:root {
  --bg: #f7f6f0;
  --surface: #fffefa;
  --surface-2: #f3f2ea;
  --ink: #183e3a;
  --ink-2: #4c625b;
  --ink-3: #84928b;
  --line: #e2e5da;
  --line-2: #cfd6c6;
  --primary: #1f5f55;
  --on-primary: #fffefa;
  --primary-hover: #174b43;
  --primary-soft: #e3eee8;
  --good: #2f8a5b;
  --good-soft: #eaf4ec;
  --bad: #b4532a;
  --bad-soft: #fbefe8;
  --focus-ring: #1f5f5566;
  --space: 16px;
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, system-ui, sans-serif;
  color: var(--ink);
  background: var(--bg);
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
  scroll-padding-top: 24px;
}
body {
  margin: 0;
  font-size: 16px;
  line-height: 1.6;
}
a {
  color: var(--primary);
  text-underline-offset: 4px;
}
a:hover {
  text-decoration-thickness: 2px;
}
button,
a,
summary {
  -webkit-tap-highlight-color: transparent;
}
a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 5px;
}
h1,
h2,
h3,
h4,
p {
  margin-top: 0;
}
h1,
h2 {
  font-family: "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  font-weight: 400;
  letter-spacing: -0.045em;
  line-height: 1.06;
}
h1 {
  font-size: clamp(3rem, 6vw, 5.75rem);
  margin-bottom: 26px;
}
h2 {
  font-size: clamp(2.2rem, 4vw, 3.75rem);
  margin-bottom: 24px;
}
h3 {
  font-size: 1.18rem;
  line-height: 1.4;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}
h4 {
  font-size: 1.05rem;
}
p {
  margin-bottom: 20px;
}
em {
  font-weight: 400;
}
main,
.site-header,
footer {
  max-width: 1280px;
  margin: auto;
  padding-left: 56px;
  padding-right: 56px;
}
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 25px;
  padding-bottom: 25px;
  border-bottom: 1px solid var(--line);
  gap: 16px;
}
.brand {
  font-size: 1.8rem;
  font-weight: 750;
  letter-spacing: -0.075em;
  color: var(--ink);
  text-decoration: none;
  line-height: 1;
}
.site-header nav {
  display: flex;
  align-items: center;
  gap: 30px;
}
.site-header nav > a:not(.button) {
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
}
.button,
button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 26px;
  padding: 11px 22px;
  background: var(--primary);
  color: var(--surface);
  border: 1px solid var(--primary);
  border-radius: 7px;
  font: inherit;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
}
.button:hover,
button:hover {
  background: var(--primary-hover);
  text-decoration: none;
}
.button.secondary {
  background: transparent;
  color: var(--primary);
}
.site-header .button {
  min-height: 44px;
  font-size: 0.875rem;
  padding: 9px 17px;
  gap: 20px;
}
.skip {
  position: absolute;
  top: 0;
  left: 20px;
  z-index: 10;
  background: var(--surface);
  padding: 10px;
  transform: translateY(-120%);
}
.skip:focus {
  transform: none;
}
.hero {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 64px;
  align-items: center;
  padding-top: 80px;
  padding-bottom: 92px;
}
.eyebrow {
  font-size: 0.72rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink-2);
  margin-bottom: 25px;
}
.eyebrow .dot {
  margin-right: 9px;
}
.dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  background: var(--primary);
  border-radius: 50%;
}
.lead {
  font-size: 1.14rem;
  line-height: 1.65;
  max-width: 570px;
  color: var(--ink-2);
}
.actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 25px;
  margin: 30px 0 16px;
}
.text-link {
  font-size: 0.94rem;
  font-weight: 600;
  text-decoration: none;
}
.fine {
  font-size: 0.81rem;
  color: var(--ink-2);
  line-height: 1.6;
}
.hero-demo {
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 24px;
  box-shadow: 0 18px 40px -30px #183e3a50;
  transform: rotate(1deg);
}
.demo-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  margin-bottom: 24px;
  font-size: 0.7rem;
  color: var(--ink-2);
}
.amp-wordmark {
  font-weight: 800;
  font-size: 1.45rem;
  letter-spacing: -0.05em;
  color: var(--primary);
}
.amp-wordmark .dot {
  margin-left: 4px;
  width: 5px;
  height: 5px;
}
.problem {
  background: var(--surface);
  border: 1px solid var(--line-2);
  border-radius: 9px;
  padding: 24px;
  overflow: hidden;
}
.problem-label {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.67rem;
  line-height: 1.5;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--ink-2);
  margin-bottom: 27px;
}
.problem :is(h2, h3) {
  font-family: inherit;
  font-size: 1.25rem;
  line-height: 1.5;
  font-weight: 500;
  letter-spacing: -0.025em;
  min-height: 3em;
}
.figure {
  display: block;
  width: 100%;
  max-height: 240px;
  margin: 20px auto 26px;
}
.figure text {
  fill: var(--ink);
  font-family: Arial, sans-serif;
  font-size: 20px;
}
.solution {
  margin-top: 30px;
  border-top: 1px solid var(--line);
  padding-top: 16px;
}
.solution summary {
  cursor: pointer;
  font-size: 0.87rem;
  font-weight: 650;
  list-style: none;
  display: flex;
  justify-content: space-between;
  min-height: 30px;
  align-items: center;
}
.solution summary::-webkit-details-marker {
  display: none;
}
.solution[open] summary span {
  transform: rotate(90deg);
}
.solution-body {
  padding-top: 18px;
  font-size: 0.9rem;
}
.solution-body ol {
  padding-left: 22px;
}
.solution-body li {
  margin-bottom: 9px;
}
.solution-body p:last-child {
  margin-bottom: 0;
}
.demo-caption {
  font-size: 0.73rem;
  color: var(--ink-2);
  margin: 18px 0 0;
}
.section {
  padding: 76px 0;
  border-top: 1px solid var(--line);
}
.section-heading {
  max-width: 660px;
}
.section-heading > p:not(.eyebrow) {
  color: var(--ink-2);
  max-width: 540px;
}
.section-heading > a {
  font-size: 0.94rem;
}
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 84px;
}
.steps {
  list-style: none;
  padding: 0;
  margin: 0;
}
.steps > li {
  display: grid;
  grid-template-columns: 32px 1fr;
  gap: 20px;
  padding-bottom: 25px;
  margin-bottom: 25px;
  border-bottom: 1px solid var(--line);
}
.steps > li:last-child {
  border: 0;
  margin: 0;
  padding: 0;
}
.steps h3 {
  font-size: 1.1rem;
}
.steps p {
  font-size: 0.95rem;
  color: var(--ink-2);
  margin: 0;
}
.step-number {
  font-size: 0.76rem;
  line-height: 1.8;
  color: var(--primary);
}
.lesson-excerpt {
  background: var(--surface);
  padding: 30px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--primary);
  font-size: 0.95rem;
}
.lesson-excerpt .eyebrow {
  font-size: 0.65rem;
}
.lesson-excerpt > p {
  color: var(--ink-2);
}
.closing {
  display: flex;
  align-items: center;
  flex-direction: column;
  text-align: center;
  gap: 15px;
  padding: 85px 0 95px;
}
.closing h2 {
  margin-bottom: 10px;
}
.closing .eyebrow {
  margin-bottom: 5px;
}
.closing > a:not(.button) {
  font-size: 0.85rem;
}
.page-intro {
  padding: 70px 0 65px;
  max-width: 850px;
}
.page-intro h1 {
  font-size: clamp(2.8rem, 5.5vw, 4.8rem);
}
.page-intro .lead {
  max-width: 700px;
}
.sample-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin: 35px 0 25px;
  align-items: start;
}
.sample-grid .problem {
  padding: 20px;
}
.sample-grid .problem :is(h2, h3) {
  font-family: inherit;
  font-size: 1.05rem;
}
.sample-grid .figure {
  height: 180px;
}
.sample-grid .problem-label {
  font-size: 0.61rem;
}
.sample-grid .solution summary {
  font-size: 0.8rem;
}
.coverage-summary {
  display: flex;
  gap: 50px;
  padding: 25px 0;
}
.coverage-summary > div {
  display: flex;
  flex-direction: column;
  max-width: 190px;
}
.coverage-summary strong {
  font-family: Georgia, serif;
  font-size: 2.6rem;
  font-weight: 400;
}
.coverage-summary span {
  font-size: 0.82rem;
  color: var(--ink-2);
}
.coverage-list {
  border-top: 1px solid var(--line);
  margin: 30px 0;
}
.coverage-list details,
.faq details {
  border-bottom: 1px solid var(--line);
  padding: 20px 0;
}
.coverage-list summary,
.faq summary {
  font-weight: 600;
  cursor: pointer;
  padding-right: 10px;
}
.coverage-list summary span {
  float: right;
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--ink-2);
}
.coverage-list ul {
  padding-left: 25px;
  font-size: 0.9rem;
}
.coverage-list li {
  padding: 7px 0;
}
.plans {
  display: flex;
  align-items: stretch;
  gap: 20px;
  margin-top: 35px;
}
.plan {
  padding: 28px;
  border: 1px solid var(--line-2);
  background: var(--surface);
  flex: 1;
  border-radius: 9px;
}
.plan h3 {
  font-size: 1.2rem;
}
.plan p {
  font-size: 0.9rem;
}
.plan .price {
  font-size: 2.5rem;
  font-family: Georgia, serif;
}
.price span {
  font-family: system-ui, sans-serif;
  font-size: 0.8rem;
}
.plan-note {
  padding: 20px;
  flex: 1;
  font-size: 0.9rem;
}
.plan-note p {
  margin-bottom: 10px;
}
.plan-note a + p {
  margin-top: 25px;
}
.two-column {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
}
.two-column h2 {
  font-size: 2rem;
}
.two-column p {
  color: var(--ink-2);
}
.state-links {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}
.state-links a {
  min-width: 44px;
  min-height: 44px;
  border: 1px solid var(--line-2);
  padding: 8px;
  text-align: center;
}
.state {
  padding: 30px 0;
  border-bottom: 1px solid var(--line);
}
.state article {
  max-width: 750px;
}
.notice {
  padding: 20px;
  border: 1px solid var(--line-2);
  background: var(--surface-2);
  margin: 30px 0;
  font-size: 0.94rem;
}
.notice p:last-child {
  margin-bottom: 0;
}
.faq {
  max-width: 850px;
  padding-bottom: 60px;
}
.faq p {
  margin: 20px 25px 0 0;
  color: var(--ink-2);
}
.prose {
  max-width: 780px;
  padding-bottom: 75px;
}
.prose h2 {
  font-family: inherit;
  font-size: 1.25rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  margin: 35px 0 14px;
}
.prose p {
  color: var(--ink-2);
}
.prose li {
  margin-bottom: 10px;
}
.worksheet {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 25px;
}
.worksheet-problem h2 {
  font-family: inherit;
  font-size: 1.1rem;
  letter-spacing: 0;
  font-weight: 600;
  line-height: 1.5;
}
.worksheet-problem > p {
  min-height: 6em;
}
.print-figure .problem {
  padding: 0;
  border: none;
  background: none;
}
.print-figure .problem-label,
.print-figure .problem :is(h2, h3),
.print-figure .solution {
  display: none;
}
.working-space {
  height: 160px;
  background: repeating-linear-gradient(
    transparent,
    transparent 31px,
    var(--line) 32px
  );
  margin: 25px 0;
}
.answer-key {
  margin: 60px 0;
  padding: 50px 0;
  border-top: 1px solid var(--line);
}
.answer-key article {
  margin-bottom: 35px;
}
footer {
  padding-top: 45px;
  padding-bottom: 35px;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
}
.footer-lead p {
  font-size: 0.82rem;
  margin-top: 15px;
  color: var(--ink-2);
}
footer nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 24px;
}
footer nav a {
  font-size: 0.8rem;
  text-decoration: none;
  padding: 4px 0;
}
footer > .fine {
  grid-column: 1/-1;
  margin: 0;
}
.katex {
  font-size: 1.07em;
}
.katex .katex-mathml {
  position: absolute;
  clip: rect(1px, 1px, 1px, 1px);
  padding: 0;
  border: 0;
  height: 1px;
  width: 1px;
  overflow: hidden;
}
@media (max-width: 900px) {
  main,
  .site-header,
  footer {
    padding-left: 30px;
    padding-right: 30px;
  }
  .hero {
    gap: 35px;
    padding-top: 60px;
    padding-bottom: 65px;
  }
  .hero-demo {
    padding: 18px;
  }
  .split {
    gap: 40px;
  }
  .sample-grid {
    grid-template-columns: 1fr;
  }
  .sample-grid .problem {
    display: block;
    max-width: 600px;
    width: 100%;
    margin: auto;
  }
  .sample-grid .problem :is(h2, h3) {
    font-family: inherit;
    min-height: 0;
  }
  .sample-grid .figure {
    max-width: 400px;
  }
  .plans {
    flex-wrap: wrap;
  }
  .plan {
    min-width: 250px;
  }
  .demo-top > span:last-child {
    display: none;
  }
  .worksheet {
    grid-template-columns: 1fr;
  }
  .worksheet-problem {
    max-width: 600px;
  }
  .worksheet-problem > p {
    min-height: 0;
  }
}
@media (max-width: 680px) {
  main,
  .site-header,
  footer {
    padding-left: 22px;
    padding-right: 22px;
  }
  .site-header {
    padding-top: 20px;
    padding-bottom: 20px;
  }
  .brand {
    font-size: 1.6rem;
  }
  .site-header nav {
    gap: 18px;
  }
  .site-header .nav-secondary {
    display: none;
  }
  .site-header .button {
    padding: 8px 13px;
    gap: 14px;
  }
  .hero {
    display: flex;
    flex-direction: column;
    gap: 35px;
    padding-top: 43px;
    padding-bottom: 50px;
  }
  .hero h1 {
    font-size: 3.35rem;
  }
  .hero-copy {
    width: 100%;
  }
  .eyebrow {
    margin-bottom: 20px;
  }
  .lead {
    font-size: 1.02rem;
  }
  .actions {
    gap: 20px;
    margin-top: 25px;
  }
  .hero-demo {
    width: 100%;
    transform: none;
    padding: 19px;
  }
  .demo-top {
    margin-bottom: 18px;
  }
  .demo-top > span:last-child {
    display: block;
  }
  .problem {
    padding: 20px;
  }
  .problem :is(h2, h3) {
    font-family: inherit;
    font-size: 1.15rem;
    min-height: 0;
  }
  .problem-label {
    font-size: 0.62rem;
  }
  .figure {
    margin: 14px 0 20px;
  }
  .section {
    padding: 48px 0;
  }
  .split,
  .two-column {
    grid-template-columns: 1fr;
    gap: 28px;
  }
  .section h2 {
    font-size: 2.6rem;
  }
  .steps > li {
    gap: 14px;
  }
  .lesson-excerpt {
    padding: 24px;
  }
  .closing {
    padding: 60px 0;
    gap: 18px;
  }
  .page-intro {
    padding: 45px 0;
  }
  .page-intro h1 {
    font-size: 3rem;
  }
  .coverage-summary {
    gap: 18px;
  }
  .coverage-summary strong {
    font-size: 2.1rem;
  }
  .coverage-summary span {
    font-size: 0.7rem;
  }
  .coverage-list summary span {
    font-size: 0.7rem;
  }
  .plan,
  .plan-note {
    flex-basis: 100%;
    min-width: 0;
  }
  .plan {
    padding: 24px;
  }
  .two-column h2 {
    font-size: 2rem;
  }
  .prose {
    padding-bottom: 50px;
  }
  footer {
    grid-template-columns: 1fr;
    gap: 25px;
  }
  footer nav {
    gap: 8px 16px;
  }
  footer nav a {
    padding: 7px 0;
  }
  .solution-body {
    font-size: 0.85rem;
  }
}
@media (max-width: 350px) {
  main,
  .site-header,
  footer {
    padding-left: 18px;
    padding-right: 18px;
  }
  .hero h1 {
    font-size: 2.9rem;
  }
  .site-header nav {
    gap: 12px;
  }
  .site-header nav > a:not(.button) {
    font-size: 0.8rem;
  }
  .site-header .button {
    gap: 10px;
    font-size: 0.8rem;
    padding: 8px 10px;
  }
  .hero-demo {
    padding: 14px;
  }
  .problem {
    padding: 17px;
  }
  .problem-label {
    font-size: 0.6rem;
  }
  .demo-top > span:last-child {
    font-size: 0.6rem;
  }
  .page-intro h1 {
    font-size: 2.65rem;
  }
  .coverage-list summary span {
    float: none;
    display: block;
    padding-left: 16px;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  * {
    transition: none !important;
  }
}
@media print {
  body {
    background: white;
    color: #111;
    font-size: 11pt;
  }
  main {
    max-width: none;
    padding: 0;
  }
  .site-header,
  footer,
  .skip,
  .page-intro button,
  .page-intro .eyebrow {
    display: none;
  }
  .page-intro {
    padding: 0 0 20px;
  }
  .page-intro h1 {
    font-size: 26pt;
  }
  .page-intro p {
    font-size: 11pt;
  }
  .worksheet {
    display: block;
  }
  .worksheet-problem {
    break-inside: avoid;
    max-width: none;
    margin-bottom: 20px;
  }
  .worksheet-problem h2 {
    font-size: 13pt;
    margin: 0;
  }
  .worksheet-problem > p {
    min-height: 0;
    margin: 8px 0;
  }
  .print-figure {
    max-width: 230px;
  }
  .print-figure .figure {
    max-height: 120px;
    margin: 5px 0;
  }
  .working-space {
    height: 65px;
    border-bottom: 1px solid #bbb;
    background: none;
  }
  .answer-key {
    break-before: page;
    border: 0;
    margin: 0;
    padding: 0;
  }
  .answer-key h2 {
    font-size: 26pt;
  }
  .answer-key article {
    break-inside: avoid;
  }
  .answer-key h3 {
    font-size: 13pt;
  }
  @page {
    margin: 18mm;
  }
}

.inventory {
  margin: 24px 0;
  padding: 18px 0;
  border-top: 1px solid var(--line);
}
.inventory summary {
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
}