/* =========================================================
   Fun & animations layer — loaded after styles.css
   ========================================================= */

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

@keyframes spin { to { transform: rotate(360deg); } }
@keyframes wiggle { 0%, 100% { transform: rotate(0); } 25% { transform: rotate(-14deg); } 75% { transform: rotate(14deg); } }
@keyframes pop { 0%, 100% { transform: scale(1); } 45% { transform: scale(1.3); } 70% { transform: scale(.9); } }
@keyframes swing { 0%, 100% { transform: rotate(0); } 20% { transform: rotate(18deg); } 45% { transform: rotate(-12deg); } 70% { transform: rotate(6deg); } }
@keyframes shake { 0%, 100% { transform: translateX(0); } 20%, 60% { transform: translateX(-6px); } 40%, 80% { transform: translateX(6px); } }
@keyframes blink { 50% { opacity: 0; } }

/* ---------- Pencil scroll progress ---------- */
.pencil-progress { position: absolute; left: 0; right: 0; bottom: -2px; height: 3px; pointer-events: none; }
.pp-line {
  height: 100%; transform-origin: left; transform: scaleX(0);
  background: linear-gradient(90deg, #f472b6, var(--accent), var(--primary));
}
.pp-pencil {
  position: absolute; top: 50%; left: 0; width: 34px; height: 10px; margin-top: -5px;
  opacity: 0; transition: opacity .3s; filter: drop-shadow(0 2px 3px rgba(15, 23, 42, .25));
}

/* ---------- Logo cap toss ---------- */
.logo:hover .logo-mark i { animation: capToss .8s ease; }
@keyframes capToss {
  0%, 100% { transform: translateY(0) rotate(0); }
  40% { transform: translateY(-9px) rotate(-25deg); }
  70% { transform: translateY(1px) rotate(8deg); }
}

/* ---------- Hero ---------- */
.hero { isolation: isolate; }
.badge i { animation: twinkle 2.4s ease-in-out infinite; }
@keyframes twinkle { 0%, 100% { transform: scale(1) rotate(0); } 50% { transform: scale(1.35) rotate(72deg); } }

.hero-actions .btn-primary { position: relative; overflow: hidden; }
.hero-actions .btn-primary::after {
  content: ""; position: absolute; top: 0; left: 0; width: 40%; height: 100%; pointer-events: none;
  background: linear-gradient(100deg, transparent, rgba(255, 255, 255, .45), transparent);
  transform: skewX(-20deg) translateX(-150%); animation: shine 4.5s ease-in-out infinite;
}
@keyframes shine { 0%, 55% { transform: skewX(-20deg) translateX(-150%); } 100% { transform: skewX(-20deg) translateX(300%); } }

/* Typewriter line */
.typer { font: 700 clamp(1.6rem, 3vw, 2.1rem)/1.3 "Caveat", cursive; color: var(--ink); margin: -4px 0 14px; min-height: 1.3em; }
.typer-word { color: #db2777; background: linear-gradient(transparent 62%, rgba(251, 191, 36, .45) 62%); padding: 0 4px; }
.typer-caret {
  display: inline-block; width: 3px; height: .95em; margin-left: 2px; vertical-align: -.1em;
  background: var(--primary); border-radius: 2px; animation: blink 1s steps(1) infinite;
}

/* Subject chips under the hero buttons */
.subject-chips { display: flex; flex-wrap: wrap; gap: 10px; }
.chip {
  display: inline-flex; align-items: center; gap: 8px; padding: 8px 16px; border-radius: 999px; cursor: pointer;
  border: 1px solid rgba(15, 23, 42, .06); font: 600 14px "Poppins", sans-serif;
  transition: transform .2s, box-shadow .2s;
}
.chip:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.chip:hover i { animation: pop .5s ease; }
.chip:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }

/* Floating doodles */
.hero-doodles { position: absolute; inset: 0; z-index: -1; pointer-events: none; color: var(--primary); }
.doodle, .formula {
  position: absolute; left: var(--x); top: var(--y);
  transform: translate3d(calc(var(--mx, 0) * var(--d) * -1px), calc(var(--my, 0) * var(--d) * -1px), 0);
  transition: transform .5s ease-out;
}
.doodle { width: var(--s); height: var(--s); }
.doodle svg {
  width: 100%; height: 100%; overflow: visible; opacity: .22;
  fill: none; stroke: currentColor; stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round;
  transform: rotate(var(--r)); animation: doodleFloat 7s ease-in-out var(--delay) infinite;
}
.doodle .fill { fill: currentColor; stroke: none; }
.doodle svg.spin-slow { animation: doodleFloat 7s ease-in-out var(--delay) infinite, spin 26s linear infinite; }
.doodle svg.glow { color: var(--accent); opacity: .35; animation: doodleFloat 7s ease-in-out var(--delay) infinite, glow 3s ease-in-out infinite; }
.doodle .needle { transform-box: view-box; transform-origin: 32px 46px; animation: needle 5s ease-in-out infinite; }
@keyframes doodleFloat { 0%, 100% { translate: 0 0; } 50% { translate: 0 -14px; } }
@keyframes glow { 0%, 100% { opacity: .25; } 50% { opacity: .6; } }
@keyframes needle { 0%, 100% { transform: rotate(0); } 50% { transform: rotate(-100deg); } }
.formula {
  font: 700 26px "Caveat", cursive; color: var(--primary); opacity: .28; white-space: nowrap;
  animation: formulaFloat 8s ease-in-out var(--delay) infinite;
}
@keyframes formulaFloat { 0%, 100% { translate: 0 0; rotate: -4deg; } 50% { translate: 0 -12px; rotate: 4deg; } }

/* Compass that draws a circle — arm and circle share one 6s timeline */
.doodle-compass svg { opacity: .4; stroke-width: 2.6; }
.cmp-guide { stroke-dasharray: 1 6; opacity: .45; }
.cmp-circle { stroke: #db2777; stroke-dasharray: 100; stroke-dashoffset: 100; animation: cmpDraw 6s linear infinite; }
.cmp-arm { transform-box: view-box; transform-origin: 0 0; animation: cmpSpin 6s linear infinite; }
@keyframes cmpSpin { 0% { transform: rotate(0deg); } 75%, 100% { transform: rotate(360deg); } }
@keyframes cmpDraw {
  0% { stroke-dashoffset: 100; opacity: 1; }
  75% { stroke-dashoffset: 0; opacity: 1; }
  90% { stroke-dashoffset: 0; opacity: 1; }
  100% { stroke-dashoffset: 0; opacity: 0; }
}

/* Orbiting subject icons */
.main-card { position: relative; z-index: 1; }
.float-card { z-index: 2; }
.fc-2 { top: 20%; } /* keep it clear of the card heading */
.orbit {
  --size: min(440px, 88vw);
  position: absolute; top: 50%; left: 50%; width: var(--size); height: var(--size);
  margin: calc(var(--size) / -2) 0 0 calc(var(--size) / -2);
  border: 2px dashed rgba(79, 70, 229, .22); border-radius: 50%;
  animation: spin 44s linear infinite; pointer-events: none; rotate: var(--boost, 0deg);
}
.orbit-item {
  position: absolute; top: 50%; left: 50%; width: 46px; height: 46px; margin: -23px 0 0 -23px;
  transform: rotate(var(--a)) translate(calc(var(--size) / 2)) rotate(calc(var(--a) * -1));
}
.oi {
  width: 100%; height: 100%; border-radius: 50%; display: grid; place-items: center; font-size: 18px;
  border: 3px solid #fff; box-shadow: var(--shadow); animation: spin 44s linear infinite reverse;
  rotate: calc(var(--boost, 0deg) * -1);
}

/* Click anywhere in the hero → maths symbols burst */
.fx-layer { position: fixed; inset: 0; z-index: 90; pointer-events: none; overflow: hidden; }
.fx-particle {
  position: absolute; left: 0; top: 0; font: 700 24px "Caveat", "Poppins", sans-serif;
  user-select: none; will-change: transform, opacity;
}

/* ---------- Section title squiggle ---------- */
.section-title::after {
  content: ""; display: block; width: 110px; height: 12px; margin-top: 10px;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 120 12'%3E%3Cpath d='M2 7q8-6 16 0t16 0 16 0 16 0 16 0 16 0 16 0' fill='none' stroke='%23f59e0b' stroke-width='3' stroke-linecap='round'/%3E%3C/svg%3E") no-repeat center / 100% 100%;
  transform-origin: left; transition: transform .9s .3s cubic-bezier(.65, 0, .35, 1);
}
.section-head .section-title::after { margin-inline: auto; transform-origin: center; }
.reveal .section-title::after { transform: scaleX(0); }
.reveal.visible .section-title::after { transform: scaleX(1); }

/* ---------- Course & why-us icon tricks ---------- */
.course-card p { margin-bottom: 14px; }
.topic-tags { display: flex; flex-wrap: wrap; gap: 6px; list-style: none; margin-bottom: 18px; }
.topic-tags li {
  padding: 3px 10px; border-radius: 999px; border: 1px solid var(--border);
  background: var(--bg-alt); color: var(--muted); font-size: 12px; font-weight: 600;
}
.cc-icon { position: relative; }
.cc-icon i { display: inline-block; }
.course-card:hover .c1 i { animation: wiggle .6s ease-in-out; }
.course-card:hover .c2 i { animation: pop .5s ease; }
.course-card:hover .c3 i { animation: wiggle .5s ease-in-out 2; }
.course-card:hover .c4 i { animation: flip 1s ease; } /* DNA twists */
.course-card:hover .c5 i { animation: spin 1.4s linear infinite; } /* atom spins */
.course-card:hover .c6 i { animation: pop .5s ease 2; }
.cc-icon.c3::before, .cc-icon.c3::after {
  content: ""; position: absolute; left: 44%; top: 26%; width: 6px; height: 6px;
  border-radius: 50%; background: #16a34a; opacity: 0;
}
.course-card:hover .cc-icon.c3::before { animation: bubble 1s ease-out infinite; }
.course-card:hover .cc-icon.c3::after { left: 56%; animation: bubble 1s ease-out .5s infinite; }
@keyframes bubble { 0% { opacity: .8; transform: translateY(0) scale(.5); } 100% { opacity: 0; transform: translateY(-28px) scale(1.2); } }

.why i { transition: transform .2s; }
.why:hover i { animation: flip .8s ease; }
@keyframes flip { from { transform: perspective(300px) rotateY(0); } to { transform: perspective(300px) rotateY(360deg); } }

/* ---------- Fun Zone ---------- */
.fun-zone { padding-bottom: 0; }
.fun-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.board {
  position: relative; display: flex; flex-direction: column; min-height: 440px;
  padding: 22px 24px 40px; border: 12px solid #9a6235; border-radius: 18px; color: #f1f5f9;
  background:
    radial-gradient(circle at 18% 12%, rgba(255, 255, 255, .07), transparent 40%),
    radial-gradient(circle at 85% 85%, rgba(255, 255, 255, .05), transparent 45%),
    #1f4037;
  box-shadow: inset 0 0 40px rgba(0, 0, 0, .35), 0 0 0 2px #6f421e, 0 18px 40px rgba(15, 23, 42, .18);
}
.board-head { display: flex; align-items: center; justify-content: space-between; gap: 10px; flex-wrap: wrap; }
.chalk-title { font: 700 30px "Caveat", cursive; color: #fff; text-shadow: 0 0 1px rgba(255, 255, 255, .6); }
.board-hint { display: inline-flex; align-items: center; gap: 6px; font-size: 13px; color: #a7f3d0; }
.board-hint i { animation: tap 1.6s ease-in-out infinite; }
@keyframes tap { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-4px); } }
.chalk-tray {
  position: absolute; left: 10%; right: 10%; bottom: -12px; height: 10px; padding-left: 18px;
  display: flex; align-items: flex-end; gap: 14px; background: #6f421e; border-radius: 4px 4px 0 0;
}
.chalk-tray span { width: 28px; height: 7px; border-radius: 3px; background: #f8fafc; transform: translateY(-6px) rotate(-3deg); }
.chalk-tray span:nth-child(2) { background: #f9a8d4; transform: translateY(-6px) rotate(4deg); }
.chalk-tray span:nth-child(3) { background: #fde68a; }

.board-subject {
  margin-left: 6px; padding: 2px 9px; border: 1px dashed rgba(167, 243, 208, .6); border-radius: 999px;
  color: #a7f3d0; font: 600 12px "Inter", sans-serif; vertical-align: middle; text-shadow: none;
}

/* Protractor */
.protractor {
  display: block; width: 100%; max-width: 420px; margin: 10px auto 0; overflow: visible;
  cursor: pointer; touch-action: pan-y; outline: none; user-select: none; -webkit-user-select: none;
}
.protractor:focus-visible { outline: 2px dashed #fde68a; outline-offset: 6px; border-radius: 8px; }
.pr-body { fill: rgba(255, 255, 255, .08); stroke: rgba(255, 255, 255, .75); stroke-width: 2; }
.pr-inner { fill: none; stroke: rgba(255, 255, 255, .25); stroke-width: 1.5; stroke-dasharray: 3 5; }
.pr-tick { stroke: rgba(255, 255, 255, .65); stroke-width: 1.2; }
.pr-tick.major { stroke: #fff; stroke-width: 2; }
.pr-label { fill: rgba(255, 255, 255, .9); font: 600 11px "Inter", sans-serif; text-anchor: middle; dominant-baseline: middle; }
.pr-wedge, .pr-square { fill: rgba(251, 191, 36, .3); stroke: #fbbf24; stroke-width: 2; }
.pr-square { opacity: 0; }
.protractor.is-right .pr-square { opacity: 1; }
.protractor.is-right .pr-wedge { opacity: 0; }
.pr-base { stroke: #fff; stroke-width: 3; stroke-linecap: round; }
.pr-arm { stroke: #f472b6; stroke-width: 3.5; stroke-linecap: round; }
.pr-knob { fill: #f472b6; stroke: #fff; stroke-width: 3; pointer-events: none; transform-box: fill-box; transform-origin: center; animation: knobPulse 1.8s ease-in-out infinite; }
.pr-knob-hit { fill: transparent; cursor: grab; }
.protractor.dragging .pr-knob-hit { cursor: grabbing; }
.protractor.dragging .pr-knob { animation: none; transform: scale(1.25); }
.pr-center { fill: #fff; }
@keyframes knobPulse { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.25); } }
.angle-readout { display: flex; align-items: baseline; justify-content: center; gap: 14px; margin-top: 4px; }
.angle-value { min-width: 2.4em; text-align: right; font: 700 48px/1 "Caveat", cursive; color: #fde68a; font-variant-numeric: tabular-nums; }
.angle-type { font: 700 28px "Caveat", cursive; color: #fff; }
.board-note { text-align: center; color: #d1fae5; font-size: 15px; min-height: 3em; margin-top: 6px; }
/* Centre the angle explorer vertically when the quiz board next to it is taller */
.board > .protractor { margin-top: auto; }
.protractor ~ .board-note { margin-bottom: auto; }

/* Quiz */
.quiz-tabs { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 12px; }
.quiz-tab {
  padding: 5px 12px; border: 1.5px solid rgba(255, 255, 255, .35); border-radius: 999px; cursor: pointer;
  background: transparent; color: #e2e8f0; font: 600 13px "Poppins", sans-serif; transition: background .2s, color .2s, border-color .2s;
}
.quiz-tab:hover { border-color: #fde68a; }
.quiz-tab[aria-pressed="true"] { background: #fde68a; border-color: #fde68a; color: #1f4037; }
.quiz-tab:focus-visible { outline: 2px solid #fde68a; outline-offset: 2px; }
.quiz-tag {
  align-self: flex-start; margin-top: 14px; padding: 3px 10px; border-radius: 999px;
  background: rgba(255, 255, 255, .1); color: #d1fae5; font: 600 12px "Inter", sans-serif;
}
.quiz-q { font: 700 27px/1.25 "Caveat", cursive; color: #fff; margin: 8px 0 16px; min-height: 2.5em; }
.quiz-opts { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.quiz-opt {
  padding: 12px 10px; border: 2px dashed rgba(255, 255, 255, .45); border-radius: 12px; cursor: pointer;
  background: rgba(255, 255, 255, .04); color: #f8fafc; font: 600 15px "Poppins", sans-serif;
  transition: background .2s, border-color .2s, transform .2s;
}
.quiz-opt:hover:not([aria-disabled="true"]) { background: rgba(255, 255, 255, .12); transform: translateY(-2px); }
.quiz-opt:focus-visible { outline: 2px solid #fde68a; outline-offset: 2px; }
.quiz-opt[aria-disabled="true"] { cursor: default; }
.quiz-opt.correct { background: rgba(74, 222, 128, .25); border: 2px solid #4ade80; animation: pop .5s ease; }
.quiz-opt.wrong { background: rgba(248, 113, 113, .16); border-color: #f87171; color: #fecaca; text-decoration: line-through; animation: shake .45s; }
.quiz-feedback { min-height: 4.2em; margin: 14px 0 10px; padding-right: 110px; font-size: 15px; color: #d1fae5; }
.quiz-feedback strong { color: #fde68a; font: 700 22px "Caveat", cursive; margin-right: 4px; }
.btn-chalk { align-self: flex-start; margin-top: auto; padding: 10px 20px; background: #fde68a; color: #1f4037; }
.btn-chalk:hover { background: #fcd34d; }
.score { display: inline-flex; align-items: center; gap: 6px; padding: 4px 12px; border-radius: 999px; background: rgba(253, 230, 138, .15); color: #fde68a; font-weight: 600; }
.score.bump { animation: pop .5s ease; }

/* Binary lights */
.binary-board { grid-column: 1 / -1; min-height: 0; }
.binary-goal { margin: 10px 0 20px; text-align: center; color: #d1fae5; font-size: 16px; }
.binary-goal b { margin-left: 6px; color: #fde68a; font: 700 34px/1 "Caveat", cursive; vertical-align: -3px; }
.bits { display: grid; grid-template-columns: repeat(8, 1fr); gap: 12px; width: 100%; max-width: 760px; margin: 0 auto; }
.bit {
  display: flex; flex-direction: column; align-items: center; gap: 4px; padding: 8px 0 4px;
  border: 0; border-radius: 14px; background: none; color: #e2e8f0; cursor: pointer; font: inherit;
}
.bit:hover .bulb { border-color: #fde68a; }
.bit:focus-visible { outline: 2px dashed #fde68a; outline-offset: 2px; }
.bulb {
  position: relative; width: 46px; height: 46px; border-radius: 50% 50% 46% 46%;
  border: 2px dashed rgba(255, 255, 255, .4); background: rgba(255, 255, 255, .06);
  transition: background .25s, box-shadow .25s, border-color .25s, transform .25s;
}
.bulb::after {
  content: ""; position: absolute; left: 50%; bottom: -9px; width: 18px; height: 8px; margin-left: -9px;
  border-radius: 0 0 5px 5px; background: rgba(255, 255, 255, .35);
}
.bit.on .bulb {
  border: 2px solid #fde68a; transform: scale(1.06);
  background: radial-gradient(circle at 40% 35%, #fffbeb, #fde68a 45%, #f59e0b);
  box-shadow: 0 0 22px 6px rgba(253, 230, 138, .55);
}
.bit-val { margin-top: 10px; color: #fff; font: 700 15px "Poppins", sans-serif; }
.bit-digit { color: #a7f3d0; font: 700 24px/1 "Caveat", cursive; }
.bit.on .bit-digit { color: #fde68a; }
.binary-readout { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: center; gap: 14px; margin-top: 18px; }
.bin-code { color: #a7f3d0; font: 700 30px/1 ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace; letter-spacing: 4px; }
.bin-eq { color: #fff; font: 700 30px/1 "Caveat", cursive; }
.bin-dec { min-width: 2ch; color: #fde68a; font: 700 50px/1 "Caveat", cursive; }
.binary-board .btn-chalk { align-self: center; margin-top: 6px; }

/* Owl mascot */
.owl { position: absolute; right: 14px; bottom: 6px; width: 108px; height: 108px; transform-origin: 50% 100%; }
.owl-body { fill: #8b5cf6; }
.owl-belly { fill: #ddd6fe; }
.owl-feather { fill: none; stroke: #a78bfa; stroke-width: 2; stroke-linecap: round; }
.owl-eye { fill: #fff; stroke: #5b21b6; stroke-width: 2.5; }
.owl-pupil { fill: #1e1b4b; }
.owl-shine { fill: #fff; }
.owl-pupil, .owl-shine { transition: transform .15s ease-out; }
.owl-beak { fill: #f59e0b; }
.owl-cap path:first-child { fill: #1e1b4b; }
.owl-tassel { fill: none; stroke: #fbbf24; stroke-width: 2.5; stroke-linecap: round; }
.owl-tassel-end { fill: #fbbf24; }
.owl-eyes { transform-box: fill-box; transform-origin: center; animation: owlBlink 5s infinite; }
@keyframes owlBlink { 0%, 93%, 100% { transform: scaleY(1); } 96% { transform: scaleY(.1); } }
.owl.happy { animation: owlHop .55s ease 2; }
.owl.sad { animation: owlTilt .8s ease; }
@keyframes owlHop { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-16px) rotate(-6deg); } }
@keyframes owlTilt { 0%, 100% { transform: rotate(0); } 30% { transform: rotate(-12deg); } 70% { transform: rotate(8deg); } }

/* Did-you-know ticker */
.facts { display: flex; align-items: stretch; margin-top: 70px; background: #fff; border-block: 1px solid var(--border); }
.facts-label {
  flex: none; display: flex; align-items: center; gap: 8px; padding: 14px 20px;
  background: var(--accent); color: #fff; font: 700 15px "Poppins", sans-serif;
}
.facts-label i { animation: glow 2s ease-in-out infinite; }
.facts-window {
  flex: 1; overflow: hidden;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 3%, #000 97%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 3%, #000 97%, transparent);
}
.facts-track { display: flex; width: max-content; list-style: none; animation: ticker 80s linear infinite; }
.facts-track li { padding: 14px 28px; white-space: nowrap; color: var(--ink); font-weight: 500; border-right: 1px dashed var(--border); }
.facts:hover .facts-track { animation-play-state: paused; }
@keyframes ticker { to { transform: translateX(-50%); } }

/* ---------- Paper plane across the CTA ---------- */
.cta-banner { position: relative; overflow: hidden; }
.cta-inner { position: relative; z-index: 1; }
.plane-track { position: absolute; inset: 0; pointer-events: none; }
.plane { position: absolute; top: 22%; left: 0; font-size: 26px; color: rgba(255, 255, 255, .8); animation: planeX 16s linear infinite; }
.plane i { display: inline-block; animation: planeY 3.6s ease-in-out infinite; }
@keyframes planeX { from { transform: translateX(-80px); } to { transform: translateX(calc(100vw + 80px)); } }
@keyframes planeY { 0%, 100% { transform: translateY(0) rotate(30deg); } 50% { transform: translateY(34px) rotate(50deg); } }

/* ---------- Rocket back-to-top ---------- */
.rocket-top {
  position: fixed; left: 22px; bottom: 22px; z-index: 60; width: 54px; height: 54px;
  display: grid; place-items: center; border: 0; border-radius: 50%; cursor: pointer;
  background: linear-gradient(135deg, var(--primary), #7c3aed); color: #fff; font-size: 20px; box-shadow: var(--shadow-lg);
  opacity: 0; visibility: hidden; transform: translateY(20px); transition: opacity .3s, transform .3s, visibility .3s;
}
.rocket-top.show { opacity: 1; visibility: visible; transform: none; }
.rocket-top i { transform: rotate(-45deg); }
.rocket-top:hover i, .rocket-top:focus-visible i { animation: rumble .25s linear infinite; }
.rocket-top .flame {
  position: absolute; top: 100%; left: 50%; width: 12px; height: 0; margin-left: -6px; pointer-events: none;
  border-radius: 50% 50% 50% 50% / 30% 30% 70% 70%; background: linear-gradient(#fbbf24, #f97316, transparent);
  transition: height .2s;
}
.rocket-top:hover .flame { height: 16px; }
.rocket-top.launch { animation: launch .9s cubic-bezier(.5, 0, .75, 0) forwards; }
.rocket-top.launch .flame { height: 38px; animation: flicker .08s infinite alternate; }
@keyframes rumble { 0%, 100% { transform: rotate(-45deg) translate(0, 0); } 50% { transform: rotate(-45deg) translate(1px, -1px); } }
@keyframes flicker { to { transform: scaleX(.75); opacity: .8; } }
@keyframes launch { 0% { transform: translateY(0); } 15% { transform: translateY(6px); } 100% { transform: translateY(-110vh); } }

/* ---------- Scroll-driven fun ---------- */
/* Staggered entrances (classes added by fun.js) */
.reveal.reveal-flip { transform: perspective(900px) rotateX(16deg) translateY(50px); transform-origin: 50% 100%; }
.reveal.reveal-pop { transform: scale(.82); }
.reveal.reveal-swing { transform: translateY(50px) rotate(-2deg) scale(.94); transform-origin: 50% 50%; }
.reveal.reveal-right { transform: translateX(40px); }
.reveal.reveal-left { transform: translateX(-40px); }
.reveal.reveal-flip, .reveal.reveal-pop, .reveal.reveal-swing, .reveal.reveal-right, .reveal.reveal-left {
  transition-delay: calc(var(--i, 0) * 110ms);
}
.reveal.visible.reveal-flip, .reveal.visible.reveal-pop, .reveal.visible.reveal-swing,
.reveal.visible.reveal-right, .reveal.visible.reveal-left { transform: none; }
.reveal.visible.course-card:hover { transform: translateY(-8px); }
.course-card.reveal-flip.visible .cc-icon { animation: iconPop .7s cubic-bezier(.34, 1.56, .64, 1) calc(var(--stagger, 0) * 110ms + .3s) both; }
@keyframes iconPop { from { transform: scale(0) rotate(-40deg); } to { transform: none; } }

/* Entrance transforms must never cause sideways scrolling on phones */
html, body { overflow-x: clip; }

/* Science lines drawn by scrolling */
.section { position: relative; }
.section > .container { position: relative; z-index: 1; }
.sci-divider { --c: var(--primary); position: relative; height: 64px; margin: -46px 0 34px; }
.sci-divider svg { display: block; width: 100%; height: 100%; overflow: visible; }
.sd-ghost { fill: none; stroke: var(--c); stroke-opacity: .18; stroke-width: 2; stroke-dasharray: 2 7; stroke-linecap: round; }
.sd-line { fill: none; stroke: var(--c); stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.sd-ring { fill: none; stroke: var(--c); stroke-width: 2.5; opacity: 0; transform-box: fill-box; transform-origin: center; transform: scale(.3); transition: opacity .35s, transform .45s cubic-bezier(.34, 1.56, .64, 1); }
.sd-ring.on { opacity: 1; transform: none; }
.sd-dot { fill: #fff; stroke: var(--c); stroke-width: 3; opacity: 0; filter: drop-shadow(0 0 5px var(--c)); }
.sd-label {
  position: absolute; right: 0; top: -24px; color: var(--c); font: 700 22px "Caveat", cursive;
  opacity: 0; transform: translateY(8px) rotate(-3deg); transition: opacity .5s, transform .5s;
}
.sd-label.show { opacity: 1; transform: rotate(-3deg); }

/* Doodles that drift and turn with the scroll (wide screens only) */
.sec-doodles { position: absolute; inset: 0; z-index: 0; overflow: hidden; pointer-events: none; }
.sd-item {
  position: absolute; left: var(--x); top: var(--y); width: var(--s); height: var(--s);
  display: grid; place-items: center; opacity: .16; will-change: transform;
}
.sd-item svg {
  width: 100%; height: 100%; overflow: visible;
  fill: none; stroke: currentColor; stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round;
}
.sd-item .fill { fill: currentColor; stroke: none; }
.sd-text { font: 700 calc(var(--s) * .8)/1 "Caveat", cursive; }
.fun-zone .facts { position: relative; z-index: 1; }
@media (max-width: 1199px) {
  /* Phones & tablets: doodles peek in from the screen edges */
  .sd-item { left: var(--mx); top: var(--my); width: var(--ms); height: var(--ms); opacity: .2; }
  .sd-text { font-size: calc(var(--ms) * .8); }
  .sd-item.desk-only { display: none; }
}

/* Test-tube scroll meter */
.tube-meter {
  position: fixed; right: 22px; top: 50%; z-index: 40; display: none; flex-direction: column; align-items: center;
  opacity: 0; transform: translateY(-50%); transition: opacity .4s; pointer-events: none;
}
@media (min-width: 1320px) { .tube-meter { display: flex; } }
.tube-meter.show { opacity: 1; }
.tube-meter::before { content: ""; position: relative; z-index: 1; width: 34px; height: 7px; margin-bottom: -2px; border-radius: 4px; background: #a5b4fc; }
.tube {
  position: relative; width: 24px; height: 160px; overflow: hidden;
  border: 2.5px solid #a5b4fc; border-top: 0; border-radius: 0 0 14px 14px;
  background: rgba(255, 255, 255, .75); box-shadow: 0 8px 20px rgba(79, 70, 229, .15);
}
.tube-liquid {
  --h: 262; position: absolute; inset: 0; clip-path: inset(100% 0 0 0);
  background: linear-gradient(180deg, hsl(var(--h) 90% 82%), hsl(var(--h) 78% 58%) 40%, hsl(var(--h) 72% 46%));
}
.tube-liquid i {
  position: absolute; bottom: 6px; width: 5px; height: 5px; border-radius: 50%;
  background: rgba(255, 255, 255, .8); animation: tubeBubble 2.6s ease-in infinite;
}
.tube-liquid i:nth-child(1) { left: 4px; }
.tube-liquid i:nth-child(2) { left: 12px; width: 4px; height: 4px; animation-delay: .7s; }
.tube-liquid i:nth-child(3) { left: 7px; animation-delay: 1.3s; }
.tube-liquid i:nth-child(4) { left: 14px; width: 3px; height: 3px; animation-delay: 1.9s; }
@keyframes tubeBubble { 0% { transform: translateY(0); opacity: 0; } 15% { opacity: 1; } 100% { transform: translateY(-150px); opacity: 0; } }
.tube-label { margin-top: 8px; padding: 0 7px; border-radius: 8px; background: rgba(255, 255, 255, .9); color: var(--primary); font: 700 18px "Caveat", cursive; box-shadow: 0 2px 8px rgba(15, 23, 42, .12); }

/* ---------- Universe mode (hero hover / tap) ---------- */
.hero-space {
  position: absolute; inset: 0; z-index: -1; opacity: 0; pointer-events: none; transition: opacity .8s ease;
  background:
    radial-gradient(ellipse at 18% 28%, rgba(124, 58, 237, .55), transparent 55%),
    radial-gradient(ellipse at 82% 18%, rgba(219, 39, 119, .38), transparent 50%),
    radial-gradient(ellipse at 60% 90%, rgba(14, 165, 233, .32), transparent 55%),
    #0b1026;
}
.hero-space::before {
  /* a second nebula that slowly fades in and out, so the colours keep changing */
  content: ""; position: absolute; inset: 0; opacity: 0;
  background:
    radial-gradient(ellipse at 75% 70%, rgba(34, 197, 94, .3), transparent 55%),
    radial-gradient(ellipse at 30% 80%, rgba(245, 158, 11, .28), transparent 50%),
    radial-gradient(ellipse at 50% 10%, rgba(56, 189, 248, .35), transparent 55%);
  animation: nebula 14s ease-in-out infinite; animation-play-state: paused;
}
.hero.space .hero-space { opacity: 1; }
.hero.space .hero-space::before { animation-play-state: running; }
@keyframes nebula { 0%, 100% { opacity: 0; } 50% { opacity: 1; } }
#cosmos { position: absolute; inset: 0; width: 100%; height: 100%; }

.hero h1, .hero .lead, .hero .lead strong, .typer, .formula { transition: color .8s ease, opacity .8s ease, text-shadow .8s ease; }
.hero-doodles { transition: color .8s ease; }
.doodle svg { transition: opacity .8s ease, filter .8s ease; }
.hero.space h1 { color: #fff; }
.hero.space .highlight { background-image: linear-gradient(135deg, #a5b4fc, #f9a8d4); }
.hero.space .lead { color: #cbd5e1; }
.hero.space .lead strong { color: #fff; }
.hero.space .typer { color: #e2e8f0; }
.hero.space .typer-word { color: #f9a8d4; background: linear-gradient(transparent 62%, rgba(251, 191, 36, .28) 62%); }
.hero.space .typer-caret { background: #f9a8d4; }
.hero.space .hero-doodles { color: #c7d2fe; }
.hero.space .doodle svg { opacity: .5; filter: drop-shadow(0 0 6px rgba(165, 180, 252, .9)); }
.hero.space .formula { color: #e0e7ff; opacity: .55; text-shadow: 0 0 10px rgba(165, 180, 252, .9); }
.hero.space .cmp-circle { stroke: #f9a8d4; }
.hero.space .orbit { border-color: rgba(199, 210, 254, .35); }
.hero.space .chip { box-shadow: 0 0 0 1px rgba(255, 255, 255, .18), 0 0 18px rgba(165, 180, 252, .25); }

.space-hint {
  position: absolute; left: 50%; bottom: 22px; z-index: 2; padding: 6px 14px; border-radius: 999px;
  background: rgba(255, 255, 255, .8); color: var(--primary); box-shadow: var(--shadow);
  font: 600 13px "Poppins", sans-serif; white-space: nowrap; pointer-events: none;
  transform: translateX(-50%); animation: hintBob 2.6s ease-in-out infinite;
  transition: background .8s, color .8s, box-shadow .8s;
}
.hero.space .space-hint { background: rgba(255, 255, 255, .1); color: #e0e7ff; box-shadow: 0 0 0 1px rgba(255, 255, 255, .22); }
@keyframes hintBob { 0%, 100% { translate: 0 0; } 50% { translate: 0 -5px; } }

/* ---------- Cards come alive in the middle of the screen ---------- */
.course-card.in-focus { box-shadow: var(--shadow-lg); border-color: transparent; }
.course-card.in-focus .c1 i { animation: wiggle .6s ease-in-out; }
.course-card.in-focus .c2 i { animation: pop .5s ease; }
.course-card.in-focus .c3 i { animation: wiggle .5s ease-in-out 2; }
.course-card.in-focus .c4 i { animation: flip 1s ease; }
.course-card.in-focus .c5 i { animation: spin 1.4s linear infinite; }
.course-card.in-focus .c6 i { animation: pop .5s ease 2; }
.course-card.in-focus .cc-icon.c3::before { animation: bubble 1s ease-out infinite; }
.course-card.in-focus .cc-icon.c3::after { left: 56%; animation: bubble 1s ease-out .5s infinite; }
.course-card.in-focus .topic-tags li { animation: tagPop .45s cubic-bezier(.34, 1.56, .64, 1) both; }
.course-card.in-focus .topic-tags li:nth-child(2) { animation-delay: .08s; }
.course-card.in-focus .topic-tags li:nth-child(3) { animation-delay: .16s; }
@keyframes tagPop { 0% { transform: scale(1); } 50% { transform: scale(1.15); background: #fde68a; color: #92400e; } 100% { transform: scale(1); } }
.why.in-focus { background: var(--bg-alt); border-color: #c7d2fe; }
.why.in-focus i { animation: flip .8s ease; }

/* Section labels drop in letter by letter */
.eyebrow .ch {
  display: inline-block; opacity: 0; transform: translateY(10px) rotate(10deg);
  transition: opacity .35s, transform .5s cubic-bezier(.34, 1.56, .64, 1);
  transition-delay: calc(var(--c) * 35ms + .1s);
}
.visible .eyebrow .ch { opacity: 1; transform: none; }

/* Binary bulbs light-chase when the board scrolls into view */
.bits.chase .bit .bulb { animation: chase 1.5s ease both; animation-delay: calc(var(--n) * 110ms); }
@keyframes chase {
  0%, 100% { background: rgba(255, 255, 255, .06); box-shadow: none; }
  25%, 55% {
    border-color: #fde68a; box-shadow: 0 0 22px 6px rgba(253, 230, 138, .55);
    background: radial-gradient(circle at 40% 35%, #fffbeb, #fde68a 45%, #f59e0b);
  }
}

/* Rocket fuel ring fills as you scroll */
.rocket-ring { position: absolute; inset: -6px; width: calc(100% + 12px); height: calc(100% + 12px); overflow: visible; transform: rotate(-90deg); pointer-events: none; }
.rr-track { fill: none; stroke: rgba(79, 70, 229, .15); stroke-width: 4; }
.rr-fill { fill: none; stroke: #f59e0b; stroke-width: 4; stroke-linecap: round; stroke-dasharray: 100; stroke-dashoffset: 100; transition: stroke-dashoffset .15s linear, stroke .3s; }
.rocket-top.full .rr-fill { stroke: #22c55e; }
.rocket-top.full:not(.launch) { animation: readyGlow 1.2s ease-in-out infinite; }
.rocket-top.full:not(.launch)::after {
  content: "Ready for lift-off!"; position: absolute; left: calc(100% + 12px); top: 50%; translate: 0 -50%;
  padding: 4px 10px; border-radius: 10px; background: #fff; color: var(--ink); box-shadow: var(--shadow);
  font: 700 17px "Caveat", cursive; white-space: nowrap;
}
@keyframes readyGlow { 0%, 100% { box-shadow: var(--shadow-lg); } 50% { box-shadow: 0 0 0 8px rgba(34, 197, 94, .2), var(--shadow-lg); } }

/* Pause decorative animations while their section is off screen */
.is-paused, .is-paused * { animation-play-state: paused !important; }

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .fun-grid { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .hide-sm { display: none; }
  .doodle { scale: .7; }
  .formula { font-size: 21px; }
  .hero-visual { min-height: 420px; }
  .main-card { width: min(250px, 70vw); padding: 26px 18px; }
  .main-card h3 { font-size: 1.15rem; }
  .main-card p { font-size: 14px; }
  .card-icon { width: 64px; height: 64px; margin-bottom: 14px; border-radius: 18px; font-size: 28px; }
  .float-card { padding: 8px 12px; font-size: 12px; }
  .fc-1 { top: 0; left: 0; }
  .fc-2 { top: auto; bottom: 0; right: 0; }
  .fc-3 { display: none; }
  .orbit-item { width: 40px; height: 40px; margin: -20px 0 0 -20px; }
  .oi { font-size: 15px; }
  .board { padding: 18px 16px 36px; border-width: 9px; min-height: 0; }
  .chalk-title { font-size: 26px; }
  .quiz-q { font-size: 24px; }
  .quiz-opt { font-size: 14px; padding: 11px 8px; }
  .owl { width: 82px; height: 82px; right: 8px; }
  .chip { padding: 7px 13px; font-size: 13px; }
  .quiz-tab { padding: 5px 10px; font-size: 12px; }
  .bits { grid-template-columns: repeat(4, 1fr); gap: 10px 8px; }
  .bulb { width: 40px; height: 40px; }
  .bin-code { font-size: 22px; letter-spacing: 2px; }
  .bin-dec { font-size: 42px; }
  .quiz-feedback { padding-right: 84px; }
  .angle-value { font-size: 42px; }
  .angle-type { font-size: 24px; }
  .facts-label { padding: 12px 14px; font-size: 14px; }
  .facts-track li { padding: 12px 22px; }
  .rocket-top { left: 16px; bottom: 16px; width: 48px; height: 48px; font-size: 18px; }
  .sci-divider { height: 48px; margin: -34px 0 26px; }
  .sd-label { top: -20px; font-size: 19px; }
}

/* ---------- Respect reduced-motion preferences ---------- */
@media (prefers-reduced-motion: reduce) {
  .doodle svg, .formula, .orbit, .oi, .float-card, .plane, .plane i, .facts-track, .cmp-arm, .cmp-circle,
  .badge i, .hero-actions .btn-primary::after, .chip:hover i, .owl-eyes, .board-hint i, .pr-knob, .typer-caret,
  .facts-label i, .doodle .needle, .chat-fab::before, .photo-tag, .tube-liquid i, .cc-icon,
  .space-hint, .hero-space::before, .rocket-top.full {
    animation: none !important;
  }
  .reveal, .reveal.reveal-flip, .reveal.reveal-pop, .reveal.reveal-swing, .reveal.reveal-right, .reveal.reveal-left {
    opacity: 1 !important; transform: none !important; transition: none !important;
  }
  .cmp-circle { stroke-dashoffset: 0; }
  .plane-track { display: none; }
  .facts-window { overflow-x: auto; -webkit-mask-image: none; mask-image: none; }
  .reveal .section-title::after { transform: none; transition: none; }
  .eyebrow .ch { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}