

.answer-letter {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-md);
  background: var(--color-card);
  border: 1.5px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 700;
  flex-shrink: 0;
  font-family: var(--font-display);
  transition: all var(--transition-interactive);
}

.answer-option.selected .answer-letter {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

.answer-option.correct .answer-letter {
  background: var(--color-success);
  border-color: var(--color-success);
  color: white;
}

.answer-option.incorrect .answer-letter {
  background: var(--color-error);
  border-color: var(--color-error);
  color: white;
}

.answer-text {
  font-size: var(--text-sm);
  color: var(--color-text);
  flex: 1;
  transition: color var(--transition-interactive);
}

.answer-option.correct .answer-text { color: var(--color-success); }
.answer-option.incorrect .answer-text { color: var(--color-error); }

.answer-result-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  display: none;
}

.answer-option.correct .answer-result-icon,
.answer-option.incorrect .answer-result-icon {
  display: block;
}

/* Quiz explanation */
.answer-explanation {
  margin-top: var(--space-2);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface);
  border-radius: var(--radius-md);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  display: none;
}

.answer-explanation.visible { display: block; }

/* Quiz Actions */
.quiz-actions {
  display: flex;
  justify-content: center;
  gap: var(--space-4);
  margin-top: var(--space-8);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border-subtle);
}

/* Quiz Score Summary */
.quiz-score {
  text-align: center;
  padding: var(--space-8);
  display: none;
}

.quiz-score.visible { display: block; }

.score-circle {
  width: 100px;
  height: 100px;
  border-radius: var(--radius-full);
  margin: 0 auto var(--space-5);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-2xl);
  font-weight: 800;
  font-family: var(--font-display);
  position: relative;
}

.score-circle.pass {
  background: var(--color-success-subtle);
  color: var(--color-success);
  border: 3px solid var(--color-success);
}

.score-circle.fail {
  background: var(--color-error-subtle);
  color: var(--color-error);
  border: 3px solid var(--color-error);
}

.score-label {
  font-size: var(--text-xl);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: var(--space-2);
  letter-spacing: -0.02em;
}

.score-sub {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

/* ----------------------------------------------------------------------------
   LESSON NAVIGATION (Prev / Next)
   ---------------------------------------------------------------------------- */
.lesson-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
  padding: var(--space-8) var(--space-12) var(--space-12);
  border-top: 1px solid var(--color-border-subtle);
  margin-top: var(--space-12);
}

.lesson-nav-btn {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-4) var(--space-5);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  transition: all var(--transition-interactive);
  color: var(--color-text);
  min-height: 72px;
}

.lesson-nav-btn:hover {
  border-color: var(--color-primary);
  background: var(--color-card-hover);
  color: var(--color-text);
}

.lesson-nav-btn.next { justify-content: flex-end; text-align: right; }
.lesson-nav-btn.prev { text-align: left; }

.nav-btn-content { flex: 1; min-width: 0; }

.nav-btn-label {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 2px;
}

.nav-btn-title {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-btn-arrow {
  color: var(--color-text-faint);
  flex-shrink: 0;
  transition: transform var(--transition-interactive);
}

.lesson-nav-btn.next:hover .nav-btn-arrow { transform: translateX(4px); }
.lesson-nav-btn.prev:hover .nav-btn-arrow { transform: translateX(-4px); }

/* Complete Lesson Button */
.complete-lesson-wrap {
  padding: var(--space-8) var(--space-12) 0;
  display: flex;
  justify-content: flex-end;
  gap: var(--space-3);
}

.btn-complete {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  background: var(--color-success);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-interactive);
}

.btn-complete:hover {
  background: var(--color-success-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px var(--color-success-subtle);
}

.btn-complete.completed {
  background: var(--color-success-subtle);
  color: var(--color-success);
  border: 1px solid rgba(34, 197, 94, 0.2);
  cursor: default;
  transform: none;
  box-shadow: none;
}

/* ----------------------------------------------------------------------------
   FADE-IN ANIMATIONS
   ---------------------------------------------------------------------------- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }
.fade-in-delay-4 { transition-delay: 0.4s; }

/* Stagger children */
.stagger-children > * {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.stagger-children.visible > *:nth-child(1) { opacity: 1; transform: translateY(0); transition-delay: 0s; }
.stagger-children.visible > *:nth-child(2) { opacity: 1; transform: translateY(0); transition-delay: 0.08s; }
.stagger-children.visible > *:nth-child(3) { opacity: 1; transform: translateY(0); transition-delay: 0.16s; }
.stagger-children.visible > *:nth-child(4) { opacity: 1; transform: translateY(0); transition-delay: 0.24s; }
.stagger-children.visible > *:nth-child(5) { opacity: 1; transform: translateY(0); transition-delay: 0.32s; }
.stagger-children.visible > *:nth-child(6) { opacity: 1; transform: translateY(0); transition-delay: 0.40s; }
.stagger-children.visible > *:nth-child(7) { opacity: 1; transform: translateY(0); transition-delay: 0.48s; }
.stagger-children.visible > *:nth-child(8) { opacity: 1; transform: translateY(0); transition-delay: 0.56s; }

/* ----------------------------------------------------------------------------
   DIVIDERS & UTILITIES
   ---------------------------------------------------------------------------- */
.divider {
  height: 1px;
  background: var(--color-border-subtle);
  margin: var(--space-12) 0;
}

.text-primary { color: var(--color-primary); }
.text-success  { color: var(--color-success); }
.text-error    { color: var(--color-error); }
.text-warning  { color: var(--color-warning); }
.text-muted    { color: var(--color-text-muted); }

.bg-surface  { background: var(--color-surface); }
.bg-card     { background: var(--color-card); }

.surface-alt {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-subtle);
  border-bottom: 1px solid var(--color-border-subtle);
}

/* Highlight / glow utility */
.glow-primary {
  box-shadow: 0 0 20px var(--color-primary-glow);
}

/* Gradient text */
.gradient-text {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Loading spinner */
.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: var(--radius-full);
  animation: spin 0.7s linear infinite;
}

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

/* Pulse dot */
@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  background: var(--color-success);
  animation: pulse-dot 2s ease-in-out infinite;
}

/* Chart grid line utility */
.chart-tick {
  stroke: var(--color-border);
  stroke-dasharray: 4 4;
}

/* ----------------------------------------------------------------------------
   RESPONSIVE — MOBILE
   ---------------------------------------------------------------------------- */
@media (max-width: 1024px) {
  .footer-top {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }

  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 768px) {
  /* Nav */
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
  #login-btn { display: none; } /* Login available in mobile menu */

  /* Hero */
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  /* Courses */
  .courses-grid { grid-template-columns: 1fr; }

  /* Steps */
  .steps-grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  .steps-grid::before { display: none; }

  /* Concepts */
  .concepts-grid { grid-template-columns: 1fr 1fr; }

  /* Footer */
  .footer-top { grid-template-columns: 1fr; }

  /* Lesson sidebar → bottom sheet */
  .lesson-sidebar {
    top: auto;
    bottom: 0;
    left: 0;
    right: 0;
    width: 100%;
    height: 70vh;
    border-right: none;
    border-top: 1px solid var(--color-border);
    border-radius: var(--radius-2xl) var(--radius-2xl) 0 0;
    transform: translateY(100%);
    transition: transform var(--transition-slow);
    z-index: 500;
  }

  .lesson-sidebar.mobile-open {
    transform: translateY(0);
  }

  .sidebar-toggle-btn { display: flex; }

  .lesson-content-wrapper { margin-left: 0; }

  .lesson-main {
    padding: var(--space-6) var(--space-5);
  }

  .lesson-nav {
    grid-template-columns: 1fr;
    padding: var(--space-6) var(--space-5) var(--space-10);
  }

  .complete-lesson-wrap {
    padding: var(--space-5) var(--space-5) 0;
    justify-content: stretch;
  }

  .complete-lesson-wrap .btn-complete {
    width: 100%;
    justify-content: center;
  }

  /* Quiz */
  .quiz-section { padding: var(--space-5); }
  .quiz-actions { flex-direction: column; }
  .quiz-actions .btn { width: 100%; }
}

@media (max-width: 480px) {
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-actions .btn { text-align: center; justify-content: center; }
  .concepts-grid { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: 1fr; }
}

/* ----------------------------------------------------------------------------
   PRINT
   ---------------------------------------------------------------------------- */
@media print {
  .nav, .lesson-sidebar, .sidebar-toggle-btn, .modal-overlay { display: none !important; }
  .lesson-content-wrapper { margin-left: 0 !important; }
  body { background: white; color: black; }
}

/* =========================================================
   QUIZ COMPONENTS (lesson page inline quizzes)
   ========================================================= */

.quiz-container {
  background: var(--color-surface-1);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg, 12px);
  padding: var(--space-6, 2rem);
  margin: var(--space-6, 2rem) 0;
}

.quiz-container h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--color-text-primary);
}

.quiz-question {
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--color-border);
}

.quiz-question:last-of-type {
  border-bottom: none;
}

.quiz-question p {
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--color-text-primary);
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  margin-bottom: 0.5rem;
  border-radius: var(--radius-md, 8px);
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all 0.2s ease;
  color: var(--color-text-secondary);
}

.quiz-option:hover {
  border-color: var(--color-primary);
  background: rgba(59, 130, 246, 0.05);
}

.quiz-option input[type="radio"] {
  accent-color: var(--color-primary);
}

.quiz-option.correct {
  border-color: var(--color-success);
  background: rgba(34, 197, 94, 0.1);
  color: var(--color-success);
}

.quiz-option.incorrect {
  border-color: var(--color-error);
  background: rgba(239, 68, 68, 0.1);
  color: var(--color-error);
}

.quiz-option.show-correct {
  border-color: var(--color-success);
  background: rgba(34, 197, 94, 0.05);
  color: var(--color-success);
  outline: 2px dashed var(--color-success);
  outline-offset: 2px;
}

.quiz-submit {
  margin-top: 1rem;
}

.quiz-results {
  margin-top: 1rem;
}

.quiz-msg {
  padding: 1rem;
  border-radius: var(--radius-md, 8px);
  font-weight: 500;
}

.quiz-msg.quiz-pass {
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.3);
  color: var(--color-success);
}

.quiz-msg.quiz-retry {
  background: rgba(245, 158, 11, 0.1);
  border: 1px solid rgba(245, 158, 11, 0.3);
  color: var(--color-warning);
}

.quiz-msg.quiz-warn {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: var(--color-error);
}

/* =========================================================
   LESSON LAYOUT & COMPONENTS
   ========================================================= */

.lesson-layout {
  display: flex;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--space-4, 1rem);
  gap: var(--space-6, 2rem);
  min-height: 100vh;
}

.lesson-sidebar {
  width: 300px;
  flex-shrink: 0;
  position: sticky;
  top: 80px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  padding: var(--space-4, 1rem);
  border-right: 1px solid var(--color-border);
}

.sidebar-module {
  margin-bottom: var(--space-4, 1rem);
}

.sidebar-module-title, .sidebar-module-header {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  padding: 0.5rem 0;
  margin-bottom: 0.25rem;
  cursor: pointer;
}

.sidebar-lesson, .sidebar-lesson-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  text-decoration: none;
  border-radius: var(--radius-md, 8px);
  transition: all 0.2s ease;
  border-left: 3px solid transparent;
}

.sidebar-lesson:hover, .sidebar-lesson-item:hover {
  background: rgba(59, 130, 246, 0.05);
  color: var(--color-text-primary);
}

.sidebar-lesson.active, .sidebar-lesson-item.active {
  border-left-color: var(--color-primary);
  background: rgba(59, 130, 246, 0.1);
  color: var(--color-primary);
  font-weight: 600;
}

.sidebar-lesson.completed .lesson-check {
  color: var(--color-success);
  font-weight: bold;
}

.lesson-check {
  font-size: 0.8rem;
  width: 1.2em;
  text-align: center;
  color: var(--color-text-muted);
}

.lesson-content {
  flex: 1;
  max-width: 800px;
  padding: var(--space-6, 2rem) 0;
}

.lesson {
  padding-bottom: var(--space-8, 3rem);
  margin-bottom: var(--space-8, 3rem);
  border-bottom: 1px solid var(--color-border);
}

.lesson:last-child {
  border-bottom: none;
}

.lesson-header {
  margin-bottom: var(--space-5, 1.5rem);
}

.lesson-number {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.lesson-header h2 {
  font-family: var(--font-display);
  font-size: 1.75rem;
  margin: 0.5rem 0;
  color: var(--color-text-primary);
}

.reading-time {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.lesson-body {
  line-height: 1.8;
  color: var(--color-text-secondary);
}

.lesson-body h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  margin: 1.5rem 0 0.75rem;
  color: var(--color-text-primary);
}

.lesson-body p {
  margin-bottom: 1rem;
}

.lesson-body ul, .lesson-body ol {
  margin: 1rem 0;
  padding-left: 1.5rem;
}

.lesson-body li {
  margin-bottom: 0.5rem;
}

/* Callout Boxes */
.callout {
  display: flex;
  gap: 1rem;
  padding: 1.25rem;
  border-radius: var(--radius-md, 8px);
  margin: 1.5rem 0;
  border-left: 4px solid;
}

.callout-icon {
  font-size: 1.25rem;
  flex-shrink: 0;
}

.callout-content {
  flex: 1;
}

.callout-content strong {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--color-text-primary);
}

.callout-content p, .callout-content ul {
  margin: 0;
  font-size: 0.95rem;
}

.callout-content ul {
  padding-left: 1.25rem;
}

.callout-takeaway {
  border-left-color: var(--color-primary);
  background: rgba(59, 130, 246, 0.05);
}

.callout-notes {
  border-left-color: var(--color-warning, #F59E0B);
  background: rgba(245, 158, 11, 0.05);
}

.callout-info {
  border-left-color: #8B5CF6;
  background: rgba(139, 92, 246, 0.05);
}

.callout-warning {
  border-left-color: var(--color-error, #EF4444);
  background: rgba(239, 68, 68, 0.05);
}

/* Chart Container */
.chart-container {
  margin: 1.5rem 0;
  background: var(--color-surface-1);
  border-radius: var(--radius-lg, 12px);
  padding: 1rem;
  border: 1px solid var(--color-border);
  text-align: center;
}

.chart-container img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md, 8px);
}

.chart-caption {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 0.75rem;
  font-style: italic;
}

/* Lesson Actions & Navigation */
.lesson-actions {
  margin: 2rem 0 1rem;
  text-align: center;
}

.btn-complete {
  background: var(--color-surface-2, #1e293b);
  border: 2px solid var(--color-success);
  color: var(--color-success);
  padding: 0.75rem 2rem;
  border-radius: var(--radius-md, 8px);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-complete:hover {
  background: rgba(34, 197, 94, 0.1);
}

.btn-complete.done {
  background: var(--color-success);
  color: #fff;
  cursor: default;
}

.lesson-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 1.5rem;
  gap: 1rem;
}

.btn-prev, .btn-next {
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md, 8px);
  text-decoration: none;
  font-weight: 600;
  transition: all 0.2s ease;
}

.btn-prev {
  background: var(--color-surface-2, #1e293b);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}

.btn-prev:hover {
  border-color: var(--color-primary);
  color: var(--color-text-primary);
}

.btn-next {
  background: var(--color-primary);
  color: #fff;
}

.btn-next:hover {
  background: var(--color-primary-hover, #2563EB);
}

/* Course Header */
.course-header {
  text-align: center;
  padding: var(--space-8, 3rem) var(--space-4, 1rem);
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-surface-1) 100%);
  border-bottom: 1px solid var(--color-border);
}

.breadcrumb {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 1rem;
}

.course-header h1 {
  font-family: var(--font-display);
  font-size: 2.5rem;
  margin: 0.75rem 0;
}

.course-header p {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.course-meta {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 1.5rem;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.course-progress-bar {
  max-width: 400px;
  height: 6px;
  background: var(--color-border);
  border-radius: 3px;
  margin: 1.5rem auto 0;
  overflow: hidden;
}

.course-progress-fill {
  height: 100%;
  background: var(--color-primary);
  border-radius: 3px;
  width: 0%;
  transition: width 0.5s ease;
}

/* Level Badges */
.level-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.level-beginner { background: rgba(34, 197, 94, 0.15); color: #22C55E; }
.level-intermediate { background: rgba(59, 130, 246, 0.15); color: #3B82F6; }
.level-advanced { background: rgba(139, 92, 246, 0.15); color: #8B5CF6; }
.level-j3 { background: rgba(245, 158, 11, 0.15); color: #F59E0B; }

/* Scroll Progress */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 9999;
  background: transparent;
}

.scroll-progress-bar {
  height: 100%;
  background: var(--color-primary);
  width: 0%;
  transition: width 0.1s linear;
}

/* Module Divider */
.module-divider {
  text-align: center;
  padding: 2rem 0;
  margin: 2rem 0;
  border-top: 2px solid var(--color-border);
}

.module-divider h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: var(--color-text-primary);
}

/* Strategy-specific styles */
.strategy-steps {
  counter-reset: step;
}

.strategy-step {
  counter-increment: step;
  padding: 1.5rem;
  margin-bottom: 1rem;
  background: var(--color-surface-1);
  border-radius: var(--radius-md, 8px);
  border-left: 4px solid var(--color-primary);
}

.strategy-step::before {
  content: "Step " counter(step);
  display: block;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.keyword-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
}

.keyword-table th, .keyword-table td {
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.keyword-table th {
  font-weight: 700;
  color: var(--color-text-primary);
  background: var(--color-surface-1);
}

.keyword-table td:first-child {
  font-weight: 600;
  color: var(--color-primary);
  white-space: nowrap;
}

/* Responsive Lesson Layout */
@media (max-width: 1024px) {
  .lesson-sidebar {
    display: none;
  }
  .lesson-layout {
    padding: 0 var(--space-3, 0.75rem);
  }
}

@media (max-width: 768px) {
  .course-header h1 {
    font-size: 1.75rem;
  }
  .course-meta {
    flex-wrap: wrap;
    gap: 1rem;
  }
  .lesson-header h2 {
    font-size: 1.4rem;
  }
  .lesson-nav {
    flex-direction: column;
  }
}

/* Animation for mark complete pulse */
@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); box-shadow: 0 0 20px rgba(34, 197, 94, 0.3); }
}

/* Session cards (beginner page) */
.session-card {
  background: var(--color-surface-1);
  border-radius: var(--radius-md, 8px);
  padding: 1.25rem;
  margin-bottom: 1rem;
  border-left: 4px solid var(--color-primary);
}

.session-card h4 {
  margin: 0 0 0.5rem;
  color: var(--color-text-primary);
}

.session-card p {
  margin: 0;
  font-size: 0.9rem;
}

/* Checklist items (J3 strategy) */
.checklist {
  list-style: none;
  padding: 0;
}

.checklist li {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-border);
}

.checklist li::before {
  content: "☐";
  font-size: 1.2rem;
  color: var(--color-primary);
  flex-shrink: 0;
}

/* Completion celebration */
.course-completion {
  display: none;
  text-align: center;
  padding: 3rem;
  margin: 2rem 0;
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(139, 92, 246, 0.1));
  border-radius: var(--radius-lg, 12px);
  border: 2px solid var(--color-primary);
}

.course-completion.visible {
  display: block;
}