:root {
  --paper: #fff6ea;
  --ink: #2b2b33;
  --coral: #ff6b5b;
  --coral-deep: #e8503f;
  --sunshine: #ffc83d;
  --sky: #5bb8e8;
  --sky-deep: #3d9bd0;
  --green: #7fb069;
  --green-deep: #648f51;
  --lilac: #b69ce8;
  --lilac-deep: #9678d4;
  --pink: #ffa8c5;
  --cream: #fffdf8;
  --shadow-pop: 6px 6px 0 var(--ink);
  --shadow-pop-lg: 12px 12px 0 var(--ink);
  --radius: 26px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Nunito", -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.55;
}

a {
  color: inherit;
  text-decoration: none;
}

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

button {
  font: inherit;
}

.shell {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.lab-topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 14px clamp(16px, 4vw, 40px);
  background: rgba(255, 246, 234, 0.9);
  border-bottom: 3px solid var(--ink);
  backdrop-filter: blur(14px);
}

.wordmark {
  display: flex;
  gap: 5px;
  flex-shrink: 0;
}

.wordmark-block {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 3px solid var(--ink);
  border-radius: 11px;
  color: var(--ink);
  font-family: "Fredoka", sans-serif;
  font-size: 22px;
  font-weight: 700;
}

.b1 { background: var(--coral); transform: rotate(-4deg); }
.b2 { background: var(--sunshine); transform: rotate(3deg); }
.b3 { background: var(--sky); transform: rotate(-2deg); }
.b4 { background: var(--lilac); transform: rotate(5deg); }

.lab-nav {
  display: flex;
  gap: clamp(14px, 2.6vw, 30px);
  margin-left: auto;
  font-size: 15px;
  font-weight: 900;
}

.lab-nav a {
  padding: 7px 0;
  border-bottom: 4px solid transparent;
}

.lab-nav a:hover {
  border-color: var(--sunshine);
}

.lab-hero {
  padding: clamp(56px, 8vw, 96px) 0 clamp(42px, 7vw, 78px);
  overflow: hidden;
}

.lab-hero-inner {
  position: relative;
}

.lab-hero-inner::after {
  content: "";
  position: absolute;
  right: 8%;
  top: 6%;
  width: clamp(110px, 18vw, 210px);
  height: clamp(110px, 18vw, 210px);
  border: 4px solid var(--ink);
  border-radius: 36px;
  background:
    linear-gradient(135deg, var(--sunshine) 0 34%, transparent 34%),
    linear-gradient(45deg, var(--sky) 0 50%, var(--lilac) 50%);
  box-shadow: var(--shadow-pop-lg);
  transform: rotate(8deg);
  z-index: -1;
}

.kicker {
  display: inline-block;
  max-width: min(100%, 760px);
  padding: 7px 14px;
  border: 3px solid var(--ink);
  border-radius: 99px;
  background: var(--cream);
  box-shadow: 4px 4px 0 var(--ink);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.05em;
  line-height: 1.2;
  text-align: center;
  text-transform: uppercase;
}

.kicker-coral { background: var(--coral); }
.kicker-yellow { background: var(--sunshine); }
.kicker-sky { background: var(--sky); }
.kicker-green { background: var(--green); }
.kicker-lilac { background: var(--lilac); }

h1,
h2,
h3 {
  margin: 0;
  font-family: "Fredoka", "Nunito", sans-serif;
  font-weight: 700;
  line-height: 1.02;
}

h1 {
  max-width: 840px;
  margin-top: 22px;
  font-size: clamp(48px, 8vw, 106px);
}

h2 {
  max-width: 900px;
  font-size: clamp(36px, 5vw, 66px);
}

h3 {
  font-size: clamp(28px, 3.5vw, 44px);
}

p {
  margin: 0;
}

.lab-hero p:not(.kicker),
.section-heading p:not(.kicker),
.compound-copy p {
  max-width: 660px;
  margin-top: 20px;
  font-size: clamp(18px, 1.8vw, 22px);
}

.lab-section {
  padding: clamp(74px, 10vw, 122px) 0;
}

.section-paper {
  background: var(--paper);
}

.section-green {
  background: var(--green);
  border-block: 4px solid var(--ink);
}

.section-sky {
  background: var(--sky);
  border-block: 4px solid var(--ink);
}

.section-cream {
  background: var(--cream);
}

.section-ink {
  background: var(--ink);
  color: var(--paper);
}

.section-proof {
  background: var(--ink);
  color: var(--paper);
  border-block: 4px solid var(--ink);
}

.section-research {
  background: var(--paper);
}

.section-heading {
  margin-bottom: clamp(28px, 5vw, 50px);
}

.section-heading .kicker {
  margin-bottom: 20px;
}

.section-heading.centered {
  display: grid;
  justify-items: center;
  text-align: center;
}

/* Proof */
.proof-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.9fr);
  gap: clamp(30px, 6vw, 76px);
  align-items: center;
}

.proof-copy .kicker {
  margin-bottom: 20px;
}

.proof-copy h2 {
  color: var(--paper);
}

.proof-copy p {
  max-width: 640px;
  margin-top: 22px;
  color: rgba(255, 246, 234, 0.78);
  font-size: clamp(18px, 1.7vw, 22px);
}

.proof-copy strong {
  color: var(--sunshine);
  font-weight: 900;
}

.proof-card {
  position: relative;
  margin: 0;
  min-height: 480px;
  aspect-ratio: 1055 / 1491;
  border: 4px solid var(--paper);
  border-radius: 34px;
  background: var(--cream);
  box-shadow: 12px 12px 0 var(--lilac), 12px 12px 0 4px var(--paper);
  overflow: hidden;
  transform: rotate(1.5deg);
}

.proof-slides {
  position: absolute;
  inset: 0;
}

.proof-card img {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  min-height: 480px;
  object-fit: contain;
  opacity: 0;
  filter: saturate(0.96) brightness(0.92);
  transform: none;
  transition: opacity 650ms ease, transform 2400ms ease;
}

.proof-card img.is-active {
  opacity: 1;
  transform: none;
}

.proof-card figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: grid;
  gap: 8px;
  padding: 24px;
  background: linear-gradient(to top, rgba(43, 43, 51, 0.92), rgba(43, 43, 51, 0));
  z-index: 2;
}

.proof-card figcaption span {
  color: var(--sunshine);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.proof-card figcaption strong {
  color: var(--paper);
  font-family: "Fredoka", sans-serif;
  font-size: clamp(28px, 3.5vw, 42px);
  line-height: 1;
}

/* Distributed learning */
.learning-card {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: clamp(24px, 4vw, 54px);
  align-items: stretch;
  padding: clamp(18px, 3vw, 34px);
  border: 4px solid var(--ink);
  border-radius: 34px;
  background: var(--cream);
  box-shadow: var(--shadow-pop-lg);
}

.learning-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-width: 0;
}

.learning-copy p {
  margin: 18px 0 28px;
  font-size: 18px;
}

.toggle-row {
  display: grid;
  gap: 12px;
}

.rhythm-pill {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  width: 100%;
  padding: 14px 16px;
  border: 3px solid var(--ink);
  border-radius: 18px;
  background: var(--paper);
  color: var(--ink);
  cursor: pointer;
  text-align: left;
  box-shadow: 3px 3px 0 var(--ink);
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.rhythm-pill:hover {
  transform: translate(-2px, -2px);
  box-shadow: 5px 5px 0 var(--ink);
}

.rhythm-pill.is-active {
  background: var(--sunshine);
}

.rhythm-pill strong {
  font-family: "Fredoka", sans-serif;
  font-size: 19px;
  line-height: 1.08;
}

.rhythm-pill span {
  flex-shrink: 0;
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
}

.chart-panel {
  position: relative;
  min-height: 360px;
  padding: 28px 28px 24px;
  border: 3px solid var(--ink);
  border-radius: 26px;
  background:
    linear-gradient(to right, rgba(43, 43, 51, 0.08) 2px, transparent 2px),
    linear-gradient(to bottom, rgba(43, 43, 51, 0.08) 2px, transparent 2px),
    #fffaf2;
  background-size: 42px 42px;
  overflow: hidden;
}

.chart-label {
  position: absolute;
  z-index: 2;
  padding: 4px 8px;
  border: 2px solid var(--ink);
  border-radius: 99px;
  background: var(--cream);
  font-size: 11px;
  font-weight: 900;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.chart-label-y {
  top: 16px;
  left: 18px;
}

.chart-label-x {
  right: 18px;
  bottom: 112px;
}

.retention-chart {
  display: block;
  width: 100%;
  height: 280px;
  margin-top: 12px;
  overflow: visible;
}

.axis {
  stroke: rgba(43, 43, 51, 0.42);
  stroke-width: 3;
  stroke-linecap: round;
}

.weekend-line,
.blox-line {
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: opacity 260ms ease, stroke-width 260ms ease, filter 260ms ease;
}

.weekend-line {
  stroke: var(--coral);
  stroke-width: 5;
}

.blox-line {
  stroke: var(--green-deep);
  stroke-width: 6;
  filter: drop-shadow(0 5px 0 rgba(43, 43, 51, 0.16));
}

.chart-dots circle {
  fill: var(--sunshine);
  stroke: var(--ink);
  stroke-width: 3;
  transition: opacity 260ms ease;
}

.learning-card[data-mode="weekend"] .blox-line,
.learning-card[data-mode="weekend"] .chart-dots {
  opacity: 0.22;
}

.learning-card[data-mode="weekend"] .weekend-line {
  stroke-width: 7;
  filter: drop-shadow(0 5px 0 rgba(255, 107, 91, 0.25));
}

.learning-card[data-mode="blox"] .weekend-line {
  opacity: 0.25;
  stroke-width: 4;
  stroke-dasharray: 8 10;
}

.chart-caption {
  min-height: 54px;
  margin: 12px 0 0;
  color: var(--green-deep);
  font-family: "Fredoka", sans-serif;
  font-size: clamp(20px, 2.2vw, 27px);
  font-weight: 700;
  line-height: 1.1;
  text-align: center;
}

/* Practice blocks */
.practice-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(320px, 1fr);
  gap: clamp(26px, 5vw, 64px);
  align-items: center;
}

.practice-copy .kicker {
  margin-bottom: 20px;
}

.practice-copy p {
  max-width: 590px;
  margin-top: 20px;
  font-size: clamp(18px, 1.8vw, 22px);
}

.practice-card {
  display: grid;
  gap: 30px;
  padding: clamp(22px, 4vw, 34px);
  border: 4px solid var(--ink);
  border-radius: 30px;
  background: var(--cream);
  box-shadow: var(--shadow-pop-lg);
}

.practice-row {
  display: grid;
  gap: 13px;
}

.practice-label {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  font-size: 15px;
  font-weight: 900;
  line-height: 1.15;
  text-transform: uppercase;
}

.practice-label strong {
  color: var(--ink);
}

.practice-label span {
  color: var(--green-deep);
  text-align: right;
}

.practice-row:last-child .practice-label span {
  color: var(--coral-deep);
}

.practice-blocks {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 8px;
  min-height: 62px;
}

.practice-blocks span {
  display: block;
  min-height: 62px;
  border: 3px solid var(--ink);
  border-radius: 13px;
  background: #dde4df;
  box-shadow: 3px 3px 0 var(--ink);
  transform: translateY(5px) scale(0.96);
  opacity: 0.72;
}

.practice-distributed span {
  animation: blockFillGreen 3.8s ease-in-out infinite;
}

.practice-distributed span:nth-child(2) { animation-delay: 120ms; }
.practice-distributed span:nth-child(3) { animation-delay: 240ms; }
.practice-distributed span:nth-child(4) { animation-delay: 360ms; }
.practice-distributed span:nth-child(5) { animation-delay: 480ms; }
.practice-distributed span:nth-child(6) { animation-delay: 600ms; }
.practice-distributed span:nth-child(7) { animation-delay: 720ms; }

.practice-massed span {
  background: #d9dedc;
}

.practice-massed span.is-active {
  animation: blockFillCoral 3.8s ease-in-out infinite;
}

.practice-massed span.is-active:nth-child(2) {
  animation-delay: 160ms;
}

@keyframes blockFillGreen {
  0%,
  17% {
    background: #d9e4d4;
    transform: translateY(5px) scale(0.96);
    opacity: 0.75;
  }
  32%,
  82% {
    background: var(--green);
    transform: translateY(0) scale(1);
    opacity: 1;
  }
  100% {
    background: #d9e4d4;
    transform: translateY(5px) scale(0.96);
    opacity: 0.75;
  }
}

@keyframes blockFillCoral {
  0%,
  17% {
    background: #ead8d4;
    transform: translateY(5px) scale(0.96);
    opacity: 0.75;
  }
  32%,
  82% {
    background: var(--coral);
    transform: translateY(0) scale(1);
    opacity: 1;
  }
  100% {
    background: #ead8d4;
    transform: translateY(5px) scale(0.96);
    opacity: 0.75;
  }
}

/* Formula */
.formula-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(12px, 2.2vw, 24px);
  padding: clamp(22px, 4vw, 44px);
  border: 4px solid var(--ink);
  border-radius: 34px;
  background: var(--cream);
  box-shadow: var(--shadow-pop-lg);
}

.formula-item,
.formula-result {
  display: grid;
  justify-items: center;
  gap: 7px;
  min-width: 128px;
  text-align: center;
}

.formula-icon {
  display: grid;
  place-items: center;
  width: 70px;
  height: 70px;
  margin-bottom: 4px;
  border: 3px solid var(--ink);
  border-radius: 50%;
  background: var(--sunshine);
  box-shadow: 4px 4px 0 var(--ink);
  transition: transform 220ms ease, background 220ms ease;
}

.formula-icon svg {
  width: 31px;
  height: 31px;
  fill: none;
  stroke: var(--ink);
  stroke-width: 2.2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.icon-lilac {
  background: var(--lilac);
}

.icon-sky {
  background: var(--sky);
}

.formula-item strong,
.formula-result strong {
  color: var(--ink);
  font-family: "Fredoka", sans-serif;
  font-size: clamp(22px, 2.8vw, 32px);
  line-height: 1;
}

.formula-item span:last-child,
.formula-result span {
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.formula-op {
  font-family: "Fredoka", sans-serif;
  font-size: clamp(30px, 4vw, 52px);
  font-weight: 700;
  line-height: 1;
  transition: transform 220ms ease, color 220ms ease;
}

.formula-result {
  min-width: 170px;
  padding: 20px;
  border: 3px solid var(--ink);
  border-radius: 24px;
  background: var(--coral);
  box-shadow: 5px 5px 0 var(--ink);
  transition: transform 220ms ease, background 220ms ease;
}

.formula-card [data-step].is-lit .formula-icon,
.formula-card .formula-op.is-lit,
.formula-card .formula-result.is-lit {
  transform: translateY(-6px) rotate(-2deg) scale(1.04);
}

.formula-card .formula-op.is-lit {
  color: var(--coral-deep);
}

.formula-card .formula-result.is-lit {
  background: var(--sunshine);
}

/* Compound */
.compound-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.9fr);
  gap: clamp(28px, 5vw, 62px);
  align-items: center;
}

.compound-copy .kicker {
  margin-bottom: 20px;
}

.compound-graph {
  position: relative;
  margin-top: 34px;
  padding: 26px;
  border: 4px solid var(--ink);
  border-radius: 26px;
  background:
    linear-gradient(to right, rgba(43, 43, 51, 0.06) 2px, transparent 2px),
    linear-gradient(to bottom, rgba(43, 43, 51, 0.06) 2px, transparent 2px),
    var(--paper);
  background-size: 38px 38px;
  box-shadow: var(--shadow-pop);
}

.compound-graph svg {
  display: block;
  width: 100%;
  min-height: 270px;
  overflow: visible;
}

.standard-curve,
.compound-curve {
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.standard-curve {
  stroke: var(--coral);
  stroke-width: 5;
  stroke-dasharray: 9 10;
}

.compound-curve {
  stroke: var(--green-deep);
  stroke-width: 8;
  filter: drop-shadow(0 6px 0 rgba(43, 43, 51, 0.15));
}

.graph-tag,
.axis-note {
  position: absolute;
  z-index: 2;
  padding: 5px 9px;
  border: 2px solid var(--ink);
  border-radius: 99px;
  background: var(--cream);
  font-size: 12px;
  font-weight: 900;
  text-transform: uppercase;
}

.tag-blox {
  top: 34px;
  right: 28px;
  background: var(--green);
}

.tag-standard {
  right: 28px;
  top: 62%;
  background: var(--coral);
}

.y-note {
  left: 22px;
  top: 24px;
}

.x-note {
  right: 24px;
  bottom: 22px;
}

.compound-image-card {
  position: relative;
  margin: 0;
  border: 4px solid var(--ink);
  border-radius: 34px;
  background: var(--sunshine);
  box-shadow: 12px 12px 0 var(--sky), 12px 12px 0 4px var(--ink);
  overflow: hidden;
  transform: rotate(2deg);
}

.compound-image-card img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border-bottom: 4px solid var(--ink);
}

.compound-image-card figcaption {
  padding: 20px;
  font-family: "Fredoka", sans-serif;
  font-size: clamp(27px, 4vw, 42px);
  font-weight: 700;
  line-height: 0.98;
}

/* Multiplier */
.multiplier-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 30px);
}

.neuro-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 350px;
  padding: clamp(26px, 4vw, 44px) 24px 30px;
  border: 4px solid var(--ink);
  border-radius: 30px;
  background: var(--cream);
  color: var(--ink);
  box-shadow: var(--shadow-pop);
  text-align: center;
  overflow: hidden;
  transition: transform 190ms ease, box-shadow 190ms ease;
}

.neuro-card::before {
  content: "";
  position: absolute;
  top: 18px;
  width: 116px;
  height: 116px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.18;
  filter: blur(12px);
  animation: softPulse 3.2s ease-in-out infinite;
}

.neuro-card:hover {
  transform: translateY(-8px) rotate(-1deg);
  box-shadow: 9px 13px 0 var(--ink);
}

.card-yellow { color: #c28a00; }
.card-coral { color: var(--coral-deep); }
.card-sky { color: var(--sky-deep); }

.neuro-icon {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  width: 86px;
  height: 86px;
  margin-bottom: 26px;
  border: 3px solid var(--ink);
  border-radius: 50%;
  background: var(--paper);
  box-shadow: 5px 5px 0 var(--ink);
}

.neuro-icon svg {
  width: 39px;
  height: 39px;
  fill: currentColor;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linejoin: round;
}

.neuro-card h3 {
  position: relative;
  z-index: 1;
  margin-bottom: 8px;
  color: var(--ink);
  font-size: clamp(28px, 3vw, 36px);
}

.neuro-card strong {
  position: relative;
  z-index: 1;
  display: block;
  margin-bottom: 20px;
  color: currentColor;
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.neuro-card p {
  position: relative;
  z-index: 1;
  max-width: 290px;
  margin: 0;
  color: var(--ink);
  font-size: 17px;
}

/* Research flip cards */
.tap-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-top: 24px;
  padding: 8px 16px;
  border: 3px solid var(--ink);
  border-radius: 99px;
  background: var(--sunshine);
  box-shadow: 4px 4px 0 var(--ink);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.research-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 28px);
  align-items: start;
}

.research-card {
  position: relative;
  min-height: 134px;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  perspective: 1000px;
  text-align: left;
  transition: min-height 260ms ease;
}

.research-card.is-flipped {
  min-height: 430px;
}

.research-front,
.research-back {
  position: absolute;
  inset: 0;
  display: flex;
  border: 4px solid var(--ink);
  border-radius: 26px;
  background: var(--cream);
  box-shadow: var(--shadow-pop);
  backface-visibility: hidden;
  transform-style: preserve-3d;
  transition: transform 420ms cubic-bezier(0.22, 0.61, 0.36, 1), box-shadow 180ms ease;
}

.research-front {
  align-items: center;
  gap: 18px;
  padding: 22px;
}

.research-back {
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
  min-height: 430px;
  padding: 24px;
  transform: rotateY(180deg);
}

.research-card.is-flipped .research-front {
  transform: rotateY(180deg);
}

.research-card.is-flipped .research-back {
  transform: rotateY(360deg);
}

.research-card:hover .research-front,
.research-card:hover .research-back,
.research-card:focus-visible .research-front,
.research-card:focus-visible .research-back {
  box-shadow: 9px 9px 0 var(--ink);
}

.research-card:focus-visible {
  outline: 0;
}

.research-icon {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 62px;
  height: 62px;
  border: 3px solid var(--ink);
  border-radius: 18px;
  background: var(--sunshine);
  box-shadow: 4px 4px 0 var(--ink);
  font-family: "Fredoka", sans-serif;
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  text-align: center;
}

.research-front-text {
  display: grid;
  gap: 6px;
}

.research-front-text em {
  color: rgba(43, 43, 51, 0.72);
  font-size: 15px;
  font-style: italic;
  font-weight: 800;
  line-height: 1.25;
}

.research-front strong,
.research-back strong {
  font-family: "Fredoka", sans-serif;
  font-size: clamp(23px, 2.5vw, 30px);
  line-height: 1.06;
}

.research-back span {
  color: var(--ink);
  font-size: 16px;
  line-height: 1.42;
}

.research-back em {
  display: block;
  padding-top: 16px;
  border-top: 3px solid rgba(43, 43, 51, 0.14);
  color: rgba(43, 43, 51, 0.72);
  font-style: normal;
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.04em;
  line-height: 1.35;
  text-transform: uppercase;
}

.card-blue .research-icon { background: var(--sky); }
.card-coral-research .research-icon { background: var(--coral); }
.card-green-research .research-icon { background: var(--green); }
.card-yellow-research .research-icon { background: var(--sunshine); }
.card-lilac-research .research-icon { background: var(--lilac); }
.card-sky-research .research-icon { background: var(--sky); }

.card-blue .research-back { background: #eef8ff; }
.card-coral-research .research-back { background: #fff0ee; }
.card-green-research .research-back { background: #eff8ec; }
.card-yellow-research .research-back { background: #fff8dc; }
.card-lilac-research .research-back { background: #f5efff; }
.card-sky-research .research-back { background: #eef8ff; }

@keyframes softPulse {
  0%,
  100% {
    transform: scale(0.88);
    opacity: 0.14;
  }
  50% {
    transform: scale(1.12);
    opacity: 0.24;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 960px) {
  .lab-topbar {
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }

  .lab-nav {
    width: 100%;
    margin-left: 0;
    overflow-x: auto;
    padding-bottom: 3px;
    white-space: nowrap;
  }

  .learning-card,
  .proof-grid,
  .practice-grid,
  .compound-grid {
    grid-template-columns: 1fr;
  }

  .proof-card {
    max-width: 560px;
    margin: 0 auto;
  }

  .compound-image-card {
    max-width: 520px;
    margin: 0 auto;
  }

  .formula-card {
    align-items: stretch;
    flex-wrap: wrap;
    justify-content: center;
  }

  .formula-result {
    flex-basis: 100%;
    max-width: 320px;
  }

  .multiplier-grid {
    grid-template-columns: 1fr;
  }

  .research-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 620px) {
  .shell {
    width: min(100% - 28px, 1180px);
  }

  .lab-hero-inner::after {
    opacity: 0.16;
    right: -64px;
    top: 36px;
  }

  .learning-card,
  .proof-card,
  .formula-card {
    border-radius: 24px;
    box-shadow: 7px 7px 0 var(--ink);
  }

  .proof-card {
    min-height: 340px;
    transform: none;
  }

  .proof-card img {
    min-height: 340px;
  }

  .rhythm-pill {
    align-items: flex-start;
    flex-direction: column;
    gap: 5px;
  }

  .practice-card {
    border-radius: 24px;
    box-shadow: 7px 7px 0 var(--ink);
  }

  .practice-label {
    align-items: flex-start;
    flex-direction: column;
    gap: 5px;
  }

  .practice-label span {
    text-align: left;
  }

  .practice-blocks {
    gap: 5px;
    min-height: 52px;
  }

  .practice-blocks span {
    min-height: 52px;
    border-radius: 10px;
    box-shadow: 2px 2px 0 var(--ink);
  }

  .chart-panel {
    min-height: 310px;
    padding: 20px 16px;
  }

  .retention-chart {
    height: 230px;
  }

  .formula-card {
    flex-direction: column;
  }

  .formula-op {
    transform: rotate(90deg);
    text-align: center;
  }

  .formula-card [data-step].is-lit.formula-op {
    transform: rotate(90deg) scale(1.1);
  }

  .formula-item,
  .formula-result {
    width: 100%;
  }

  .tag-standard {
    top: 64%;
  }

  .compound-image-card {
    transform: none;
  }

  .research-grid {
    grid-template-columns: 1fr;
  }

  .research-card.is-flipped,
  .research-back {
    min-height: 640px;
  }
}