:root {
  --primary: #0066cc;
  --primary-focus: #0071e3;
  --primary-on-dark: #2997ff;
  --ink: #1d1d1f;
  --muted: #7a7a7a;
  --canvas: #ffffff;
  --parchment: #f5f5f7;
  --pearl: #fafafc;
  --tile-1: #272729;
  --tile-2: #2a2a2c;
  --tile-3: #252527;
  --hairline: #e0e0e0;
  --nav: #000000;
  --shadow-product: rgba(0, 0, 0, 0.22) 3px 5px 30px 0;
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--canvas);
  font-family: "SF Pro Text", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 17px;
  line-height: 1.47;
  letter-spacing: -0.374px;
}

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

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

.global-nav {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 44px;
  padding: 0 32px;
  background: var(--nav);
  color: #fff;
  font-size: 12px;
  letter-spacing: -0.12px;
}

.brand-mark,
.global-links a {
  color: #fff;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
}

.brand-dot {
  width: 13px;
  height: 13px;
  border-radius: 999px;
  border: 2px solid #fff;
  display: inline-block;
}

.global-links {
  display: flex;
  align-items: center;
  gap: 22px;
}

.sub-nav {
  position: sticky;
  top: 44px;
  z-index: 19;
  min-height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 32px;
  background: rgba(245, 245, 247, 0.84);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  backdrop-filter: blur(18px);
}

.sub-nav strong {
  font-family: "SF Pro Display", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 21px;
  line-height: 1.19;
  letter-spacing: 0.231px;
}

.sub-actions {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 14px;
}

.nav-cta,
.button-primary,
.button-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 9999px;
  transition: transform 160ms ease, background 160ms ease, border-color 160ms ease;
  white-space: nowrap;
}

.nav-cta,
.button-primary {
  color: #fff;
  background: var(--primary);
}

.nav-cta {
  padding: 6px 14px;
  font-size: 14px;
}

.button-primary,
.button-secondary {
  min-height: 44px;
  padding: 11px 22px;
  font-size: 17px;
}

.button-secondary {
  color: var(--primary);
  border: 1px solid var(--primary);
  background: transparent;
}

.button-primary:hover,
.button-secondary:hover,
.nav-cta:hover {
  text-decoration: none;
}

.button-primary:active,
.button-secondary:active,
.nav-cta:active,
.copy-button:active {
  transform: scale(0.95);
}

.button-primary:focus-visible,
.button-secondary:focus-visible,
.nav-cta:focus-visible,
.copy-button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--primary-focus);
  outline-offset: 3px;
}

.tile-light,
.tile-parchment,
.tile-dark {
  min-height: calc(100vh - 96px);
  padding: 80px max(32px, calc((100vw - 1180px) / 2));
}

.tile-light {
  background: var(--canvas);
}

.tile-parchment {
  background: var(--parchment);
}

.tile-dark {
  color: #fff;
  background: var(--tile-1);
}

.dark-2 {
  background: var(--tile-2);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(360px, 1.05fr);
  align-items: center;
  gap: 58px;
}

.hero-copy,
.section-copy {
  max-width: 720px;
}

.centered {
  margin: 0 auto 48px;
  text-align: center;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--primary);
  font-size: 14px;
  font-weight: 600;
  line-height: 1.29;
}

.tile-dark .eyebrow {
  color: var(--primary-on-dark);
}

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

h1,
h2 {
  font-family: "SF Pro Display", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-weight: 600;
}

h1 {
  max-width: 760px;
  margin-bottom: 22px;
  font-size: 56px;
  line-height: 1.07;
  letter-spacing: -0.28px;
}

h2 {
  margin-bottom: 20px;
  font-size: 40px;
  line-height: 1.1;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 21px;
  line-height: 1.19;
  letter-spacing: 0.231px;
}

.lead {
  max-width: 760px;
  margin-bottom: 28px;
  font-family: "SF Pro Display", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 28px;
  line-height: 1.14;
  letter-spacing: 0.196px;
}

.tile-dark .lead,
.tile-dark p {
  color: #e7e7ea;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.product-render {
  width: min(100%, 640px);
  margin-inline: auto;
  border-radius: 18px;
  overflow: hidden;
  background: #fff;
  color: var(--ink);
  box-shadow: var(--shadow-product);
}

.browser-top {
  height: 44px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 16px;
  background: var(--parchment);
  border-bottom: 1px solid var(--hairline);
}

.browser-top span {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: #d2d2d7;
}

.browser-top small {
  margin-left: auto;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: -0.12px;
}

.chat-shell {
  display: grid;
  grid-template-columns: 168px 1fr;
  min-height: 420px;
}

.chat-sidebar {
  padding: 22px 18px;
  background: #f7f7f8;
  border-right: 1px solid var(--hairline);
}

.chat-sidebar b,
.chat-sidebar p {
  display: block;
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.29;
}

.chat-sidebar p {
  color: #555;
}

.chat-main {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 18px;
  padding: 28px;
}

.assistant-bubble,
.teacher-bubble,
.prompt-bar {
  max-width: 85%;
  border-radius: 18px;
  padding: 14px 16px;
}

.assistant-bubble {
  background: var(--parchment);
}

.teacher-bubble {
  align-self: flex-end;
  color: #fff;
  background: var(--ink);
}

.prompt-bar {
  width: 100%;
  max-width: none;
  margin-top: 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 1px solid rgba(0, 0, 0, 0.08);
  color: var(--muted);
}

.prompt-bar i {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 999px;
  color: #fff;
  background: var(--primary);
  font-style: normal;
}

.check-grid,
.prompt-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.check-card,
.prompt-card,
.timeline article,
.formula-panel > div,
.faq-list details {
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: 18px;
  background: #fff;
  color: var(--ink);
}

.check-card {
  min-height: 190px;
  display: grid;
  align-content: start;
  gap: 14px;
  padding: 24px;
  cursor: pointer;
}

.check-card input {
  width: 24px;
  height: 24px;
  accent-color: var(--primary);
}

.check-card span {
  font-weight: 600;
}

.check-card small {
  color: #555;
  font-size: 14px;
  line-height: 1.43;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.timeline article {
  min-height: 245px;
  padding: 24px;
}

.timeline span {
  display: inline-block;
  margin-bottom: 28px;
  color: var(--primary);
  font-size: 14px;
  font-weight: 600;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(360px, 1fr);
  align-items: center;
  gap: 56px;
}

.formula-panel {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.formula-panel > div {
  min-height: 150px;
  padding: 24px;
}

.formula-panel b {
  display: block;
  margin-bottom: 18px;
  color: var(--primary);
  font-size: 14px;
}

.formula-panel span {
  font-size: 24px;
  font-weight: 300;
  line-height: 1.5;
}

.prompt-card {
  min-height: 290px;
  padding: 24px;
  display: flex;
  flex-direction: column;
}

.prompt-card p {
  color: #333;
}

.copy-button {
  width: fit-content;
  margin-top: auto;
  border: 0;
  border-radius: 999px;
  padding: 10px 18px;
  color: #fff;
  background: var(--primary);
  font: inherit;
  cursor: pointer;
}

.copy-button.is-copied {
  background: #1d1d1f;
}

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-list details {
  padding: 0 24px;
}

.faq-list summary {
  cursor: pointer;
  padding: 22px 0;
  font-weight: 600;
}

.faq-list p {
  margin-bottom: 22px;
  color: #333;
}

.safety-band {
  min-height: 70vh;
  display: grid;
  place-items: center;
  background: var(--tile-3);
}

.footer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 0.7fr);
  gap: 48px;
  padding: 64px max(32px, calc((100vw - 1180px) / 2));
  background: var(--parchment);
  color: #333;
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: -0.12px;
}

.footer ul {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (max-width: 900px) {
  .global-nav {
    padding: 0 20px;
  }

  .global-links {
    display: none;
  }

  .sub-nav {
    top: 44px;
    padding: 10px 20px;
  }

  .sub-actions a:not(.nav-cta) {
    display: none;
  }

  .tile-light,
  .tile-parchment,
  .tile-dark {
    padding: 64px 24px;
  }

  .hero,
  .split,
  .footer {
    grid-template-columns: 1fr;
  }

  .hero {
    gap: 42px;
  }

  .check-grid,
  .timeline,
  .prompt-grid {
    grid-template-columns: 1fr;
  }

  h1 {
    font-size: 42px;
  }

  h2 {
    font-size: 34px;
    line-height: 1.18;
  }

  .lead {
    font-size: 24px;
    line-height: 1.25;
  }
}

@media (max-width: 560px) {
  body {
    font-size: 16px;
  }

  .sub-nav strong {
    font-size: 17px;
  }

  h1 {
    font-size: 34px;
  }

  h2 {
    font-size: 30px;
  }

  .lead {
    font-size: 21px;
  }

  .hero-actions {
    flex-direction: column;
  }

  .button-primary,
  .button-secondary {
    width: 100%;
  }

  .chat-shell {
    grid-template-columns: 1fr;
  }

  .chat-sidebar {
    display: none;
  }

  .product-render {
    border-radius: 11px;
  }

  .formula-panel {
    grid-template-columns: 1fr;
  }

  .formula-panel span {
    font-size: 21px;
  }
}