:root {
  --bg: #FAFAF7;
  --surface: #FFFFFF;
  --surface-dim: #F4F3EF;
  --border: #E8E6E1;
  --border-light: #F0EEEA;
  --ink: #1C1917;
  --ink-secondary: #57534E;
  --ink-tertiary: #A8A29E;
  --accent: #2563EB;
  --accent-light: #EFF6FF;
  --orange: #EA580C;
  --orange-light: #FFF7ED;
  --teal: #0D9488;
  --teal-light: #F0FDFA;
  --rose: #E11D48;
  --rose-light: #FFF1F2;
  --indigo: #4338CA;
  --indigo-light: #EEF2FF;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow-sm: 0 1px 3px rgba(28,25,23,0.04), 0 1px 2px rgba(28,25,23,0.03);
  --shadow: 0 4px 16px rgba(28,25,23,0.05), 0 1px 3px rgba(28,25,23,0.04);
  --shadow-lg: 0 12px 40px rgba(28,25,23,0.08), 0 4px 12px rgba(28,25,23,0.04);
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'DM Sans', sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* ── Header ── */
.site-header {
  position: sticky; top: 0; z-index: 200;
  background: rgba(250,250,247,0.92);
  backdrop-filter: blur(20px) saturate(1.2);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  max-width: 840px;
  margin: 0 auto;
  display: flex; align-items: center;
  height: 52px; padding: 0 24px; gap: 16px;
}
.header-home {
  font-family: 'DM Serif Display', serif;
  font-size: 1.05rem;
  color: var(--ink);
  cursor: pointer;
  letter-spacing: -0.01em;
  flex-shrink: 0;
  transition: opacity 0.2s;
}
.header-home:hover { opacity: 0.6; }
.breadcrumbs {
  display: flex; align-items: center; gap: 4px;
  font-size: 0.82rem; font-weight: 500;
  color: var(--ink-tertiary);
  overflow-x: auto; scrollbar-width: none;
}
.breadcrumbs::-webkit-scrollbar { display: none; }
.crumb {
  cursor: pointer; padding: 3px 8px;
  border-radius: 6px; white-space: nowrap;
  transition: all 0.2s;
}
.crumb:hover { background: var(--surface-dim); color: var(--ink-secondary); }
.crumb.current { color: var(--ink); font-weight: 600; }
.crumb-sep { color: var(--border); font-size: 0.75rem; }

/* ── Pages ── */
.page {
  display: none;
  max-width: 840px;
  margin: 0 auto;
  padding: 36px 24px 100px;
  animation: fadeIn 0.35s var(--ease);
}
.page.active { display: block; }
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ── Page hero ── */
.page-hero {
  margin-bottom: 40px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--border-light);
}
.page-hero h1 {
  font-family: 'DM Serif Display', serif;
  font-size: clamp(1.8rem, 4.5vw, 2.6rem);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}
.page-hero .tagline {
  font-size: 1.05rem;
  color: var(--ink-secondary);
  font-weight: 400;
}

/* ── Subject grid ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
}
.subject-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  cursor: pointer;
  transition: all 0.25s var(--ease);
  position: relative; overflow: hidden;
}
.subject-card:hover:not(.locked) {
  box-shadow: var(--shadow-lg);
  border-color: transparent;
  transform: translateY(-2px);
}
.subject-card.locked {
  opacity: 0.45;
  cursor: default;
}
.subject-card .card-emoji {
  font-size: 2rem;
  display: block;
  margin-bottom: 12px;
  transition: transform 0.3s var(--ease);
}
.subject-card:hover:not(.locked) .card-emoji { transform: scale(1.1); }
.subject-card .card-title {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 2px;
  letter-spacing: -0.01em;
}
.subject-card .card-desc {
  font-size: 0.8rem;
  color: var(--ink-tertiary);
  font-weight: 500;
}
.coming-badge {
  position: absolute;
  top: 10px; right: -30px;
  background: var(--ink);
  color: var(--bg);
  font-size: 0.6rem;
  font-weight: 700;
  padding: 2px 36px;
  transform: rotate(35deg);
  letter-spacing: 0.08em;
}

/* special adventures card */
.card-adventures {
  background: linear-gradient(145deg, #1C1917, #292524);
  border-color: #292524;
  color: #FAFAF7;
}
.card-adventures .card-title { color: #FAFAF7; }
.card-adventures .card-desc { color: #A8A29E; }
.card-adventures:hover {
  border-color: transparent;
  box-shadow: 0 12px 40px rgba(28,25,23,0.25);
}

/* ── Module nav ── */
.module-nav {
  display: flex; gap: 4px;
  margin-bottom: 32px;
  overflow-x: auto; scrollbar-width: none;
  padding: 4px;
  background: var(--surface-dim);
  border-radius: 12px;
  border: 1px solid var(--border-light);
}
.module-nav::-webkit-scrollbar { display: none; }
.module-nav { scroll-margin-top: 60px; }
.mod-btn {
  font-family: 'DM Sans', sans-serif;
  font-size: 0.82rem; font-weight: 600;
  padding: 8px 16px;
  border: none;
  border-radius: 9px;
  background: transparent;
  color: var(--ink-tertiary);
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s var(--ease);
}
.mod-btn:hover { color: var(--ink-secondary); }
.mod-btn.active {
  background: var(--surface);
  color: var(--ink);
  box-shadow: var(--shadow-sm);
}

.mod-section { display: none; animation: fadeIn 0.35s var(--ease); }
.mod-section.active { display: block; }
.frac-section { display: none; animation: fadeIn 0.35s var(--ease); }
.frac-section.active { display: block; }
.dec-section { display: none; animation: fadeIn 0.35s var(--ease); }
.dec-section.active { display: block; }
.mul-section { display: none; animation: fadeIn 0.35s var(--ease); }
.mul-section.active { display: block; }
.geo-section { display: none; animation: fadeIn 0.35s var(--ease); }
.geo-section.active { display: block; }
.rat-section { display: none; animation: fadeIn 0.35s var(--ease); }
.rat-section.active { display: block; }
.mau-section { display: none; animation: fadeIn 0.35s var(--ease); }
.mau-section.active { display: block; }
.gup-section { display: none; animation: fadeIn 0.35s var(--ease); }
.gup-section.active { display: block; }
.ind-section { display: none; animation: fadeIn 0.35s var(--ease); }
.ind-section.active { display: block; }
.ved-section { display: none; animation: fadeIn 0.35s var(--ease); }
.ved-section.active { display: block; }
.gre-section { display: none; animation: fadeIn 0.35s var(--ease); }
.gre-section.active { display: block; }
.rom-section { display: none; animation: fadeIn 0.35s var(--ease); }
.rom-section.active { display: block; }
.egy-section { display: none; animation: fadeIn 0.35s var(--ease); }
.egy-section.active { display: block; }
.per-section { display: none; animation: fadeIn 0.35s var(--ease); }
.per-section.active { display: block; }
.mes-section { display: none; animation: fadeIn 0.35s var(--ease); }
.mes-section.active { display: block; }
.chi-section { display: none; animation: fadeIn 0.35s var(--ease); }
.chi-section.active { display: block; }
.hin-section { display: none; animation: fadeIn 0.35s var(--ease); }
.hin-section.active { display: block; }
.bud-section { display: none; animation: fadeIn 0.35s var(--ease); }
.bud-section.active { display: block; }
.jai-section { display: none; animation: fadeIn 0.35s var(--ease); }
.jai-section.active { display: block; }
.sik-section { display: none; animation: fadeIn 0.35s var(--ease); }
.sik-section.active { display: block; }
.jud-section { display: none; animation: fadeIn 0.35s var(--ease); }
.jud-section.active { display: block; }
.chr-section { display: none; animation: fadeIn 0.35s var(--ease); }
.chr-section.active { display: block; }
.isl-section { display: none; animation: fadeIn 0.35s var(--ease); }
.isl-section.active { display: block; }
.zor-section { display: none; animation: fadeIn 0.35s var(--ease); }
.zor-section.active { display: block; }
.tao-section { display: none; animation: fadeIn 0.35s var(--ease); }
.tao-section.active { display: block; }
.shi-section { display: none; animation: fadeIn 0.35s var(--ease); }
.shi-section.active { display: block; }
.idg-section { display: none; animation: fadeIn 0.35s var(--ease); }
.idg-section.active { display: block; }
.g4b-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4b-section.active { display: block; }
.g4i-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4i-section.active { display: block; }
.g4q-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4q-section.active { display: block; }
.g4h-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4h-section.active { display: block; }
.g4en-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4en-section.active { display: block; }
.g4lt-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4lt-section.active { display: block; }
.g4es-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4es-section.active { display: block; }
.g4pa-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4pa-section.active { display: block; }
.g4fm-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4fm-section.active { display: block; }
.g4wc-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4wc-section.active { display: block; }
.g4ht-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4ht-section.active { display: block; }
.g4ed-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4ed-section.active { display: block; }
.g4w-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4w-section.active { display: block; }
.g4k-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4k-section.active { display: block; }
.g4gr-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4gr-section.active { display: block; }
.g4t-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4t-section.active { display: block; }
.g4f-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4f-section.active { display: block; }
.g4np-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4np-section.active { display: block; }
.g4da-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4da-section.active { display: block; }
.g4sy-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4sy-section.active { display: block; }
.g4ms-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4ms-section.active { display: block; }
.svg-illustration { display: flex; justify-content: center; margin: 20px 0; overflow: hidden; }
.svg-illustration svg { filter: drop-shadow(0 2px 8px rgba(0,0,0,0.08)); max-width: 100%; height: auto; }
.timeline-item { display: flex; gap: 16px; position: relative; padding-bottom: 24px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot { width: 14px; height: 14px; border-radius: 50%; flex-shrink: 0; margin-top: 4px; position: relative; z-index: 1; }
.timeline-line { position: absolute; left: 6px; top: 18px; bottom: 0; width: 2px; background: var(--border); }
.timeline-item:last-child .timeline-line { display: none; }
.timeline-date { font-family: 'Caveat', cursive; font-size: 1.15rem; font-weight: 700; color: var(--accent); min-width: 80px; }
.timeline-text { font-size: 0.9rem; color: var(--ink-secondary); line-height: 1.5; }
.ruler-card { background: var(--surface-dim); border-radius: var(--radius-sm); padding: 16px; display: flex; gap: 14px; align-items: flex-start; }
.ruler-emoji { font-size: 2rem; flex-shrink: 0; }
.ruler-name { font-weight: 700; font-size: 0.95rem; }
.ruler-years { font-size: 0.8rem; color: var(--ink-tertiary); margin-top: 2px; }
.ruler-desc { font-size: 0.84rem; color: var(--ink-secondary); margin-top: 6px; line-height: 1.5; }

/* ── Content cards ── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 16px;
  transition: box-shadow 0.3s var(--ease);
}
.card:hover { box-shadow: var(--shadow); }
.card p { font-size: 1rem; margin-bottom: 10px; color: var(--ink-secondary); }
.card p:last-child { margin-bottom: 0; }
.card strong { color: var(--ink); }
.card h2 {
  font-family: 'DM Serif Display', serif;
  font-size: 1.25rem;
  font-weight: 400;
  margin-bottom: 14px;
  color: var(--ink);
  letter-spacing: -0.01em;
  display: flex; align-items: center; gap: 10px;
}

.stripe-left { border-left: 3px solid var(--accent); }
.stripe-left.orange { border-left-color: var(--orange); }
.stripe-left.teal { border-left-color: var(--teal); }
.stripe-left.rose { border-left-color: var(--rose); }

/* ── Callouts ── */
.callout {
  border-radius: var(--radius-sm);
  padding: 18px 20px;
  margin: 16px 0;
  font-weight: 500;
  font-size: 0.95rem;
  line-height: 1.65;
  overflow-wrap: break-word;
  word-wrap: break-word;
}
.callout.blue { background: var(--accent-light); color: #1E40AF; border: 1px solid #DBEAFE; }
.callout.orange { background: var(--orange-light); color: #9A3412; border: 1px solid #FED7AA; }
.callout.teal { background: var(--teal-light); color: #115E59; border: 1px solid #99F6E4; }
.callout.rose { background: var(--rose-light); color: #9F1239; border: 1px solid #FECDD3; }
.callout .big {
  font-family: 'Caveat', cursive;
  font-size: 1.7rem; display: block; margin: 6px 0 2px;
  color: inherit;
}

/* ── Tanks ── */
.tank-row {
  display: flex; align-items: flex-end;
  justify-content: center; gap: 36px;
  margin: 24px 0; flex-wrap: wrap;
}
.tank { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.tank-body {
  width: 72px;
  border: 2.5px solid var(--ink);
  border-radius: 0 0 12px 12px;
  border-top: none;
  position: relative; overflow: hidden;
  background: var(--surface-dim);
}
.tank-body::before {
  content: ''; position: absolute; top: 0; left: 0;
  width: 100%; height: 3px; background: var(--ink);
}
.tank-water {
  position: absolute; bottom: 0; left: 0; width: 100%;
  transition: height 0.6s var(--ease);
  border-radius: 0 0 9px 9px;
}
.tank-label {
  font-weight: 600; font-size: 0.82rem;
  text-align: center; color: var(--ink-secondary);
}
.tank-pct {
  font-family: 'Caveat', cursive;
  font-size: 1.5rem; font-weight: 700; color: var(--accent);
}

/* ── Stretch bars ── */
.stretch-bar-outer {
  height: 44px;
  background: var(--surface-dim);
  border-radius: var(--radius-sm);
  overflow: hidden; margin: 8px 0;
  border: 1px solid var(--border);
}
.stretch-bar-fill {
  height: 100%; border-radius: 9px;
  transition: width 0.5s var(--ease), background 0.3s;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; color: #fff; font-size: 0.9rem;
  min-width: 40px;
}
.stretch-ticks {
  display: flex; justify-content: space-between;
  padding: 0 2px; font-size: 0.7rem;
  color: var(--ink-tertiary); font-weight: 600;
}

/* ── Controls ── */
.control-row {
  display: flex; align-items: center; gap: 12px;
  margin: 12px 0; flex-wrap: wrap;
}
.control-row label {
  font-weight: 600; font-size: 0.9rem;
  min-width: 100px; color: var(--ink-secondary);
}
input[type="range"] {
  flex: 1; min-width: 140px; height: 6px;
  -webkit-appearance: none; appearance: none;
  border-radius: 6px; outline: none;
  background: var(--border);
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--surface);
  cursor: pointer;
  box-shadow: 0 1px 4px rgba(0,0,0,0.15), 0 0 0 2px var(--accent);
  border: none;
}
.control-val {
  font-weight: 700; font-size: 1.15rem;
  min-width: 36px; text-align: right;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

/* ── Comparisons ── */
.compare-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 12px; margin: 16px 0;
}
@media (max-width: 500px) { .compare-grid { grid-template-columns: 1fr; } }
.compare-box {
  background: var(--surface-dim); border-radius: var(--radius-sm);
  padding: 20px; text-align: center;
  border: 1px solid var(--border-light);
}
.compare-box.hl { border-color: var(--accent); background: var(--accent-light); }
.compare-box .emoji-grid { font-size: 1.5rem; line-height: 1.8; margin: 8px 0; min-height: 40px; }
.compare-box .compare-title { font-weight: 700; font-size: 0.9rem; margin-bottom: 4px; }
.compare-box .compare-pct {
  font-family: 'Caveat', cursive;
  font-size: 1.8rem; font-weight: 700; color: var(--accent);
}

/* ── Quiz ── */
.quiz-q {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px; margin-bottom: 12px;
  transition: all 0.3s var(--ease);
}
.quiz-q.correct { border-color: var(--teal); background: var(--teal-light); }
.quiz-q.wrong { border-color: var(--rose); background: var(--rose-light); }
.quiz-q h3 {
  font-size: 0.95rem; font-weight: 700;
  margin-bottom: 12px; color: var(--ink);
}
.q-options { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
@media (max-width: 500px) { .q-options { grid-template-columns: 1fr; } }
.q-opt {
  font-family: 'DM Sans', sans-serif;
  font-size: 0.88rem; font-weight: 600;
  padding: 10px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  cursor: pointer; transition: all 0.15s var(--ease);
  color: var(--ink-secondary); text-align: left;
}
.q-opt:hover:not(:disabled) {
  border-color: var(--accent); color: var(--accent);
  transform: translateY(-1px); box-shadow: var(--shadow-sm);
}
.q-opt.right { border-color: var(--teal); background: var(--teal-light); color: #115E59; }
.q-opt.nope { border-color: var(--rose); background: var(--rose-light); color: #9F1239; }
.q-opt.show-right { border-color: var(--teal); background: var(--teal-light); }
.q-opt:disabled { cursor: default; }
.q-fb {
  margin-top: 10px; padding: 12px 14px;
  border-radius: var(--radius-sm);
  font-weight: 600; font-size: 0.88rem; display: none;
}
.q-fb.show { display: block; }
.q-fb.ok { background: var(--teal-light); color: #115E59; border: 1px solid #99F6E4; }
.q-fb.no { background: var(--orange-light); color: #9A3412; border: 1px solid #FED7AA; }
.score-pill {
  text-align: center; font-size: 1rem; font-weight: 700;
  padding: 12px;
  border-radius: var(--radius-sm);
  background: var(--surface-dim);
  border: 1px solid var(--border);
  margin-bottom: 20px;
  color: var(--ink-secondary);
}

/* ── Next btn ── */
.next-btn {
  display: inline-flex; align-items: center; gap: 6px;
  margin: 28px auto 0;
  font-family: 'DM Sans', sans-serif;
  font-size: 0.92rem; font-weight: 700;
  padding: 12px 28px; border: none;
  border-radius: 99px; color: #fff;
  cursor: pointer;
  transition: all 0.2s var(--ease);
  text-align: center;
}
.next-btn:hover { transform: translateY(-1px); box-shadow: var(--shadow-lg); }
.next-btn.blue { background: var(--accent); }
.next-btn.orange { background: var(--orange); }
.next-btn.teal { background: var(--teal); }
.next-btn.rose { background: var(--rose); }

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

/* ── Footer ── */
.site-footer {
  text-align: center; padding: 24px; font-size: 0.78rem;
  color: var(--ink-tertiary); font-weight: 500;
  position: relative; z-index: 1;
}

/* ── Science section visibility ── */
.frc-section { display: none; animation: fadeIn 0.35s var(--ease); }
.frc-section.active { display: block; }
.lts-section { display: none; animation: fadeIn 0.35s var(--ease); }
.lts-section.active { display: block; }
.elc-section { display: none; animation: fadeIn 0.35s var(--ease); }
.elc-section.active { display: block; }
.smm-section { display: none; animation: fadeIn 0.35s var(--ease); }
.smm-section.active { display: block; }
.stm-section { display: none; animation: fadeIn 0.35s var(--ease); }
.stm-section.active { display: block; }
.atm-section { display: none; animation: fadeIn 0.35s var(--ease); }
.atm-section.active { display: block; }
.mix-section { display: none; animation: fadeIn 0.35s var(--ease); }
.mix-section.active { display: block; }
.rxn-section { display: none; animation: fadeIn 0.35s var(--ease); }
.rxn-section.active { display: block; }
.cel-section { display: none; animation: fadeIn 0.35s var(--ease); }
.cel-section.active { display: block; }
.bod-section { display: none; animation: fadeIn 0.35s var(--ease); }
.bod-section.active { display: block; }
.eco-section { display: none; animation: fadeIn 0.35s var(--ease); }
.eco-section.active { display: block; }
.cls-section { display: none; animation: fadeIn 0.35s var(--ease); }
.cls-section.active { display: block; }
.div-section { display: none; animation: fadeIn 0.35s var(--ease); }
.div-section.active { display: block; }
.dat-section { display: none; animation: fadeIn 0.35s var(--ease); }
.dat-section.active { display: block; }
.pvl-section { display: none; animation: fadeIn 0.35s var(--ease); }
.pvl-section.active { display: block; }
.msr-section { display: none; animation: fadeIn 0.35s var(--ease); }
.msr-section.active { display: block; }
.pos-section { display: none; animation: fadeIn 0.35s var(--ease); }
.pos-section.active { display: block; }
.ads-section { display: none; animation: fadeIn 0.35s var(--ease); }
.ads-section.active { display: block; }
.es-section { display: none; animation: fadeIn 0.35s var(--ease); }
.es-section.active { display: block; }
.lcy-section { display: none; animation: fadeIn 0.35s var(--ease); }
.lcy-section.active { display: block; }
.nrg-section { display: none; animation: fadeIn 0.35s var(--ease); }
.nrg-section.active { display: block; }
.prp-section { display: none; animation: fadeIn 0.35s var(--ease); }
.prp-section.active { display: block; }
.hgd-section { display: none; animation: fadeIn 0.35s var(--ease); }
.hgd-section.active { display: block; }


.content-section { display: none; animation: fadeIn 0.35s var(--ease); }
.content-section.active { display: block; }
.g1a-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1a-section.active { display: block; }
.g1c-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1c-section.active { display: block; }
.g1e-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1e-section.active { display: block; }
.g1h-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1h-section.active { display: block; }
.g1n-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1n-section.active { display: block; }
.g1p-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1p-section.active { display: block; }
.g1r-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1r-section.active { display: block; }
.g1s-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1s-section.active { display: block; }
.g1t-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1t-section.active { display: block; }
.g1v-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1v-section.active { display: block; }
.g1w-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1w-section.active { display: block; }
.g1x-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1x-section.active { display: block; }
.g1d-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1d-section.active { display: block; }
.g1f-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1f-section.active { display: block; }
.g1k-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1k-section.active { display: block; }
.g1q-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1q-section.active { display: block; }
.g1y-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1y-section.active { display: block; }
.g1z-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g1z-section.active { display: block; }
.g2c-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2c-section.active { display: block; }
.g2f-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2f-section.active { display: block; }
.g2h-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2h-section.active { display: block; }
.g2k-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2k-section.active { display: block; }
.g2l-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2l-section.active { display: block; }
.g2m-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2m-section.active { display: block; }
.g2p-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2p-section.active { display: block; }
.g2r-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2r-section.active { display: block; }
.g2s-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2s-section.active { display: block; }
.g2t-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2t-section.active { display: block; }
.g2u-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2u-section.active { display: block; }
.g2x-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2x-section.active { display: block; }
.g2a-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2a-section.active { display: block; }
.g2me-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2me-section.active { display: block; }
.g2sh-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2sh-section.active { display: block; }
.g2st-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2st-section.active { display: block; }
.g2pl-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2pl-section.active { display: block; }
.g2an-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2an-section.active { display: block; }
.g2gr-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g2gr-section.active { display: block; }
.g5a-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g5a-section.active { display: block; }
.g5g-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g5g-section.active { display: block; }
.g5v-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g5v-section.active { display: block; }
.g5w-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g5w-section.active { display: block; }
.g5sp-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g5sp-section.active { display: block; }
.g5nf-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g5nf-section.active { display: block; }
.g5po-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g5po-section.active { display: block; }
.g6a-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6a-section.active { display: block; }
.g6r-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6r-section.active { display: block; }
.g6st-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6st-section.active { display: block; }
.g6p-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6p-section.active { display: block; }
.g6pl-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6pl-section.active { display: block; }
.g6pe-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6pe-section.active { display: block; }
.g6pf-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6pf-section.active { display: block; }
.g6ws-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6ws-section.active { display: block; }
.g6cp-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6cp-section.active { display: block; }
.g6ca-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6ca-section.active { display: block; }
.g6cc-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6cc-section.active { display: block; }
.g6cm-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6cm-section.active { display: block; }
.g6be-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6be-section.active { display: block; }
.g6bb-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6bb-section.active { display: block; }
.g6br-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6br-section.active { display: block; }
.g6bc-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6bc-section.active { display: block; }
.g6lt-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6lt-section.active { display: block; }
.g6pw-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6pw-section.active { display: block; }
.g6rs-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6rs-section.active { display: block; }
.g6ag-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6ag-section.active { display: block; }
.g6fdp-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6fdp-section.active { display: block; }
.g6geo-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6geo-section.active { display: block; }
.g6num-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6num-section.active { display: block; }
.g6meas-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6meas-section.active { display: block; }
.g6es-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6es-section.active { display: block; }
.g6sp-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6sp-section.active { display: block; }
.g6vc-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6vc-section.active { display: block; }
.g6rc-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6rc-section.active { display: block; }
.g6wr-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6wr-section.active { display: block; }
.g6po-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6po-section.active { display: block; }
.g6nf-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6nf-section.active { display: block; }
.g6esys-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6esys-section.active { display: block; }
.g6cl-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6cl-section.active { display: block; }
.g6mx-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6mx-section.active { display: block; }
.g6sc-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6sc-section.active { display: block; }
.g6fmp-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g6fmp-section.active { display: block; }
/* ── Confetti ── */
#confetti { position: fixed; inset: 0; pointer-events: none; z-index: 9999; }

@media (max-width: 600px) {
  .card { padding: 20px; }
  .card-grid { grid-template-columns: 1fr 1fr; gap: 8px; }
  .subject-card { padding: 18px 14px; }
  .subject-card .card-emoji { font-size: 1.7rem; }
  .page { padding: 24px 16px 80px; }
  .header-inner { padding: 0 16px; }
}

/* ════════════════════════════════════════════════════════════ */
/* Grade 4 Module Section Visibility Classes */
/* ════════════════════════════════════════════════════════════ */

/* Maths Modules */
.g4n-section { display: none; }
.g4n-section.active { display: block; }

.g4d-section { display: none; }
.g4d-section.active { display: block; }

.g4r-section { display: none; }
.g4r-section.active { display: block; }

.g4g-section { display: none; }
.g4g-section.active { display: block; }

.g4as-section { display: none; }
.g4as-section.active { display: block; }

.g4md-section { display: none; }
.g4md-section.active { display: block; }

.g4sh-section { display: none; }
.g4sh-section.active { display: block; }

.g4co-section { display: none; }
.g4co-section.active { display: block; }

.g4wp-section { display: none; }
.g4wp-section.active { display: block; }

/* Science Modules */
.g4o-section { display: none; }
.g4o-section.active { display: block; }

.g4b-section { display: none; }
.g4b-section.active { display: block; }

.g4i-section { display: none; }
.g4i-section.active { display: block; }

.g4q-section { display: none; }
.g4q-section.active { display: block; }

/* English Modules */
.g4y-section { display: none; }
.g4y-section.active { display: block; }

.g4j-section { display: none; }
.g4j-section.active { display: block; }

.g4k-section { display: none; }
.g4k-section.active { display: block; }

.g4z-section { display: none; }
.g4z-section.active { display: block; }

.g4u-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4u-section.active { display: block; }

.g4v-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4v-section.active { display: block; }

.g4c-section { display: none; animation: fadeIn 0.35s var(--ease); }
.g4c-section.active { display: block; }

/* quiz-section is a visual wrapper only; visibility is controlled by the parent section class */

/* ── Nav Pills (grade quiz navigation) ── */
.nav-pill {
  display: inline-block;
  font-family: 'DM Sans', sans-serif;
  font-size: 0.82rem; font-weight: 600;
  padding: 8px 16px;
  border: none;
  border-radius: 9px;
  background: transparent;
  color: var(--ink-tertiary);
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s var(--ease);
}
.nav-pill:hover { color: var(--ink-secondary); background: var(--surface); }
.nav-pill.active {
  background: var(--surface);
  color: var(--ink);
  box-shadow: var(--shadow-sm);
}


/* ── btn-primary ── */
.btn-primary {
  font-family: 'DM Sans', sans-serif;
  font-size: 0.9rem; font-weight: 700;
  padding: 10px 24px; border: none;
  border-radius: 99px; color: #fff;
  background: var(--accent);
  cursor: pointer;
  transition: all 0.2s var(--ease);
  margin-top: 12px;
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: var(--shadow-lg); }

/* ── Next button indigo variant ── */
.next-btn.indigo { background: var(--indigo); }
.callout.indigo { background: var(--indigo-light); color: #3730A3; border: 1px solid #C7D2FE; }
.stripe-left.indigo { border-left-color: var(--indigo); }

/* ── Utility: extracted from inline styles ── */
.score-display {
  font-family: 'Caveat', cursive;
  font-size: 3.5rem;
  color: var(--accent);
  margin: 12px 0;
  line-height: 1;
}
.test-section-header {
  font-family: 'DM Serif Display', serif;
  font-size: 1.4rem;
  margin-bottom: 16px;
  color: var(--ink);
}
.subheading-accent {
  color: #E65100;
}

/* ── Graded Test Modal & Timer ── */
.frac-test-modal { position: fixed; inset: 0; background: rgba(28,25,23,0.5); display: flex; align-items: center; justify-content: center; z-index: 300; backdrop-filter: blur(4px); }
.frac-test-timer { position: fixed; top: 60px; right: 16px; z-index: 250; display: none; align-items: center; gap: 8px; background: var(--surface); border: 1px solid var(--border); border-radius: 99px; padding: 8px 16px; font-weight: 700; font-size: 0.95rem; box-shadow: var(--shadow); }
.frac-test-timer.active { display: flex; }
.frac-test-timer.warning { border-color: var(--orange); color: var(--orange); animation: pulse 1s infinite; }
.frac-test-timer.danger { border-color: var(--rose); color: var(--rose); animation: pulse 0.5s infinite; }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.6; } }

/* Test progress bar (score pill + stretch bar) — sticks just below the site
 * header while scrolling through questions, so users always see how many
 * they've answered without scrolling back up. */
.test-progress-sticky {
  position: sticky;
  top: 60px;
  z-index: 100;
  background: var(--bg);
  padding: 10px 16px;
  border-radius: 12px;
  margin-bottom: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}