/* Periodically Nerdy: chemistry in deep space */
:root {
  --abyss: #07120d;      /* page base: deep forest-space green */
  --moss: #0f1f18;       /* raised surfaces */
  --line: rgba(180, 225, 200, 0.14);
  --mint: #8ff0bf;       /* phosphor highlight */
  --malachite: #22a874;  /* primary action */
  --malachite-hi: #2fc488;
  --paper: #edf4ef;      /* body text */
  --muted: #a2b8ab;
  --brass: #e6b866;      /* warm second accent, used sparingly */

  --display: "Unbounded", "Segoe UI", system-ui, sans-serif;
  --body: "Hanken Grotesk", "Segoe UI", system-ui, sans-serif;

  --step--1: 0.875rem;
  --step-0: 1.0625rem;
  --step-1: 1.25rem;
  --step-2: 1.6rem;
  --step-3: clamp(1.9rem, 1.3rem + 2.4vw, 3rem);
  --step-4: clamp(2.5rem, 1.4rem + 4.6vw, 5.2rem);

  --gutter: clamp(16px, 4vw, 56px);
  --max: 1240px;
  --r-sm: 10px;
  --r-lg: 22px;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  margin: 0;
  background: var(--abyss);
  color: var(--paper);
  font: 400 var(--step-0)/1.6 var(--body);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; }
h1, h2, h3 { margin: 0; font-weight: 600; }
p { margin: 0; }

.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip {
  position: fixed; left: 16px; top: -60px; z-index: 100;
  background: var(--mint); color: var(--abyss); padding: 10px 16px; border-radius: var(--r-sm);
  font-weight: 600; text-decoration: none;
}
.skip:focus { top: 16px; }
:focus-visible { outline: 2px solid var(--mint); outline-offset: 3px; border-radius: 4px; }

/* The particle field sits behind everything and stays put while the page scrolls */
#field { position: fixed; inset: 0; width: 100%; height: 100%; z-index: 0; }
.vignette {
  position: fixed; inset: 0; z-index: 1; pointer-events: none;
  background:
    radial-gradient(120% 90% at 50% 40%, transparent 55%, rgba(4, 11, 8, 0.85) 100%);
}
/* space layer: shooting stars and the background rocket, above the particles, below the content */
.sky { position: fixed; inset: 0; z-index: 1; pointer-events: none; overflow: hidden; }
.shooting-star {
  position: absolute; top: 0; left: 0; width: 180px; height: 2px; border-radius: 2px;
  background: linear-gradient(90deg, rgba(255, 255, 255, 0), rgba(143, 245, 194, 0.6) 60%, #fff);
  filter: drop-shadow(0 0 6px rgba(255, 255, 255, 0.9));
  transform-origin: right center;
  opacity: 0;
}
.shooting-star::after {
  content: ""; position: absolute; right: -2px; top: -2px; width: 6px; height: 6px; border-radius: 50%;
  background: #fff; box-shadow: 0 0 12px 3px rgba(255, 255, 255, 0.8);
}
.rocket {
  position: absolute; top: 0; left: 0; width: 40px;
  opacity: 0; filter: drop-shadow(0 0 14px rgba(255, 201, 77, 0.35));
  will-change: transform, opacity;
}
.rk-flame { transform-origin: 20px 66px; animation: flame .12s ease-in-out infinite alternate; }
@keyframes flame { from { transform: scaleY(0.75) scaleX(0.9); opacity: .8; } to { transform: scaleY(1.15) scaleX(1.05); opacity: 1; } }
@media (prefers-reduced-motion: reduce) { .sky { display: none; } }

main, .foot { position: relative; z-index: 2; }
main { overflow-x: clip; } /* the tilted ribbon overhangs the edges */

.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 var(--gutter); }

/* ---------- type ---------- */
.display {
  font-family: var(--display);
  font-weight: 800;
  font-size: var(--step-4);
  line-height: 1.02;
  letter-spacing: -0.035em;
  text-wrap: balance;
}
.h2 {
  font-family: var(--display);
  font-weight: 600;
  font-size: var(--step-3);
  line-height: 1.08;
  letter-spacing: -0.025em;
  text-wrap: balance;
}
h3 { font-family: var(--body); font-size: var(--step-1); font-weight: 600; line-height: 1.3; }
.lede { font-size: var(--step-1); color: var(--muted); max-width: 34em; line-height: 1.55; }
.center { text-align: center; margin-left: auto; margin-right: auto; }

/* ---------- element tiles (the brand mark) ---------- */
.tile {
  position: relative; display: inline-grid; place-items: center;
  width: 56px; aspect-ratio: 1; flex: none;
  border: 1.5px solid var(--mint); border-radius: 8px;
  background: rgba(143, 240, 191, 0.06);
  color: var(--mint);
}
.tile b { font-family: var(--display); font-weight: 600; font-size: 1.3rem; letter-spacing: -0.02em; }
.tile small { position: absolute; top: 4px; left: 6px; font-size: 0.7rem; font-weight: 600; opacity: 0.8; }
.tile--logo { width: 40px; border-radius: 6px; }
.tile--logo b { font-size: 0.95rem; }
.tile--logo small { font-size: 0.55rem; top: 2px; left: 4px; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 48px; padding: 0 24px;
  border: 1.5px solid var(--malachite); border-radius: 999px;
  background: var(--malachite); color: #02130c;
  font: 600 1rem/1 var(--body); text-decoration: none; cursor: pointer;
  transition: background-color .18s ease, border-color .18s ease, color .18s ease, transform .18s ease;
}
.btn:hover { background: var(--malachite-hi); border-color: var(--malachite-hi); }
.btn:active { transform: translateY(1px); }
.btn--ghost { background: transparent; color: var(--paper); border-color: rgba(237, 244, 239, 0.32); }
.btn--ghost:hover { background: rgba(143, 240, 191, 0.08); border-color: var(--mint); color: var(--mint); }
.btn--small { min-height: 42px; padding: 0 18px; font-size: 0.95rem; }
.btn--wide { width: 100%; }

/* ---------- nav ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  display: flex; align-items: center; gap: 28px;
  padding: 14px var(--gutter);
  transition: background-color .3s ease, border-color .3s ease, backdrop-filter .3s ease;
  border-bottom: 1px solid transparent;
}
.nav.is-solid {
  background: rgba(7, 18, 13, 0.78);
  background: rgba(7, 18, 13, 0.88);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  border-bottom-color: var(--line);
}
.brand { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; }
.brand-name { font-family: var(--display); font-weight: 600; font-size: 1rem; letter-spacing: -0.01em; }
.nav-links { display: flex; gap: 28px; margin-left: auto; }
.nav-links a { white-space: nowrap; display: inline-flex; align-items: center; min-height: 44px; text-decoration: none; color: var(--muted); font-weight: 500; font-size: 0.98rem; padding: 0 2px; transition: color .18s ease; }
.nav-links a:hover, .nav-links a[aria-current="true"] { color: var(--paper); }
.menu { display: none; }
/* below 1080px the five links no longer fit on one line, so the menu button takes over */
@media (max-width: 1080px) {
  .nav-links, .nav > .btn { display: none; }
  .menu {
    display: grid; gap: 6px; place-content: center; margin-left: auto;
    width: 44px; height: 44px; border: 1px solid var(--line); border-radius: 50%;
    background: rgba(7, 18, 13, 0.6); cursor: pointer;
  }
  .menu span { display: block; width: 18px; height: 1.5px; background: var(--paper); transition: transform .2s ease; }
  .menu[aria-expanded="true"] span:first-child { transform: translateY(3.75px) rotate(45deg); }
  .menu[aria-expanded="true"] span:last-child { transform: translateY(-3.75px) rotate(-45deg); }
}

.mobile-nav {
  position: fixed; inset: 70px 0 auto 0; z-index: 49;
  display: grid; gap: 4px; padding: 12px var(--gutter) 24px;
  background: rgba(7, 18, 13, 0.96); border-bottom: 1px solid var(--line);
}
.mobile-nav[hidden] { display: none; }
.mobile-nav a:not(.btn) { padding: 14px 0; font-size: 1.15rem; text-decoration: none; border-bottom: 1px solid var(--line); }
.mobile-nav .btn { margin-top: 16px; }

/* ---------- scenes ---------- */
.scene { position: relative; padding: clamp(96px, 14vh, 160px) 0; }
.copy { max-width: 560px; }
.wrap--right { display: flex; justify-content: flex-end; }

/* hero */
.hero { min-height: 100svh; display: flex; align-items: center; padding-top: 120px; }
.hero .lede { margin-top: 16px; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }

/* hero lockup: the brand name, with "Nerdy" spelled in real elements (N, Er, Dy) */
.copy--hero { max-width: 760px; }
.lockup { margin: 0; display: grid; gap: clamp(10px, 1.4vw, 18px); }
.lockup-word {
  font-family: var(--display); font-weight: 800;
  font-size: clamp(2.6rem, 5.6vw, 5.6rem); line-height: 0.95; letter-spacing: -0.045em;
  background: linear-gradient(100deg, var(--paper) 0%, var(--paper) 55%, #b9f5d3 80%, #ffd98a 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.lockup-tiles { display: flex; gap: clamp(8px, 1.1vw, 16px); perspective: 700px; }
.etile {
  --c: #2fd88a; --rx: 0deg; --ry: 0deg; --gx: 50%; --gy: 50%;
  position: relative; display: grid; place-items: center;
  width: clamp(92px, 9.6vw, 156px); aspect-ratio: 1;
  border: 2px solid var(--c); border-radius: clamp(10px, 1vw, 16px);
  background:
    radial-gradient(120px 120px at var(--gx) var(--gy), color-mix(in srgb, var(--c) 34%, transparent), transparent 70%),
    color-mix(in srgb, var(--c) 9%, rgba(7, 18, 13, 0.75));
  color: var(--c);
  transform: rotateX(var(--rx)) rotateY(var(--ry));
  transform-style: preserve-3d;
  transition: transform .5s cubic-bezier(.2, .8, .2, 1), box-shadow .3s ease;
  box-shadow: 0 0 0 0 transparent, inset 0 0 30px color-mix(in srgb, var(--c) 14%, transparent);
}
.etile.is-live { transition: transform .08s linear, box-shadow .3s ease; box-shadow: 0 18px 60px -18px var(--c), inset 0 0 40px color-mix(in srgb, var(--c) 22%, transparent); }
.etile b { font-family: var(--display); font-weight: 600; font-size: clamp(2.4rem, 4.2vw, 4.3rem); letter-spacing: -0.04em; line-height: 1; transform: translateZ(30px); margin-top: -18%; }
.etile small { position: absolute; top: 8%; left: 10%; font-weight: 600; font-size: clamp(0.72rem, 0.9vw, 0.95rem); }
.etile i { position: absolute; bottom: 19%; font-style: normal; font-size: clamp(0.62rem, 0.75vw, 0.8rem); color: var(--paper); opacity: 0.85; }
.etile em { position: absolute; bottom: 7%; font-style: normal; font-size: clamp(0.58rem, 0.68vw, 0.72rem); color: var(--muted); }
.etile--n { --c: #2fd88a; }
.etile--er { --c: #ffc94d; }
.etile--dy { --c: #2ec9b7; }
.tagline {
  margin-top: clamp(26px, 3vw, 40px);
  font-family: var(--display); font-weight: 600; font-size: clamp(1.6rem, 2.6vw, 2.5rem);
  line-height: 1.1; letter-spacing: -0.025em; max-width: 24em;
  background: linear-gradient(90deg, #8ff5c2, #c6f36b 50%, #ffc94d);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  width: fit-content;
}
.hero .tagline + .lede { margin-top: 16px; }

/* marquee band of topics between the hero and the course content */
/* a tilted double ribbon: element-tagged topics on top, finer terms sliding the other way below */
.marquee {
  position: relative; z-index: 2;
  margin: clamp(10px, 2vw, 30px) -4vw;
  transform: rotate(-2.2deg);
  display: grid;
}
.marquee-row {
  overflow: hidden;
  mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
}
.marquee-row:first-child {
  padding: clamp(14px, 1.8vw, 22px) 0;
  background: linear-gradient(90deg, rgba(47, 216, 138, 0.16), rgba(46, 201, 183, 0.12) 50%, rgba(255, 201, 77, 0.14));
  border-block: 1px solid rgba(143, 245, 194, 0.28);
  box-shadow: 0 20px 60px -30px rgba(47, 216, 138, 0.5);
  background-color: rgba(7, 18, 13, 0.55);
}
.marquee-row--rev { padding: 12px 0; background: rgba(4, 11, 8, 0.7); border-bottom: 1px solid var(--line); }
/* tracks are moved by app.js as you scroll; children use margins (not gap) so the doubled
   content loops seamlessly at exactly half the track width */
.marquee-track { display: flex; align-items: center; width: max-content; will-change: transform; }
.marquee-track > * { margin-right: clamp(22px, 2.4vw, 40px); }
.marquee-row--rev .marquee-track > * { margin-right: 22px; }

.mq {
  --c: #2fd88a;
  display: inline-flex; align-items: center; gap: clamp(14px, 1.3vw, 20px);
  font-family: var(--display); font-weight: 800; font-size: clamp(1.45rem, 3vw, 2.8rem);
  letter-spacing: -0.035em; white-space: nowrap; color: var(--paper);
  transition: color .25s ease, text-shadow .25s ease;
}
.mq b {
  position: relative; display: grid; place-items: center; flex: none;
  width: 1.5em; aspect-ratio: 1; border-radius: 0.22em;
  border: 2px solid var(--c); color: var(--c);
  background: radial-gradient(circle at 30% 25%, color-mix(in srgb, var(--c) 28%, transparent), color-mix(in srgb, var(--c) 8%, rgba(7, 18, 13, 0.6)) 70%);
  font-weight: 600; font-size: 0.6em; letter-spacing: -0.02em; line-height: 1; padding-top: 0.12em;
  box-shadow: 0 0 24px -6px var(--c), inset 0 0 14px color-mix(in srgb, var(--c) 18%, transparent);
  transition: transform .3s cubic-bezier(.2, .8, .2, 1), box-shadow .3s ease;
}
.mq b small { position: absolute; top: 0.18em; left: 0.24em; font-size: 0.34em; font-weight: 700; opacity: 0.85; }
.mq:hover { color: var(--c); text-shadow: 0 0 24px color-mix(in srgb, var(--c) 55%, transparent); }
.mq:hover b { transform: rotate(-6deg) scale(1.08); box-shadow: 0 0 34px -4px var(--c), inset 0 0 18px color-mix(in srgb, var(--c) 28%, transparent); }
.mq--t { --c: #2ec9b7; }
.mq--l { --c: #c6f36b; }
.mq--y { --c: #ffc94d; }
/* tiny orbiting atom between topics */
.mq-atom { position: relative; flex: none; width: 22px; height: 22px; border-radius: 50%; border: 1.5px solid rgba(143, 245, 194, 0.45); transform: rotate(-30deg) scaleY(0.45); }
.mq-atom::before { content: ""; position: absolute; inset: 7px; border-radius: 50%; background: #ffc94d; box-shadow: 0 0 10px #ffc94d; transform: scaleY(2.2); }
.mq-atom::after { content: ""; position: absolute; top: -3px; left: 8px; width: 5px; height: 5px; border-radius: 50%; background: #8ff5c2; box-shadow: 0 0 8px #8ff5c2; transform: scaleY(2.2); }
/* second row: real chemistry equations */
.mq-eq {
  font-family: "Cambria Math", "Times New Roman", serif; font-style: italic;
  font-size: clamp(1rem, 1.5vw, 1.3rem); white-space: nowrap; color: #c9ffe4; opacity: 0.85;
}
.mq-eq sub, .mq-eq sup { font-size: 0.65em; }
.mq-dot { flex: none; width: 6px; height: 6px; border-radius: 50%; background: #ffc94d; box-shadow: 0 0 10px #ffc94d; }

/* custom cursor (fine pointers only, added by app.js) */
.has-cursor, .has-cursor a, .has-cursor button, .has-cursor summary, .has-cursor label, .has-cursor select { cursor: none; }
.cursor-dot, .cursor-ring {
  position: fixed; top: 0; left: 0; z-index: 200; pointer-events: none; border-radius: 50%;
  transform: translate3d(-100px, -100px, 0);
}
.cursor-dot { width: 6px; height: 6px; margin: -3px 0 0 -3px; background: var(--paper); }
.cursor-ring {
  width: 36px; height: 36px; margin: -18px 0 0 -18px;
  border: 1.5px solid rgba(237, 244, 239, 0.7);
  display: grid; place-items: center;
  transition: width .25s ease, height .25s ease, margin .25s ease, border-color .25s ease, background-color .25s ease, opacity .2s ease;
}
.cursor-ring.is-link { width: 56px; height: 56px; margin: -28px 0 0 -28px; border-color: var(--mint); background: rgba(143, 245, 194, 0.08); }
.cursor-ring.is-text { opacity: 0; }
/* over the 3D shape the ring swells into a soft gold circle */
.cursor-ring.is-object { width: 84px; height: 84px; margin: -42px 0 0 -42px; border-color: #ffc94d; background: rgba(255, 201, 77, 0.14); box-shadow: 0 0 30px rgba(255, 201, 77, 0.35); }
body[data-over-object] { cursor: none; }

/* topics: element tiles in a grid */
.topics .lede { margin-top: 18px; }
.elements {
  list-style: none; padding: 0; margin: 64px 0 0;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px;
  background: var(--line); border: 1px solid var(--line); border-radius: var(--r-lg); overflow: hidden;
}
.el {
  padding: 28px 24px 30px;
  background: rgba(7, 18, 13, 0.6);
  transition: background-color .25s ease;
}
.el:hover { background: rgba(14, 32, 24, 0.8); }
.el h3 { margin-top: 20px; font-size: 1.08rem; }
.el p { margin-top: 6px; color: var(--muted); font-size: 0.95rem; line-height: 1.5; }

/* bundles */
.bundles .lede { margin-top: 18px; }
.hint { margin-top: 14px; max-width: 40em; font-size: 0.95rem; color: var(--muted); }
.copy--plans { max-width: 600px; }
.plans { display: grid; gap: 14px; margin-top: 40px; }
.plan {
  display: grid; grid-template-columns: 56px 1fr auto; column-gap: 20px; align-items: start;
  padding: 24px;
  border: 1px solid var(--line); border-radius: var(--r-lg);
  background: rgba(7, 18, 13, 0.76);
  transition: border-color .25s ease, background-color .25s ease;
}
.plan:hover, .plan:focus-within { border-color: rgba(143, 240, 191, 0.45); }
.plan .tile { grid-row: 1 / span 2; }
.plan h3 { grid-column: 2; font-family: var(--display); font-weight: 600; font-size: 1.15rem; letter-spacing: -0.015em; }
.plan-for { grid-column: 2; margin-top: 6px; color: var(--muted); font-size: 0.95rem; }
.plan-price { grid-column: 3; grid-row: 1; text-align: right; color: var(--muted); font-size: 0.85rem; white-space: nowrap; }
.plan-price span { display: block; font-family: var(--display); font-weight: 800; font-size: 2.1rem; letter-spacing: -0.04em; color: var(--paper); line-height: 1; margin-bottom: 4px; }
.plan-week { grid-column: 3; grid-row: 2; text-align: right; margin-top: 6px; font-size: 0.85rem; color: var(--muted); white-space: nowrap; }
.plan-list { grid-column: 2 / -1; list-style: none; padding: 16px 0 0; margin: 16px 0 18px; display: flex; flex-wrap: wrap; gap: 8px 20px; border-top: 1px solid var(--line); }
.plan .btn { grid-column: 2 / -1; justify-self: start; }
.plan-list li { position: relative; padding-left: 20px; font-size: 0.92rem; }
.plan-list li::before {
  content: ""; position: absolute; left: 2px; top: 0.55em;
  width: 10px; height: 10px; border-radius: 50%;
  border: 1.5px solid var(--mint);
}
.plan--mix { border-color: rgba(143, 240, 191, 0.55); background: rgba(12, 36, 26, 0.86); box-shadow: 0 0 0 1px rgba(143, 240, 191, 0.12), 0 30px 80px -30px rgba(34, 168, 116, 0.45); }
.plan--mix .tile { border-color: #c6f36b; color: #c6f36b; background: rgba(198, 243, 107, 0.08); }
.plan[data-key="individual"] .tile { border-color: #ffc94d; color: #ffc94d; background: rgba(255, 201, 77, 0.08); }

/* how it works */
.how .copy, .faq .copy { max-width: 540px; }
.how .lede { margin-top: 14px; }

/* reaction pathway: element tiles joined by a glowing line, ending in the product */
.pathway {
  --tile: 64px;
  position: relative; list-style: none; padding: 0; margin: 44px 0 0;
  display: grid; gap: 14px;
}
/* the reaction line runs behind the tiles, green into gold */
.pathway::before {
  content: ""; position: absolute; left: calc(var(--tile) / 2 - 1px); top: 32px; bottom: 40px; width: 2px;
  background: linear-gradient(#2fd88a, #2ec9b7 35%, #c6f36b 65%, #ffc94d);
  opacity: 0.55; border-radius: 2px;
}
/* a spark travels down the line once the section is on screen */
.pathway::after {
  content: ""; position: absolute; left: calc(var(--tile) / 2 - 5px); top: 32px;
  width: 10px; height: 10px; border-radius: 50%;
  background: #fff; box-shadow: 0 0 10px #fff, 0 0 24px #8ff5c2;
  opacity: 0;
}
.pathway.is-on::after { animation: spark 3.2s cubic-bezier(.5, 0, .3, 1) .2s infinite; }
@keyframes spark {
  0% { top: 32px; opacity: 0; }
  8% { opacity: 1; }
  88% { opacity: 1; }
  100% { top: calc(100% - 44px); opacity: 0; }
}

.step {
  --c: #2fd88a;
  position: relative; display: grid; grid-template-columns: var(--tile) 1fr; gap: 20px; align-items: center;
  padding: 10px 18px 10px 0;
  border-radius: 14px;
  transition: background-color .25s ease;
}
.step:hover { background: color-mix(in srgb, var(--c) 7%, transparent); }
.step-tile {
  position: relative; display: grid; place-items: center;
  width: var(--tile); aspect-ratio: 1; border-radius: 12px;
  border: 1.5px solid var(--c); color: var(--c);
  background: color-mix(in srgb, var(--c) 12%, var(--abyss));
  box-shadow: 0 0 0 6px var(--abyss), 0 10px 30px -12px var(--c);
  transition: transform .3s cubic-bezier(.2, .8, .2, 1), box-shadow .3s ease;
}
.step:hover .step-tile { transform: scale(1.08) rotate(-4deg); box-shadow: 0 0 0 6px var(--abyss), 0 14px 40px -10px var(--c); }
.step-tile b { font-family: var(--display); font-weight: 600; font-size: 1.45rem; letter-spacing: -0.03em; }
.step-tile small { position: absolute; top: 4px; left: 7px; font-size: 0.66rem; font-weight: 600; }
.step h3 { font-size: 1.12rem; }
.step p { margin-top: 4px; color: var(--muted); font-size: 0.98rem; }
.step--pk { --c: #2fd88a; }
.step--tm { --c: #2ec9b7; }
.step--lv { --c: #c6f36b; }
.step--pg { --c: #8ff5c2; }
.step--cf { --c: #ffc94d; margin-top: 10px; padding-top: 18px; border-top: 1px dashed color-mix(in srgb, #ffc94d 40%, transparent); border-radius: 0; }
.step--cf .step-tile { background: linear-gradient(140deg, #ffc94d, #ff9a4a); color: #241503; border-color: transparent; box-shadow: 0 0 0 6px var(--abyss), 0 0 40px -6px #ffc94d; }
.step--cf h3 { font-family: var(--display); font-weight: 600; letter-spacing: -0.015em; color: #ffd98a; }
.step--cf:hover { background: transparent; }

@media (prefers-reduced-motion: reduce) {
  .pathway.is-on::after { animation: none; }
}

/* about */
.about .copy p { margin-top: 20px; color: var(--muted); max-width: 34em; }
.about .copy p:first-of-type { margin-top: 28px; }
.about .aside { padding-top: 20px; border-top: 1px solid var(--line); font-size: 0.95rem; }
.about .aside a { color: var(--mint); text-underline-offset: 3px; }

/* faq */
.qa { margin-top: 36px; border-top: 1px solid var(--line); }
.qa details { border-bottom: 1px solid var(--line); }
.qa summary {
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  padding: 22px 0; cursor: pointer; list-style: none;
  font-weight: 600; font-size: 1.08rem;
}
.qa summary::-webkit-details-marker { display: none; }
.qa summary::after {
  content: ""; flex: none; width: 12px; height: 12px;
  border-right: 1.5px solid var(--mint); border-bottom: 1.5px solid var(--mint);
  transform: rotate(45deg) translateY(-3px); transition: transform .25s ease;
}
.qa details[open] summary::after { transform: rotate(-135deg) translateY(-3px); }
.qa details p { padding: 0 0 22px; color: var(--muted); max-width: 36em; }

/* book */
.book { padding-bottom: clamp(96px, 16vh, 180px); }
.book .lede { margin-top: 14px; }

/* the booking form as a periodic table */
.ptable {
  max-width: 980px; margin: 48px auto 0;
  display: grid; gap: 10px;
  grid-template-columns: repeat(5, 1fr);
  grid-template-areas:
    "nm nm em em gc"
    "gr mx in ms ms"
    "go go go ms ms"
    "note note note note note";
}
.bundles-pick { display: contents; border: 0; margin: 0; padding: 0; }
.cell {
  --c: #2fd88a;
  position: relative; display: flex; flex-direction: column; justify-content: flex-end; gap: 6px;
  min-height: 136px; padding: 40px 16px 14px;
  border: 1.5px solid color-mix(in srgb, var(--c) 45%, transparent);
  border-radius: 12px;
  background: color-mix(in srgb, var(--c) 6%, rgba(7, 18, 13, 0.86));
  transition: border-color .2s ease, background-color .2s ease, box-shadow .25s ease, transform .2s ease;
}
.cell:focus-within { border-color: var(--c); box-shadow: 0 0 0 3px color-mix(in srgb, var(--c) 22%, transparent), 0 20px 50px -24px var(--c); }
.cell-no { position: absolute; top: 10px; left: 14px; font-size: 0.8rem; font-weight: 600; color: var(--c); }
.cell-sym {
  position: absolute; top: 8px; right: 14px;
  font-family: var(--display); font-weight: 600; font-size: 1.7rem; letter-spacing: -0.03em; line-height: 1;
  color: var(--c); opacity: 0.9;
}
.cell label:not(.pick) { font-weight: 600; font-size: 0.92rem; }
.cell input:not([type="radio"]), .cell textarea {
  width: 100%; min-height: 44px; padding: 8px 2px;
  border: 0; border-bottom: 1.5px solid rgba(180, 225, 200, 0.3); border-radius: 0;
  background: transparent; color: var(--paper);
  font: 400 1.05rem/1.4 var(--body);
}
.cell textarea { resize: vertical; flex: 1; min-height: 120px; border: 1.5px solid rgba(180, 225, 200, 0.22); border-radius: 8px; padding: 10px 12px; }
.cell input::placeholder, .cell textarea::placeholder { color: #6f877a; }
.cell input:focus, .cell textarea:focus { outline: none; border-color: var(--c); }
.cell [aria-invalid="true"] { border-color: #ff8f8f; }
.opt { font-weight: 400; color: var(--muted); }
.err { color: #ffadad; font-size: 0.86rem; }

.cell--nm { grid-area: nm; }
.cell--em { grid-area: em; --c: #2ec9b7; }
.cell--gc { grid-area: gc; --c: #8ff5c2; }
.cell--ms { grid-area: ms; --c: #2ec9b7; justify-content: flex-start; padding-top: 44px; }
.pick--gr { grid-area: gr; --c: #2fd88a; }
.pick--mx { grid-area: mx; --c: #c6f36b; }
.pick--in { grid-area: in; --c: #ffc94d; }

/* bundle tiles: radio buttons drawn as element squares */
.pick { cursor: pointer; justify-content: flex-end; align-items: flex-start; }
.pick input { position: absolute; opacity: 0; pointer-events: none; }
.pick .cell-sym { position: static; font-size: 2.6rem; margin-bottom: auto; margin-top: -6px; align-self: center; }
.pick-name { font-weight: 600; font-size: 0.9rem; }
.pick-mass { font-family: var(--display); font-weight: 600; font-size: 1.05rem; color: var(--paper); }
.pick:hover { border-color: var(--c); transform: translateY(-2px); }
.pick:has(input:checked) {
  border-color: var(--c);
  background: color-mix(in srgb, var(--c) 22%, rgba(7, 18, 13, 0.86));
  box-shadow: 0 0 0 1px var(--c), 0 22px 60px -22px var(--c);
}
.pick:has(input:checked)::after {
  content: "Selected"; position: absolute; top: 10px; right: 12px;
  font-size: 0.72rem; font-weight: 600; color: #04140c; background: var(--c);
  padding: 3px 8px; border-radius: 999px;
}
.pick:has(input:focus-visible) { outline: 2px solid var(--mint); outline-offset: 3px; }

.cell--go {
  grid-area: go; --c: #2fd88a;
  min-height: 110px; cursor: pointer; text-align: left; color: #04140c;
  background: linear-gradient(120deg, #2fd88a, #8ff5c2 60%, #ffc94d);
  border-color: transparent;
  font: inherit;
}
.cell--go .cell-no, .cell--go .cell-sym { color: #04140c; }
.cell--go:hover { transform: translateY(-2px); box-shadow: 0 24px 60px -24px #2fd88a; }
.go-label { font-family: var(--display); font-weight: 600; font-size: clamp(1.1rem, 1.6vw, 1.45rem); letter-spacing: -0.02em; }
.form-note { grid-area: note; color: var(--mint); font-size: 0.95rem; min-height: 1.4em; text-align: center; }

/* ---------- Teacher resources page ---------- */
.res-hero { min-height: 78svh; }
/* the resources page has no 3D shape above its headline, so it doesn't need the home hero's top gap */
@media (max-width: 900px) and (orientation: portrait), (max-width: 600px) { .hero.res-hero { padding-top: 120px; min-height: 0; } }
.res-kicker { font-size: 0.92rem; color: var(--muted); margin-bottom: 18px; }
.res-kicker a { color: var(--mint); text-decoration: none; }
.res-kicker a:hover { text-decoration: underline; text-underline-offset: 3px; }
.res-title {
  font-family: var(--display); font-weight: 800; font-size: clamp(2.3rem, 5vw, 4.6rem);
  line-height: 1; letter-spacing: -0.04em; text-wrap: balance;
}
.res-hero .lede { margin-top: 22px; }
.res-group { padding-block: clamp(64px, 10vh, 110px); }
.res-group .lede { margin-top: 10px; }
.res-list { list-style: none; padding: 0; margin: 36px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
/* cards with a cover: the cover carries the element tile, so the small one is hidden */
.res:has(.res-cover) { grid-template-columns: 1fr; align-content: start; }
.res:has(.res-cover) .res-tile { display: none; }
.res:has(.res-cover) .res-buy { grid-column: 1; margin-top: auto; padding-top: 14px; }
.res:has(.res-cover) .res-body h3 { margin-top: 2px; }
.res-list--mega { grid-template-columns: repeat(3, 1fr); }
.res {
  --c: #2fd88a;
  display: grid; grid-template-columns: 60px 1fr; grid-template-rows: auto auto; gap: 6px 18px; align-items: start;
  padding: 22px; border-radius: 18px;
  border: 1px solid color-mix(in srgb, var(--c) 30%, transparent);
  background: color-mix(in srgb, var(--c) 6%, rgba(7, 18, 13, 0.88));
  transition: border-color .2s ease, transform .2s ease, box-shadow .25s ease;
}
.res:hover { border-color: var(--c); transform: translateY(-2px); box-shadow: 0 22px 50px -28px var(--c); }
.res-tile {
  position: relative; grid-row: 1 / span 2; display: grid; place-items: center;
  width: 60px; aspect-ratio: 1; border-radius: 10px;
  border: 1.5px solid var(--c); color: var(--c);
  background: color-mix(in srgb, var(--c) 12%, transparent);
}
.res-tile b { font-family: var(--display); font-weight: 600; font-size: 1.35rem; letter-spacing: -0.03em; }
.res-tile small { position: absolute; top: 4px; left: 6px; font-size: 0.62rem; font-weight: 600; }
.res-body h3 { font-size: 1.05rem; line-height: 1.3; }
.res-body p { margin-top: 6px; color: var(--muted); font-size: 0.94rem; line-height: 1.5; }
.res-buy { grid-column: 2; display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 12px; flex-wrap: wrap; }
.res-price { font-family: var(--display); font-weight: 600; font-size: 1.3rem; letter-spacing: -0.02em; }
.res-list--mega .res { grid-template-columns: 1fr; padding: 26px; }
.res-list--mega .res-tile { grid-row: auto; width: 72px; }
.res-list--mega .res-tile b { font-size: 1.6rem; }
.res-list--mega .res-buy { grid-column: 1; margin-top: auto; padding-top: 16px; border-top: 1px solid var(--line); }
.res-list--mega .res-body h3 { font-family: var(--display); font-weight: 600; font-size: 1.2rem; letter-spacing: -0.015em; margin-top: 8px; }
.res-list--mega .res-price { font-size: 1.7rem; }
.res-note { margin-top: 28px; font-size: 0.85rem; color: var(--muted); }
.res-cta-actions { justify-content: center; }

@media (max-width: 1080px) { .res-list, .res-list--mega { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 720px) { .res-list, .res-list--mega { grid-template-columns: 1fr; } }
@media (max-width: 900px) { .res { backdrop-filter: none; -webkit-backdrop-filter: none; background: color-mix(in srgb, var(--c) 6%, rgba(7, 18, 13, 0.9)); } }

/* ---------- bundle covers: static JPG, swapped for a live animated cover by covers.js ---------- */
.res-cover {
  --k: 0.3;
  position: relative; grid-column: 1 / -1; aspect-ratio: 16 / 9; overflow: hidden;
  border-radius: 12px; margin-bottom: 12px; background: #061009;
  border: 1px solid color-mix(in srgb, var(--c) 30%, transparent);
}
.res-cover img { display: block; width: 100%; height: 100%; object-fit: cover; }
.res-cover.is-live img { visibility: hidden; }
.live-cover {
  --c: #2fd88a;
  position: absolute; top: 0; left: 0; width: 1200px; height: 675px;
  transform: scale(var(--k)); transform-origin: 0 0;
  color: #edf4ef; font-family: var(--body);
  background:
    radial-gradient(560px 460px at 880px 330px, color-mix(in srgb, var(--c) 26%, transparent), transparent 70%),
    radial-gradient(420px 320px at 80px 640px, rgba(46, 201, 183, 0.12), transparent 70%),
    linear-gradient(160deg, #0a1f16, #061009);
}
.lc-grid { position: absolute; inset: 0; background-image: linear-gradient(rgba(143, 245, 194, .05) 1px, transparent 1px), linear-gradient(90deg, rgba(143, 245, 194, .05) 1px, transparent 1px); background-size: 48px 48px; mask-image: radial-gradient(700px 500px at 850px 330px, #000, transparent 75%); -webkit-mask-image: radial-gradient(700px 500px at 850px 330px, #000, transparent 75%); }
.lc-art { position: absolute; right: 40px; top: 70px; width: 560px; height: 470px; overflow: visible; filter: drop-shadow(0 0 10px color-mix(in srgb, var(--c) 70%, transparent)); }
.lc-art * { transform-box: view-box; }
.lc-tile { position: absolute; left: 64px; top: 56px; width: 92px; height: 92px; border-radius: 14px; border: 3px solid var(--c); color: var(--c); display: grid; place-items: center; background: color-mix(in srgb, var(--c) 14%, #07120d); box-shadow: 0 0 30px -6px var(--c); }
.lc-tile b { font-family: var(--display); font-weight: 600; font-size: 38px; letter-spacing: -0.03em; }
.lc-tile small { position: absolute; top: 6px; left: 9px; font-weight: 700; font-size: 15px; }
.lc-ribbon { position: absolute; left: 172px; top: 80px; padding: 10px 20px; border-radius: 999px; background: var(--c); color: #04140c; font-family: var(--display); font-weight: 800; font-size: 22px; letter-spacing: 0.02em; }
.lc-brand { position: absolute; right: 56px; top: 50px; font-family: var(--display); font-weight: 600; font-size: 18px; color: rgba(237, 244, 239, 0.7); }
.lc-title { position: absolute; left: 64px; top: 186px; width: 600px; font-family: var(--display); font-weight: 800; font-size: 60px; line-height: 1.02; letter-spacing: -0.04em; }
.lc-title--long { font-size: 50px; }
.lc-formula { position: absolute; left: 64px; bottom: 150px; padding: 10px 18px; border-radius: 12px; border: 2px solid color-mix(in srgb, var(--c) 60%, transparent); background: rgba(4, 11, 8, 0.6); font-family: "Cambria Math", "Times New Roman", serif; font-style: italic; font-size: 34px; color: #fff; }
.lc-chips { position: absolute; left: 64px; right: 64px; bottom: 54px; display: flex; flex-wrap: wrap; gap: 10px; }
.lc-chips span { padding: 10px 16px; border-radius: 999px; font-weight: 700; font-size: 21px; background: rgba(4, 11, 8, 0.72); border: 1.5px solid color-mix(in srgb, var(--c) 45%, transparent); }
.lc-chips b { color: var(--c); margin-right: 6px; }

/* the motion: everything is paused unless the cover is on screen */
.live-cover [class^="a-"], .live-cover [class*=" a-"] { animation-play-state: paused; }
.is-playing .live-cover [class^="a-"], .is-playing .live-cover [class*=" a-"] { animation-play-state: running; }
.a-swing { animation: lc-swing 2.4s ease-in-out infinite alternate; }
.a-barA { animation: lc-bar 1.2s ease-in-out infinite alternate; }
.a-barB { animation: lc-bar 1.2s ease-in-out infinite alternate-reverse; }
.a-slide { animation: lc-slide 2.6s ease-in-out infinite alternate; }
.a-bob { animation: lc-stretch 1.4s ease-in-out infinite alternate; }
.a-bobmass { animation: lc-drop 1.4s ease-in-out infinite alternate; }
.a-bob--slow { animation-duration: 1.9s; }
.a-turn { animation: lc-turn 2.4s ease-in-out infinite alternate; }
.a-down { animation: lc-down 2.4s ease-in-out infinite alternate; }
.a-up { animation: lc-up 2.4s ease-in-out infinite alternate; }
.a-spin { animation: lc-spin 6s linear infinite; }
.a-pulse { animation: lc-pulse 1.6s ease-in-out infinite alternate; }
.a-pulse--2 { animation-delay: -0.8s; }
.a-roll { animation: lc-roll 3s ease-in-out infinite alternate; }
.a-roll--short { animation-name: lc-roll-short; }
.a-nudge { animation: lc-nudge 1.8s ease-in-out infinite alternate; }
.a-draw { stroke-dasharray: 1; animation: lc-draw 3.2s linear infinite; }
.a-fill { animation: lc-fade 1.6s ease-in-out infinite alternate; }
.a-bubble { animation: lc-bubble 2.1s ease-in infinite; }
.a-talk { opacity: 0; animation: lc-talk 5.4s ease-in-out infinite; }
.a-glow { animation: lc-fade 1.8s ease-in-out infinite alternate; }
.a-write { stroke-dasharray: 1; animation: lc-write 4.5s ease-in-out infinite; }
@keyframes lc-talk { 0%, 100% { opacity: 0; } 6%, 14% { opacity: 1; } 20% { opacity: 0; } }
@keyframes lc-write { 0% { stroke-dashoffset: 1; } 70%, 88% { stroke-dashoffset: 0; } 100% { stroke-dashoffset: 1; } }
@keyframes lc-swing { from { transform: rotate(-24deg); } to { transform: rotate(24deg); } }
@keyframes lc-bar { from { transform: scaleY(1); } to { transform: scaleY(0.15); } }
@keyframes lc-slide { from { transform: translate(-20px, -11px); } to { transform: translate(40px, 22px); } }
@keyframes lc-stretch { from { transform: scaleY(1); } to { transform: scaleY(1.15); } }
@keyframes lc-drop { from { transform: translateY(0); } to { transform: translateY(var(--d, 20px)); } }
@keyframes lc-turn { from { transform: rotate(0); } to { transform: rotate(41deg); } }
@keyframes lc-down { from { transform: translateY(-20px); } to { transform: translateY(20px); } }
@keyframes lc-up { from { transform: translateY(20px); } to { transform: translateY(-20px); } }
@keyframes lc-spin { to { transform: rotate(360deg); } }
@keyframes lc-pulse { from { transform: scale(0.94); } to { transform: scale(1.06); } }
@keyframes lc-roll { from { transform: translateX(0); } to { transform: translateX(200px); } }
@keyframes lc-roll-short { from { transform: translateX(0); } to { transform: translateX(110px); } }
@keyframes lc-nudge { from { transform: translateX(-10px); } to { transform: translateX(24px); } }
@keyframes lc-draw { from { stroke-dashoffset: 1; } to { stroke-dashoffset: 0; } }
@keyframes lc-fade { from { opacity: 0.3; } to { opacity: 1; } }
@keyframes lc-bubble { from { transform: translateY(0); opacity: 1; } to { transform: translateY(-90px); opacity: 0; } }
@media (prefers-reduced-motion: reduce) { .live-cover [class^="a-"], .live-cover [class*=" a-"] { animation: none !important; } .a-draw { stroke-dasharray: none; } }
/* phones: skip the glow filter (expensive to redraw while animating) and keep buttons finger-sized */
@media (max-width: 900px), (hover: none) { .lc-art { filter: none; } }
@media (max-width: 720px) { .res .btn--small { min-height: 44px; padding: 0 20px; } .brand { min-height: 44px; } }

/* resources page: slow drifting colour glows behind the molecule canvas */
.res-nebula { --tint: 47, 216, 138; position: fixed; inset: 0; z-index: 0; pointer-events: none; overflow: hidden; }
/* moved by molecules.js with your scroll and pointer, not on a timer */
.res-nebula i { position: absolute; width: 70vmax; height: 70vmax; border-radius: 50%; opacity: 0.55; will-change: transform; }
.res-nebula i:nth-child(1) { left: -20vmax; top: -25vmax; background: radial-gradient(closest-side, rgba(var(--tint), 0.3), transparent); }
.res-nebula i:nth-child(2) { right: -25vmax; top: 20vh; background: radial-gradient(closest-side, rgba(46, 201, 183, 0.22), transparent); }
.res-nebula i:nth-child(3) { left: 10vw; bottom: -35vmax; background: radial-gradient(closest-side, rgba(255, 201, 77, 0.14), transparent); }

/* covers are clickable: a small enlarge badge appears on hover/focus */
.res .res-cover { cursor: zoom-in; }
.res .res-cover::after {
  content: ""; position: absolute; right: 10px; bottom: 10px; width: 34px; height: 34px; border-radius: 50%;
  background: rgba(4, 11, 8, 0.75) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23edf4ef' stroke-width='2' stroke-linecap='round'%3E%3Cpath d='M15 3h6v6M9 21H3v-6M21 3l-7 7M3 21l7-7'/%3E%3C/svg%3E") center / 16px no-repeat;
  border: 1px solid rgba(237, 244, 239, 0.25); opacity: 0.85; transition: opacity .2s ease, transform .2s ease;
}
.res .res-cover:hover::after, .res .res-cover:focus-visible::after { opacity: 1; transform: scale(1.08); }
.res .res-cover:focus-visible { outline: 2px solid var(--mint); outline-offset: 3px; }
@media (hover: hover) { .res .res-cover::after { opacity: 0; } }

/* the big viewer */
.lightbox {
  width: min(1100px, calc(100vw - 24px)); max-width: none; max-height: calc(100dvh - 24px); overflow: auto;
  padding: clamp(14px, 3vw, 28px); border: 1px solid rgba(143, 245, 194, 0.28); border-radius: 22px;
  background: #081510; color: var(--paper);
  box-shadow: 0 40px 120px -30px rgba(47, 216, 138, 0.45);
}
.lightbox::backdrop { background: rgba(2, 8, 5, 0.82); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px); }
.lightbox[open] { animation: pop-in .35s cubic-bezier(.2, .9, .2, 1.1); }
.has-cursor .lightbox, .has-cursor .lightbox * { cursor: auto; }
.has-cursor .lightbox button, .has-cursor .lightbox a { cursor: pointer; }
.lb-close { position: absolute; top: 10px; right: 10px; z-index: 3; width: 44px; height: 44px; display: grid; place-items: center; border-radius: 50%; border: 1px solid var(--line); background: rgba(7, 18, 13, 0.85); color: var(--paper); cursor: pointer; }
.lb-close:hover { border-color: var(--mint); color: var(--mint); }
.lb-frame { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 12px; margin-top: 38px; }
.lb-stage { margin: 0; cursor: default; }
.lb-nav { width: 48px; height: 48px; display: grid; place-items: center; border-radius: 50%; border: 1px solid var(--line); background: rgba(7, 18, 13, 0.8); color: var(--paper); cursor: pointer; transition: border-color .2s ease, color .2s ease; }
.lb-nav:hover { border-color: var(--mint); color: var(--mint); }
.lb-info { display: flex; align-items: center; justify-content: space-between; gap: 16px 24px; flex-wrap: wrap; margin-top: 18px; padding: 0 60px; }
.lb-title { font-family: var(--display); font-weight: 600; font-size: clamp(1.1rem, 2.2vw, 1.5rem); letter-spacing: -0.02em; }
.lb-count { margin-top: 4px; color: var(--muted); font-size: 0.9rem; }
.lb-buy { display: flex; align-items: center; gap: 16px; }
.lb-price { font-family: var(--display); font-weight: 600; font-size: 1.6rem; letter-spacing: -0.02em; }
@media (max-width: 720px) {
  .lb-frame { grid-template-columns: 1fr 1fr; }
  .lb-stage { grid-column: 1 / -1; grid-row: 1; }
  .lb-prev { grid-row: 2; justify-self: start; } .lb-next { grid-row: 2; justify-self: end; }
  .lb-info { padding: 0; }
  .lb-buy { width: 100%; justify-content: space-between; }
}

/* ---------- Course package details page ---------- */
.pkg-section { padding-block: clamp(56px, 9vh, 100px); }
.pkg.res { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr); gap: clamp(20px, 3vw, 40px); align-items: center; padding: clamp(18px, 2.4vw, 30px); }
.pkg.res:hover { transform: none; }
.pkg .res-cover { margin: 0; grid-column: auto; }
.pkg--flip .res-cover { order: 2; }
.pkg-step { font-size: 0.9rem; color: var(--c); font-weight: 600; }
.pkg-title { margin-top: 6px; font-family: var(--display); font-weight: 600; font-size: clamp(1.6rem, 3vw, 2.3rem); letter-spacing: -0.03em; line-height: 1.05; }
.pkg-lede { margin-top: 12px; color: var(--muted); font-size: 1.05rem; max-width: 36em; }
.pkg-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 22px; }
.pkg-cols h4 { margin: 0 0 10px; font-size: 0.95rem; font-weight: 600; }
.pkg-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.pkg-list li { position: relative; padding-left: 22px; font-size: 0.95rem; color: var(--paper); line-height: 1.45; }
.pkg-list li::before { content: ""; position: absolute; left: 2px; top: 0.5em; width: 9px; height: 9px; border-radius: 50%; border: 1.5px solid var(--c); }
.pkg .res-buy.pkg-buy { grid-column: auto; margin-top: 24px; padding-top: 18px; border-top: 1px solid var(--line); }
.pkg-buy p { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.pkg-per { color: var(--muted); font-size: 0.92rem; }
.pkg .res-price { font-size: 1.9rem; }

.compare-wrap { margin: 36px auto 0; max-width: 980px; overflow-x: auto; border-radius: 18px; border: 1px solid var(--line); background: rgba(7, 18, 13, 0.82); }
.compare { width: 100%; border-collapse: collapse; min-width: 560px; }
.compare th, .compare td { padding: 14px 18px; text-align: center; border-bottom: 1px solid var(--line); font-size: 0.98rem; }
.compare thead th { font-family: var(--display); font-weight: 600; font-size: 1rem; letter-spacing: -0.01em; padding-top: 20px; }
.compare tbody th { text-align: left; font-weight: 500; color: var(--muted); }
.compare tfoot td, .compare tfoot th { border-bottom: 0; padding-bottom: 20px; }
.compare .is-mix { background: rgba(198, 243, 107, 0.06); }
.compare thead .is-mix { color: #c6f36b; }
.compare .yes { color: #8ff5c2; font-weight: 600; }
.compare .no { color: rgba(162, 184, 171, 0.6); }

/* phones: the comparison table fits the screen instead of scrolling sideways */
@media (max-width: 640px) {
  .compare { min-width: 0; table-layout: fixed; }
  .compare th, .compare td { padding: 10px 6px; font-size: 0.8rem; }
  .compare thead th { font-size: 0.78rem; padding-top: 14px; }
  .compare tbody th { width: 34%; font-size: 0.78rem; }
  .compare tfoot .btn { min-height: 40px; padding: 0 10px; font-size: 0.8rem; width: 100%; }
}
@media (max-width: 860px) {
  .pkg.res { grid-template-columns: 1fr; }
  .pkg--flip .res-cover { order: 0; }
  .pkg-cols { grid-template-columns: 1fr; }
  .pkg-buy { flex-direction: column; align-items: stretch; }
  .pkg-buy .btn { width: 100%; }
}

/* package cards on the home page: details link next to the book button */
.plan-actions { grid-column: 2 / -1; display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.plan .plan-actions .btn { grid-column: auto; justify-self: auto; }
.plan-more { min-height: 44px; display: inline-flex; align-items: center; gap: 6px; padding: 0 6px; color: var(--mint); font-weight: 600; font-size: 0.95rem; text-decoration: underline; text-underline-offset: 4px; text-decoration-thickness: 1px; }
.plan-more:hover { color: var(--paper); }
@media (max-width: 640px) { .plan-actions { grid-column: 1 / -1; flex-direction: column; align-items: stretch; } .plan-more { justify-content: center; } }

.about-more { margin-top: 22px; }
/* ---------- About page ---------- */
.now-teaching { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.nt {
  display: inline-flex; align-items: center; gap: 10px; padding: 6px 16px 6px 6px; border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--c) 40%, transparent); background: color-mix(in srgb, var(--c) 8%, rgba(7, 18, 13, 0.6));
  font-weight: 600; font-size: 0.95rem;
}
.nt b { display: grid; place-items: center; width: 34px; height: 34px; border-radius: 8px; border: 1.5px solid var(--c); color: var(--c); font-family: var(--display); font-weight: 600; font-size: 0.85rem; }
.about-block .copy p { margin-top: 18px; color: var(--muted); max-width: 36em; }
.about-block .copy h2 + p { margin-top: 24px; }
.about-block em { color: var(--paper); font-style: italic; }
.values { list-style: none; padding: 0; margin: 30px 0 0; display: grid; gap: 12px; }
.values li { display: flex; gap: 16px; align-items: center; padding: 14px 16px; border-radius: 14px; border: 1px solid color-mix(in srgb, var(--c) 30%, transparent); background: color-mix(in srgb, var(--c) 6%, rgba(7, 18, 13, 0.7)); }
.values .vt { position: relative; flex: none; display: grid; place-items: center; width: 52px; height: 52px; border-radius: 10px; border: 1.5px solid var(--c); color: var(--c); font-family: var(--display); font-weight: 600; font-size: 1.2rem; }
.values .vt small { position: absolute; top: 3px; left: 6px; font-family: var(--body); font-size: 0.62rem; font-weight: 700; }
.values h3 { font-size: 1.02rem; }
.values p { margin: 2px 0 0 !important; font-size: 0.92rem; }

.edu { list-style: none; padding: 0; margin: 44px auto 0; max-width: 1080px; display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; }
.edu-item {
  display: flex; flex-direction: column; gap: 16px; padding: 18px; border-radius: 16px;
  border: 1px solid color-mix(in srgb, var(--c) 32%, transparent);
  background: color-mix(in srgb, var(--c) 6%, rgba(7, 18, 13, 0.8));
  transition: transform .25s ease, border-color .25s ease, box-shadow .25s ease;
}
.edu-item:hover { transform: translateY(-3px); border-color: var(--c); box-shadow: 0 20px 50px -26px var(--c); }
.edu-tile {
  position: relative; display: grid; place-items: center; width: 84px; aspect-ratio: 1; border-radius: 12px;
  border: 2px solid var(--c); color: var(--c);
  background: radial-gradient(circle at 30% 25%, color-mix(in srgb, var(--c) 26%, transparent), color-mix(in srgb, var(--c) 6%, rgba(7, 18, 13, 0.7)) 70%);
  box-shadow: 0 0 26px -8px var(--c);
}
.edu-tile b { font-family: var(--display); font-weight: 600; font-size: 1.9rem; letter-spacing: -0.03em; margin-top: -10px; }
.edu-tile small { position: absolute; top: 5px; left: 8px; font-size: 0.7rem; font-weight: 700; }
.edu-tile i { position: absolute; bottom: 6px; font-style: normal; font-size: 0.62rem; color: var(--paper); opacity: 0.8; }
.edu-item h3 { font-size: 1rem; line-height: 1.3; }
.edu-where { margin-top: 4px; color: var(--c); font-size: 0.86rem; font-weight: 600; }
.edu-item p:not(.edu-where) { margin-top: 8px; color: var(--muted); font-size: 0.9rem; line-height: 1.5; }
@media (max-width: 1080px) { .edu { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 720px) {
  .edu { grid-template-columns: 1fr; }
  .edu-item { flex-direction: row; align-items: flex-start; padding: 16px; }
  .edu-tile { width: 68px; }
  .edu-tile b { font-size: 1.5rem; }
  .edu-item, .values li { background: color-mix(in srgb, var(--c) 6%, rgba(7, 18, 13, 0.9)); }
}

/* ---------- scroll-linked reactions (reveal.js sets --p from 0 to 1 as things scroll in) ---------- */
/* headings: each word rises, sharpens and brightens in turn */
.rv-on [data-rv="words"] .rv-w {
  --w: clamp(0, calc(var(--p, 1) * (var(--n) + 3) - var(--i)), 1);
  display: inline-block;
  opacity: calc(0.08 + var(--w) * 0.92);
  translate: 0 calc((1 - var(--w)) * 0.55em);
  filter: blur(calc((1 - var(--w)) * 6px));
}
/* boxes: rise, settle from slightly smaller, and fade in, staggered within each group */
.rv-on [data-rv="box"] {
  --b: clamp(0, calc(var(--p, 1) * 1.35 - var(--d, 0) * 0.07), 1);
  opacity: calc(var(--b));
  translate: 0 calc((1 - var(--b)) * 46px);
  scale: calc(0.95 + var(--b) * 0.05);
}
@media (max-width: 720px) {
  .rv-on [data-rv="box"] { translate: 0 calc((1 - var(--b)) * 28px); }
  .rv-on [data-rv="words"] .rv-w { filter: none; }
}

/* discount applied in the booking table */
.discount-banner {
  max-width: 980px; margin: 28px auto 0; padding: 12px 18px; border-radius: 12px;
  border: 1px solid rgba(255, 201, 77, 0.5); background: rgba(255, 201, 77, 0.1); color: #ffe2a3;
  text-align: center; font-weight: 500;
}
.discount-banner b { font-family: var(--display); font-weight: 600; color: #ffc94d; letter-spacing: 0.02em; }
.pick-mass s { color: var(--muted); font-family: var(--body); font-weight: 400; font-size: 0.8em; margin-right: 6px; }

/* ---------- Book now pop-up with the spin wheel ---------- */
.spin {
  width: min(880px, calc(100vw - 32px)); max-height: calc(100dvh - 32px); overflow: auto;
  padding: 0; border: 1px solid rgba(143, 245, 194, 0.3); border-radius: 24px;
  background:
    radial-gradient(120% 90% at 0% 0%, rgba(47, 216, 138, 0.16), transparent 60%),
    radial-gradient(100% 80% at 100% 100%, rgba(255, 201, 77, 0.12), transparent 60%),
    #081510;
  color: var(--paper);
  box-shadow: 0 40px 120px -30px rgba(47, 216, 138, 0.45);
}
/* the pop-up sits above the custom cursor, so it uses the normal one */
.has-cursor .spin, .has-cursor .spin * { cursor: auto; }
.has-cursor .spin button, .has-cursor .spin a { cursor: pointer; }
.spin::backdrop { background: rgba(2, 8, 5, 0.72); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px); }
.spin[open] { animation: pop-in .45s cubic-bezier(.2, .9, .2, 1.1); }
@keyframes pop-in { from { opacity: 0; transform: translateY(16px) scale(.96); } }
.spin-close {
  position: absolute; top: 14px; right: 14px; z-index: 2;
  width: 44px; height: 44px; display: grid; place-items: center;
  border: 1px solid var(--line); border-radius: 50%; background: rgba(7, 18, 13, 0.7); color: var(--paper); cursor: pointer;
}
.spin-close:hover { border-color: var(--mint); color: var(--mint); }
.spin-grid { display: grid; grid-template-columns: 1fr 1fr; align-items: center; gap: 32px; padding: clamp(24px, 4vw, 48px); }
.wheel-wrap { position: relative; width: 100%; max-width: 360px; aspect-ratio: 1; margin: 0 auto; }
.wheel {
  width: 100%; height: 100%; display: block;
  filter: drop-shadow(0 18px 40px rgba(47, 216, 138, 0.35));
  overflow: visible;
}
.wheel-spin { transform-box: fill-box; transform-origin: center; transition: transform 5s cubic-bezier(.12, .8, .1, 1); }
.wheel text { font-family: var(--display); font-weight: 600; fill: #04140c; }
.wheel .sym { font-size: 15px; }
.wheel .lbl { font-size: 8.5px; font-family: var(--body); font-weight: 700; }
.wheel text.miss { fill: #a2b8ab; }
.wheel .lbl.miss { font-size: 7.5px; }
.code-row { margin-top: 10px; }
.wheel-pointer {
  position: absolute; top: -6px; left: 50%; z-index: 2; transform: translateX(-50%);
  width: 0; height: 0; border-left: 14px solid transparent; border-right: 14px solid transparent; border-top: 26px solid #fff;
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.5));
}
.wheel-hub {
  position: absolute; inset: 50% auto auto 50%; transform: translate(-50%, -50%);
  width: 26%; aspect-ratio: 1; border-radius: 50%; display: grid; place-items: center;
  background: #081510; border: 3px solid #ffc94d; box-shadow: 0 0 30px rgba(255, 201, 77, 0.5);
}
.wheel-hub b { font-family: var(--display); font-weight: 800; font-size: clamp(1rem, 2.4vw, 1.4rem); color: #ffc94d; letter-spacing: -0.03em; }
.spin-title { font-family: var(--display); font-weight: 800; font-size: clamp(1.7rem, 3.4vw, 2.6rem); line-height: 1.05; letter-spacing: -0.035em; }
.spin-sub { margin-top: 12px; color: var(--muted); font-size: 1.05rem; }
.spin-actions { display: grid; gap: 6px; margin-top: 26px; }
.spin-later { min-height: 44px; border: 0; background: none; color: var(--muted); font: 500 0.95rem var(--body); cursor: pointer; text-decoration: underline; text-underline-offset: 3px; }
.spin-later:hover { color: var(--paper); }
.spin-result { margin-top: 22px; display: grid; gap: 14px; animation: pop-in .4s ease; }
.spin-result strong { color: #ffc94d; }
.code-row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.code {
  font-family: var(--display); font-weight: 800; font-size: 1.5rem; letter-spacing: 0.06em;
  padding: 8px 16px; border: 2px dashed #ffc94d; border-radius: 10px; color: #ffc94d; background: rgba(255, 201, 77, 0.08);
}
.spin-fine { margin-top: 18px; font-size: 0.82rem; color: var(--muted); }

/* inline button in the bundles section to open the offer */
.offer-inline {
  display: inline-flex; align-items: center; gap: 10px; min-height: 48px; margin-top: 18px; padding: 6px 18px 6px 6px;
  border: 1px solid rgba(255, 201, 77, 0.55); border-radius: 999px;
  background: rgba(255, 201, 77, 0.08); color: var(--paper);
  font: 600 0.95rem var(--body); cursor: pointer;
  transition: transform .2s ease, border-color .2s ease, background-color .2s ease;
}
.offer-inline:hover { transform: translateY(-2px); border-color: #ffc94d; background: rgba(255, 201, 77, 0.14); }
.offer-fab-tile {
  width: 36px; height: 36px; border-radius: 50%; display: grid; place-items: center;
  background: conic-gradient(#2fd88a 0 25%, #2ec9b7 0 50%, #c6f36b 0 75%, #ffc94d 0);
  color: #04140c; font-family: var(--display); font-weight: 800; font-size: 0.8rem;
  animation: fab-spin 6s linear infinite;
}
@keyframes fab-spin { 0%, 80% { transform: rotate(0); } 100% { transform: rotate(360deg); } }

@media (max-width: 640px) {
  .spin-grid { grid-template-columns: 1fr; gap: 18px; padding: 56px 20px 24px; text-align: center; }
  .wheel-wrap { max-width: 250px; }
  .code-row { justify-content: center; }
}
@media (prefers-reduced-motion: reduce) {
  .wheel-spin { transition-duration: .8s; }
  .offer-fab-tile { animation: none; }
}

/* footer */
.foot { border-top: 1px solid var(--line); background: rgba(4, 11, 8, 0.9); padding: 36px 0; }
.foot-row { display: flex; flex-wrap: wrap; align-items: center; gap: 24px 40px; }
.foot nav { display: flex; gap: 24px; flex-wrap: wrap; }
.foot nav a { color: var(--muted); text-decoration: none; }
.foot nav a:hover { color: var(--paper); }
.copy-small { margin-left: auto; color: var(--muted); font-size: 0.9rem; }

/* ---------- responsive ---------- */
@media (max-width: 1080px) {
  .elements { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 900px) {
  .nav-links, .nav > .btn { display: none; }
  .menu {
    display: grid; gap: 6px; place-content: center; margin-left: auto;
    width: 44px; height: 44px; border: 1px solid var(--line); border-radius: 50%;
    background: rgba(7, 18, 13, 0.6); cursor: pointer;
  }
  .menu span { display: block; width: 18px; height: 1.5px; background: var(--paper); transition: transform .2s ease; }
  .menu[aria-expanded="true"] span:first-child { transform: translateY(3.75px) rotate(45deg); }
  .menu[aria-expanded="true"] span:last-child { transform: translateY(-3.75px) rotate(-45deg); }
  .hero { padding-top: 96px; padding-bottom: 72px; }
  /* blur is expensive on phones while the particles animate; use solid panels instead */
  .el, .plan, .marquee-row:first-child { backdrop-filter: none; -webkit-backdrop-filter: none; }
  .el { background: rgba(7, 18, 13, 0.5); }
  .elements { background: rgba(180, 225, 200, 0.1); }
  .el h3, .el p { text-shadow: 0 0 2px #07120d, 0 1px 10px #07120d, 0 0 18px rgba(7, 18, 13, 0.9); }
  .plan { background: rgba(7, 18, 13, 0.86); }
  .plan--mix { background: rgba(12, 36, 26, 0.92); }
  .scene:not(.hero) { padding: 80px 0; }
  .foot nav a { display: inline-flex; align-items: center; min-height: 44px; }
}
/* portrait phones and tablets: one column, with the top of the hero left open for the atom.
   Landscape phones keep the side-by-side layout (scene.js uses the same query). */
@media (max-width: 900px) and (orientation: portrait), (max-width: 600px) {
  .wrap--right { justify-content: flex-start; }
  .hero { align-items: flex-start; padding-top: max(300px, 44svh); min-height: 0; }
  /* the field sits behind text here, so give copy a soft backing */
  .how .copy, .about .copy, .faq .copy, .copy--plans > .h2, .copy--plans > p {
    background: radial-gradient(120% 100% at 30% 50%, rgba(7, 18, 13, 0.7), transparent 80%);
  }
}
/* landscape phones: keep text to one side and narrower so the shape has room */
@media (max-width: 900px) and (orientation: landscape) and (min-width: 601px) {
  .copy, .copy--hero, .copy--plans { max-width: 54%; }
  .hero { min-height: 100svh; }
  .lockup-word { font-size: 2.4rem; }
  .etile { width: 78px; }
  .etile b { font-size: 2rem; }
  .etile em { display: none; }
}
@media (max-width: 640px) {
  .lede { font-size: 1.1rem; }
  .lockup-word { font-size: 9.2vw; }
  .etile { width: calc((100vw - 2 * var(--gutter) - 24px) / 3.4); }
  .etile b { font-size: 2.1rem; margin-top: -14px; }
  .etile i { bottom: 10%; }
  .etile em { display: none; }
  .hero .lede { margin-top: 20px; }
  .actions { margin-top: 28px; }
  .elements { margin-top: 40px; }
  .el { padding: 18px 16px 20px; }
  .el .tile { width: 44px; }
  .el .tile b { font-size: 1.05rem; }
  .el .tile small { font-size: 0.6rem; top: 2px; left: 4px; }
  .el h3 { margin-top: 14px; font-size: 0.98rem; }
  .el p { font-size: 0.86rem; }
  /* compact periodic-table form on phones: name + email share a row, packages sit three across */
  .book .lede { font-size: 1rem; }
  .ptable {
    margin-top: 28px; gap: 8px;
    grid-template-columns: repeat(6, 1fr);
    grid-template-areas:
      "nm nm nm em em em"
      "gc gc gc gc gc gc"
      "gr gr mx mx in in"
      "ms ms ms ms ms ms"
      "go go go go go go"
      "note note note note note note";
  }
  .cell { min-height: 0; padding: 28px 12px 10px; border-radius: 10px; gap: 4px; }
  .cell-no { top: 8px; left: 10px; font-size: 0.7rem; }
  .cell-sym { top: 6px; right: 10px; font-size: 1.15rem; }
  .cell label:not(.pick) { font-size: 0.82rem; }
  .cell input:not([type="radio"]) { min-height: 40px; font-size: 16px; padding: 6px 0; }
  .cell textarea { min-height: 84px; font-size: 16px; }
  .cell--ms { padding-top: 30px; }
  .pick { min-height: 112px; padding: 26px 8px 10px; }
  .pick .cell-sym { font-size: 1.7rem; margin-top: -4px; }
  .pick-name { font-size: 0.8rem; line-height: 1.2; }
  .pick-mass { font-size: 0.95rem; }
  .pick-mass s { display: block; font-size: 0.72rem; margin: 0; }
  .pick:has(input:checked)::after { content: none; }
  .cell--go { min-height: 72px; padding-top: 26px; }
  .go-label { font-size: 1.05rem; }
  .discount-banner { margin-top: 20px; font-size: 0.92rem; }
  .plan { grid-template-columns: 56px 1fr; padding: 20px; column-gap: 16px; }
  .plan-price, .plan-week { grid-column: 2; grid-row: auto; text-align: left; }
  .plan-price { margin-top: 16px; }
  .plan-price span { display: inline; margin-right: 6px; }
  .plan-list { grid-column: 1 / -1; }
  .plan .btn { grid-column: 1 / -1; justify-self: stretch; }
  .copy-small { margin-left: 0; }
  .brand-name { font-size: 0.92rem; }
  .actions .btn { flex: 1 1 100%; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition-duration: .01ms !important; }
}