:root {
  --ink: #18211e;
  --paper: #f3efe4;
  --paper-2: #fffdf7;
  --line: #b9b5a9;
  --muted: #686b66;
  --green: #183a31;
  --acid: #d8ff45;
  --blue: #4568ff;
  --orange: #ef5a31;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Yu Gothic", sans-serif; }
button, input, textarea { font: inherit; }
a { color: inherit; }
[hidden] { display: none !important; }

.skip-link { position: fixed; z-index: 99; top: 12px; left: 12px; padding: 10px 14px; transform: translateY(-150%); color: white; background: var(--ink); }
.skip-link:focus { transform: none; }

.site-header { position: sticky; z-index: 20; top: 0; display: flex; min-height: 72px; padding: 0 5vw; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); background: rgba(243,239,228,.94); backdrop-filter: blur(12px); }
.brand { display: inline-flex; align-items: center; gap: 11px; font-size: 13px; font-weight: 900; text-decoration: none; }
.brand-mark { display: grid; width: 37px; height: 37px; place-items: center; color: var(--acid); background: var(--ink); font-family: ui-monospace, monospace; font-size: 10px; }
.site-header nav { display: flex; align-items: center; gap: 11px; font-family: ui-monospace, monospace; font-size: 9px; letter-spacing: .08em; }
.site-header nav a { text-decoration: none; }
.site-header nav span { color: var(--muted); }

main { overflow: hidden; }
.hero { display: grid; min-height: 620px; padding: 90px max(5vw, calc((100vw - 1180px) / 2)); align-items: center; grid-template-columns: 1.2fr .8fr; gap: clamp(50px, 8vw, 110px); border-bottom: 1px solid var(--line); }
.eyebrow, .section-number { margin: 0 0 24px; font-family: ui-monospace, monospace; font-size: 10px; font-weight: 900; letter-spacing: .17em; }
.eyebrow { color: var(--orange); }
.hero h1, .section-heading h2, .next-step h2 { margin: 0; font-family: "Yu Mincho", Georgia, serif; letter-spacing: -.06em; line-height: 1.12; }
.hero h1 { font-size: clamp(65px, 10vw, 138px); }
.hero h1 em, .section-heading h2 em { color: var(--orange); font-style: normal; }
.subtitle { max-width: 650px; margin: 34px 0 0; font-size: clamp(16px, 2vw, 23px); font-weight: 800; line-height: 1.8; }
.hero-note { padding: 34px; border: 1px solid var(--ink); box-shadow: 12px 12px 0 var(--blue); background: var(--paper-2); }
.hero-note > span, .type-label, .transfer > span { color: var(--orange); font-family: ui-monospace, monospace; font-size: 9px; font-weight: 900; letter-spacing: .16em; }
.hero-note p { margin: 22px 0; font-family: "Yu Mincho", Georgia, serif; font-size: clamp(22px, 3vw, 34px); line-height: 1.55; }
.hero-note small { color: var(--muted); }

.challenge, .explanation, .next-step { padding: 120px max(5vw, calc((100vw - 1080px) / 2)); }
.section-heading { max-width: 830px; margin-bottom: 55px; }
.section-heading h2, .next-step h2 { font-size: clamp(43px, 7vw, 84px); }
.section-heading > p:last-child { max-width: 720px; margin: 28px 0 0; color: var(--muted); font-size: 16px; line-height: 2; }
code { padding: .08em .28em; color: var(--ink); background: rgba(69,104,255,.12); font-family: ui-monospace, monospace; }

.answer-form { max-width: 920px; }
.prompt-list { display: grid; margin: 0; padding: 0; grid-template-columns: repeat(2, 1fr); gap: 12px; list-style: none; }
.prompt-list li { padding: 24px; border: 1px solid var(--line); background: var(--paper-2); }
.prompt-list label { display: flex; align-items: center; gap: 15px; }
.prompt-list label span { display: grid; width: 30px; height: 30px; place-items: center; color: white; background: var(--ink); font-family: ui-monospace, monospace; font-size: 9px; }
.prompt-list label b { font-family: "Yu Mincho", Georgia, serif; font-size: 23px; }
.prompt-list input { width: 100%; margin-top: 20px; padding: 14px 4px; border: 0; border-bottom: 2px solid var(--ink); border-radius: 0; outline: none; background: transparent; font-family: ui-monospace, monospace; font-size: 18px; }
.prompt-list input:focus { border-color: var(--blue); box-shadow: 0 3px 0 rgba(69,104,255,.18); }
.form-note { margin: 18px 0 28px; color: var(--muted); font-size: 12px; }
.action-button { min-height: 54px; padding: 0 24px; border: 1px solid var(--ink); color: white; background: var(--ink); font-weight: 900; cursor: pointer; }
.action-button span { margin-left: 22px; color: var(--acid); }
.action-button:hover, .action-button:focus-visible { box-shadow: 6px 6px 0 var(--blue); transform: translate(-2px, -2px); }

.friction, .retry { padding: 120px max(5vw, calc((100vw - 1080px) / 2)); color: white; background: var(--green); }
.light-heading .section-number { color: var(--acid); }
.light-heading h2 { color: white; }
.light-heading h2 em { color: var(--acid); }
.light-heading > p:last-child { color: #c9d3cf; }
.comparison-table { display: grid; border-top: 1px solid rgba(255,255,255,.35); }
.comparison-table > div { display: grid; min-height: 96px; padding: 20px 0; align-items: center; border-bottom: 1px solid rgba(255,255,255,.25); grid-template-columns: 160px 1fr minmax(160px, .8fr); gap: 20px; }
.comparison-table span { color: #bbc7c2; font-size: 13px; }
.comparison-table p { margin: 0; font-family: ui-monospace, monospace; font-size: clamp(24px, 4vw, 42px); font-weight: 900; }
.comparison-table p b { padding: 2px 8px; color: var(--ink); background: var(--acid); }
.comparison-table small { color: #a9b7b1; line-height: 1.6; }
.comparison-table small:not(:empty)::before { content: "YOUR ANSWER\A"; white-space: pre; color: var(--acid); font-family: ui-monospace, monospace; font-size: 8px; font-weight: 900; letter-spacing: .12em; }
.why-box { margin-top: 70px; padding: clamp(25px, 5vw, 55px); border: 1px solid rgba(255,255,255,.38); background: #102a23; }
.why-box > span { color: var(--acid); font-family: ui-monospace, monospace; font-size: 10px; font-weight: 900; letter-spacing: .17em; }
.why-box h3 { max-width: 820px; margin: 25px 0 35px; font-family: "Yu Mincho", Georgia, serif; font-size: clamp(26px, 4vw, 48px); line-height: 1.5; }
.why-box code { color: var(--ink); background: var(--acid); }
.why-box label { display: block; margin-bottom: 10px; color: #c2cfca; font-size: 12px; }
.why-box textarea { display: block; width: 100%; max-width: 760px; margin-bottom: 22px; padding: 16px; border: 1px solid rgba(255,255,255,.4); color: white; background: rgba(255,255,255,.06); resize: vertical; }
.why-box textarea:focus { outline: 3px solid var(--acid); outline-offset: 3px; }
.inverse { border-color: white; color: var(--ink); background: white; }
.inverse span { color: var(--blue); }

.answer-lead { color: var(--ink) !important; font-size: clamp(18px, 2.5vw, 25px) !important; font-weight: 700; }
.word-types { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.word-types article { padding: clamp(25px, 4vw, 44px); border: 1px solid var(--ink); }
.adverb-card { background: var(--acid); }
.noun-card { color: white; background: var(--blue); }
.type-label { display: flex; align-items: center; gap: 10px; color: inherit; }
.type-label span { display: grid; width: 30px; height: 30px; place-items: center; border: 1px solid currentColor; }
.word-types h3 { margin: 32px 0; font-family: "Yu Mincho", Georgia, serif; font-size: clamp(25px, 3.2vw, 39px); line-height: 1.5; }
.formula { display: flex; min-height: 62px; margin-top: 8px; padding: 12px; align-items: center; justify-content: center; gap: 12px; border: 1px solid currentColor; font-family: ui-monospace, monospace; }
.formula b { font-size: 20px; }
.formula i { opacity: .45; font-style: normal; }
.formula strong { font-size: clamp(20px, 3vw, 31px); }
.formula em { padding: 3px 8px; color: var(--ink); background: var(--acid); font-size: 24px; font-style: normal; font-weight: 900; }
.not-this { display: flex; margin-top: 13px; flex-wrap: wrap; gap: 8px; }
.not-this s { padding: 6px 9px; color: #8a201a; background: rgba(255,255,255,.55); font-family: ui-monospace, monospace; font-size: 12px; font-weight: 800; }
.word-types article > p { margin: 30px 0 0; line-height: 2; }
.word-types article code { color: inherit; background: rgba(255,255,255,.25); }
.adverb-card code { background: rgba(24,33,30,.12); }
.model-update { display: grid; margin-top: 55px; align-items: center; grid-template-columns: 1fr auto 1fr; gap: 24px; }
.model-update > div { min-height: 150px; padding: 26px; border: 1px solid var(--line); background: var(--paper-2); }
.model-update span { color: var(--orange); font-family: ui-monospace, monospace; font-size: 9px; font-weight: 900; letter-spacing: .16em; }
.model-update p { margin: 22px 0 0; font-size: 19px; font-weight: 800; line-height: 1.7; }
.model-update > i { font-size: 28px; font-style: normal; }
.home-note { margin-top: 25px; padding: 24px 30px; border-left: 6px solid var(--orange); background: var(--paper-2); }
.home-note span { color: var(--orange); font-family: ui-monospace, monospace; font-size: 9px; font-weight: 900; letter-spacing: .15em; }
.home-note p { margin: 12px 0 0; line-height: 1.9; }

.retry-form { max-width: none; }
.retry .prompt-list li { border-color: rgba(255,255,255,.25); background: #102a23; }
.retry .prompt-list label span { color: var(--ink); background: var(--acid); }
.retry .prompt-list input { border-color: rgba(255,255,255,.55); color: white; }
.retry .prompt-list input::placeholder { color: #8da099; }
.model-answer { margin: 15px 0 0; padding: 11px; color: var(--ink); background: var(--acid); font-family: ui-monospace, monospace; font-size: 15px; font-weight: 900; }
.light-action { margin-top: 28px; border-color: white; color: var(--ink); background: white; }
.light-action span { color: var(--blue); }
.transfer { margin-top: 65px; padding: clamp(25px, 5vw, 52px); border: 1px solid rgba(255,255,255,.35); }
.transfer h3 { margin: 20px 0 28px; font-family: "Yu Mincho", Georgia, serif; font-size: clamp(28px, 4vw, 46px); }
.transfer-phrases { display: flex; flex-wrap: wrap; gap: 10px; }
.transfer-phrases code { padding: 10px 15px; color: var(--ink); background: var(--acid); font-size: 16px; }
.transfer details { margin-top: 30px; border-top: 1px solid rgba(255,255,255,.3); }
.transfer summary { padding: 20px 0; font-weight: 900; cursor: pointer; }
.transfer details p { max-width: 740px; margin: 0 0 15px; color: #ced8d4; line-height: 1.9; }

.next-step { text-align: center; }
.next-step .section-number { color: var(--orange); }
.next-step > p:not(.section-number) { max-width: 800px; margin: 35px auto; color: var(--muted); line-height: 2; }
.next-links { display: grid; max-width: 800px; margin: 45px auto 0; gap: 15px; }
.next-primary { display: flex; min-height: 96px; padding: 22px 26px; align-items: center; justify-content: space-between; color: white; background: var(--ink); text-align: left; text-decoration: none; }
.next-primary small { display: block; margin-bottom: 8px; color: var(--acid); font-family: ui-monospace, monospace; font-size: 8px; letter-spacing: .14em; }
.next-primary > b { color: var(--acid); font-size: 25px; }
.next-secondary { font-size: 12px; font-weight: 900; }

footer { display: flex; min-height: 120px; padding: 30px 5vw; align-items: center; justify-content: space-between; border-top: 1px solid var(--line); }
footer p { color: var(--muted); font-size: 11px; }

a:focus-visible, button:focus-visible, summary:focus-visible { outline: 3px solid var(--blue); outline-offset: 4px; }

@media (max-width: 760px) {
  .site-header { min-height: 62px; }
  .site-header nav { display: none; }
  .hero { min-height: auto; padding-top: 65px; padding-bottom: 85px; grid-template-columns: 1fr; }
  .hero h1 { font-size: clamp(58px, 19vw, 92px); }
  .hero-note { box-shadow: 7px 7px 0 var(--blue); }
  .challenge, .friction, .explanation, .retry, .next-step { padding-top: 85px; padding-bottom: 85px; }
  .prompt-list, .word-types { grid-template-columns: 1fr; }
  .comparison-table > div { grid-template-columns: 105px 1fr; }
  .comparison-table small { grid-column: 2; }
  .model-update { grid-template-columns: 1fr; }
  .model-update > i { transform: rotate(90deg); }
  footer { align-items: flex-start; flex-direction: column; gap: 25px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}