/* EEG Lab — quiet mobile-first lesson UI */

.eeg-app {
  --font-display: "Literata", Georgia, serif;
  --font-body: "Manrope", system-ui, sans-serif;
  --lab-bg: oklch(0.985 0.006 155);
  --lab-ink: oklch(0.22 0.025 165);
  --lab-muted: oklch(0.51 0.018 160);
  --lab-soft: oklch(0.95 0.012 155);
  --lab-card: oklch(0.968 0.009 155);
  --lab-line: oklch(0.87 0.015 155);
  --lab-teal: oklch(0.5 0.1 175);
  --lab-teal-soft: oklch(0.5 0.1 175 / 0.1);
  --lab-teal-strong: oklch(0.4 0.085 175);
  --lab-shadow: 0 24px 70px oklch(0.22 0.025 165 / 0.08);
  min-height: 100dvh;
  background: var(--lab-bg);
  color: var(--lab-ink);
  font-family: var(--font-body, "Manrope", sans-serif);
}

html[data-theme="dark"] .eeg-app {
  --lab-bg: oklch(0.17 0.02 165);
  --lab-ink: oklch(0.93 0.012 150);
  --lab-muted: oklch(0.7 0.02 155);
  --lab-soft: oklch(0.21 0.022 165);
  --lab-card: oklch(0.2 0.02 165);
  --lab-line: oklch(0.3 0.025 165);
  --lab-teal: oklch(0.78 0.1 175);
  --lab-teal-soft: oklch(0.78 0.1 175 / 0.11);
  --lab-teal-strong: oklch(0.83 0.095 175);
  --lab-shadow: 0 24px 70px oklch(0.08 0.01 165 / 0.36);
  background: var(--lab-bg);
}

*, *::before, *::after { box-sizing: border-box; }
.is-hidden { display: none !important; }

.eeg-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 40;
  height: 2px;
  background: var(--lab-teal);
  pointer-events: none;
  transition: width 380ms cubic-bezier(0.22, 1, 0.36, 1), opacity 220ms;
}

.eeg-topbar {
  position: fixed;
  inset: 0 0 auto;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: clamp(1rem, 2.5vw, 1.5rem);
  pointer-events: none;
}

.eeg-topbar > * { pointer-events: auto; }

.eeg-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--lab-ink);
  text-decoration: none;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.eeg-brand-mark {
  display: grid;
  width: 2.35rem;
  height: 2.35rem;
  place-items: center;
  color: var(--lab-teal);
}

.eeg-brand-mark svg {
  display: block;
  width: 100%;
  height: 100%;
}

.eeg-top-actions {
  display: flex;
  align-items: center;
  gap: clamp(0.35rem, 1.5vw, 0.8rem);
}

.eeg-top-link {
  min-height: 2.75rem;
  padding: 0.55rem 0.65rem;
  border: 0;
  background: transparent;
  color: var(--lab-muted);
  font: 700 0.78rem/1 var(--font-body);
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
}

.eeg-top-link:hover {
  color: var(--lab-ink);
}

.eeg-theme-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  min-height: 2.1rem;
  padding: 0.25rem 0.7rem;
  border: 1px solid var(--lab-line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--lab-bg) 82%, transparent);
  color: var(--lab-muted);
  font: 800 0.72rem/1 var(--font-body, "Manrope", sans-serif);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
}

.eeg-top-link:focus-visible,
.eeg-theme-btn:focus-visible,
.btn-primary:focus-visible,
.btn-ghost:focus-visible,
.btn-text:focus-visible,
.eeg-module-row:focus-visible,
.interact-binary-btn:focus-visible,
.eeg-sandbox-link:focus-visible {
  outline: 3px solid var(--lab-teal);
  outline-offset: 3px;
}

.eeg-screen {
  display: flex;
  width: 100%;
  min-height: 100dvh;
  align-items: center;
  justify-content: center;
  padding: clamp(5.4rem, 10vh, 7rem) clamp(1.1rem, 4vw, 2rem) 2rem;
}

.eeg-screen.is-hidden { display: none; }

.eeg-welcome,
.eeg-stage,
.eeg-primer,
.eeg-look,
.eeg-lesson,
.eeg-answer,
.eeg-complete,
.eeg-map {
  width: min(100%, 43rem);
  margin: 0 auto;
  text-align: center;
}

.eeg-welcome {
  display: grid;
  min-height: min(38rem, 72dvh);
  align-content: center;
  justify-items: center;
}

.eeg-welcome-actions {
  display: grid;
  width: min(100%, 34rem);
  justify-items: center;
}

.btn-text {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  margin-top: 0.55rem;
  padding: 0.5rem 0.75rem;
  border: 0;
  background: transparent;
  color: var(--lab-teal-strong);
  font: 750 0.9rem/1.2 var(--font-body);
  text-decoration: none;
  cursor: pointer;
}

.btn-text:hover {
  color: var(--lab-ink);
}

.eeg-boundary {
  margin: 1.25rem 0 0;
  color: var(--lab-muted);
  font-size: 0.78rem;
  font-weight: 650;
}

.eeg-kicker {
  margin: 0 0 0.9rem;
  color: var(--lab-teal);
  font-size: 0.92rem;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.eeg-welcome h1,
.eeg-stage h2,
.eeg-primer h2,
.eeg-look h2,
.eeg-lesson h2,
.eeg-answer h2,
.eeg-complete h2 {
  margin: 0;
  color: var(--lab-ink);
  font-family: var(--font-display, "Literata", serif);
  font-weight: 650;
  line-height: 1.04;
  letter-spacing: 0;
}

.eeg-welcome h1 {
  font-size: clamp(3.1rem, 13vw, 6rem);
}

.eeg-stage h2,
.eeg-primer h2,
.eeg-look h2,
.eeg-complete h2 {
  font-size: clamp(2.8rem, 12vw, 5.2rem);
}

.eeg-lesson h2,
.eeg-answer h2 {
  font-size: clamp(2.7rem, 11vw, 4.8rem);
}

.eeg-title-rule {
  display: block;
  width: 4.2rem;
  height: 0.22rem;
  margin: 1.25rem auto 1.35rem;
  border-radius: 999px;
  background: var(--lab-teal);
}

.eeg-lede,
.eeg-question {
  max-width: 34rem;
  margin: 0 auto 2rem;
  color: var(--lab-muted);
  font-size: clamp(1.02rem, 3.6vw, 1.35rem);
  line-height: 1.55;
}

.eeg-question {
  margin-bottom: 1.5rem;
  color: var(--lab-ink);
}

.btn-primary,
.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3.7rem;
  width: min(100%, 34rem);
  border-radius: 1.15rem;
  font: 800 1.08rem/1 var(--font-body, "Manrope", sans-serif);
  text-decoration: none;
  cursor: pointer;
  transition: transform 140ms ease, background 140ms ease, border-color 140ms ease;
}

.btn-primary {
  border: 0;
  background: linear-gradient(90deg, var(--lab-teal-strong), var(--lab-teal));
  color: #fff;
  box-shadow: 0 12px 32px rgba(18, 120, 110, 0.18);
}

html[data-theme="dark"] .btn-primary {
  color: #10221d;
}

.btn-primary:hover {
  transform: translateY(-1px);
}

.btn-ghost {
  margin-top: 0.75rem;
  border: 1px solid var(--lab-line);
  background: transparent;
  color: var(--lab-muted);
}

.btn-ghost:hover {
  border-color: var(--lab-teal);
  color: var(--lab-ink);
}

.btn-ghost:disabled {
  opacity: 0.35;
  cursor: default;
}

.eeg-dot-row {
  display: flex;
  gap: 0.72rem;
  justify-content: center;
  margin-top: 1.6rem;
}

.eeg-dot-row span {
  width: 1.35rem;
  height: 0.28rem;
  border-radius: 999px;
  background: var(--lab-line);
}

.eeg-dot-row .is-active {
  background: var(--lab-teal);
}

.eeg-welcome-wave {
  position: fixed;
  right: 0;
  bottom: 8vh;
  left: 0;
  height: min(12rem, 20vh);
  opacity: 0.22;
  pointer-events: none;
}

html[data-theme="dark"] .eeg-welcome-wave {
  opacity: 0.18;
}

.eeg-map-screen {
  align-items: flex-start;
  padding-top: clamp(6.5rem, 12vh, 8.5rem);
  padding-bottom: clamp(4rem, 8vh, 7rem);
}

.eeg-map {
  width: min(100%, 54rem);
  text-align: left;
}

.eeg-map-intro {
  display: grid;
  justify-items: start;
  max-width: 44rem;
  margin-bottom: clamp(2rem, 6vw, 3.5rem);
}

.eeg-map-intro h2 {
  margin: 0 0 1.2rem;
  color: var(--lab-ink);
  font-family: var(--font-display);
  font-size: clamp(2.65rem, 8vw, 5.5rem);
  font-weight: 650;
  line-height: 0.99;
  letter-spacing: -0.035em;
}

.eeg-map-intro .eeg-lede {
  max-width: 40rem;
  margin: 0;
  text-align: left;
}

.eeg-map-progress {
  display: grid;
  gap: 0.85rem;
  margin-bottom: 1.35rem;
}

.eeg-map-progress > div:first-child {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}

.eeg-map-progress span {
  color: var(--lab-muted);
  font-size: 0.78rem;
  font-weight: 650;
}

.eeg-map-progress strong {
  color: var(--lab-ink);
  font-size: 0.86rem;
}

.eeg-map-progress-track {
  height: 0.3rem;
  overflow: hidden;
  border-radius: 999px;
  background: var(--lab-line);
}

.eeg-map-progress-track span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--lab-teal);
  transition: width 320ms cubic-bezier(0.22, 1, 0.36, 1);
}

.eeg-module-list {
  border-top: 1px solid var(--lab-line);
}

.eeg-module-row {
  display: grid;
  width: 100%;
  min-height: 6.2rem;
  grid-template-columns: 3rem minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(0.75rem, 2vw, 1.35rem);
  padding: 1rem 0.45rem;
  border: 0;
  border-bottom: 1px solid var(--lab-line);
  background: transparent;
  color: var(--lab-ink);
  text-align: left;
  cursor: pointer;
  transition: background 160ms ease, color 160ms ease;
}

.eeg-module-row:hover,
.eeg-module-row[aria-current="step"] {
  background: var(--lab-soft);
}

.eeg-module-number {
  align-self: start;
  padding-top: 0.25rem;
  color: var(--lab-teal);
  font: 800 0.78rem/1 var(--font-body);
  letter-spacing: 0.08em;
}

.eeg-module-copy {
  display: grid;
  gap: 0.3rem;
}

.eeg-module-copy strong {
  font-family: var(--font-display);
  font-size: clamp(1.15rem, 3vw, 1.55rem);
  font-weight: 650;
  line-height: 1.2;
}

.eeg-module-copy small {
  max-width: 50ch;
  color: var(--lab-muted);
  font-size: 0.79rem;
  line-height: 1.45;
}

.eeg-module-status {
  display: grid;
  min-width: 4.7rem;
  justify-items: end;
  gap: 0.3rem;
  color: var(--lab-teal-strong);
  font-size: 0.75rem;
  font-weight: 800;
}

.eeg-module-status::after {
  content: attr(data-progress);
  color: var(--lab-muted);
  font-size: 0.68rem;
  font-weight: 650;
}

.eeg-map-actions {
  display: grid;
  width: min(100%, 34rem);
  justify-items: center;
  margin: 2.4rem auto 0;
}

.eeg-map-note {
  max-width: 58ch;
  margin: 2rem auto 0;
  color: var(--lab-muted);
  font-size: 0.78rem;
  line-height: 1.6;
  text-align: center;
}

.eeg-map-note a {
  color: var(--lab-teal-strong);
  font-weight: 700;
}

.eeg-welcome-wave canvas,
.eeg-stage-viz canvas,
.answer-wave canvas,
#ex-viz-canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.eeg-stepbar {
  display: flex;
  width: min(100%, 28rem);
  justify-content: center;
  gap: clamp(0.25rem, 1.4vw, 0.55rem);
  margin: 0 auto clamp(4.2rem, 12vh, 7rem);
}

.eeg-stepbar span {
  flex: 1 1 0;
  max-width: 2.1rem;
  height: 0.28rem;
  border-radius: 999px;
  background: var(--lab-line);
}

.eeg-stepbar span.is-active {
  background: var(--lab-teal);
}

.eeg-stage {
  display: grid;
  justify-items: center;
}

.eeg-primer {
  display: grid;
  min-height: calc(100dvh - 8rem);
  align-content: center;
  justify-items: center;
}

.eeg-look {
  display: grid;
  min-height: calc(100dvh - 8rem);
  align-content: center;
  justify-items: center;
}

.eeg-primer .eeg-stepbar {
  margin-bottom: clamp(2.8rem, 8vh, 5.5rem);
}

.eeg-look .eeg-stepbar {
  margin-bottom: clamp(2.4rem, 7vh, 4.8rem);
}

.eeg-primer-viz {
  width: min(100%, 34rem);
  min-height: 13.75rem;
  margin: 0 auto 1.5rem;
  overflow: visible;
}

#primer-viz-canvas {
  display: block;
  width: 100%;
  height: auto;
  min-height: 11.5rem;
  max-height: 16.25rem;
}

.eeg-primer #primer-copy {
  max-width: 42rem;
  margin-bottom: 1.35rem;
  font-size: clamp(1rem, 2.6vw, 1.16rem);
  line-height: 1.7;
}

.eeg-primer #primer-report-wrap {
  min-height: 12.5rem;
}

.primer-graphic {
  display: grid;
  min-height: 9.5rem;
  place-items: center;
  color: var(--lab-teal);
}

.primer-address {
  position: relative;
  width: min(100%, 19rem);
  aspect-ratio: 1.45 / 1;
}

.primer-address-head {
  position: absolute;
  inset: 10% 3%;
  border: 1.5px solid color-mix(in srgb, var(--lab-muted) 35%, transparent);
  border-radius: 50%;
}

.primer-address-head::before,
.primer-address-head::after {
  content: "";
  position: absolute;
  top: 50%;
  width: 1.1rem;
  height: 1.7rem;
  border: 1.5px solid color-mix(in srgb, var(--lab-muted) 28%, transparent);
  transform: translateY(-50%);
}

.primer-address-head::before {
  left: -0.65rem;
  border-right: 0;
  border-radius: 999px 0 0 999px;
}

.primer-address-head::after {
  right: -0.65rem;
  border-left: 0;
  border-radius: 0 999px 999px 0;
}

.primer-dot {
  position: absolute;
  width: 1.1rem;
  height: 1.1rem;
  border-radius: 50%;
  background: color-mix(in srgb, var(--lab-muted) 28%, transparent);
}

.primer-dot.is-target {
  width: 1.55rem;
  height: 1.55rem;
  background: var(--lab-teal);
  box-shadow: 0 0 0 0.75rem var(--lab-teal-soft);
}

.primer-dot.is-target::after {
  content: attr(data-label);
  position: absolute;
  left: 50%;
  top: -1.45rem;
  transform: translateX(-50%);
  color: var(--lab-teal);
  font-size: 0.75rem;
  font-weight: 900;
}

.primer-rhythm,
.primer-compare,
.primer-report,
.primer-field {
  width: min(100%, 29rem);
}

.primer-rhythm {
  display: grid;
  gap: 0.75rem;
}

.primer-rhythm-row {
  display: grid;
  grid-template-columns: 4.2rem 1fr;
  align-items: center;
  gap: 1rem;
  color: var(--lab-muted);
  font-size: 0.78rem;
  font-weight: 900;
}

.primer-wave {
  height: 1.2rem;
  border-radius: 999px;
  background:
    linear-gradient(90deg, transparent 0 10%, var(--lab-teal) 10% 12%, transparent 12% 24%, var(--lab-teal) 24% 26%, transparent 26% 100%);
  opacity: 0.75;
}

.primer-wave.slow { background-size: 8rem 100%; }
.primer-wave.mid { background-size: 4rem 100%; }
.primer-wave.fast { background-size: 1.7rem 100%; opacity: 0.55; }

.primer-compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.primer-compare em {
  grid-column: 1 / -1;
  justify-self: center;
  width: fit-content;
  max-width: 100%;
  margin-top: -0.15rem;
  padding: 0.38rem 0.78rem;
  border-radius: 999px;
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
  font-size: 0.75rem;
  font-style: normal;
  font-weight: 900;
}

.primer-compare-card,
.primer-report,
.primer-field {
  border: 1px solid var(--lab-line);
  border-radius: 1rem;
  background: color-mix(in srgb, var(--lab-card) 62%, transparent);
}

.primer-compare-card {
  display: grid;
  min-height: 7.8rem;
  align-content: center;
  gap: 0.9rem;
  padding: 1rem;
}

.primer-compare-card span {
  color: var(--lab-muted);
  font-size: 0.75rem;
  font-weight: 900;
}

.primer-compare-line {
  height: 2.3rem;
  border-top: 2px solid var(--lab-teal);
  transform: skewY(var(--tilt, 0deg));
  opacity: 0.76;
}

.primer-report {
  display: grid;
  gap: 0.8rem;
  padding: 1rem;
  text-align: left;
}

.primer-report-line {
  display: grid;
  grid-template-columns: 5rem 1fr;
  gap: 0.7rem;
  align-items: center;
  color: var(--lab-muted);
  font-size: 0.82rem;
}

.primer-report-line strong {
  color: var(--lab-ink);
}

.primer-report-mark {
  height: 0.55rem;
  border-radius: 999px;
  background: color-mix(in srgb, var(--lab-muted) 22%, transparent);
}

.primer-report-mark.is-active {
  background: var(--lab-teal);
}

.primer-field {
  display: grid;
  min-height: 8.4rem;
  place-items: center;
  padding: 1rem;
}

.primer-field-line {
  width: min(100%, 21rem);
  height: 3.5rem;
  border-radius: 999px;
  background:
    radial-gradient(circle at var(--focus-x, 50%) 50%, var(--lab-teal-soft) 0 18%, transparent 19%),
    linear-gradient(90deg, transparent, color-mix(in srgb, var(--lab-teal) 58%, transparent), transparent);
  opacity: 0.9;
}

.concept-line,
.concept-sensor,
.concept-regions,
.concept-code,
.concept-landmarks,
.concept-measure,
.concept-intersections,
.concept-midline,
.concept-dipole,
.concept-timing,
.concept-spike-tail,
.concept-polarity {
  width: min(100%, 28rem);
}

.concept-landmarks,
.concept-intersections,
.concept-midline {
  position: relative;
  min-height: 9rem;
}

.concept-landmarks .concept-head,
.concept-intersections i,
.concept-midline i {
  position: absolute;
  inset: 12% 10%;
  border: 1.5px solid color-mix(in srgb, var(--lab-muted) 34%, transparent);
  border-radius: 50%;
}

.concept-landmarks .concept-head::before,
.concept-landmarks .concept-head::after,
.concept-midline i::before,
.concept-midline i::after {
  content: "";
  position: absolute;
  top: 50%;
  width: 0.95rem;
  height: 1.45rem;
  border: 1.5px solid color-mix(in srgb, var(--lab-muted) 26%, transparent);
  transform: translateY(-50%);
}

.concept-landmarks .concept-head::before,
.concept-midline i::before {
  left: -0.56rem;
  border-right: 0;
  border-radius: 999px 0 0 999px;
}

.concept-landmarks .concept-head::after,
.concept-midline i::after {
  right: -0.56rem;
  border-left: 0;
  border-radius: 0 999px 999px 0;
}

.concept-landmarks em,
.concept-intersections em,
.concept-intersections b,
.concept-midline em {
  position: absolute;
  display: block;
  background: color-mix(in srgb, var(--lab-teal) 52%, transparent);
}

.concept-landmarks em {
  left: 50%;
  top: 20%;
  width: 1.5px;
  height: 60%;
  transform: translateX(-50%);
}

.concept-landmarks.is-ears em {
  left: 17%;
  top: 50%;
  width: 66%;
  height: 1.5px;
  transform: translateY(-50%);
}

.concept-landmark-dot {
  position: absolute;
  width: 1.15rem;
  height: 1.15rem;
  border-radius: 50%;
  background: var(--lab-teal);
  box-shadow: 0 0 0 0.62rem var(--lab-teal-soft);
}

.concept-landmark-dot b {
  position: absolute;
  left: 50%;
  width: 6.8rem;
  transform: translateX(-50%);
  color: var(--lab-muted);
  font-size: 0.72rem;
  font-style: normal;
  font-weight: 900;
}

.concept-landmark-dot.is-a {
  left: calc(50% - 0.575rem);
  top: 10%;
}

.concept-landmark-dot.is-a b {
  bottom: 1.45rem;
}

.concept-landmark-dot.is-b {
  left: calc(50% - 0.575rem);
  bottom: 9%;
}

.concept-landmark-dot.is-b b {
  top: 1.45rem;
}

.concept-landmarks.is-ears .concept-landmark-dot.is-a {
  left: 8%;
  top: calc(50% - 0.575rem);
}

.concept-landmarks.is-ears .concept-landmark-dot.is-b {
  left: auto;
  right: 8%;
  top: calc(50% - 0.575rem);
  bottom: auto;
}

.concept-landmarks.is-ears .concept-landmark-dot b {
  top: 1.55rem;
  bottom: auto;
}

.concept-measure {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 0;
  align-items: center;
  min-height: 8.5rem;
  color: var(--lab-muted);
  font-size: 0.76rem;
  font-weight: 900;
}

.concept-measure i {
  grid-column: 1 / -1;
  grid-row: 1;
  display: block;
  height: 0.16rem;
  border-radius: 999px;
  background: color-mix(in srgb, var(--lab-teal) 58%, transparent);
}

.concept-measure span {
  position: relative;
  grid-row: 1;
  padding-top: 2rem;
  text-align: center;
}

.concept-measure span::before {
  content: "";
  position: absolute;
  left: 50%;
  top: -0.55rem;
  width: 0.72rem;
  height: 0.72rem;
  border-radius: 50%;
  background: var(--lab-bg);
  border: 2px solid var(--lab-teal);
  transform: translateX(-50%);
}

.concept-intersections em {
  left: 50%;
  top: 16%;
  width: 1.5px;
  height: 68%;
  transform: translateX(-50%);
}

.concept-intersections b {
  left: 18%;
  top: 50%;
  width: 64%;
  height: 1.5px;
  transform: translateY(-50%);
}

.concept-intersections span {
  position: absolute;
  width: 1rem;
  height: 1rem;
  border-radius: 50%;
  background: var(--lab-teal);
  box-shadow: 0 0 0 0.48rem var(--lab-teal-soft);
  transform: translate(-50%, -50%);
}

.concept-midline em {
  left: 50%;
  top: 16%;
  width: 2px;
  height: 68%;
  border-radius: 999px;
  transform: translateX(-50%);
}

.concept-midline span {
  position: absolute;
  left: 50%;
  display: grid;
  width: 2.1rem;
  height: 2.1rem;
  place-items: center;
  border-radius: 50%;
  background: var(--lab-teal);
  box-shadow: 0 0 0 0.42rem var(--lab-teal-soft);
  color: var(--lab-bg);
  font-size: 0.72rem;
  font-weight: 900;
  transform: translate(-50%, -50%);
}

.concept-dipole {
  position: relative;
  min-height: 9rem;
}

.concept-dipole i {
  position: absolute;
  inset: 24% 18%;
  border: 1.5px solid color-mix(in srgb, var(--lab-muted) 32%, transparent);
  border-radius: 55% 45% 45% 55% / 50%;
}

.concept-dipole i::before {
  content: "";
  position: absolute;
  left: 28%;
  top: 50%;
  width: 1.8rem;
  height: 1.8rem;
  border-radius: 50%;
  background: var(--lab-teal-soft);
  box-shadow: inset 0 0 0 0.5rem var(--lab-teal);
  transform: translateY(-50%);
}

.concept-dipole span {
  position: absolute;
  display: grid;
  min-width: 5.4rem;
  min-height: 2rem;
  place-items: center;
  border-radius: 999px;
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
  font-size: 0.72rem;
  font-weight: 900;
}

.concept-dipole .is-front {
  left: 62%;
  top: 32%;
}

.concept-dipole .is-back {
  left: 19%;
  top: 58%;
  background: color-mix(in srgb, var(--lab-muted) 14%, transparent);
  color: var(--lab-muted);
}

.concept-dipole em {
  position: absolute;
  left: 50%;
  bottom: 0.2rem;
  transform: translateX(-50%);
  color: var(--lab-teal);
  font-size: 0.76rem;
  font-style: normal;
  font-weight: 900;
}

.concept-timing {
  position: relative;
  display: grid;
  gap: 0.72rem;
  padding: 1rem 0 2.2rem;
}

.concept-timing::before,
.concept-timing::after {
  content: "";
  position: absolute;
  top: 0.7rem;
  bottom: 2rem;
  width: 1.5px;
  background: color-mix(in srgb, var(--lab-teal) 48%, transparent);
}

.concept-timing::before { left: 48%; }
.concept-timing::after { left: 73%; }

.concept-timing span {
  display: grid;
  grid-template-columns: 5.5rem 1fr;
  align-items: center;
  color: var(--lab-muted);
  font-size: 0.76rem;
  font-weight: 900;
}

.concept-timing span i {
  grid-column: 2;
  grid-row: 1;
  width: 100%;
  height: 1.1rem;
  border-radius: 999px;
  background:
    linear-gradient(90deg, transparent 0 45%, var(--lab-teal) 45% 47%, transparent 47% 70%, var(--lab-teal) 70% 72%, transparent 72% 100%);
  opacity: 0.76;
}

.concept-timing b {
  position: absolute;
  left: 50%;
  bottom: 0;
  padding: 0.32rem 0.68rem;
  border-radius: 999px;
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
  font-size: 0.72rem;
  transform: translateX(-50%);
}

.concept-spike-tail {
  position: relative;
  min-height: 8.8rem;
}

.concept-spike-tail::before {
  content: "";
  position: absolute;
  left: 8%;
  right: 8%;
  top: 54%;
  height: 1.5px;
  background: color-mix(in srgb, var(--lab-muted) 24%, transparent);
}

.concept-spike-tail i {
  position: absolute;
  left: 37%;
  top: 24%;
  width: 2.2rem;
  height: 4.2rem;
  background:
    linear-gradient(120deg, transparent 0 45%, var(--lab-teal) 46% 50%, transparent 51%),
    linear-gradient(60deg, transparent 0 48%, var(--lab-teal) 49% 53%, transparent 54%);
}

.concept-spike-tail em {
  position: absolute;
  left: 52%;
  top: 50%;
  width: 6.5rem;
  height: 2.4rem;
  border-bottom: 2px solid var(--lab-teal);
  border-radius: 0 0 999px 999px;
  opacity: 0.78;
}

.concept-spike-tail b {
  position: absolute;
  left: 63%;
  top: 74%;
  padding: 0.32rem 0.68rem;
  border-radius: 999px;
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
  font-size: 0.72rem;
  transform: translateX(-50%);
}

.concept-polarity {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
}

.concept-polarity span {
  display: grid;
  min-height: 7.6rem;
  align-content: center;
  gap: 0.7rem;
  padding: 1rem;
  border: 1px solid var(--lab-line);
  border-radius: 1rem;
  color: var(--lab-muted);
  font-size: 0.76rem;
  font-weight: 900;
}

.concept-polarity span.is-on {
  border-color: color-mix(in srgb, var(--lab-teal) 48%, var(--lab-line));
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
}

.concept-polarity i {
  display: block;
  height: 2.5rem;
  border-radius: 999px;
}

.concept-polarity .is-up {
  background:
    linear-gradient(120deg, transparent 0 46%, color-mix(in srgb, var(--lab-muted) 52%, transparent) 47% 50%, transparent 51%),
    linear-gradient(60deg, transparent 0 48%, color-mix(in srgb, var(--lab-muted) 52%, transparent) 49% 52%, transparent 53%);
}

.concept-polarity .is-down {
  background:
    linear-gradient(60deg, transparent 0 46%, var(--lab-teal) 47% 50%, transparent 51%),
    linear-gradient(120deg, transparent 0 48%, var(--lab-teal) 49% 52%, transparent 53%);
}

.concept-line {
  display: grid;
  min-height: 8.5rem;
  place-items: center;
  gap: 0.8rem;
}

.concept-line i {
  display: block;
  width: min(100%, 23rem);
  height: 2.8rem;
  border-radius: 999px;
  background:
    linear-gradient(90deg, transparent 0 8%, var(--lab-teal) 9% 11%, transparent 12% 20%, var(--lab-teal) 21% 23%, transparent 24% 36%, var(--lab-teal) 37% 39%, transparent 40%);
  background-size: 4.6rem 100%;
  opacity: 0.72;
}

.concept-semantic-tag {
  display: inline-grid;
  justify-items: center;
  gap: 0.1rem;
  max-width: min(100%, 18rem);
  padding: 0.45rem 0.8rem;
  border: 1px solid color-mix(in srgb, var(--lab-teal) 35%, transparent);
  border-radius: 999px;
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
}

.concept-semantic-tag b {
  font-size: 0.78rem;
  font-weight: 900;
}

.concept-semantic-tag small {
  color: var(--lab-muted);
  font-size: 0.68rem;
  font-weight: 800;
}

.concept-sensor {
  position: relative;
  min-height: 9rem;
}

.concept-sensor i {
  position: absolute;
  inset: 12% 10%;
  border: 1.5px solid color-mix(in srgb, var(--lab-muted) 32%, transparent);
  border-radius: 50%;
}

.concept-sensor span {
  position: absolute;
  width: 1.2rem;
  height: 1.2rem;
  border-radius: 50%;
  background: color-mix(in srgb, var(--lab-muted) 25%, transparent);
}

.concept-sensor span.is-on {
  background: var(--lab-teal);
  box-shadow: 0 0 0 0.72rem var(--lab-teal-soft);
}

.concept-sensor span.is-on b {
  position: absolute;
  left: 50%;
  top: 1.75rem;
  width: 8rem;
  transform: translateX(-50%);
  color: var(--lab-teal);
  font-size: 0.72rem;
  font-weight: 900;
}

.concept-regions {
  display: grid;
  gap: 0.55rem;
}

.concept-regions span {
  display: grid;
  min-height: 2.05rem;
  place-items: center;
  align-content: center;
  gap: 0.16rem;
  border: 1px solid var(--lab-line);
  border-radius: 999px;
  color: var(--lab-muted);
  font-size: 0.78rem;
  font-weight: 900;
}

.concept-regions span.is-on {
  border-color: color-mix(in srgb, var(--lab-teal) 45%, var(--lab-line));
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
}

.concept-regions span b {
  color: var(--lab-teal);
  font-size: 0.68rem;
}

.concept-code {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.8rem;
}

.concept-code span {
  display: grid;
  min-height: 7rem;
  place-items: center;
  align-content: center;
  gap: 0.4rem;
  border: 1px solid color-mix(in srgb, var(--lab-teal) 42%, var(--lab-line));
  border-radius: 1rem;
  background: var(--lab-teal-soft);
}

.concept-code b {
  color: var(--lab-teal);
  font-family: var(--font-display, "Literata", serif);
  font-size: clamp(2.6rem, 12vw, 4.6rem);
  line-height: 1;
}

.concept-code small {
  color: var(--lab-muted);
  font-size: 0.78rem;
  font-weight: 900;
}

.eeg-look-viz {
  width: min(100%, 32rem);
  min-height: 8.8rem;
  margin: -0.2rem auto 1.35rem;
}

.look-graphic {
  display: grid;
  min-height: 8.8rem;
  place-items: center;
  color: var(--lab-teal);
}

.look-side,
.look-flip,
.look-speed,
.look-spread,
.look-story,
.look-report {
  width: min(100%, 28rem);
}

.look-side {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.look-side span {
  display: grid;
  min-height: 7.2rem;
  place-items: center;
  align-content: center;
  gap: 0.4rem;
  border: 1px solid var(--lab-line);
  border-radius: 1rem;
  color: var(--lab-muted);
  font-size: 0.78rem;
  font-weight: 900;
}

.look-side span b {
  min-height: 0.9rem;
  color: var(--lab-teal);
  font-size: 0.72rem;
}

.look-side span.is-on {
  border-color: color-mix(in srgb, var(--lab-teal) 44%, var(--lab-line));
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
}

.look-flip {
  position: relative;
  display: grid;
  min-height: 8.5rem;
  place-items: center;
  align-content: center;
  gap: 0.55rem;
}

.look-flip::before {
  content: "";
  position: absolute;
  top: 1rem;
  bottom: 1rem;
  left: 50%;
  border-left: 1px solid color-mix(in srgb, var(--lab-teal) 62%, transparent);
}

.look-flip i,
.look-speed i,
.look-spread i,
.look-story i {
  display: block;
  width: min(100%, 24rem);
  height: 2.4rem;
  border-radius: 999px;
}

.look-flip i {
  background:
    linear-gradient(110deg, transparent 0 43%, var(--lab-teal) 44% 46%, transparent 47%),
    linear-gradient(70deg, transparent 0 53%, var(--lab-teal) 54% 56%, transparent 57%);
  opacity: 0.85;
}

.look-speed {
  display: grid;
  gap: 0.72rem;
}

.look-speed span {
  display: grid;
  grid-template-columns: 3.8rem 1fr minmax(4.5rem, auto);
  gap: 0.85rem;
  align-items: center;
  color: var(--lab-muted);
  font-size: 0.78rem;
  font-weight: 900;
}

.look-speed span b {
  justify-self: start;
  padding: 0.22rem 0.52rem;
  border-radius: 999px;
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
  font-size: 0.7rem;
}

.look-speed span.is-on {
  color: var(--lab-teal);
}

.look-speed i {
  height: 1.2rem;
  background:
    linear-gradient(90deg, transparent 0 14%, var(--lab-teal) 15% 17%, transparent 18% 36%, var(--lab-teal) 37% 39%, transparent 40%);
}

.look-speed span:nth-child(1) i { background-size: 7rem 100%; opacity: 0.45; }
.look-speed span:nth-child(2) i { background-size: 3.8rem 100%; opacity: 0.85; }
.look-speed span:nth-child(3) i { background-size: 1.8rem 100%; opacity: 0.55; }

.look-spread {
  position: relative;
  display: grid;
  min-height: 8.2rem;
  place-items: center;
}

.look-spread i {
  height: 5rem;
  background:
    radial-gradient(circle at var(--x, 50%) 50%, var(--lab-teal) 0 7%, var(--lab-teal-soft) 8% 20%, transparent 21%),
    radial-gradient(circle at var(--x, 50%) 50%, color-mix(in srgb, var(--lab-teal) 28%, transparent) 0 32%, transparent 33%),
    linear-gradient(90deg, transparent, color-mix(in srgb, var(--lab-muted) 16%, transparent), transparent);
}

.look-spread span {
  position: absolute;
  left: var(--x, 50%);
  top: 50%;
  max-width: 9.5rem;
  padding: 0.34rem 0.68rem;
  border-radius: 999px;
  background: var(--lab-bg);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--lab-teal) 38%, transparent), 0 0 0 0.55rem var(--lab-teal-soft);
  color: var(--lab-teal);
  font-size: 0.7rem;
  font-weight: 900;
  transform: translate(-50%, -50%);
}

.look-story {
  position: relative;
  display: grid;
  gap: 0.7rem;
}

.look-story b {
  justify-self: center;
  width: fit-content;
  max-width: min(100%, 16rem);
  padding: 0.38rem 0.74rem;
  border-radius: 999px;
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
  font-size: 0.74rem;
  font-weight: 900;
}

.look-story i {
  height: 1.1rem;
  background: linear-gradient(90deg, var(--lab-teal-soft), var(--lab-teal), var(--lab-teal-soft));
}

.look-story i:nth-of-type(2) { width: 72%; justify-self: center; opacity: 0.62; }
.look-story i:nth-of-type(3) { width: 38%; justify-self: end; opacity: 0.36; }

.look-report {
  display: grid;
  gap: 0.65rem;
  padding: 0.7rem 0;
}

.look-report span {
  display: grid;
  grid-template-columns: 4.5rem 1fr;
  gap: 0.7rem;
  align-items: center;
  color: var(--lab-muted);
  font-size: 0.78rem;
  font-weight: 900;
}

.look-report i {
  height: 0.55rem;
  border-radius: 999px;
  background: color-mix(in srgb, var(--lab-muted) 20%, transparent);
}

.look-report span.is-on i {
  background: var(--lab-teal);
}

.look-report span.is-on b {
  color: var(--lab-teal);
}

.look-terms {
  display: grid;
  width: min(100%, 31rem);
  gap: 0.55rem;
  margin: 0 auto 1.35rem;
}

.look-term {
  display: grid;
  grid-template-columns: minmax(4rem, 7.5rem) 1fr;
  gap: 0.75rem;
  align-items: baseline;
  padding: 0.78rem 0;
  border-top: 1px solid var(--lab-line);
  text-align: left;
}

.look-term strong {
  color: var(--lab-ink);
  font-size: 0.82rem;
}

.look-term span {
  color: var(--lab-muted);
  font-size: 0.88rem;
  line-height: 1.45;
}

.eeg-stage-viz {
  width: min(100%, 34rem);
  height: 4.6rem;
  margin: 0 auto 2.4rem;
  opacity: 0.22;
  overflow: hidden;
}

.eeg-lesson {
  display: grid;
  justify-items: center;
  min-height: calc(100dvh - 8rem);
}

.eeg-lesson .eeg-stepbar {
  margin-bottom: clamp(2rem, 7vh, 4rem);
}

.eeg-visual-shell {
  width: min(100%, 40rem);
  min-height: 15rem;
  margin: 0 auto 1.45rem;
  overflow: hidden;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

#ex-viz-canvas {
  min-height: 15rem;
  background: var(--lab-bg);
}

.eeg-report-visual {
  padding: clamp(1.25rem, 4vw, 2rem);
  text-align: left;
}

.report-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
  margin-bottom: 1.2rem;
  color: var(--lab-muted);
  font-size: 0.9rem;
}

.report-tabs span {
  padding: 0.62rem 0.4rem;
  border-radius: 999px;
  text-align: center;
}

.report-tabs span.is-active {
  border: 1px solid color-mix(in srgb, var(--lab-teal) 42%, transparent);
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
  font-weight: 800;
}

.report-rows {
  display: grid;
  gap: 0.95rem;
  padding-top: 1rem;
  border-top: 1px solid var(--lab-line);
}

.report-row {
  display: grid;
  grid-template-columns: 7.3rem 1fr;
  gap: 1rem;
  align-items: start;
}

.report-row strong {
  color: var(--lab-ink);
  font-size: 0.95rem;
}

.report-row span {
  color: var(--lab-muted);
  line-height: 1.5;
}

.eeg-source {
  min-height: 1.1rem;
  margin: -0.35rem 0 1.2rem;
  color: var(--lab-muted);
  font-size: 0.78rem;
}

.eeg-interact {
  width: min(100%, 34rem);
  margin: 0 auto;
}

.interact-prompt {
  margin: 0 0 1rem;
  color: var(--lab-ink);
  font-size: 1.08rem;
  font-weight: 800;
  line-height: 1.45;
}

.interact-binary-btns {
  display: grid;
  gap: 0.85rem;
}

.interact-binary-btn {
  min-height: 3.7rem;
  border: 1px solid var(--lab-line);
  border-radius: 1.05rem;
  background: transparent;
  color: var(--lab-ink);
  font: 800 1.05rem/1.2 var(--font-body, "Manrope", sans-serif);
  cursor: pointer;
}

.interact-binary-btn:hover:not(:disabled) {
  border-color: var(--lab-teal);
  background: transparent;
}

.interact-binary-btn.is-correct {
  border-color: var(--lab-teal);
  background: var(--lab-teal-soft);
  color: var(--lab-teal);
}

.interact-binary-btn.is-wrong {
  opacity: 0.46;
}

.interact-hint {
  margin: -0.3rem 0 0;
  color: var(--lab-muted);
  font-size: 0.85rem;
}

.eeg-nav {
  display: grid;
  width: min(100%, 34rem);
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 1rem;
  margin-top: 1.2rem;
}

.eeg-nav .btn-ghost {
  width: auto;
  min-height: 2.75rem;
  margin: 0;
  padding: 0 1rem;
  border-radius: 999px;
  font-size: 0.86rem;
}

.eeg-sandbox-link {
  justify-self: end;
  color: var(--lab-muted);
  font-size: 0.86rem;
  font-weight: 800;
  text-decoration: none;
}

.eeg-sandbox-link:hover {
  color: var(--lab-teal);
}

.eeg-answer {
  display: grid;
  justify-items: center;
}

.answer-icon {
  display: grid;
  width: 4.3rem;
  height: 4.3rem;
  place-items: center;
  margin-bottom: 1.4rem;
  border: 2px solid var(--lab-teal);
  border-radius: 50%;
  color: var(--lab-teal);
  font-size: 1.55rem;
}

.answer-icon.is-wrong {
  border-color: var(--lab-muted);
  color: var(--lab-muted);
}

.answer-wave {
  width: min(100%, 32rem);
  height: 5.5rem;
  margin: -0.4rem auto 1.4rem;
  opacity: 0.36;
  overflow: hidden;
}

.answer-card {
  width: min(100%, 34rem);
  margin: 0 auto 1.6rem;
  overflow: hidden;
  border: 1px solid var(--lab-line);
  border-radius: 1.25rem;
  background: var(--lab-card);
  text-align: left;
}

.answer-card-section {
  padding: 1.25rem;
}

.answer-card-section + .answer-card-section {
  border-top: 1px solid var(--lab-line);
}

.answer-card-label {
  margin: 0 0 0.45rem;
  color: var(--lab-teal);
  font-size: 0.9rem;
  font-weight: 900;
}

.answer-card-text {
  margin: 0;
  color: var(--lab-ink);
  font-size: 0.98rem;
  line-height: 1.62;
}

.eeg-complete {
  display: grid;
  justify-items: center;
}

.eeg-complete .btn-ghost {
  width: min(100%, 34rem);
}

@keyframes eeg-fade-up {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.eeg-screen:not(.is-hidden) {
  animation: eeg-fade-up 320ms cubic-bezier(0.22, 1, 0.36, 1) both;
}

@media (min-width: 820px) {
  .eeg-app {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .eeg-screen {
    width: min(100%, 55rem);
    min-height: 100dvh;
  }

  .eeg-visual-shell {
    min-height: 17rem;
  }

  #ex-viz-canvas {
    min-height: 17rem;
  }
}

@media (min-width: 820px) and (max-height: 760px) {
  .eeg-screen {
    padding-top: 4.2rem;
    padding-bottom: 0.9rem;
  }

  .eeg-lesson {
    min-height: calc(100dvh - 5.1rem);
  }

  .eeg-lesson .eeg-stepbar {
    margin-bottom: 1.15rem;
  }

  .eeg-lesson h2 {
    font-size: clamp(3.2rem, 6vw, 4.2rem);
  }

  .eeg-title-rule {
    margin-top: 0.72rem;
    margin-bottom: 0.85rem;
  }

  .eeg-question {
    margin-bottom: 0.75rem;
    font-size: 1.04rem;
    line-height: 1.35;
  }

  .eeg-visual-shell {
    min-height: 13rem;
    margin-bottom: 0.65rem;
  }

  #ex-viz-canvas {
    min-height: 13rem;
  }

  .interact-prompt {
    margin-bottom: 0.55rem;
    font-size: 1rem;
    line-height: 1.34;
  }

  .interact-binary-btns {
    gap: 0.6rem;
  }

  .interact-binary-btn {
    min-height: 3rem;
  }

  .eeg-nav {
    margin-top: 0.65rem;
  }
}

@media (max-width: 520px) {
  .eeg-brand span:last-child {
    display: none;
  }

  .eeg-topbar {
    padding: 0.8rem;
  }

  .eeg-top-actions {
    gap: 0.1rem;
  }

  .eeg-top-link {
    padding: 0.45rem;
    font-size: 0.68rem;
  }

  .eeg-theme-btn {
    min-width: 2.75rem;
    min-height: 2.75rem;
    justify-content: center;
    padding: 0.35rem;
  }

  .eeg-theme-btn span {
    display: none;
  }

  .eeg-screen {
    padding-right: 1rem;
    padding-left: 1rem;
  }

  .eeg-stepbar {
    margin-bottom: 3.5rem;
  }

  .eeg-primer .eeg-stepbar {
    margin-bottom: 2.2rem;
  }

  .eeg-primer-viz {
    min-height: 11.5rem;
  }

  #primer-viz-canvas {
    min-height: 10.5rem;
  }

  .eeg-map-screen {
    padding-top: 5.8rem;
  }

  .eeg-map-intro h2 {
    font-size: clamp(2.45rem, 13vw, 3.7rem);
  }

  .eeg-map-progress > div:first-child {
    align-items: flex-start;
    flex-direction: column;
    gap: 0.25rem;
  }

  .eeg-module-row {
    grid-template-columns: 2.2rem minmax(0, 1fr);
    gap: 0.65rem;
    padding: 1rem 0.2rem;
  }

  .eeg-module-status {
    grid-column: 2;
    grid-auto-flow: column;
    justify-content: start;
    justify-items: start;
  }

  .eeg-visual-shell {
    min-height: 14.5rem;
    border-radius: 1.05rem;
  }

  #ex-viz-canvas {
    min-height: 14.5rem;
  }

  .report-row {
    grid-template-columns: 1fr;
    gap: 0.25rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .eeg-screen:not(.is-hidden) {
    animation: none;
  }

  .eeg-progress-bar,
  .eeg-map-progress-track span,
  .eeg-module-row,
  .btn-primary,
  .btn-ghost,
  .interact-binary-btn {
    transition: none;
  }
}