:root {
  --color-canvas: #f2f6f3;
  --color-canvas-warm: #f8f8f2;
  --color-surface: #ffffff;
  --color-ink: #17221d;
  --color-muted: #526159;
  --color-line: #cbd7d0;
  --color-line-soft: #dde6e1;
  --color-brand: #006b58;
  --color-brand-hover: #005746;
  --color-brand-dark: #173f35;
  --color-brand-panel: #245649;
  --color-brand-soft: #e2f0eb;
  --color-mint: #ddf3e8;
  --color-mint-strong: #82d7c3;
  --color-gold: #f3be52;
  --color-gold-strong: #e3a229;
  --color-gold-soft: #fff4d6;
  --color-pink-soft: #f4cad3;
  --color-pink: #a92d46;
  --color-blue: #3f70b5;
  --color-blue-soft: #c8d7ec;
  --color-focus: #075fd8;
  --font-sans: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --shadow-soft: 0 24px 70px rgb(23 34 29 / 0.1);
  --shadow-phone: 0 34px 80px rgb(23 63 53 / 0.24);
  --radius-small: 0.5rem;
  --radius-medium: 0.75rem;
  --radius-large: 1.25rem;
  --radius-xlarge: 2rem;
  --content-width: 78rem;
  --reading-width: 46rem;
  --header-height: 4.75rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 1.5rem);
}

body {
  margin: 0;
  min-width: 20rem;
  overflow-x: clip;
  color: var(--color-ink);
  background: var(--color-canvas-warm);
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

main {
  min-width: 0;
}

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

a {
  color: inherit;
  text-underline-offset: 0.2em;
  text-decoration-thickness: 0.08em;
}

button,
input,
textarea,
select,
summary {
  font: inherit;
}

button,
summary,
a {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 4px;
  border-radius: 0.2rem;
}

::selection {
  color: var(--color-ink);
  background: var(--color-mint-strong);
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  text-wrap: balance;
}

h1 {
  margin-bottom: 1.5rem;
  font-size: clamp(2.8rem, 11vw, 6.4rem);
  font-weight: 760;
  letter-spacing: -0.055em;
  line-height: 0.98;
}

h2 {
  margin-bottom: 1.25rem;
  font-size: clamp(2.1rem, 7vw, 4.25rem);
  font-weight: 730;
  letter-spacing: -0.045em;
  line-height: 1.04;
}

h3 {
  margin-bottom: 0.65rem;
  font-size: 1.25rem;
  line-height: 1.25;
}

.shell {
  width: min(100% - 2rem, var(--content-width));
  margin-inline: auto;
}

.section {
  padding-block: clamp(4.5rem, 10vw, 8.5rem);
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin-bottom: 1.15rem;
  color: var(--color-brand);
  font-size: 0.76rem;
  font-weight: 760;
  letter-spacing: 0.13em;
  line-height: 1.4;
  text-transform: uppercase;
}

.eyebrow > span:first-child {
  width: 1.8rem;
  height: 2px;
  flex: none;
  background: currentColor;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.75rem 1rem;
  color: #fff;
  background: var(--color-brand-dark);
  font-weight: 700;
  transform: translateY(-150%);
  transition: transform 160ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.button {
  display: inline-flex;
  min-height: 3.25rem;
  align-items: center;
  justify-content: center;
  gap: 0.8rem;
  padding: 0.75rem 1.2rem;
  border: 1px solid var(--color-brand);
  border-radius: var(--radius-small);
  color: #fff;
  background: var(--color-brand);
  font-size: 0.92rem;
  font-weight: 720;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
  transition: background-color 150ms ease, border-color 150ms ease, transform 150ms ease;
}

.button span {
  font-size: 1.15em;
}

.button-small {
  min-height: 2.75rem;
  padding-inline: 1rem;
  font-size: 0.84rem;
}

.text-link {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  gap: 0.65rem;
  color: var(--color-brand);
  font-size: 0.93rem;
  font-weight: 720;
  text-decoration-line: underline;
  text-decoration-color: rgb(0 107 88 / 0.38);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.85rem 1.35rem;
}

@media (hover: hover) {
  .button:hover {
    border-color: var(--color-brand-hover);
    background: var(--color-brand-hover);
    transform: translateY(-2px);
  }

  .text-link:hover {
    color: var(--color-brand-hover);
    text-decoration-color: currentColor;
  }
}

/* Header */
.site-header {
  position: relative;
  z-index: 100;
  border-bottom: 1px solid rgb(203 215 208 / 0.7);
  background: rgb(248 248 242 / 0.92);
  backdrop-filter: blur(14px);
}

.header-inner {
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.wordmark {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  gap: 0.7rem;
  color: var(--color-ink);
  font-size: 1.22rem;
  font-weight: 790;
  letter-spacing: -0.035em;
  text-decoration: none;
}

.wordmark-path {
  width: 1.55rem;
  display: flex;
  align-items: center;
  gap: 0.13rem;
}

.wordmark-path i {
  width: 0.43rem;
  height: 0.43rem;
  border: 1.5px solid var(--color-brand);
  border-radius: 50%;
}

.wordmark-path i:nth-child(1) {
  background: var(--color-mint-strong);
}

.wordmark-path i:nth-child(2) {
  width: 0.54rem;
  height: 0.54rem;
  border: 2px solid var(--color-brand);
  box-shadow: inset 0 0 0 0.1rem var(--color-canvas-warm);
  background: var(--color-gold);
}

.desktop-nav,
.header-actions {
  display: none;
}

.mobile-menu {
  position: static;
}

.mobile-menu summary {
  min-width: 4.5rem;
  min-height: 2.75rem;
  display: flex;
  cursor: pointer;
  list-style: none;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-small);
  background: var(--color-surface);
  font-size: 0.82rem;
  font-weight: 700;
}

.mobile-menu summary::-webkit-details-marker {
  display: none;
}

.menu-icon {
  width: 0.9rem;
  height: 0.75rem;
  display: grid;
  align-content: center;
  gap: 0.25rem;
}

.menu-icon i {
  height: 1.5px;
  background: currentColor;
  transition: transform 150ms ease;
}

.mobile-menu[open] .menu-icon i:first-child {
  transform: translateY(0.125rem) rotate(45deg);
}

.mobile-menu[open] .menu-icon i:last-child {
  transform: translateY(-0.125rem) rotate(-45deg);
}

.mobile-menu-panel {
  position: absolute;
  top: calc(100% + 1px);
  right: 0;
  left: 0;
  padding: 0.75rem 1rem 1rem;
  border-bottom: 1px solid var(--color-line);
  background: var(--color-canvas-warm);
  box-shadow: 0 18px 40px rgb(23 34 29 / 0.12);
}

.mobile-menu-panel ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.mobile-menu-panel li + li {
  border-top: 1px solid var(--color-line-soft);
}

.mobile-menu-panel nav a {
  min-height: 3.15rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 680;
  text-decoration: none;
}

.mobile-menu-panel a[aria-current="page"] {
  color: var(--color-brand);
}

.mobile-language {
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  margin-top: 0.75rem;
  color: var(--color-brand);
  font-size: 0.84rem;
  font-weight: 750;
}

/* Hero */
.hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding-block: 3.25rem 4rem;
  background:
    radial-gradient(circle at 88% 8%, rgb(130 215 195 / 0.24), transparent 28rem),
    radial-gradient(circle at 5% 90%, rgb(243 190 82 / 0.15), transparent 24rem),
    var(--color-canvas-warm);
}

.hero::before {
  position: absolute;
  z-index: -1;
  top: 0;
  right: 0;
  width: min(45vw, 38rem);
  height: 100%;
  background-image: radial-gradient(rgb(0 107 88 / 0.18) 1px, transparent 1px);
  background-size: 20px 20px;
  content: "";
  mask-image: linear-gradient(to left, #000, transparent);
  pointer-events: none;
}

.hero-grid {
  display: grid;
  align-items: center;
  gap: 3.5rem;
}

.hero-copy,
.lesson-visual {
  min-width: 0;
}

.hero-copy h1 {
  max-width: 11ch;
}

.hero-lead {
  max-width: 39rem;
  margin-bottom: 1rem;
  font-size: clamp(1.16rem, 3.8vw, 1.55rem);
  line-height: 1.45;
}

.hero-support {
  max-width: 39rem;
  margin-bottom: 2rem;
  color: var(--color-muted);
  font-size: 1rem;
}

.status-line {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin: 1.75rem 0 0;
  color: var(--color-muted);
  font-size: 0.8rem;
  font-weight: 650;
}

.status-line i {
  width: 0.68rem;
  height: 0.68rem;
  border: 2px solid var(--color-brand);
  border-radius: 50%;
  box-shadow: 0 0 0 0.25rem var(--color-brand-soft);
  background: var(--color-gold);
}

/* Code-native product visual, derived from the implemented MVP's panel grammar. */
.lesson-visual {
  position: relative;
  width: min(100%, 23rem);
  margin: 0 auto;
  padding: 1.4rem 0 0;
}

.lesson-glow {
  position: absolute;
  inset: 13% -18% 8%;
  border-radius: 50%;
  background: rgb(130 215 195 / 0.35);
  filter: blur(35px);
}

.phone-frame {
  position: relative;
  z-index: 2;
  width: 100%;
  padding: 0.55rem;
  border: 1px solid #315047;
  border-radius: 2.15rem;
  background: #102b24;
  box-shadow: var(--shadow-phone);
}

.phone-speaker {
  position: absolute;
  z-index: 4;
  top: 0.38rem;
  left: 50%;
  width: 4.5rem;
  height: 0.32rem;
  border-radius: 1rem;
  background: #315047;
  transform: translateX(-50%);
}

.phone-screen {
  overflow: hidden;
  border-radius: 1.65rem;
  background: var(--color-canvas);
}

.lesson-topbar {
  height: 3.4rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.65rem 1rem 0;
  color: #fff;
  background: var(--color-brand-dark);
}

.lesson-brand {
  font-size: 0.85rem;
  font-weight: 800;
}

.lesson-close {
  width: 1.7rem;
  height: 1.7rem;
  display: grid;
  place-items: center;
  border: 1px solid #9ab4ac;
  border-radius: 0.4rem;
  font-size: 1.1rem;
}

.lesson-orientation {
  position: relative;
  padding: 0.75rem 1rem 1rem;
  border-bottom: 0.24rem solid var(--color-gold-strong);
  color: #fff;
  background: var(--color-brand-dark);
}

.lesson-meta {
  display: flex;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.7rem;
  color: #d3e2dd;
  font-size: 0.59rem;
}

.lesson-meta span {
  font-weight: 780;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.path-dots {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.path-dots::before {
  position: absolute;
  right: 0.35rem;
  left: 0.35rem;
  height: 0.2rem;
  background: #70958a;
  content: "";
}

.path-dots i {
  position: relative;
  z-index: 1;
  width: 1rem;
  height: 1rem;
  display: grid;
  place-items: center;
  border: 0.12rem solid #bdd2cb;
  border-radius: 50%;
  background: var(--color-brand-dark);
  color: var(--color-brand-dark);
  font-size: 0.5rem;
  font-style: normal;
  font-weight: 900;
}

.path-dots i.done {
  border-color: var(--color-mint-strong);
  background: var(--color-mint-strong);
}

.path-dots i.current {
  width: 1.35rem;
  height: 1.35rem;
  border: 0.18rem solid #fff;
  box-shadow: inset 0 0 0 0.25rem var(--color-brand-dark);
  background: var(--color-gold-strong);
}

.current-step {
  width: fit-content;
  display: block;
  margin: 0.65rem auto 0;
  padding: 0.25rem 0.75rem;
  border-radius: 2rem;
  color: var(--color-ink);
  background: var(--color-brand-soft);
  font-size: 0.57rem;
  font-weight: 750;
}

.lesson-body {
  display: grid;
  gap: 0.65rem;
  padding: 0.75rem;
}

.task-card,
.work-card {
  border: 1px solid var(--color-line);
  border-radius: var(--radius-medium);
  background: #fff;
}

.task-card {
  position: relative;
  padding: 0.7rem 0.8rem 0.75rem 1rem;
}

.task-card::before {
  position: absolute;
  inset: 0.25rem auto 0.25rem 0;
  width: 0.27rem;
  border-radius: 1rem;
  background: var(--color-gold-strong);
  content: "";
}

.task-card span,
.work-heading > span {
  display: block;
  margin-bottom: 0.18rem;
  color: var(--color-brand);
  font-size: 0.54rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.task-card strong {
  display: block;
  font-size: 0.82rem;
}

.work-card {
  padding: 0.75rem 0.8rem;
}

.work-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.work-heading em {
  padding: 0.24rem 0.45rem;
  border-radius: 2rem;
  color: var(--color-ink);
  background: var(--color-gold-soft);
  font-size: 0.48rem;
  font-style: normal;
  font-weight: 700;
}

.equation {
  display: block;
  margin-block: 0.4rem;
  font-size: clamp(1.15rem, 6vw, 1.6rem);
  line-height: 1.2;
  text-align: center;
}

.fraction-visual {
  height: 4.35rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
}

.fraction-circle {
  width: 3.7rem;
  height: 3.7rem;
  display: block;
  border: 0.13rem solid #315047;
  border-radius: 50%;
  background-color: #f5f0e4;
  background-image:
    linear-gradient(30deg, transparent 49%, #315047 50%, transparent 52%),
    linear-gradient(90deg, transparent 49%, #315047 50%, transparent 52%),
    linear-gradient(150deg, transparent 49%, #315047 50%, transparent 52%);
}

.fraction-five {
  background-color: #bfdcd5;
  background-image:
    conic-gradient(var(--color-pink-soft) 0 60deg, transparent 60deg),
    linear-gradient(30deg, transparent 49%, #315047 50%, transparent 52%),
    linear-gradient(90deg, transparent 49%, #315047 50%, transparent 52%),
    linear-gradient(150deg, transparent 49%, #315047 50%, transparent 52%);
}

.fraction-one {
  background-image:
    conic-gradient(#f2d79d 0 60deg, transparent 60deg),
    linear-gradient(30deg, transparent 49%, #315047 50%, transparent 52%),
    linear-gradient(90deg, transparent 49%, #315047 50%, transparent 52%),
    linear-gradient(150deg, transparent 49%, #315047 50%, transparent 52%);
}

.plus {
  font-size: 1.2rem;
  font-weight: 750;
}

.answer-slots {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.2rem;
  font-size: 0.54rem;
  font-weight: 700;
}

.answer-slots i {
  width: 0.55rem;
  border-top: 1px solid var(--color-ink);
}

.answer-slots b {
  margin-inline: 0.3rem;
}

.feedback-card {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 0.7rem;
  border-radius: var(--radius-medium);
  background: var(--color-gold-soft);
  color: var(--color-muted);
  font-size: 0.55rem;
  font-weight: 620;
  line-height: 1.35;
}

.feedback-card i {
  width: 1.1rem;
  height: 1.1rem;
  display: grid;
  flex: none;
  place-items: center;
  border-radius: 50%;
  color: var(--color-ink);
  background: var(--color-gold-strong);
  font-style: normal;
  font-weight: 800;
}

.lesson-action {
  min-height: 3.15rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  margin: 0 0.75rem 0.75rem;
  border-radius: var(--radius-small);
  color: #fff;
  background: var(--color-brand);
  font-size: 0.68rem;
  font-weight: 760;
}

.lesson-note {
  position: absolute;
  z-index: 3;
  display: none;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-small);
  background: rgb(255 255 255 / 0.94);
  box-shadow: var(--shadow-soft);
  font-size: 0.68rem;
}

.lesson-note span {
  color: var(--color-brand);
  font-size: 0.6rem;
  font-weight: 800;
}

.lesson-note-top {
  top: 20%;
  left: -5rem;
}

.lesson-note-bottom {
  right: -5.25rem;
  bottom: 16%;
}

.lesson-visual figcaption {
  position: relative;
  z-index: 3;
  margin: 1rem auto 0;
  color: var(--color-muted);
  font-size: 0.72rem;
  line-height: 1.4;
  text-align: center;
}

/* Home sections */
.fact-strip {
  border-block: 1px solid var(--color-line);
  background: var(--color-surface);
}

.fact-grid {
  display: grid;
}

.fact {
  display: grid;
  gap: 0.1rem;
  padding: 1.2rem 0;
}

.fact + .fact {
  border-top: 1px solid var(--color-line-soft);
}

.fact span {
  color: var(--color-muted);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.fact strong {
  font-size: 1rem;
}

.intro-section {
  background: var(--color-surface);
}

.intro-grid {
  display: grid;
  gap: 3rem;
}

.section-heading > p:last-child,
.split-heading > p,
.documentation-header .section-heading > p:last-child {
  max-width: 43rem;
  color: var(--color-muted);
  font-size: 1.04rem;
}

.principle-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.principle-list li {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  gap: 1rem;
  padding-block: 1.5rem;
  border-top: 1px solid var(--color-line);
}

.principle-list > li:last-child {
  border-bottom: 1px solid var(--color-line);
}

.principle-list > li > span {
  color: var(--color-brand);
  font-size: 0.72rem;
  font-weight: 800;
}

.principle-list h3 {
  margin-bottom: 0.5rem;
  font-size: 1.3rem;
}

.principle-list p {
  margin-bottom: 0;
  color: var(--color-muted);
}

.flow-section {
  background: var(--color-canvas);
}

.centered-heading {
  max-width: 50rem;
  margin: 0 auto clamp(3rem, 8vw, 5rem);
  text-align: center;
}

.centered-heading .eyebrow {
  justify-content: center;
}

.centered-heading > p:last-child {
  margin-inline: auto;
}

.flow-grid {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.flow-grid li {
  position: relative;
  display: grid;
  grid-template-columns: 2.1rem minmax(0, 1fr);
  column-gap: 1rem;
  padding: 0 0 2rem;
}

.flow-grid li:not(:last-child)::before {
  position: absolute;
  top: 1.9rem;
  bottom: 0;
  left: 1rem;
  width: 1px;
  background: var(--color-line);
  content: "";
}

.flow-number {
  grid-column: 2;
  color: var(--color-brand);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.flow-node {
  grid-row: 1 / span 3;
  width: 2.1rem;
  height: 2.1rem;
  display: grid;
  place-items: center;
  border: 1px solid var(--color-brand);
  border-radius: 50%;
  background: var(--color-canvas);
}

.flow-node i {
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 50%;
  background: var(--color-brand);
}

.flow-grid li:nth-child(3) .flow-node,
.flow-grid li:nth-child(5) .flow-node {
  border-width: 2px;
  box-shadow: inset 0 0 0 0.27rem var(--color-canvas);
  background: var(--color-gold);
}

.flow-grid h3,
.flow-grid p {
  grid-column: 2;
}

.flow-grid h3 {
  margin: 0.15rem 0 0.45rem;
}

.flow-grid p {
  max-width: 25rem;
  margin: 0;
  color: var(--color-muted);
  font-size: 0.92rem;
}

.documentation-section {
  background: var(--color-brand-dark);
  color: #fff;
}

.documentation-section .eyebrow {
  color: var(--color-mint-strong);
}

.documentation-header {
  display: grid;
  gap: 1.5rem;
  margin-bottom: clamp(2.5rem, 7vw, 4.5rem);
}

.documentation-header .section-heading > p:last-child {
  color: #d3e2dd;
}

.documentation-header .text-link {
  align-self: end;
  color: #fff;
  text-decoration-color: rgb(255 255 255 / 0.4);
}

.documentation-grid {
  display: grid;
  gap: 1rem;
}

.document-card {
  min-width: 0;
  padding: 1.5rem;
  border: 1px solid #5f8278;
  border-radius: var(--radius-medium);
  background: var(--color-brand-panel);
}

.document-card h3 {
  font-size: 1.35rem;
}

.document-card > p:last-child {
  margin: 0;
  color: #d3e2dd;
  font-size: 0.92rem;
}

.card-meta {
  margin-bottom: 0.6rem;
  color: var(--color-mint-strong);
  font-size: 0.67rem;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.document-icon {
  width: 3rem;
  height: 2rem;
  display: grid;
  align-content: space-between;
  margin-bottom: 2rem;
}

.document-icon span {
  height: 0.2rem;
  border-radius: 1rem;
  background: #9ab4ac;
}

.document-icon span:first-child {
  width: 55%;
  background: var(--color-gold);
}

.document-icon span:last-child {
  width: 75%;
}

.subjects-section {
  background: var(--color-surface);
}

.split-heading {
  display: grid;
  gap: 1.5rem;
  margin-bottom: clamp(3rem, 8vw, 5rem);
}

.subjects-grid {
  display: grid;
  gap: 0.8rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.subject-card {
  min-height: 11rem;
  display: flex;
  flex-direction: column;
  padding: 1.25rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-medium);
  background: var(--color-canvas-warm);
}

.subject-current {
  border-color: var(--color-brand);
  background: var(--color-brand-soft);
}

.subject-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.subject-symbol {
  width: 2.3rem;
  height: 2.3rem;
  display: grid;
  place-items: center;
  border: 1px solid var(--color-line);
  border-radius: 50%;
  color: var(--color-brand);
  background: #fff;
  font-size: 1rem;
  font-weight: 720;
}

.status-badge {
  padding: 0.28rem 0.5rem;
  border: 1px solid var(--color-line);
  border-radius: 2rem;
  color: var(--color-muted);
  background: #fff;
  font-size: 0.6rem;
  font-weight: 760;
  white-space: nowrap;
}

.subject-current .status-badge {
  border-color: var(--color-brand);
  color: var(--color-brand);
}

.subject-card h3 {
  margin-top: auto;
  margin-bottom: 0;
  font-size: 1.1rem;
}

.subject-card p {
  margin: 0.55rem 0 0;
  color: var(--color-muted);
  font-size: 0.78rem;
  line-height: 1.45;
}

.validation-section {
  padding-block: 0;
  background: var(--color-surface);
}

.validation-card {
  position: relative;
  overflow: hidden;
  display: grid;
  gap: 2rem;
  padding: clamp(2rem, 7vw, 5rem);
  border-radius: var(--radius-large);
  color: #fff;
  background: var(--color-brand-dark);
}

.validation-card::before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 0.35rem;
  background: var(--color-gold);
  content: "";
}

.eyebrow-light {
  color: var(--color-mint-strong);
}

.validation-copy > p:not(.eyebrow) {
  max-width: 45rem;
  color: #d3e2dd;
}

.validation-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem 1.5rem;
  margin-top: 1.75rem;
}

.validation-actions a {
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  color: #fff;
  font-weight: 700;
}

.light-badge {
  padding: 0.45rem 0.7rem;
  border: 1px solid #82d7c3;
  border-radius: 2rem;
  color: #fff;
  background: rgb(130 215 195 / 0.12);
  font-size: 0.72rem;
  font-weight: 720;
}

.validation-path {
  display: flex;
  align-items: center;
  gap: 0;
}

.validation-path::before,
.validation-path::after {
  height: 2px;
  flex: 1;
  background: #70958a;
  content: "";
}

.validation-path i {
  width: 1.1rem;
  height: 1.1rem;
  border: 2px solid #9ab4ac;
  border-radius: 50%;
}

.validation-path i + i {
  margin-left: 0.8rem;
}

.validation-path .active {
  width: 1.6rem;
  height: 1.6rem;
  border: 0.25rem solid #fff;
  box-shadow: inset 0 0 0 0.18rem var(--color-brand-dark);
  background: var(--color-gold);
}

.contact-section {
  background: var(--color-surface);
}

.contact-card {
  display: grid;
  gap: 2rem;
  padding-block: 2.5rem;
  border-block: 1px solid var(--color-line);
}

.contact-card h2 {
  margin-bottom: 0;
}

.contact-card > div:last-child > p {
  max-width: 38rem;
  margin-bottom: 1.6rem;
  color: var(--color-muted);
}

/* Shared secondary page hero */
.page-hero {
  padding-block: clamp(4rem, 10vw, 8rem);
  border-bottom: 1px solid var(--color-line);
  background:
    radial-gradient(circle at 85% 20%, rgb(130 215 195 / 0.22), transparent 24rem),
    var(--color-canvas);
}

.page-hero h1 {
  max-width: 14ch;
  margin-bottom: 0;
  font-size: clamp(2.8rem, 9vw, 5.9rem);
}

.page-hero-grid {
  display: grid;
  gap: 2rem;
}

.page-lead {
  max-width: 38rem;
  margin: 0;
  color: var(--color-muted);
  font-size: clamp(1.12rem, 3vw, 1.4rem);
  line-height: 1.5;
}

.narrow-hero {
  max-width: 66rem;
}

.narrow-hero h1 {
  max-width: 16ch;
}

.narrow-hero .page-lead {
  max-width: 48rem;
  margin-top: 1.75rem;
}

/* Documentation */
.docs-page {
  background: var(--color-surface);
}

.docs-layout {
  display: grid;
  gap: 3rem;
  padding-block: clamp(3.5rem, 8vw, 7rem);
}

.docs-aside nav {
  padding: 1rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-medium);
  background: var(--color-canvas);
}

.docs-aside nav > p {
  margin-bottom: 0.5rem;
  color: var(--color-muted);
  font-size: 0.67rem;
  font-weight: 750;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.docs-aside ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

.docs-aside a {
  min-height: 2.65rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  border-top: 1px solid var(--color-line-soft);
  color: var(--color-ink);
  font-size: 0.86rem;
  font-weight: 650;
  text-decoration: none;
}

.docs-aside a span {
  color: var(--color-brand);
  font-size: 0.64rem;
  font-weight: 800;
}

.docs-article {
  min-width: 0;
  max-width: 54rem;
}

.docs-section {
  padding-block: 0 4.5rem;
  scroll-margin-top: calc(var(--header-height) + 1.5rem);
}

.docs-section + .docs-section {
  padding-top: 4.5rem;
  border-top: 1px solid var(--color-line);
}

.docs-section h2 {
  max-width: 15ch;
  font-size: clamp(2rem, 6vw, 3.4rem);
}

.docs-intro {
  max-width: var(--reading-width);
  color: var(--color-muted);
  font-size: 1.04rem;
}

.scope-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
  margin: 2.5rem 0 0;
}

.scope-facts > div {
  min-width: 0;
  padding: 1.1rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-medium);
  background: var(--color-canvas);
}

.scope-facts dt {
  margin-bottom: 0.15rem;
  color: var(--color-brand);
  font-size: 1.8rem;
  font-weight: 780;
  line-height: 1;
}

.scope-facts dd {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.78rem;
  overflow-wrap: anywhere;
}

.note-card {
  display: grid;
  grid-template-columns: 2.25rem minmax(0, 1fr);
  gap: 1rem;
  margin-top: 2.5rem;
  padding: 1.35rem;
  border-left: 0.3rem solid var(--color-gold-strong);
  border-radius: 0 var(--radius-medium) var(--radius-medium) 0;
  background: var(--color-gold-soft);
}

.note-card > span {
  width: 2.1rem;
  height: 2.1rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--color-gold);
  font-weight: 800;
}

.note-card h3 {
  margin-bottom: 0.35rem;
  font-size: 1rem;
}

.note-card p {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.docs-flow-list {
  margin: 2.5rem 0 0;
  padding: 0;
  list-style: none;
}

.docs-flow-list li {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  gap: 1rem;
  padding-block: 1.1rem;
  border-top: 1px solid var(--color-line);
}

.docs-flow-list li:last-child {
  border-bottom: 1px solid var(--color-line);
}

.docs-flow-list > li > span {
  color: var(--color-brand);
  font-size: 0.68rem;
  font-weight: 800;
}

.docs-flow-list h3 {
  margin-bottom: 0.25rem;
  font-size: 1rem;
}

.docs-flow-list p {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.privacy-doc {
  position: relative;
}

.check-list {
  display: grid;
  gap: 0.55rem;
  margin: 2rem 0 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.7rem 0.8rem;
  border-radius: var(--radius-small);
  background: var(--color-brand-soft);
  font-size: 0.9rem;
  font-weight: 650;
}

.check-list span {
  width: 1.25rem;
  height: 1.25rem;
  display: grid;
  flex: none;
  place-items: center;
  border-radius: 50%;
  color: #fff;
  background: var(--color-brand);
  font-size: 0.7rem;
}

.status-quote {
  margin: 2.5rem 0 0;
  padding: 1.5rem;
  border: 0;
  border-radius: var(--radius-medium);
  color: #fff;
  background: var(--color-brand-dark);
}

.status-quote p {
  margin: 0;
  font-size: clamp(1.1rem, 3vw, 1.35rem);
  font-weight: 650;
  line-height: 1.45;
}

.boundary-grid {
  display: grid;
  gap: 1rem;
  margin-top: 2.5rem;
}

.boundary-grid > div {
  padding: 1.35rem;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-medium);
}

.boundary-grid > div:first-child {
  background: var(--color-brand-soft);
}

.boundary-grid > div:last-child {
  background: var(--color-canvas);
}

.boundary-grid h3 {
  font-size: 0.95rem;
}

.boundary-grid ul {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--color-muted);
  font-size: 0.86rem;
}

.boundary-grid li + li {
  margin-top: 0.45rem;
}

.docs-contact {
  padding: clamp(1.5rem, 5vw, 3rem);
  border-top: 0.3rem solid var(--color-gold);
  border-radius: 0 0 var(--radius-medium) var(--radius-medium);
  color: #fff;
  background: var(--color-brand-dark);
}

.docs-contact h2 {
  max-width: 18ch;
  font-size: clamp(1.8rem, 5vw, 2.75rem);
}

.docs-contact p {
  max-width: 39rem;
  color: #d3e2dd;
}

.docs-contact .button {
  color: var(--color-ink);
  border-color: var(--color-mint-strong);
  background: var(--color-mint-strong);
}

/* About */
.about-page {
  background: var(--color-surface);
}

.about-story {
  background: var(--color-surface);
}

.about-grid {
  display: grid;
  gap: 4rem;
}

.about-grid article {
  position: relative;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-line);
}

.large-index {
  display: block;
  margin-bottom: 3rem;
  color: var(--color-brand);
  font-size: 0.75rem;
  font-weight: 800;
}

.about-grid h2 {
  font-size: clamp(2rem, 6vw, 3.3rem);
}

.about-grid p {
  color: var(--color-muted);
  font-size: 1.03rem;
}

.principles-section {
  background: var(--color-canvas);
}

.principles-panel {
  display: grid;
  gap: 2.5rem;
  padding: clamp(1.5rem, 5vw, 3.5rem);
  border-left: 0.35rem solid var(--color-gold);
  border-radius: 0 var(--radius-medium) var(--radius-medium) 0;
  background: var(--color-surface);
}

.principles-panel h2 {
  margin-bottom: 0;
  font-size: clamp(2rem, 5vw, 3.2rem);
}

.principles-panel ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

.principles-panel li {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  gap: 0.75rem;
  padding-block: 0.9rem;
  border-top: 1px solid var(--color-line);
}

.principles-panel li:last-child {
  border-bottom: 1px solid var(--color-line);
}

.principles-panel li span {
  color: var(--color-brand);
  font-size: 0.64rem;
  font-weight: 800;
}

.principles-panel li strong {
  font-size: 0.95rem;
}

.about-cta {
  background: var(--color-surface);
}

/* Contact */
.contact-page {
  background: var(--color-surface);
}

.audience-section {
  padding-bottom: 3rem;
  background: var(--color-surface);
}

.audience-grid {
  display: grid;
  gap: 1rem;
}

.audience-grid article {
  padding: 1.4rem;
  border-top: 0.25rem solid var(--color-brand);
  background: var(--color-canvas);
}

.audience-grid article > span {
  display: block;
  margin-bottom: 2.5rem;
  color: var(--color-brand);
  font-size: 0.68rem;
  font-weight: 800;
}

.audience-grid h2 {
  margin-bottom: 0.7rem;
  font-size: 1.25rem;
  letter-spacing: -0.025em;
}

.audience-grid p {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.contact-state-section {
  background: var(--color-surface);
}

.contact-state {
  position: relative;
  overflow: hidden;
  padding: clamp(2rem, 7vw, 5rem);
  border-radius: var(--radius-large);
  background: var(--color-canvas);
}

.contact-state > *:not(.contact-state-mark) {
  position: relative;
  z-index: 1;
  max-width: 44rem;
}

.contact-state h2 {
  font-size: clamp(2rem, 6vw, 3.5rem);
}

.contact-state > p:not(.eyebrow, .contact-note) {
  color: var(--color-muted);
}

.contact-note {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-block: 1.5rem;
  padding: 0.8rem;
  border-radius: var(--radius-small);
  background: var(--color-gold-soft);
  color: var(--color-muted);
  font-size: 0.85rem;
}

.contact-note span {
  width: 1.25rem;
  height: 1.25rem;
  display: grid;
  flex: none;
  place-items: center;
  border-radius: 50%;
  background: var(--color-gold);
  color: var(--color-ink);
  font-size: 0.72rem;
  font-weight: 800;
}

.contact-state-mark {
  position: absolute;
  right: -2rem;
  bottom: -2rem;
  width: 14rem;
  height: 14rem;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  opacity: 0.13;
  transform: rotate(-8deg);
}

.contact-state-mark span {
  border: 0.35rem solid var(--color-brand);
  border-radius: var(--radius-medium);
}

.contact-state-mark span:nth-child(1) {
  background: var(--color-pink);
}

.contact-state-mark span:nth-child(2),
.contact-state-mark span:nth-child(4) {
  background: var(--color-gold);
}

.contact-state-mark span:nth-child(6) {
  background: var(--color-blue);
}

/* Legal */
.legal-page {
  background: var(--color-surface);
}

.legal-section {
  background: var(--color-surface);
}

.legal-card {
  max-width: 54rem;
}

.provisional-banner {
  margin-bottom: 3rem;
  padding: 1rem;
  border-left: 0.3rem solid var(--color-gold-strong);
  background: var(--color-gold-soft);
  font-size: 0.88rem;
}

.prose {
  color: var(--color-muted);
}

.prose h2 {
  color: var(--color-ink);
  font-size: clamp(1.8rem, 5vw, 2.8rem);
}

.prose p,
.prose li {
  max-width: var(--reading-width);
}

.prose a {
  color: var(--color-brand);
  font-weight: 650;
}

/* 404 */
.error-page {
  background: var(--color-canvas);
}

.error-content {
  min-height: 65vh;
  display: grid;
  align-items: center;
  padding-block: 4rem;
}

.error-grid {
  display: grid;
  align-items: center;
  gap: 4rem;
}

.error-code {
  margin-bottom: 1rem;
  color: var(--color-brand);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.1em;
}

.error-content h1 {
  max-width: 11ch;
  font-size: clamp(2.7rem, 9vw, 5.2rem);
}

.error-content p:not(.error-code) {
  max-width: 34rem;
  color: var(--color-muted);
}

.error-path {
  display: flex;
  align-items: center;
}

.error-path span {
  height: 3px;
  flex: 1;
  background: var(--color-line);
}

.error-path i {
  width: 2.5rem;
  height: 2.5rem;
  display: grid;
  place-items: center;
  border: 2px solid var(--color-brand);
  border-radius: 50%;
  background: var(--color-canvas);
  color: var(--color-brand);
  font-style: normal;
  font-weight: 800;
}

.error-path i.done {
  background: var(--color-mint-strong);
}

.error-path i.current {
  border: 0.35rem solid var(--color-surface);
  box-shadow: 0 0 0 2px var(--color-brand);
  background: var(--color-gold);
}

/* Footer */
.site-footer {
  padding-top: 4rem;
  color: #fff;
  background: #101713;
}

.footer-grid {
  display: grid;
  gap: 2.5rem;
  padding-bottom: 3.5rem;
}

.wordmark-footer {
  color: #fff;
}

.wordmark-footer .wordmark-path i {
  border-color: var(--color-mint-strong);
}

.footer-brand p {
  max-width: 20rem;
  margin: 0.5rem 0 0;
  color: #b5c2bb;
  font-size: 0.85rem;
}

.footer-nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-nav a {
  min-height: 2.4rem;
  display: inline-flex;
  align-items: center;
  color: #d3e2dd;
  font-size: 0.85rem;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem 2rem;
  padding-block: 1.3rem;
  border-top: 1px solid #344e46;
  color: #b5c2bb;
  font-size: 0.72rem;
}

.footer-bottom p {
  margin: 0;
}

/* Tablet */
@media (min-width: 48rem) {
  .shell {
    width: min(100% - 4rem, var(--content-width));
  }

  .hero {
    padding-block: 5rem;
  }

  .lesson-visual {
    width: min(100%, 24rem);
  }

  .fact-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .fact {
    padding: 1.5rem;
  }

  .fact:first-child {
    padding-left: 0;
  }

  .fact + .fact {
    border-top: 0;
    border-left: 1px solid var(--color-line-soft);
  }

  .flow-grid,
  .documentation-grid,
  .subjects-grid,
  .audience-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
  }

  .flow-grid li {
    display: block;
    padding: 1.5rem;
    border: 1px solid var(--color-line);
    border-radius: var(--radius-medium);
    background: rgb(255 255 255 / 0.65);
  }

  .flow-grid li::before {
    display: none;
  }

  .flow-number {
    display: block;
    margin-bottom: 2.5rem;
  }

  .flow-node {
    position: absolute;
    top: 1.1rem;
    right: 1.1rem;
    width: 1.7rem;
    height: 1.7rem;
  }

  .flow-grid h3,
  .flow-grid p {
    display: block;
  }

  .flow-grid p {
    max-width: none;
  }

  .documentation-header,
  .split-heading,
  .contact-card,
  .page-hero-grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(17rem, 0.8fr);
    align-items: end;
    gap: 3rem;
  }

  .documentation-grid article:last-child {
    grid-column: 1 / -1;
  }

  .subjects-grid .subject-card:first-child {
    grid-column: 1 / -1;
  }

  .validation-card {
    grid-template-columns: minmax(8rem, 0.35fr) minmax(0, 1fr);
    align-items: center;
  }

  .validation-path {
    transform: rotate(90deg);
  }

  .docs-hero .page-lead {
    padding-bottom: 0.75rem;
  }

  .scope-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .boundary-grid,
  .about-grid,
  .principles-panel {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .contact-state-mark {
    width: 22rem;
    height: 22rem;
    right: 0;
  }

  .error-grid {
    grid-template-columns: minmax(0, 1fr) minmax(15rem, 0.8fr);
  }

  .footer-grid {
    grid-template-columns: minmax(0, 1.5fr) repeat(2, minmax(8rem, 0.5fr));
  }
}

/* Desktop */
@media (min-width: 64rem) {
  :root {
    --header-height: 5.25rem;
  }

  .site-header {
    position: sticky;
    top: 0;
  }

  .desktop-nav,
  .header-actions {
    display: flex;
    align-items: center;
  }

  .mobile-menu {
    display: none;
  }

  .desktop-nav ul {
    display: flex;
    align-items: center;
    gap: 0.1rem;
    margin: 0;
    padding: 0;
    list-style: none;
  }

  .desktop-nav a,
  .language-link {
    min-height: 2.75rem;
    display: inline-flex;
    align-items: center;
    padding-inline: 0.8rem;
    color: var(--color-muted);
    font-size: 0.79rem;
    font-weight: 680;
    text-decoration: none;
  }

  .desktop-nav a[aria-current="page"],
  .desktop-nav a:hover,
  .language-link:hover {
    color: var(--color-brand);
  }

  .header-actions {
    gap: 0.5rem;
  }

  .hero {
    min-height: calc(100svh - var(--header-height));
    display: grid;
    align-items: center;
    padding-block: 4.5rem;
  }

  .hero-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(20rem, 0.9fr);
    gap: clamp(3rem, 7vw, 7rem);
  }

  .hero-copy h1 {
    max-width: 9ch;
  }

  .lesson-visual {
    width: min(100%, 24rem);
  }

  .lesson-note {
    display: flex;
  }

  .intro-grid {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: clamp(4rem, 10vw, 9rem);
  }

  .sticky-copy {
    position: sticky;
    top: calc(var(--header-height) + 2rem);
    align-self: start;
  }

  .principle-list li {
    grid-template-columns: 2.5rem minmax(0, 1fr);
    padding-block: 2rem;
  }

  .flow-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .documentation-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .documentation-grid article:last-child {
    grid-column: auto;
  }

  .document-card {
    min-height: 20rem;
    display: flex;
    flex-direction: column;
    padding: 2rem;
  }

  .document-card .card-meta {
    margin-top: auto;
  }

  .subjects-grid {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .subjects-grid .subject-card:first-child {
    grid-column: auto;
  }

  .subject-card {
    min-height: 15rem;
  }

  .docs-layout {
    grid-template-columns: minmax(13rem, 0.3fr) minmax(0, 1fr);
    gap: clamp(3rem, 8vw, 7rem);
  }

  .docs-aside nav {
    position: sticky;
    top: calc(var(--header-height) + 2rem);
  }

  .docs-section {
    padding-bottom: 6rem;
  }

  .docs-section + .docs-section {
    padding-top: 6rem;
  }

  .audience-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .audience-grid article {
    min-height: 16rem;
    display: flex;
    flex-direction: column;
  }

  .audience-grid h2 {
    margin-top: auto;
  }
}

@media (min-width: 80rem) {
  .lesson-visual {
    width: min(100%, 25rem);
  }

  .hero-copy h1 {
    font-size: 6.4rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}

@media print {
  .site-header,
  .site-footer,
  .mobile-menu,
  .button-row,
  .contact-section,
  .docs-aside {
    display: none !important;
  }

  body {
    background: #fff;
  }

  .section,
  .page-hero,
  .docs-layout {
    padding-block: 1.5rem;
  }

  a {
    text-decoration: none;
  }
}