/* Adapted site styling by Codex, 2026-10-27. The hero, section, FAQ, and footer rhythm follows the MIT template; this stylesheet is an original, dependency-free implementation. */
:root {
  color-scheme: light;
  --ink: #111c32;
  --ink-soft: #263550;
  --muted: #647087;
  --paper: #f8f8f5;
  --white: #ffffff;
  --line: #e4e6e2;
  --violet: #b8a9ff;
  --coral: #ffa58c;
  --sage: #b8d9c4;
  --content-width: 1160px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans CJK SC", "Hiragino Sans", Meiryo, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); }
button, select { font: inherit; }
a { color: inherit; }
::selection { color: #111c32; background: #c9d6ff; }

.hero-shell {
  position: relative;
  overflow: hidden;
  color: #fff;
  background:
    radial-gradient(ellipse at 82% 16%, rgba(105, 107, 198, .28), transparent 29rem),
    radial-gradient(ellipse at 16% 95%, rgba(49, 111, 130, .2), transparent 34rem),
    #101b31;
}
.hero-shell::before {
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px);
  background-size: 72px 72px;
  content: "";
  mask-image: linear-gradient(to bottom, #000, transparent 85%);
  pointer-events: none;
}
.site-header { position: relative; z-index: 5; padding: 22px 34px; }
.header-inner { width: min(100%, var(--content-width)); margin: 0 auto; display: flex; align-items: center; gap: 30px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: #fff; text-decoration: none; white-space: nowrap; }
.brand-mark { width: 36px; height: 36px; color: #bcafff; flex: 0 0 auto; }
.brand-name { font-size: 16px; font-weight: 680; letter-spacing: -.035em; }
.brand-name span { color: #b7c1d2; font-weight: 450; }
.primary-nav { display: flex; align-items: center; gap: 27px; margin-left: auto; }
.primary-nav a, .footer-nav a { color: #c4ccda; text-decoration: none; font-size: 13px; transition: color .18s ease; }
.primary-nav a:hover, .primary-nav a:focus-visible { color: #fff; }
.header-actions { display: flex; align-items: center; gap: 9px; }
.language-label { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }
.language-select {
  min-width: 116px;
  border: 1px solid rgba(218,226,244,.2);
  border-radius: 999px;
  padding: 9px 28px 9px 12px;
  color: #f5f5fb;
  background: rgba(255,255,255,.06);
  font-size: 12px;
  cursor: pointer;
}
.language-select option { color: #172138; background: #fff; }
.menu-button { display: none; border: 0; background: transparent; color: #fff; cursor: pointer; }

/* Reuses the template's centered hero-v2 section and restrained navigation hierarchy. */
.hero-v2.hero {
  position: relative;
  isolation: isolate;
  width: min(100%, var(--content-width));
  min-height: 625px;
  margin: 0 auto;
  padding: 92px 34px 88px;
  display: grid;
  grid-template-columns: minmax(0, 1.04fr) minmax(350px, .8fr);
  align-items: center;
  gap: clamp(44px, 8vw, 104px);
}
.hero-copy { position: relative; z-index: 1; max-width: 630px; }
.eyebrow { display: flex; align-items: center; gap: 10px; margin: 0 0 22px; color: #6a7689; font-size: 11px; font-weight: 680; letter-spacing: .13em; line-height: 1.4; text-transform: uppercase; }
.hero-eyebrow { color: #c4cada; }
.eyebrow-dot { width: 7px; height: 7px; border-radius: 50%; background: #b6a8ff; box-shadow: 0 0 0 5px rgba(182,168,255,.12); }
.hero h1 { max-width: 660px; margin: 0; color: #fff; font-size: clamp(47px, 6.3vw, 78px); font-weight: 530; letter-spacing: -.075em; line-height: .99; }
.hero h1 > span { display: block; }
.hero-title-accent { color: #beb2ff; }
.hero-lede { max-width: 560px; margin: 26px 0 0; color: #c4ccdb; font-size: clamp(16px, 1.55vw, 18px); line-height: 1.75; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 27px; margin-top: 32px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 18px; min-height: 48px; border-radius: 999px; padding: 0 19px; text-decoration: none; font-size: 13px; font-weight: 690; transition: transform .18s ease, box-shadow .18s ease; }
.button:hover { transform: translateY(-2px); }
.button-bright { color: #172039; background: #d8d0ff; box-shadow: 0 7px 22px rgba(168,151,255,.16); }
.button-bright:hover { box-shadow: 0 10px 29px rgba(168,151,255,.25); }
.text-link { display: inline-flex; align-items: center; gap: 10px; color: #d2d7e1; font-size: 13px; text-decoration: none; }
.text-link:hover { color: #fff; }
.hero-footnote { display: flex; align-items: center; gap: 10px; margin-top: 39px; color: #9eabc0; font-size: 12px; }
.footnote-star { color: #b7a9ff; font-size: 17px; }
.learning-card {
  position: relative;
  z-index: 1;
  max-width: 445px;
  width: 100%;
  justify-self: end;
  border: 1px solid rgba(222,228,244,.2);
  border-radius: 18px;
  padding: 23px 24px 20px;
  background: linear-gradient(155deg, rgba(255,255,255,.11), rgba(255,255,255,.045) 55%, rgba(162,150,255,.08));
  box-shadow: 0 26px 85px rgba(4, 9, 22, .28), inset 0 1px rgba(255,255,255,.12);
  backdrop-filter: blur(12px);
}
.learning-card-top { display: flex; align-items: center; gap: 11px; color: #e6e4ff; }
.mini-mark { display: flex; align-items: center; gap: 3px; }
.mini-mark span { display: block; width: 4px; height: 13px; border-radius: 4px; background: #c6baff; transform: rotate(35deg); }
.mini-mark span:nth-child(2) { height: 18px; opacity: .72; }
.mini-mark span:nth-child(3) { height: 9px; opacity: .5; }
.card-kicker { font-size: 12px; font-weight: 650; letter-spacing: .02em; }
.card-index { margin-left: auto; color: #9ca7bd; font-size: 9px; letter-spacing: .13em; }
.card-rule { height: 1px; margin: 18px 0 26px; background: rgba(255,255,255,.13); }
.card-label { margin: 0 0 10px; color: #aeb9ca; font-size: 10px; font-weight: 700; letter-spacing: .14em; text-transform: uppercase; }
.sample-prompt { margin: 0; color: #f7f5ff; font-size: 20px; font-weight: 470; letter-spacing: -.035em; line-height: 1.52; }
.answer-preview { margin-top: 26px; border: 1px solid rgba(255,255,255,.1); border-radius: 12px; padding: 16px 17px 14px; background: rgba(7,13,28,.23); }
.answer-heading { display: flex; align-items: center; gap: 8px; color: #c8c0ff; font-size: 11px; font-weight: 670; }
.answer-spark { font-size: 15px; }
.answer-preview p { margin: 9px 0 0; color: #c2cbda; font-size: 13px; line-height: 1.65; }
.card-bottom { display: flex; align-items: center; gap: 9px; margin-top: 20px; color: #9eaabe; font-size: 10px; letter-spacing: .03em; }
.card-bottom-line { width: 20px; height: 1px; background: #bbaeff; }
.hero-orbit { position: absolute; z-index: -1; border: 1px solid rgba(191,184,255,.13); border-radius: 50%; pointer-events: none; }
.orbit-one { width: 520px; height: 520px; top: 22px; right: -220px; }
.orbit-two { width: 385px; height: 385px; top: 89px; right: -152px; border-color: rgba(191,184,255,.1); }
.hero-bottom-band { position: absolute; inset: auto 0 0; height: 1px; background: linear-gradient(90deg, transparent, rgba(216,224,246,.18), transparent); }
.hero-bottom-band span { display: block; width: min(100%, var(--content-width)); height: 1px; margin: 0 auto; }

.page-content { overflow: hidden; background: var(--paper); }
.section { width: min(100%, var(--content-width)); margin: 0 auto; padding: 112px 34px; }
.section-heading { max-width: 660px; }
.section-number { color: #a08ce9; font-size: 10px; font-weight: 730; letter-spacing: .1em; }
.section-heading h2, .approach-copy h2, .faq-heading h2 { margin: 0; color: var(--ink); font-size: clamp(34px, 4.2vw, 51px); font-weight: 530; letter-spacing: -.06em; line-height: 1.08; }
.section-intro { max-width: 590px; margin: 19px 0 0; color: var(--muted); font-size: 16px; line-height: 1.75; }
.topic-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 15px; margin-top: 47px; }
.topic-card { position: relative; min-height: 270px; overflow: hidden; border-radius: 14px; padding: 24px 23px; }
.topic-card-ink { color: #fff; background: #16223b; }
.topic-card-lilac { color: #24233c; background: #ece9fa; }
.topic-card-sage { color: #18312b; background: #e2eee5; }
.topic-top { display: flex; align-items: center; gap: 11px; }
.topic-icon { position: relative; display: inline-flex; width: 28px; height: 28px; align-items: center; justify-content: center; border-radius: 9px; }
.topic-card-ink .topic-icon { background: rgba(190,177,255,.14); color: #c9bdff; }
.topic-card-lilac .topic-icon { background: rgba(118,99,192,.12); color: #7766bd; }
.topic-card-sage .topic-icon { background: rgba(55,134,91,.12); color: #4b9670; }
.topic-tag { font-size: 10px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; opacity: .72; }
.topic-card h3 { position: relative; z-index: 1; max-width: 270px; margin: 28px 0 10px; font-size: 21px; font-weight: 610; letter-spacing: -.035em; line-height: 1.25; }
.topic-card p { position: relative; z-index: 1; max-width: 300px; margin: 0; color: inherit; font-size: 13px; line-height: 1.75; opacity: .72; }
.topic-index { position: absolute; right: 15px; bottom: -35px; color: currentColor; font-size: 144px; font-weight: 680; line-height: 1; letter-spacing: -.1em; opacity: .035; }
.icon-orbit i { position: absolute; width: 17px; height: 17px; border: 1px solid currentColor; border-radius: 50%; transform: rotate(55deg) scaleX(.5); }
.icon-orbit i:nth-child(2) { transform: rotate(-55deg) scaleX(.5); }
.icon-orbit i:nth-child(3) { width: 4px; height: 4px; border: 0; background: currentColor; }
.icon-prompt i { width: 13px; height: 8px; border: 1.5px solid currentColor; border-radius: 4px; transform: translate(-2px, -2px); }
.icon-prompt i:nth-child(2) { position: absolute; transform: translate(3px, 3px); background: #ece9fa; }
.icon-check i { width: 14px; height: 9px; border-bottom: 2px solid currentColor; border-left: 2px solid currentColor; transform: translateY(-2px) rotate(-45deg); }
.icon-check i:nth-child(2) { width: 22px; height: 22px; border: 1px solid currentColor; border-radius: 50%; transform: none; }

.approach-section { position: relative; background: #eeefeb; }
.approach-section::after { position: absolute; inset: 0 0 auto; height: 1px; background: linear-gradient(90deg, transparent, #dce0dc 20%, #dce0dc 80%, transparent); content: ""; }
.approach-inner { width: min(100%, var(--content-width)); margin: 0 auto; padding: 106px 34px 112px; display: grid; grid-template-columns: .92fr 1fr; gap: clamp(44px, 9vw, 128px); align-items: start; }
.approach-copy h2 { max-width: 460px; }
.approach-copy > p:last-child { max-width: 440px; margin: 20px 0 0; color: var(--muted); font-size: 15px; line-height: 1.8; }
.learning-steps { margin: 0; padding: 0; list-style: none; }
.learning-steps li { display: grid; grid-template-columns: 44px 1fr; gap: 16px; padding: 17px 0 20px; border-bottom: 1px solid #d8dcd7; }
.learning-steps li:first-child { padding-top: 7px; }
.learning-steps li:last-child { border-bottom: 0; }
.step-marker { display: grid; width: 35px; height: 35px; place-items: center; border: 1px solid #d3d3d0; border-radius: 50%; color: #7c70af; font-size: 10px; font-weight: 700; }
.learning-steps h3 { margin: 2px 0 5px; font-size: 16px; font-weight: 640; letter-spacing: -.025em; }
.learning-steps p { margin: 0; color: #6a7483; font-size: 13px; line-height: 1.65; }

.practice-section { padding-top: 112px; padding-bottom: 115px; }
.practice-heading { max-width: 700px; }
.exercise-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 15px; margin-top: 44px; align-items: stretch; }
.exercise-card { display: flex; min-height: 350px; flex-direction: column; border: 1px solid #e4e6e2; border-radius: 14px; padding: 23px; background: #fff; box-shadow: 0 9px 26px rgba(28,39,60,.025); }
.exercise-label { display: flex; align-items: center; gap: 9px; margin: 0 0 20px; color: #747d8c; font-size: 10px; font-weight: 690; letter-spacing: .09em; text-transform: uppercase; }
.exercise-dot { width: 8px; height: 8px; border-radius: 50%; }
.dot-coral { background: #ed977c; }
.dot-violet { background: #9b88e1; }
.dot-green { background: #68a982; }
.exercise-card h3 { margin: 0; font-size: 20px; font-weight: 620; letter-spacing: -.04em; line-height: 1.3; }
.exercise-card > p:not(.exercise-label) { margin: 12px 0 20px; color: #687387; font-size: 13px; line-height: 1.75; }
.exercise-details { margin-top: auto; border-top: 1px solid #e9eae7; }
.exercise-details summary, .faq-item summary { display: flex; align-items: center; justify-content: space-between; gap: 14px; list-style: none; cursor: pointer; }
.exercise-details summary::-webkit-details-marker, .faq-item summary::-webkit-details-marker { display: none; }
.exercise-details summary { padding: 16px 0 3px; color: #6a5ba7; font-size: 12px; font-weight: 680; }
.details-plus { display: grid; width: 22px; height: 22px; place-items: center; border: 1px solid #e1ddf0; border-radius: 50%; font-size: 16px; line-height: 1; transition: transform .18s ease; }
.exercise-details[open] .details-plus { transform: rotate(45deg); }
.exercise-details > p { margin: 11px 0 2px; color: #697487; font-size: 12px; line-height: 1.7; }
.practice-note { display: flex; align-items: center; justify-content: center; gap: 8px; margin: 26px 0 0; color: #738091; font-size: 12px; text-align: center; }
.practice-note span:first-child { color: #9d89e4; }

.faq-section { background: #fff; }
.faq-inner { width: min(100%, var(--content-width)); margin: 0 auto; padding: 103px 34px 112px; display: grid; grid-template-columns: .82fr 1.18fr; gap: clamp(38px, 9vw, 120px); }
.faq-heading h2 { max-width: 350px; }
.faq-list { border-top: 1px solid var(--line); }
.faq-item { border-bottom: 1px solid var(--line); }
.faq-item summary { min-height: 69px; padding: 13px 1px; color: var(--ink); font-size: 15px; font-weight: 590; letter-spacing: -.015em; }
.faq-toggle { position: relative; width: 23px; height: 23px; flex: 0 0 auto; border: 1px solid #e1e3df; border-radius: 50%; }
.faq-toggle::before, .faq-toggle::after { position: absolute; top: 10px; left: 6px; width: 9px; height: 1px; background: #777f8c; content: ""; }
.faq-toggle::after { transform: rotate(90deg); transition: transform .18s ease; }
.faq-item[open] .faq-toggle::after { transform: rotate(0); }
.faq-item > p { max-width: 640px; margin: -3px 34px 20px 1px; color: #6c778a; font-size: 13px; line-height: 1.8; }

.site-footer { color: #fff; background: #101b31; }
.footer-top, .footer-bottom { width: min(100%, var(--content-width)); margin: 0 auto; padding-right: 34px; padding-left: 34px; }
.footer-top { display: flex; align-items: center; justify-content: space-between; gap: 30px; padding-top: 40px; padding-bottom: 30px; }
.footer-brand .brand-mark { width: 31px; height: 31px; }
.footer-brand .brand-name { font-size: 14px; }
.footer-nav { display: flex; flex-wrap: wrap; gap: 24px; }
.footer-nav a { font-size: 12px; }
.footer-nav a:hover { color: #fff; }
.footer-bottom { display: flex; justify-content: space-between; gap: 20px; border-top: 1px solid rgba(255,255,255,.13); padding-top: 17px; padding-bottom: 22px; }
.footer-bottom p { margin: 0; color: #aab4c4; font-size: 10px; line-height: 1.6; }
.footer-copyright { white-space: nowrap; }

/* Reuses and adapts the template's .tr-menu overlay behavior for compact screens. */
.tr-menu {
  position: fixed;
  inset: 0;
  z-index: 10000;
  display: flex;
  flex-direction: column;
  padding: 82px 25px 30px;
  background: rgba(11, 17, 32, .93);
  backdrop-filter: blur(13px);
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s ease;
}
.tr-menu.open { opacity: 1; pointer-events: auto; }
.tr-menu-close { position: absolute; top: 20px; right: 22px; width: 42px; height: 42px; border: 1px solid rgba(255,255,255,.2); border-radius: 50%; color: #fff; background: rgba(255,255,255,.08); font-size: 22px; cursor: pointer; }
.tr-menu .primary-nav { display: flex; flex-direction: column; align-items: stretch; gap: 0; margin: 0; }
.tr-menu .primary-nav a { border-bottom: 1px solid rgba(255,255,255,.12); padding: 18px 2px; color: #fff; font-size: 20px; }
.menu-button { width: 37px; height: 37px; flex-direction: column; align-items: center; justify-content: center; gap: 6px; border: 1px solid rgba(218,226,244,.2); border-radius: 50%; }
.menu-button span { width: 14px; height: 1.5px; background: currentColor; }
.menu-button:focus-visible, .language-select:focus-visible, a:focus-visible, summary:focus-visible, button:focus-visible { outline: 2px solid #b9aaff; outline-offset: 3px; }

@media (max-width: 900px) {
  .site-header { padding: 18px 26px; }
  .header-inner { gap: 18px; }
  .primary-nav { gap: 16px; }
  .primary-nav a { font-size: 12px; }
  .hero-v2.hero { min-height: 590px; padding-right: 26px; padding-left: 26px; gap: 42px; grid-template-columns: minmax(0, 1fr) minmax(310px, .83fr); }
  .hero h1 { font-size: clamp(48px, 7vw, 65px); }
  .section, .approach-inner, .faq-inner { padding-right: 26px; padding-left: 26px; }
  .footer-top, .footer-bottom { padding-right: 26px; padding-left: 26px; }
}
@media (max-width: 720px) {
  .site-header { padding: 16px 20px; }
  .primary-nav { display: none; }
  .header-inner { gap: 10px; }
  .brand-mark { width: 32px; height: 32px; }
  .brand-name { font-size: 14px; }
  .header-actions { margin-left: auto; gap: 8px; }
  .language-select { min-width: 105px; padding: 8px 23px 8px 10px; font-size: 11px; }
  .menu-button { display: flex; }
  .hero-v2.hero { min-height: auto; padding: 81px 22px 70px; grid-template-columns: 1fr; gap: 42px; }
  .hero-copy { max-width: 610px; }
  .hero h1 { font-size: clamp(48px, 12vw, 70px); }
  .hero-lede { max-width: 510px; font-size: 15px; }
  .hero-actions { gap: 20px; margin-top: 25px; }
  .hero-footnote { margin-top: 29px; }
  .learning-card { max-width: 520px; justify-self: start; padding: 20px; }
  .sample-prompt { font-size: 18px; }
  .section { padding: 82px 22px; }
  .section-heading h2, .approach-copy h2, .faq-heading h2 { font-size: clamp(32px, 9vw, 44px); }
  .section-intro { font-size: 14px; }
  .topic-grid, .exercise-grid { grid-template-columns: 1fr; gap: 12px; margin-top: 32px; }
  .topic-card { min-height: 225px; }
  .topic-card h3 { margin-top: 21px; }
  .approach-inner { padding: 82px 22px; grid-template-columns: 1fr; gap: 38px; }
  .learning-steps li { grid-template-columns: 40px 1fr; }
  .practice-section { padding-top: 82px; padding-bottom: 84px; }
  .exercise-card { min-height: 300px; }
  .faq-inner { padding: 80px 22px 86px; grid-template-columns: 1fr; gap: 33px; }
  .faq-heading h2 { max-width: 470px; }
  .faq-item summary { font-size: 14px; }
  .footer-top, .footer-bottom { padding-right: 22px; padding-left: 22px; }
  .footer-top { align-items: flex-start; flex-direction: column; padding-top: 31px; gap: 22px; }
  .footer-nav { gap: 18px; }
  .footer-bottom { flex-direction: column; gap: 9px; padding-top: 15px; }
}
@media (max-width: 390px) {
  .brand-name { font-size: 13px; }
  .language-select { min-width: 92px; }
  .hero-v2.hero { padding-right: 18px; padding-left: 18px; }
  .hero h1 { font-size: 46px; }
  .hero-actions { align-items: flex-start; flex-direction: column; gap: 17px; }
  .section, .approach-inner, .faq-inner { padding-right: 18px; padding-left: 18px; }
  .footer-top, .footer-bottom { padding-right: 18px; padding-left: 18px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}