/* A local, dependency-free layout. Soft 16px panels and 8px controls form the radius scale. */
:root {
  color-scheme: light dark;
  --background: #f6f8f6;
  --surface: #fdfffd;
  --tint: #e8eee9;
  --text: #183025;
  --muted: #506156;
  --line: #cbd7cd;
  --accent: #286843;
  --accent-text: #f7fff9;
  --accent-soft: #dcebdc;
  --focus: #135e31;
  --shadow: 0 18px 54px rgb(31 61 42 / 9%);
  font-family: "Segoe UI", Arial, Helvetica, sans-serif;
  font-synthesis: none;
  -webkit-text-size-adjust: 100%;
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--background); color: var(--text); font-size: 1rem; line-height: 1.65; }
[hidden] { display: none !important; }
a { color: inherit; text-underline-offset: .22em; }
button { font: inherit; }
button, summary { -webkit-tap-highlight-color: transparent; }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 3px solid var(--focus); outline-offset: 5px; }
.wrap { width: min(1120px, calc(100% - 80px)); margin-inline: auto; }
.skip-link { position: absolute; top: 8px; left: 16px; padding: 10px 18px; background: var(--surface); transform: translateY(-180%); z-index: 2; }
.skip-link:focus { transform: translateY(0); }
.site-header { min-height: 80px; display: flex; align-items: center; justify-content: space-between; gap: 32px; border-bottom: 1px solid var(--line); }
.wordmark { display: inline-flex; align-items: baseline; text-decoration: none; font-size: 1.7rem; font-weight: 800; line-height: 1; letter-spacing: -.08em; flex-shrink: 0; }
.wordmark > span:first-child { font-weight: 500; }
.brand-mark { color: var(--accent); font-size: 2.3rem; margin-left: 6px; transform: translateY(5px); }
.site-header nav { display: flex; align-items: center; gap: 30px; font-size: .88rem; font-weight: 600; }
.site-header nav a { text-decoration: none; }
.site-header nav a:hover { text-decoration: underline; }
.nav-download { color: var(--accent); }
.nav-download span { padding-left: 7px; }
.hero { display: grid; grid-template-columns: 1.12fr 1fr; align-items: center; gap: 70px; padding-block: 76px 80px; }
.eyebrow { margin: 0 0 24px; font-size: .75rem; text-transform: uppercase; letter-spacing: .14em; font-weight: 700; color: var(--accent); }
h1, h2, h3, p { margin-top: 0; }
h1 { font-size: clamp(2.7rem, 4.65vw, 3.75rem); line-height: 1.06; letter-spacing: -.055em; font-weight: 750; margin-bottom: 25px; }
.hero-description { max-width: 440px; font-size: 1.12rem; line-height: 1.7; color: var(--muted); margin-bottom: 30px; }
.button { display: inline-flex; justify-content: center; align-items: center; gap: 25px; min-height: 52px; padding: 13px 21px; border: 1px solid transparent; border-radius: 8px; font-size: .94rem; font-weight: 650; line-height: 1.4; text-decoration: none; }
.button-primary { color: var(--accent-text); background: var(--accent); }
.button:hover { filter: brightness(.93); }
.button:active, .answer:active { transform: translateY(1px); }
.button span { font-size: 1.2rem; }
.demo-area { min-width: 0; }
.flashcard { padding: 26px; border: 1px solid var(--line); background: var(--surface); border-radius: 16px; box-shadow: var(--shadow); }
.flashcard-top { display: flex; justify-content: space-between; align-items: center; gap: 10px; font-size: .76rem; font-weight: 600; color: var(--muted); }
.demo-label { background: var(--accent-soft); color: var(--text); border-radius: 6px; padding: 3px 9px; }
.demo-intro { margin: 32px 0 8px; font-size: .84rem; color: var(--muted); }
.card-question { font-size: 1.52rem; letter-spacing: -.035em; line-height: 1.25; max-width: 290px; margin-bottom: 24px; }
.answers { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.answer { display: flex; align-items: center; gap: 12px; width: 100%; padding: 10px 12px; min-height: 52px; border-radius: 8px; border: 1px solid var(--line); background: var(--background); color: var(--text); text-align: left; cursor: pointer; font-size: .88rem; }
.answer:not(:disabled):hover { border-color: var(--accent); background: var(--accent-soft); }
.answer-letter { border: 1px solid var(--line); border-radius: 4px; width: 23px; height: 25px; flex-shrink: 0; text-align: center; font-size: .7rem; line-height: 23px; color: var(--muted); }
.answer:disabled { cursor: default; opacity: 1; }
.answer.is-correct { border: 2px solid var(--accent); padding: 9px 11px; background: var(--accent-soft); }
.answer.is-selected:not(.is-correct) { border: 2px dashed var(--muted); padding: 9px 11px; }
.demo-result { min-height: 1.7em; font-size: .83rem; line-height: 1.55; margin: 17px 0 0; }
.demo-reset { margin: 10px 0 0; border: 0; background: transparent; padding: 6px 0; color: var(--accent); cursor: pointer; font-size: .83rem; text-decoration: underline; text-underline-offset: .2em; }
.demo-reset span { padding-left: 8px; }
.flashcard-bottom { margin-top: 18px; padding-top: 14px; border-top: 1px solid var(--line); display: flex; align-items: center; justify-content: space-between; font-size: .73rem; color: var(--muted); }
.flashcard-bottom > span:last-child { font-weight: 800; font-size: .84rem; letter-spacing: -.05em; color: var(--accent); }
.demo-caption { color: var(--muted); margin: 15px 10px 0; font-size: .74rem; text-align: center; }
.section-space { padding-block: 68px; scroll-margin-top: 24px; }
.how-section { border-top: 1px solid var(--line); }
h2 { font-size: clamp(1.95rem, 3vw, 2.65rem); line-height: 1.15; letter-spacing: -.045em; font-weight: 700; margin-bottom: 14px; }
.section-heading > p { color: var(--muted); margin-bottom: 38px; }
h3 { font-size: 1.05rem; line-height: 1.35; letter-spacing: -.018em; margin-bottom: 10px; }
.steps { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 38px; }
.step-number { color: var(--accent); font-size: .75rem; display: block; font-weight: 650; margin-bottom: 14px; }
.steps p { font-size: .92rem; line-height: 1.8; color: var(--muted); margin-bottom: 0; }
.controls { margin-top: 46px; padding: 26px 30px; display: grid; grid-template-columns: 1fr 1fr; gap: 48px; background: var(--tint); border-radius: 16px; }
.controls h3 { margin-bottom: 6px; }
.controls p { color: var(--muted); font-size: .88rem; margin-bottom: 0; }
.shortcuts { margin: 0; align-self: center; display: grid; gap: 12px; }
.shortcuts > div { display: grid; grid-template-columns: 130px 1fr; align-items: baseline; gap: 8px; }
.shortcuts dt { font-size: .8rem; color: var(--muted); }
.shortcuts dd { margin: 0; font-size: .74rem; }
kbd { background: var(--surface); border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 4px; padding: 3px 7px; font-family: inherit; font-size: .76rem; white-space: nowrap; }
.shortcut-note { margin-left: 10px; color: var(--muted); }
.download-section { background: var(--tint); }
.download-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 84px; align-items: center; }
.download-copy > p:not(.eyebrow) { color: var(--muted); font-size: .98rem; max-width: 380px; margin-top: 22px; }
.release-details { display: flex; gap: 34px; margin: 25px 0 0; }
.release-details dt { font-size: .73rem; color: var(--muted); }
.release-details dd { margin: 4px 0 0; font-size: .85rem; font-weight: 650; }
.download-panel { padding: 29px; background: var(--surface); border: 1px solid var(--line); border-radius: 16px; }
.download-panel p { color: var(--muted); font-size: .85rem; line-height: 1.75; margin-bottom: 16px; }
.download-panel strong { color: var(--text); font-weight: 650; }
.download-button { width: 100%; gap: 12px; font-size: .87rem; margin-top: 4px; }
.download-panel .download-note { font-size: .72rem; margin: 13px 0 0; line-height: 1.6; }
.faq-section { display: grid; grid-template-columns: .85fr 1.15fr; gap: 66px; }
.faq-section h2 { max-width: 260px; }
.faq-list { border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { cursor: pointer; font-weight: 600; font-size: .95rem; padding: 20px 0; line-height: 1.55; }
.faq-list summary::marker { color: var(--accent); }
.faq-answer { padding: 0 0 10px; font-size: .9rem; color: var(--muted); }
.faq-answer p { margin-bottom: 14px; }
.site-footer { display: flex; align-items: center; gap: 28px; padding-block: 30px; border-top: 1px solid var(--line); }
.site-footer .wordmark { font-size: 1.4rem; }
.site-footer .brand-mark { font-size: 1.8rem; }
.site-footer p { font-size: .8rem; color: var(--muted); margin: 0; }
.site-footer > a:last-child { margin-left: auto; font-size: .8rem; color: var(--muted); }
.no-script-answer { margin-block: 15px; font-size: .9rem; }
.no-script-answer summary { cursor: pointer; }
.error-page { min-height: 65dvh; padding-block: 80px; max-width: 650px; }
.error-page p { color: var(--muted); }
@media (prefers-color-scheme: dark) {
  :root { --background: #14211a; --surface: #1b2c21; --tint: #203329; --text: #edf5ee; --muted: #b9cbbd; --line: #405949; --accent: #b1dfb7; --accent-text: #14291b; --accent-soft: #2c4834; --focus: #c2edc7; --shadow: 0 18px 54px rgb(6 14 8 / 20%); }
}
@media (min-width: 1440px) { .hero { gap: 95px; padding-block: 86px; } }
@media (max-width: 1024px) {
  .wrap { width: min(1120px, calc(100% - 48px)); }
  .hero { gap: 36px; padding-block: 55px; }
  h1 { font-size: clamp(2.65rem, 4.65vw, 3.75rem); }
  .flashcard { padding: 22px; }
  .download-layout { gap: 40px; }
  .controls { gap: 28px; padding: 24px; }
  .shortcuts > div { grid-template-columns: 1fr; gap: 6px; }
  .faq-section { gap: 40px; }
}
@media (max-width: 767px) {
  .wrap { width: calc(100% - 40px); }
  .site-header { min-height: 76px; gap: 20px; }
  .site-header nav { gap: 20px; font-size: .8rem; }
  .site-header nav > a:not(.nav-download) { display: none; }
  .nav-download span { padding-left: 2px; }
  .wordmark { font-size: 1.55rem; }
  .hero { grid-template-columns: 1fr; gap: 42px; padding-block: 44px 48px; }
  h1 { font-size: clamp(2.75rem, 8.8vw, 3.7rem); }
  .hero-description { font-size: 1.05rem; max-width: 430px; }
  .eyebrow { margin-bottom: 20px; font-size: .68rem; }
  .demo-area { max-width: 480px; width: 100%; }
  .section-space { padding-block: 46px; }
  .steps { grid-template-columns: 1fr; gap: 26px; }
  .steps > li { display: grid; grid-template-columns: 25px 1fr; gap: 16px; }
  .step-number { margin-top: 3px; }
  .steps p { max-width: 530px; }
  .controls { grid-template-columns: 1fr; gap: 24px; margin-top: 30px; }
  .shortcuts > div { grid-template-columns: 120px 1fr; }
  .download-layout, .faq-section { grid-template-columns: 1fr; gap: 30px; }
  .download-copy > p:not(.eyebrow) { max-width: 100%; }
  .download-panel { padding: 24px; }
  .faq-section h2 { max-width: 100%; margin-bottom: 0; }
  .site-footer { flex-wrap: wrap; gap: 14px 24px; }
  .site-footer p { flex-basis: 100%; order: 3; }
}
@media (max-width: 380px) {
  .wrap { width: calc(100% - 32px); }
  .site-header { gap: 12px; }
  .site-header nav { font-size: .75rem; }
  .flashcard { padding: 18px; }
  .answer { padding-inline: 9px; gap: 7px; font-size: .8rem; }
  .answer.is-correct, .answer.is-selected:not(.is-correct) { padding-inline: 8px; }
  .controls { padding: 20px; }
  .shortcuts > div { grid-template-columns: 1fr; }
  .download-panel { padding: 20px; }
  .download-button { padding-inline: 12px; font-size: .8rem; gap: 8px; }
}
@media (prefers-reduced-motion: no-preference) {
  .button, .answer { transition: background-color .15s ease, border-color .15s ease, transform .15s ease; }
}
@media (forced-colors: active) { .button, .demo-label, .answer-letter, kbd { border: 1px solid ButtonText; } .answer.is-correct { outline: 2px solid Highlight; } }