/* ==========================================================================
   EducaWeb — Bold & Gamified Design System
   Dark theme, neon accents, glowing gradients, rounded shapes, XP & badges.
   Plain CSS. Headings: Fredoka. Body: Inter.
   ========================================================================== */

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

/* ==========================================================================
   1. DESIGN TOKENS
   ========================================================================== */

:root {
  /* Surfaces */
  --bg: #0B1020;
  --bg-2: #0E1530;
  --surface: #161D33;
  --surface-2: #1B2440;
  --border: rgba(255, 255, 255, .09);

  /* Text */
  --text: #E7ECF5;
  --muted: #9AA6C0;

  /* Brand & accents */
  --brand: #00E5FF;
  --brand-2: #A855F7;
  --accent: #00E5FF; /* overridden per page via body[data-subject] */

  /* Semantic */
  --ok: #34D399;
  --warn: #FBBF24;
  --danger: #F87171;

  /* Radii */
  --r-sm: 8px;
  --r: 14px;
  --r-lg: 22px;
  --r-pill: 999px;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, .25);
  --shadow: 0 10px 30px rgba(0, 0, 0, .35);
  --shadow-lg: 0 24px 60px rgba(0, 0, 0, .45);
  --glow: 0 0 0 1px color-mix(in srgb, var(--accent) 40%, transparent),
          0 8px 32px color-mix(in srgb, var(--accent) 28%, transparent);
  --glow-strong: 0 0 0 1px color-mix(in srgb, var(--accent) 55%, transparent),
          0 0 24px color-mix(in srgb, var(--accent) 45%, transparent),
          0 14px 40px color-mix(in srgb, var(--accent) 28%, transparent);

  /* Layout */
  --container: 1200px;
  --pad: clamp(16px, 4vw, 28px);
  --header-h: 68px;

  /* Motion */
  --ease: cubic-bezier(.22, 1, .36, 1);
  --t: .25s var(--ease);

  color-scheme: dark;
}

/* --- Subject accent map --------------------------------------------------- */
body[data-subject="math"]    { --accent: #22D3EE; }
body[data-subject="physics"] { --accent: #A78BFA; }
body[data-subject="nature"]  { --accent: #34D399; }
body[data-subject="stories"] { --accent: #FBBF24; }
body[data-subject="books"]   { --accent: #FB7185; }
body[data-subject="sport"]   { --accent: #F87171; }
body[data-subject="ai"]      { --accent: #2DD4BF; }
body[data-subject="coding"]  { --accent: #818CF8; }

/* ==========================================================================
   2. RESET & BASE
   ========================================================================== */

*, *::before, *::after { box-sizing: border-box; }

* { margin: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background:
    radial-gradient(1100px 600px at 12% -8%, color-mix(in srgb, var(--brand) 14%, transparent), transparent 60%),
    radial-gradient(1000px 560px at 92% 0%, color-mix(in srgb, var(--brand-2) 14%, transparent), transparent 58%),
    linear-gradient(180deg, var(--bg-2), var(--bg) 40%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Fredoka', 'Inter', sans-serif;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -.01em;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

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

button { font: inherit; color: inherit; cursor: pointer; }

ul, ol { padding-left: 1.2em; }

/* Focus visibility for keyboard users */
:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 75%, white);
  outline-offset: 2px;
  border-radius: 4px;
}

/* Selection */
::selection {
  background: color-mix(in srgb, var(--accent) 45%, transparent);
  color: #fff;
}

/* Skip link */
.skip-link {
  position: absolute;
  left: 12px;
  top: -64px;
  z-index: 1000;
  padding: 10px 16px;
  background: var(--accent);
  color: #06101c;
  font-weight: 700;
  border-radius: var(--r-sm);
  transition: top .2s var(--ease);
}
.skip-link:focus { top: 12px; text-decoration: none; }

/* ==========================================================================
   3. LAYOUT
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--pad);
}

.section { padding-block: clamp(40px, 7vw, 84px); }
.section--alt {
  background: linear-gradient(180deg, color-mix(in srgb, var(--surface) 60%, transparent), transparent);
  border-block: 1px solid var(--border);
}

.section__head {
  max-width: 760px;
  margin: 0 auto clamp(28px, 4vw, 48px);
  text-align: center;
}
.section__title {
  font-size: clamp(1.6rem, 3.4vw, 2.4rem);
}
.section__subtitle {
  margin-top: 12px;
  color: var(--muted);
  font-size: 1.05rem;
}

/* ==========================================================================
   4. HEADER
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--bg-2) 78%, transparent);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.site-header__inner {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--pad);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 18px;
}

/* Brand */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: 'Fredoka', sans-serif;
  font-weight: 700;
  color: var(--text);
}
.brand:hover { text-decoration: none; }
.brand__logo {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  font-size: 1.2rem;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  box-shadow: 0 6px 18px color-mix(in srgb, var(--brand) 40%, transparent);
}
.brand__name {
  font-size: 1.25rem;
  letter-spacing: -.02em;
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* Nav */
.main-nav { margin-left: 6px; }
.main-nav__list {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 0;
  padding: 0;
}
.main-nav__item { position: relative; }
.main-nav__link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 14px;
  border-radius: var(--r-pill);
  color: var(--muted);
  font-weight: 600;
  transition: color var(--t), background var(--t);
}
.main-nav__link:hover,
.main-nav__link:focus-visible {
  color: var(--text);
  background: var(--surface);
  text-decoration: none;
}
.main-nav__item.has-mega > .main-nav__link::after {
  content: "▾";
  font-size: .7em;
  opacity: .7;
}

/* Mega panel */
.mega-panel {
  position: absolute;
  top: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  width: min(680px, 90vw);
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--t), transform var(--t), visibility var(--t);
  z-index: 50;
}
.main-nav__item.has-mega:hover .mega-panel,
.main-nav__item.has-mega:focus-within .mega-panel {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}
.mega-panel__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 8px;
}
.mega-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--r);
  color: var(--text);
  transition: background var(--t), transform var(--t);
}
.mega-link:hover {
  background: var(--surface-2);
  transform: translateY(-1px);
  text-decoration: none;
}
.mega-link__icon {
  flex: none;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  font-size: 1.2rem;
  border-radius: 12px;
  background: var(--surface-2);
  border: 1px solid var(--border);
}
.mega-link:hover .mega-link__icon {
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 50%, transparent),
              0 6px 16px color-mix(in srgb, var(--accent) 30%, transparent);
}
.mega-link__label { font-weight: 600; }

/* Header actions cluster */
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-left: auto;
}

/* Hamburger (mobile only) */
.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  flex: none;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
  position: relative;
}
.nav-toggle::before,
.nav-toggle::after,
.nav-toggle span {
  content: "";
  position: absolute;
  left: 11px;
  right: 11px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--t), opacity var(--t);
}
.nav-toggle::before { top: 14px; }
.nav-toggle span { top: 20px; }
.nav-toggle::after { top: 26px; }
.nav-toggle[aria-expanded="true"]::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span { opacity: 0; }
.nav-toggle[aria-expanded="true"]::after { transform: translateY(-6px) rotate(-45deg); }

/* ==========================================================================
   5. GAMIFICATION (header XP / streak)
   ========================================================================== */

.xp-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 12px 6px 8px;
  border-radius: var(--r-pill);
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--brand-2) 14%, transparent);
}
.xp-badge__level {
  display: grid;
  place-items: center;
  min-width: 28px;
  height: 28px;
  padding-inline: 6px;
  border-radius: var(--r-pill);
  font-family: 'Fredoka', sans-serif;
  font-weight: 700;
  font-size: .85rem;
  color: #06101c;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  box-shadow: 0 0 14px color-mix(in srgb, var(--brand) 40%, transparent);
}
.xp-badge__bar {
  position: relative;
  width: 88px;
  height: 8px;
  border-radius: var(--r-pill);
  background: var(--surface-2);
  overflow: hidden;
}
.xp-badge__fill {
  position: absolute;
  inset: 0;
  width: var(--pct, 0%);
  border-radius: inherit;
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
  box-shadow: 0 0 10px color-mix(in srgb, var(--brand) 60%, transparent);
  transition: width .8s var(--ease);
}
.xp-badge [data-xp-display] {
  font-size: .8rem;
  font-weight: 700;
  color: var(--muted);
}
.xp-badge [data-level-display] { font-weight: 700; }

.streak {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 12px;
  border-radius: var(--r-pill);
  background: var(--surface);
  border: 1px solid var(--border);
  font-weight: 700;
  font-size: .9rem;
}
.streak::before {
  content: "🔥";
  filter: drop-shadow(0 0 6px rgba(251, 146, 60, .8));
  animation: flicker 1.8s ease-in-out infinite;
}
.streak [data-streak-display] { color: var(--warn); }

@keyframes flicker {
  0%, 100% { transform: scale(1) rotate(-2deg); }
  50% { transform: scale(1.12) rotate(2deg); }
}

/* ==========================================================================
   6. LANGUAGE SWITCHER & SEARCH
   ========================================================================== */

.lang-switcher { position: relative; }
.lang-switcher__btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 42px;
  padding: 0 14px;
  border-radius: var(--r-pill);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-weight: 600;
  transition: background var(--t);
}
.lang-switcher__btn:hover { background: var(--surface-2); }
.lang-switcher__menu {
  position: absolute;
  right: 0;
  top: calc(100% + 8px);
  min-width: 150px;
  padding: 6px;
  list-style: none;
  margin: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  transition: opacity var(--t), transform var(--t), visibility var(--t);
  z-index: 60;
}
.lang-switcher:hover .lang-switcher__menu,
.lang-switcher:focus-within .lang-switcher__menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.lang-switcher__menu a {
  display: block;
  padding: 9px 12px;
  border-radius: var(--r-sm);
  color: var(--text);
}
.lang-switcher__menu a:hover { background: var(--surface-2); text-decoration: none; }

.search-btn {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: var(--r-pill);
  border: 1px solid var(--border);
  background: var(--surface);
  font-size: 1.05rem;
  transition: background var(--t), box-shadow var(--t);
}
.search-btn:hover {
  background: var(--surface-2);
  box-shadow: var(--glow);
}

/* Full-screen search overlay */
.search-overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  justify-content: center;
  padding: clamp(24px, 12vh, 140px) var(--pad) var(--pad);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  opacity: 0;
  visibility: hidden;
  transition: opacity .2s var(--ease), visibility .2s var(--ease);
}
.search-overlay.is-open { opacity: 1; visibility: visible; }
.search-overlay__box {
  width: min(640px, 100%);
  height: max-content;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  transform: translateY(-14px) scale(.98);
  transition: transform .25s var(--ease);
}
.search-overlay.is-open .search-overlay__box { transform: translateY(0) scale(1); }
.search-input {
  width: 100%;
  padding: 20px 22px;
  border: 0;
  border-bottom: 1px solid var(--border);
  background: transparent;
  color: var(--text);
  font-size: 1.15rem;
  font-family: inherit;
}
.search-input::placeholder { color: var(--muted); }
.search-input:focus { outline: none; }
.search-results {
  max-height: 50vh;
  overflow-y: auto;
  padding: 8px;
}
.search-result {
  display: block;
  padding: 12px 14px;
  border-radius: var(--r);
  color: var(--text);
}
.search-result:hover,
.search-result:focus-visible {
  background: var(--surface-2);
  text-decoration: none;
}

/* ==========================================================================
   7. BUTTONS
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border: 1px solid transparent;
  border-radius: var(--r-pill);
  background: var(--surface-2);
  color: var(--text);
  font-weight: 700;
  font-family: 'Fredoka', sans-serif;
  line-height: 1.2;
  white-space: nowrap;
  transition: transform var(--t), box-shadow var(--t), background var(--t), border-color var(--t), filter var(--t);
}
.btn:hover { transform: translateY(-2px); text-decoration: none; }
.btn:active { transform: translateY(0); }

.btn--primary {
  background: linear-gradient(120deg, var(--brand), var(--brand-2));
  color: #06101c;
  box-shadow: 0 10px 28px color-mix(in srgb, var(--brand-2) 35%, transparent);
}
.btn--primary:hover {
  filter: brightness(1.06);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--brand) 50%, transparent),
              0 14px 38px color-mix(in srgb, var(--brand-2) 50%, transparent);
}

.btn--accent {
  background: linear-gradient(120deg, var(--accent), color-mix(in srgb, var(--accent) 55%, var(--brand-2)));
  color: #06101c;
  box-shadow: 0 10px 28px color-mix(in srgb, var(--accent) 35%, transparent);
}
.btn--accent:hover { box-shadow: var(--glow-strong); filter: brightness(1.05); }

.btn--ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}
.btn--ghost:hover {
  border-color: color-mix(in srgb, var(--accent) 60%, transparent);
  background: color-mix(in srgb, var(--accent) 8%, transparent);
  box-shadow: var(--glow);
}

.btn--lg { padding: 15px 28px; font-size: 1.1rem; }
.btn--block { display: flex; width: 100%; }

/* ==========================================================================
   8. HERO
   ========================================================================== */

.hero {
  position: relative;
  padding-block: clamp(48px, 8vw, 96px);
  text-align: center;
  overflow: hidden;
}
.hero--home {
  background:
    radial-gradient(700px 360px at 50% -10%, color-mix(in srgb, var(--brand) 22%, transparent), transparent 70%),
    radial-gradient(600px 320px at 10% 110%, color-mix(in srgb, var(--brand-2) 18%, transparent), transparent 70%);
}
.hero--home::before {
  /* subtle grid pattern */
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(color-mix(in srgb, var(--text) 6%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--text) 6%, transparent) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(700px 420px at 50% 30%, #000, transparent 75%);
  -webkit-mask-image: radial-gradient(700px 420px at 50% 30%, #000, transparent 75%);
  pointer-events: none;
}
.hero > .container { position: relative; z-index: 1; }
.hero__emoji {
  font-size: clamp(3rem, 8vw, 4.5rem);
  line-height: 1;
  filter: drop-shadow(0 8px 24px color-mix(in srgb, var(--accent) 50%, transparent));
  animation: float 4s ease-in-out infinite;
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}
.hero__title {
  margin-top: 14px;
  font-size: clamp(2.2rem, 6vw, 4rem);
  font-weight: 700;
  letter-spacing: -.02em;
  background: linear-gradient(100deg, var(--text), var(--brand) 60%, var(--brand-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__subtitle {
  margin: 16px auto 0;
  max-width: 620px;
  color: var(--muted);
  font-size: clamp(1.05rem, 2.4vw, 1.25rem);
}
.hero__actions {
  margin-top: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
}
.hero__stats {
  margin-top: 34px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}
.hero__stats > * {
  padding: 10px 18px;
  border-radius: var(--r-pill);
  background: color-mix(in srgb, var(--surface) 70%, transparent);
  border: 1px solid var(--border);
  font-weight: 600;
  font-size: .95rem;
  backdrop-filter: blur(6px);
}

/* ==========================================================================
   9. CARDS & GRIDS
   ========================================================================== */

/* Subject grid */
.subject-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 18px;
}
.subject-card {
  --accent: var(--brand); /* may be overridden inline */
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px;
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--surface), var(--surface-2));
  border: 1px solid var(--border);
  color: var(--text);
  overflow: hidden;
  transition: transform var(--t), box-shadow var(--t), border-color var(--t);
}
.subject-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(220px 140px at 80% -10%, color-mix(in srgb, var(--accent) 22%, transparent), transparent 70%);
  opacity: .7;
  transition: opacity var(--t);
}
.subject-card:hover {
  transform: translateY(-6px);
  text-decoration: none;
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  box-shadow: var(--glow-strong);
}
.subject-card:hover::before { opacity: 1; }
.subject-card > * { position: relative; z-index: 1; }
.subject-card__icon {
  width: 56px;
  height: 56px;
  display: grid;
  place-items: center;
  font-size: 1.7rem;
  border-radius: 16px;
  background: color-mix(in srgb, var(--accent) 16%, var(--surface-2));
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  box-shadow: inset 0 0 18px color-mix(in srgb, var(--accent) 22%, transparent);
}
.subject-card__title {
  font-size: 1.25rem;
  color: var(--text);
}
.subject-card__blurb { color: var(--muted); font-size: .95rem; }
.subject-card__meta {
  margin-top: auto;
  padding-top: 6px;
  font-weight: 700;
  font-size: .85rem;
  color: var(--accent);
}

/* Age grid */
.age-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}
.age-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 24px;
  text-align: center;
  border-radius: var(--r-lg);
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  transition: transform var(--t), box-shadow var(--t), border-color var(--t);
}
.age-card:hover {
  transform: translateY(-5px);
  text-decoration: none;
  border-color: color-mix(in srgb, var(--brand) 45%, transparent);
  box-shadow: var(--shadow);
}
.age-card__emoji {
  font-size: 2.6rem;
  line-height: 1;
}
.age-card__name { font-size: 1.2rem; }
.age-card__range {
  display: inline-block;
  align-self: center;
  padding: 3px 12px;
  border-radius: var(--r-pill);
  background: color-mix(in srgb, var(--brand) 16%, transparent);
  color: var(--brand);
  font-weight: 700;
  font-size: .8rem;
}
.age-card__blurb { color: var(--muted); font-size: .92rem; }

/* Generic card grid */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}
.card {
  display: flex;
  flex-direction: column;
  border-radius: var(--r-lg);
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  overflow: hidden;
  transition: transform var(--t), box-shadow var(--t), border-color var(--t);
}
.card:hover {
  transform: translateY(-4px);
  text-decoration: none;
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
  box-shadow: var(--shadow);
}
.card__media {
  position: relative;
  aspect-ratio: 16 / 9;
  display: grid;
  place-items: center;
  background:
    radial-gradient(160px 100px at 70% 20%, color-mix(in srgb, var(--accent) 30%, transparent), transparent 70%),
    linear-gradient(135deg, var(--surface-2), var(--surface));
  border-bottom: 1px solid var(--border);
}
.card__emoji {
  font-size: 3rem;
  filter: drop-shadow(0 6px 16px rgba(0, 0, 0, .35));
}
.card__body { padding: 18px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
.card__title { font-size: 1.15rem; }
.card__excerpt { color: var(--muted); font-size: .94rem; }
.card__meta {
  margin-top: auto;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  font-size: .82rem;
  color: var(--muted);
}
.card__tags { display: flex; flex-wrap: wrap; gap: 6px; }

/* Tags / chips / badges */
.tag, .chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 11px;
  border-radius: var(--r-pill);
  font-size: .78rem;
  font-weight: 600;
  line-height: 1.4;
}
.tag {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--muted);
}
.chip {
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  color: color-mix(in srgb, var(--accent) 85%, white);
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 12px;
  border-radius: var(--r-pill);
  font-weight: 700;
  font-size: .76rem;
  letter-spacing: .02em;
  color: #06101c;
  background: linear-gradient(120deg, var(--brand), var(--brand-2));
  box-shadow: 0 4px 14px color-mix(in srgb, var(--brand-2) 35%, transparent);
  position: relative;
  overflow: hidden;
}
.badge::after {
  /* shine sweep */
  content: "";
  position: absolute;
  top: 0; left: -60%;
  width: 40%; height: 100%;
  background: linear-gradient(100deg, transparent, rgba(255,255,255,.55), transparent);
  transform: skewX(-20deg);
  animation: shine 3.2s ease-in-out infinite;
}
@keyframes shine {
  0%, 60% { left: -60%; }
  100% { left: 130%; }
}

/* ==========================================================================
   10. BREADCRUMBS
   ========================================================================== */

.breadcrumbs { padding-block: 14px; }
.breadcrumbs__list {
  list-style: none;
  margin: 0; padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-size: .88rem;
}
.breadcrumbs__item { color: var(--muted); }
.breadcrumbs__item a { color: var(--muted); }
.breadcrumbs__item a:hover { color: var(--accent); }
.breadcrumbs__item[aria-current="page"] { color: var(--text); font-weight: 600; }
.breadcrumbs__sep { color: var(--muted); opacity: .6; }

/* ==========================================================================
   11. LESSON / ARTICLE LAYOUT
   ========================================================================== */

.lesson { padding-block: clamp(20px, 4vw, 40px); }
.lesson__header { margin-bottom: 28px; }
.lesson__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}
.lesson__title {
  font-size: clamp(1.9rem, 4.4vw, 3rem);
  max-width: 22ch;
}
.lesson__layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}
.lesson__main { min-width: 0; }
.lesson__aside {
  position: sticky;
  top: calc(var(--header-h) + 16px);
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* ==========================================================================
   12. PROSE (generated rich body)
   ========================================================================== */

.prose {
  font-size: 1.05rem;
  line-height: 1.75;
  color: var(--text);
  max-width: 68ch;
}
.prose > * + * { margin-top: 1.05em; }
.prose h2 {
  margin-top: 1.8em;
  font-size: 1.7rem;
  padding-bottom: .3em;
  border-bottom: 1px solid var(--border);
}
.prose h3 { margin-top: 1.6em; font-size: 1.35rem; }
.prose h4 { margin-top: 1.4em; font-size: 1.12rem; }
.prose p { color: var(--text); }
.prose ul, .prose ol { padding-left: 1.4em; }
.prose li { margin-top: .4em; }
.prose li::marker { color: var(--accent); }
.prose a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--accent) 45%, transparent);
  text-underline-offset: 3px;
}
.prose a:hover { text-decoration-color: var(--accent); }
.prose strong { color: #fff; font-weight: 700; }
.prose em { color: var(--text); }
.prose code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .9em;
  padding: .15em .45em;
  border-radius: 6px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: color-mix(in srgb, var(--accent) 80%, white);
}
.prose pre {
  padding: 18px 20px;
  border-radius: var(--r);
  background: #0a0f1f;
  border: 1px solid var(--border);
  overflow-x: auto;
  line-height: 1.6;
}
.prose pre code {
  padding: 0;
  background: none;
  border: 0;
  color: var(--text);
  font-size: .9rem;
}
.prose blockquote {
  margin-inline: 0;
  padding: 14px 20px;
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--r) var(--r) 0;
  background: color-mix(in srgb, var(--accent) 8%, transparent);
  color: var(--muted);
  font-style: italic;
}
.prose img {
  border-radius: var(--r);
  border: 1px solid var(--border);
  margin-inline: auto;
}
.prose hr {
  border: 0;
  height: 1px;
  background: var(--border);
  margin-block: 2em;
}
.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: .95rem;
  border: 1px solid var(--border);
  border-radius: var(--r);
  overflow: hidden;
}
.prose th, .prose td {
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.prose th {
  background: var(--surface-2);
  font-weight: 700;
  font-family: 'Fredoka', sans-serif;
}
.prose tbody tr:nth-child(even) { background: color-mix(in srgb, var(--surface) 50%, transparent); }
.prose tbody tr:last-child td { border-bottom: 0; }

/* ==========================================================================
   13. TOC / TAKEAWAYS / CALLOUT / AD
   ========================================================================== */

.toc {
  padding: 18px;
  border-radius: var(--r-lg);
  background: var(--surface);
  border: 1px solid var(--border);
}
.toc__title {
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
  margin-bottom: 10px;
}
.toc__list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 2px; }
.toc__link {
  display: block;
  padding: 7px 10px;
  border-radius: var(--r-sm);
  color: var(--muted);
  font-size: .92rem;
  border-left: 2px solid transparent;
}
.toc__link:hover,
.toc__link[aria-current="true"] {
  color: var(--text);
  background: var(--surface-2);
  border-left-color: var(--accent);
  text-decoration: none;
}

.takeaways {
  padding: 22px;
  border-radius: var(--r-lg);
  background: color-mix(in srgb, var(--accent) 10%, var(--surface));
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  box-shadow: inset 0 0 30px color-mix(in srgb, var(--accent) 10%, transparent);
}
.takeaways__title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.15rem;
  margin-bottom: 12px;
  color: color-mix(in srgb, var(--accent) 85%, white);
}
.takeaways__title::before { content: "💡"; }
.takeaways__list { margin: 0; padding-left: 1.3em; display: flex; flex-direction: column; gap: 8px; }
.takeaways__list li::marker { color: var(--accent); }

.callout {
  padding: 16px 20px;
  border-radius: var(--r);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
}

.ad-slot {
  margin-block: clamp(20px, 4vw, 36px);
  padding: 16px;
  min-height: 100px;
  display: grid;
  place-items: center;
  border-radius: var(--r);
  background: color-mix(in srgb, var(--surface) 50%, transparent);
  border: 1px dashed var(--border);
  text-align: center;
}
.ad-slot::before {
  content: "Advertisement";
  display: block;
  font-size: .68rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--muted);
  margin-bottom: 6px;
}

/* ==========================================================================
   14. QUIZ (gamified)
   ========================================================================== */

.quiz {
  padding: clamp(20px, 4vw, 30px);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--surface), var(--surface-2));
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}
.quiz__title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  margin-bottom: 6px;
}
.quiz__title::before { content: "🎯"; }
.quiz__progress {
  height: 8px;
  border-radius: var(--r-pill);
  background: var(--surface-2);
  overflow: hidden;
  margin-bottom: 20px;
}
.quiz__progress::after {
  content: "";
  display: block;
  height: 100%;
  width: var(--pct, 0%);
  border-radius: inherit;
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
  transition: width .5s var(--ease);
}
.quiz__item { margin-bottom: 22px; }
.quiz__item:last-of-type { margin-bottom: 0; }
.quiz__q {
  font-weight: 700;
  font-size: 1.08rem;
  margin-bottom: 12px;
  font-family: 'Fredoka', sans-serif;
}
.quiz__options { display: grid; gap: 10px; }
.quiz__option {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  text-align: left;
  padding: 13px 16px;
  border-radius: var(--r);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-weight: 500;
  transition: transform var(--t), border-color var(--t), background var(--t), box-shadow var(--t);
}
.quiz__option:hover {
  transform: translateY(-2px);
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  background: color-mix(in srgb, var(--accent) 7%, var(--surface));
}
.quiz__option[aria-pressed="true"] {
  border-color: var(--accent);
  box-shadow: var(--glow);
}
.quiz__option.is-correct {
  border-color: var(--ok);
  background: color-mix(in srgb, var(--ok) 16%, var(--surface));
  box-shadow: 0 0 0 1px var(--ok), 0 0 22px color-mix(in srgb, var(--ok) 45%, transparent);
}
.quiz__option.is-correct::after { content: "✓"; margin-left: auto; color: var(--ok); font-weight: 700; }
.quiz__option.is-wrong {
  border-color: var(--danger);
  background: color-mix(in srgb, var(--danger) 14%, var(--surface));
  box-shadow: 0 0 0 1px var(--danger);
  animation: shake .4s ease;
}
.quiz__option.is-wrong::after { content: "✕"; margin-left: auto; color: var(--danger); font-weight: 700; }
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}
.quiz__feedback {
  margin-top: 10px;
  padding: 10px 14px;
  border-radius: var(--r-sm);
  background: var(--surface-2);
  font-size: .92rem;
  color: var(--muted);
}
.quiz__submit { margin-top: 20px; }
.quiz__score {
  margin-top: 18px;
  text-align: center;
  font-family: 'Fredoka', sans-serif;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent);
}

/* ==========================================================================
   15. ACCORDION / FAQ
   ========================================================================== */

.accordion {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.accordion__item {
  border-radius: var(--r);
  background: var(--surface);
  border: 1px solid var(--border);
  overflow: hidden;
}
.accordion__button {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  text-align: left;
  padding: 16px 18px;
  background: transparent;
  color: var(--text);
  font-weight: 600;
  font-size: 1.02rem;
  font-family: 'Fredoka', sans-serif;
}
.accordion__button::after {
  content: "▾";
  flex: none;
  color: var(--accent);
  transition: transform var(--t);
}
.accordion__button[aria-expanded="true"]::after { transform: rotate(180deg); }
.accordion__button[aria-expanded="true"] { background: var(--surface-2); }
.accordion__panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows .3s var(--ease);
}
.accordion__button[aria-expanded="true"] + .accordion__panel { grid-template-rows: 1fr; }
.accordion__panel > * { overflow: hidden; min-height: 0; }
.accordion__panel > * > * { padding: 4px 18px 18px; color: var(--muted); }
/* Fallback for hidden attribute usage */
.accordion__panel[hidden] { display: none; }

/* ==========================================================================
   16. PROGRESS & COMPLETION
   ========================================================================== */

.progress {
  height: 12px;
  border-radius: var(--r-pill);
  background: var(--surface-2);
  border: 1px solid var(--border);
  overflow: hidden;
}
.progress__bar {
  height: 100%;
  width: var(--pct, 0%);
  border-radius: var(--r-pill);
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
  box-shadow: 0 0 14px color-mix(in srgb, var(--brand) 50%, transparent);
  transition: width .7s var(--ease);
  position: relative;
}
.progress__bar::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.3), transparent);
  background-size: 200% 100%;
  animation: stripe 2s linear infinite;
}
@keyframes stripe {
  from { background-position: 200% 0; }
  to { background-position: -200% 0; }
}

.complete-cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 24px;
  text-align: center;
  border-radius: var(--r-lg);
  background: color-mix(in srgb, var(--accent) 10%, var(--surface));
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
}
.complete-cta__btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border: 1px solid transparent;
  border-radius: var(--r-pill);
  font-family: 'Fredoka', sans-serif;
  font-weight: 700;
  font-size: 1.05rem;
  color: #06101c;
  background: linear-gradient(120deg, var(--accent), var(--brand-2));
  box-shadow: var(--glow);
  transition: transform var(--t), box-shadow var(--t), filter var(--t);
}
.complete-cta__btn:hover { transform: translateY(-2px); box-shadow: var(--glow-strong); }
.complete-cta__btn.is-done {
  background: linear-gradient(120deg, var(--ok), color-mix(in srgb, var(--ok) 60%, var(--brand)));
  cursor: default;
}
.complete-cta__btn.is-done::after { content: " ✓"; }

/* Floating +XP popup */
.xp-pop {
  position: fixed;
  z-index: 300;
  padding: 8px 16px;
  border-radius: var(--r-pill);
  font-family: 'Fredoka', sans-serif;
  font-weight: 700;
  color: #06101c;
  background: linear-gradient(120deg, var(--brand), var(--brand-2));
  box-shadow: 0 8px 24px color-mix(in srgb, var(--brand-2) 50%, transparent);
  pointer-events: none;
  animation: xpPop 1.4s var(--ease) forwards;
}
@keyframes xpPop {
  0% { opacity: 0; transform: translateY(10px) scale(.8); }
  20% { opacity: 1; transform: translateY(0) scale(1.1); }
  40% { transform: scale(1); }
  100% { opacity: 0; transform: translateY(-50px) scale(.95); }
}

/* ==========================================================================
   17. RELATED & PAGINATION
   ========================================================================== */

.related { margin-top: clamp(32px, 6vw, 56px); }

.pager {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  margin-top: clamp(28px, 5vw, 44px);
}
.pager__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 18px;
  border-radius: var(--r);
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-weight: 600;
  transition: transform var(--t), border-color var(--t), box-shadow var(--t);
}
.pager__link:hover {
  transform: translateY(-2px);
  text-decoration: none;
  border-color: color-mix(in srgb, var(--accent) 50%, transparent);
  box-shadow: var(--glow);
}
.pager__link[rel="prev"]::before { content: "←"; }
.pager__link[rel="next"]::after { content: "→"; }

/* ==========================================================================
   18. FOOTER
   ========================================================================== */

.site-footer {
  margin-top: clamp(48px, 8vw, 96px);
  background: linear-gradient(180deg, transparent, var(--bg-2));
  border-top: 1px solid var(--border);
}
.site-footer__inner {
  max-width: var(--container);
  margin-inline: auto;
  padding: clamp(40px, 6vw, 64px) var(--pad) 0;
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: 32px;
}
.site-footer__brand { max-width: 32ch; }
.site-footer__brand .brand { margin-bottom: 12px; }
.site-footer__brand p { color: var(--muted); font-size: .95rem; }
.footer-col__heading {
  font-size: .82rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
  margin-bottom: 14px;
}
.footer-col__links {
  list-style: none;
  margin: 0; padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-col__links a { color: var(--text); font-size: .95rem; }
.footer-col__links a:hover { color: var(--accent); }
.site-footer__bottom {
  max-width: var(--container);
  margin-inline: auto;
  margin-top: clamp(32px, 5vw, 48px);
  padding: 22px var(--pad);
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
  font-size: .88rem;
}
.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-legal a { color: var(--muted); }
.footer-legal a:hover { color: var(--text); }

/* ==========================================================================
   19. UTILITIES
   ========================================================================== */

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

.text-center { text-align: center; }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: .5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mt-5 { margin-top: 3rem; }
.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: .5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mb-5 { margin-bottom: 3rem; }

/* ==========================================================================
   20. RESPONSIVE
   ========================================================================== */

@media (max-width: 1024px) {
  .lesson__layout { grid-template-columns: 1fr; }
  .lesson__aside { position: static; }
  .site-footer__inner { grid-template-columns: 1fr 1fr; }
  .site-footer__brand { grid-column: 1 / -1; }
}

@media (max-width: 860px) {
  /* Hamburger appears, nav becomes off-canvas drawer */
  .nav-toggle { display: block; order: 5; }

  .main-nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    margin: 0;
    max-height: 0;
    overflow: hidden;
    background: var(--bg-2);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
    transition: max-height .35s var(--ease);
    z-index: 90;
  }
  .main-nav.is-open { max-height: calc(100vh - var(--header-h)); overflow-y: auto; }
  .main-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 14px var(--pad);
  }
  .main-nav__link { padding: 14px 16px; border-radius: var(--r); }
  .main-nav__item.has-mega > .main-nav__link::after { margin-left: auto; }

  /* Mega panels stack inline (no floating) */
  .mega-panel {
    position: static;
    width: auto;
    transform: none;
    opacity: 1;
    visibility: visible;
    box-shadow: none;
    background: var(--surface);
    margin-top: 4px;
  }
  .mega-panel__grid { grid-template-columns: 1fr 1fr; }

  /* Trim header gamification on small screens for clarity */
  .xp-badge__bar { display: none; }
}

@media (max-width: 560px) {
  .site-footer__inner { grid-template-columns: 1fr; }
  .mega-panel__grid { grid-template-columns: 1fr; }
  .hero__actions .btn { flex: 1 1 auto; }
  .streak { display: none; }
  .pager { flex-direction: column; }
  .pager__link { justify-content: center; }
}

/* ==========================================================================
   21. ACCESSIBILITY — REDUCED MOTION
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
  .hero__emoji,
  .streak::before,
  .badge::after,
  .progress__bar::after { animation: none !important; }
}