:root {
  color-scheme: light dark;
  --ink: #16202c;
  --muted: #607083;
  --paper: #f5f3ee;
  --surface: #fffdf9;
  --line: #dcd9d0;
  --blue: #245fd6;
  --blue-dark: #19469f;
  --blue-soft: #e8effc;
  --green: #1f7558;
  --green-soft: #e5f3ed;
  --orange: #d77934;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 300px;
  margin: 0;
  color: var(--ink);
  background: var(--paper);
}

a {
  color: inherit;
}

.site-header,
main,
footer {
  width: min(1180px, calc(100% - 48px));
  margin-inline: auto;
}

.site-header {
  height: 92px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: var(--ink);
  font-size: 20px;
  font-weight: 760;
  letter-spacing: -0.025em;
  text-decoration: none;
}

.brand img {
  border-radius: 8px;
  box-shadow: 0 7px 18px rgb(36 95 214 / 18%);
}

.header-action,
.primary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 9px;
  font-weight: 700;
  text-decoration: none;
  transition: transform 150ms ease, background 150ms ease;
}

.header-action {
  min-height: 42px;
  padding: 0 18px;
  border: 1px solid var(--line);
  font-size: 14px;
  background: rgb(255 255 255 / 38%);
}

.header-action:hover,
.primary-action:hover {
  transform: translateY(-1px);
}

.hero {
  min-height: 690px;
  padding: 84px 0 96px;
  display: grid;
  grid-template-columns: minmax(0, 0.96fr) minmax(460px, 0.84fr);
  align-items: center;
  gap: clamp(50px, 8vw, 120px);
}

.eyebrow {
  margin: 0;
  color: var(--blue);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.17em;
}

.hero h1 {
  max-width: 680px;
  margin: 20px 0 26px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(58px, 7vw, 92px);
  font-weight: 500;
  line-height: 0.94;
  letter-spacing: -0.058em;
}

.hero-intro {
  max-width: 630px;
  margin: 0;
  color: var(--muted);
  font-size: clamp(17px, 1.8vw, 20px);
  line-height: 1.65;
}

.hero-actions {
  margin-top: 38px;
  display: flex;
  align-items: center;
  gap: 25px;
}

.primary-action {
  min-height: 52px;
  padding: 0 24px;
  color: white;
  background: var(--blue);
  box-shadow: 0 12px 28px rgb(36 95 214 / 22%);
}

.primary-action:hover {
  background: var(--blue-dark);
}

.text-action {
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
  text-decoration: none;
}

.text-action span {
  margin-left: 5px;
  color: var(--blue);
}

.development-note {
  margin: 28px 0 0;
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--muted);
  font-size: 12px;
}

.development-note span {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 4px rgb(215 121 52 / 12%);
}

.dialogue-illustration {
  position: relative;
  min-height: 500px;
  padding: 60px 36px 34px;
  border: 1px solid var(--line);
  border-radius: 26px;
  background:
    radial-gradient(circle at 92% 5%, rgb(36 95 214 / 13%), transparent 32%),
    var(--surface);
  box-shadow: 0 34px 80px rgb(34 48 67 / 11%);
}

.dialogue-illustration::before {
  content: "";
  position: absolute;
  inset: 13px;
  border: 1px solid rgb(96 112 131 / 9%);
  border-radius: 18px;
  pointer-events: none;
}

.lesson-chip {
  position: relative;
  margin-bottom: 32px;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 650;
}

.lesson-chip span {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  color: var(--blue);
  background: var(--blue-soft);
  font-size: 10px;
}

.dialogue-card {
  position: relative;
  width: 88%;
  margin-bottom: 18px;
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-radius: 16px 16px 16px 5px;
  background: var(--surface);
  box-shadow: 0 10px 24px rgb(31 42 55 / 6%);
}

.dialogue-card.student-card {
  margin-left: auto;
  border-color: #cbd9f5;
  border-radius: 16px 16px 5px;
  background: var(--blue-soft);
}

.dialogue-card .speaker {
  margin: 0 0 8px;
  color: var(--blue);
  font-size: 9px;
  font-weight: 850;
  letter-spacing: 0.15em;
}

.dialogue-card > p:last-child {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 16px;
  line-height: 1.52;
}

.concept-progress {
  position: relative;
  margin-top: 30px;
  padding-top: 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 15px;
  border-top: 1px solid var(--line);
}

.concept-progress > div {
  display: flex;
  align-items: center;
  gap: 12px;
}

.check {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: white;
  background: var(--green);
  font-size: 14px;
}

.concept-progress strong,
.concept-progress small {
  display: block;
}

.concept-progress strong {
  font-size: 13px;
}

.concept-progress small {
  margin-top: 3px;
  color: var(--muted);
  font-size: 10px;
}

.progress-value {
  padding: 6px 9px;
  border-radius: 7px;
  color: var(--green);
  background: var(--green-soft);
  font-size: 10px;
  font-weight: 750;
}

.principle {
  padding: 100px clamp(24px, 7vw, 90px);
  border-block: 1px solid var(--line);
  text-align: center;
}

.principle p {
  margin: 0 0 20px;
  color: var(--blue);
  font-size: 13px;
  font-weight: 750;
}

.principle h2 {
  max-width: 820px;
  margin: auto;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(34px, 5vw, 58px);
  font-weight: 500;
  line-height: 1.12;
  letter-spacing: -0.035em;
}

.how-it-works,
.audiences,
.project-note,
.privacy-promise,
.closing {
  padding: 120px 0;
}

.section-heading {
  max-width: 670px;
}

.section-heading h2,
.audiences h2,
.project-note h2,
.privacy-promise h2,
.closing h2 {
  margin: 17px 0 18px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(40px, 5vw, 62px);
  font-weight: 500;
  line-height: 1.06;
  letter-spacing: -0.045em;
}

.section-heading > p:last-child {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.6;
}

.steps {
  margin: 70px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  list-style: none;
}

.steps li {
  min-height: 230px;
  padding: 28px 32px 30px;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.steps li:last-child {
  border-right: 1px solid var(--line);
}

.step-number {
  color: var(--blue);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 13px;
}

.steps h3 {
  margin: 48px 0 10px;
  font-size: 19px;
}

.steps p,
.audience-grid p,
.project-note > p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.privacy-promise {
  display: grid;
  grid-template-columns: minmax(280px, 0.88fr) minmax(0, 1fr);
  gap: 100px;
  border-bottom: 1px solid var(--line);
}

.privacy-copy {
  padding-top: 6px;
}

.privacy-copy p {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
}

.privacy-copy a,
.legal-return a {
  display: inline-block;
  margin-top: 13px;
  color: var(--blue);
  font-size: 14px;
  font-weight: 750;
  text-decoration: none;
}

.privacy-copy a span {
  margin-left: 5px;
}

.audiences {
  display: grid;
  grid-template-columns: minmax(280px, 0.72fr) minmax(0, 1.2fr);
  gap: 100px;
  border-top: 1px solid var(--line);
}

.audience-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.audience-grid article {
  min-height: 230px;
  padding: 30px;
  border-radius: 16px;
  background: var(--surface);
  box-shadow: 0 14px 36px rgb(34 48 67 / 6%);
}

.audience-grid article:last-child {
  background: var(--blue-soft);
}

.audience-grid h3 {
  margin: 0 0 60px;
  font-size: 17px;
}

.project-note {
  padding-inline: clamp(28px, 6vw, 80px);
  display: grid;
  grid-template-columns: 0.8fr 1fr;
  align-items: center;
  gap: 80px;
  border-radius: 22px;
  color: white;
  background: #172332;
}

.project-note .eyebrow {
  color: #91b3f8;
}

.project-note h2 {
  margin-bottom: 0;
}

.project-note > p {
  color: #c3cfdd;
  font-size: 17px;
}

.closing {
  padding-block: 150px;
  text-align: center;
}

.closing h2 {
  margin: 20px auto 34px;
}

footer {
  min-height: 110px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--line);
}

.footer-brand {
  font-size: 16px;
}

footer p {
  color: var(--muted);
  font-size: 11px;
}

.footer-meta {
  display: flex;
  align-items: center;
  gap: 22px;
}

.footer-meta a {
  color: var(--muted);
  font-size: 11px;
  font-weight: 650;
  text-decoration: none;
}

.legal-page {
  max-width: 900px;
  padding: 80px 0 130px;
}

.legal-heading {
  padding-bottom: 55px;
  border-bottom: 1px solid var(--line);
}

.legal-heading h1 {
  max-width: 800px;
  margin: 20px 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(48px, 7vw, 76px);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.052em;
}

.legal-heading > p:last-child {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
}

.privacy-summary {
  margin: 48px 0 60px;
  padding: 28px 30px;
  border: 1px solid #cbd9f5;
  border-radius: 14px;
  background: var(--blue-soft);
}

.privacy-summary strong {
  display: block;
  margin-bottom: 8px;
  color: var(--blue);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.privacy-summary p {
  margin: 0;
  font-size: 15px;
  line-height: 1.65;
}

.legal-content {
  max-width: 760px;
}

.legal-content section {
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}

.legal-content h2 {
  margin: 0 0 12px;
  font-size: 18px;
}

.legal-content p,
.legal-content li {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.legal-content p {
  margin: 0 0 13px;
}

.legal-content p:last-child {
  margin-bottom: 0;
}

.legal-content ul {
  margin: 12px 0 17px;
  padding-left: 22px;
}

.legal-content li + li {
  margin-top: 7px;
}

.legal-return {
  margin-top: 45px;
}

@media (max-width: 900px) {
  .hero {
    padding-top: 58px;
    grid-template-columns: 1fr;
  }

  .dialogue-illustration {
    width: min(560px, 100%);
    margin-inline: auto;
  }

  .audiences,
  .project-note,
  .privacy-promise {
    grid-template-columns: 1fr;
    gap: 48px;
  }
}

@media (max-width: 640px) {
  .site-header,
  main,
  footer {
    width: min(100% - 30px, 1180px);
  }

  .site-header {
    height: 76px;
  }

  .header-action {
    min-height: 38px;
    padding-inline: 13px;
    font-size: 12px;
  }

  .hero {
    min-height: auto;
    padding: 64px 0 80px;
    gap: 68px;
  }

  .hero h1 {
    font-size: clamp(52px, 17vw, 72px);
  }

  .hero-actions {
    align-items: flex-start;
    flex-direction: column;
    gap: 20px;
  }

  .dialogue-illustration {
    min-height: 0;
    padding: 45px 20px 25px;
    border-radius: 20px;
  }

  .dialogue-card {
    width: 94%;
    padding: 17px;
  }

  .concept-progress {
    align-items: flex-start;
    flex-direction: column;
  }

  .principle,
  .how-it-works,
  .audiences,
  .project-note,
  .privacy-promise,
  .closing {
    padding-block: 82px;
  }

  .principle {
    padding-inline: 8px;
  }

  .steps,
  .audience-grid {
    grid-template-columns: 1fr;
  }

  .steps li,
  .steps li:last-child {
    min-height: 190px;
    border-right: 1px solid var(--line);
  }

  .steps h3 {
    margin-top: 30px;
  }

  .audience-grid article {
    min-height: 190px;
  }

  .audience-grid h3 {
    margin-bottom: 40px;
  }

  .project-note {
    padding-inline: 25px;
  }

  footer {
    padding-block: 28px;
    align-items: flex-start;
    flex-direction: column;
    gap: 18px;
  }

  footer p {
    margin: 0;
  }

  .footer-meta {
    align-items: flex-start;
    flex-direction: column;
    gap: 9px;
  }

  .legal-page {
    padding: 58px 0 90px;
  }

  .privacy-summary {
    padding: 22px;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #edf2f7;
    --muted: #a8b4c2;
    --paper: #10151c;
    --surface: #171e27;
    --line: #2d3744;
    --blue: #78a2ff;
    --blue-dark: #5b8cf5;
    --blue-soft: #1c2a44;
    --green: #62bc98;
    --green-soft: #183b30;
  }

  .header-action {
    background: rgb(255 255 255 / 4%);
  }

  .dialogue-illustration {
    background:
      radial-gradient(circle at 92% 5%, rgb(77 126 232 / 17%), transparent 32%),
      var(--surface);
    box-shadow: 0 34px 80px rgb(0 0 0 / 25%);
  }

  .dialogue-card {
    box-shadow: 0 10px 24px rgb(0 0 0 / 14%);
  }

  .primary-action {
    color: #0c1420;
  }

  .project-note {
    background: #0a0e13;
  }
}

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

  .header-action,
  .primary-action {
    transition: none;
  }
}