/* THROWAWAY: three landing layouts on /?variant=A|B|C, development only.
   Keep the story; evaluate the current app's chalk canvas, white panels and black controls. */
body:has(.landing-prototype) { background: #dddeda; color: #151515; }
body:has(.landing-prototype) .site-header { position: relative; inset: auto; padding: 26px 40px 0; }
body:has(.landing-prototype) .site-header-inner { width: min(1180px, 100%); border-radius: 28px; padding: 16px 24px; }
body:has(.landing-prototype) .site-header .button { background: #151515; border-color: #151515; }
body:has(.landing-prototype) .site-footer { background: #f5f5f3; padding-bottom: 120px; }
.landing.landing-prototype { --ink: #151515; --muted: #636363; --line: #e4e4e2; --progress: #d6fc76; --brand-field: #f5f5f3; background: #f5f5f3; max-width: 1260px; margin: 24px auto 0; border: 2px solid white; border-radius: 42px 42px 0 0; overflow: clip; }
.landing-prototype > section::after { display: none; }
.landing-prototype .landing-wrap { width: min(1100px, calc(100% - 80px)); }
.landing-prototype .study-hero { padding: 64px 40px 46px; gap: 42px; background: transparent; }
.landing-prototype .study-hero .hero-message { width: 100%; }
.landing-prototype .hero-message h1 { font-size: clamp(2.9rem, 4.4vw, 4.3rem); line-height: 1.08; letter-spacing: -.055em; }
.landing-prototype .hero-description { font-size: .95rem; line-height: 1.8; color: var(--muted); margin-block: 24px; }
.landing-prototype .hero-free { color: var(--muted); }
.landing-prototype .landing-button { background: #151515; border-color: #151515; font-size: .85rem; font-weight: 700; min-height: 50px; }
.landing-prototype .landing-button:hover { background: #333; border-color: #333; transform: none; }
.landing-prototype .landing-text-link { font-size: .85rem; font-weight: 700; }
.landing-prototype .landing-actions { gap: 18px; }
.landing-prototype .hero-product-scene { width: 100%; padding-bottom: 20px; }
.landing-prototype .desktop-preview { height: 510px; width: calc(100% - 20px); border-radius: 30px; box-shadow: none; border: 1px solid #e4e4e2; padding: 10px; }
.landing-prototype .desktop-preview > img { border-radius: 24px; }
.landing-prototype .preview-chrome { height: 32px; }
.landing-prototype .hero-device { right: -8px; bottom: 0; }
.landing-prototype .hero-device .phone-mockup { width: 152px; box-shadow: none; border-radius: 30px; }
.landing-prototype .hero-device .phone-screen { height: 310px; border-radius: 21px; }
.landing-prototype .hero-message h1, .landing-prototype .hero-copy, .landing-prototype .desktop-preview, .landing-prototype .hero-device { animation: none; }
.landing-prototype h2, .landing-prototype .section-heading h2, .landing-prototype .journey-copy h2, .landing-prototype .lesson-copy h2, .landing-prototype .study-rhythm h2 { font-size: clamp(2rem, 3vw, 2.8rem); letter-spacing: -.045em; line-height: 1.15; }
.landing-prototype .landing-promise { padding: 52px 40px; border-top: 1px solid var(--line); }
.landing-prototype .landing-promise h2 { font-size: clamp(1.65rem, 2.5vw, 2.2rem); }
.landing-prototype .landing-section { padding-block: 62px; }
.landing-prototype .landing-examples, .landing-prototype .landing-pricing { background: #f5f5f3; }
.landing-prototype .hero-intro { color: var(--muted); font-weight: 600; }
.landing-prototype .section-heading > p { color: var(--muted); }
.landing-prototype .example-topic { border-radius: 28px; margin-top: 0; padding: 22px; }
.landing-prototype .example-topic::before, .landing-prototype .landing-plans article::before { display: none; }
.landing-prototype .example-art { height: 116px; border-radius: 20px; background: #eaf4ff; }
.landing-prototype .example-topic:nth-child(2) .example-art { background: #f1f5e9; }
.landing-prototype .example-topic:nth-child(3) .example-art { background: #efefed; color: var(--ink); }
.landing-prototype .example-art > span { font-size: 2.8rem; }
.landing-prototype .landing-how { background: white; }
.landing-prototype .journey-layout { gap: 48px; }
.landing-prototype .journey-board { background: #f5f5f3; border-radius: 32px; padding: 24px; }
.landing-prototype .journey-sources { background: white; color: var(--ink); border-radius: 24px; }
.landing-prototype .journey-sources > p { color: var(--ink); }
.landing-prototype .journey-sources li { border-color: var(--line); }
.landing-prototype .journey-sources li > span { color: var(--muted); }
.landing-prototype .journey-plan { padding: 0; background: transparent; }
.landing-prototype .journey-plan-heading { padding-inline: 4px; }
.landing-prototype .journey-screen { aspect-ratio: auto; border-radius: 24px; }
.landing-prototype .journey-screen img { transform: none; height: auto; }
.landing-prototype .journey-plan-status { background: var(--progress); }
.landing-prototype .journey-rail li > span, .landing-prototype .lesson-benefits li::before { color: #526b24; }
.landing-prototype .landing-pocket { background: #f5f5f3; padding: 62px 40px; gap: 48px; }
.landing-prototype .nova-stage { background: white; min-height: 430px; border-radius: 32px; }
.landing-prototype .nova-portrait { width: 260px; }
.landing-prototype .nova-question { background: #f5f5f3; font-size: .8rem; }
.landing-prototype .study-rhythm { padding: 62px 40px; background: white; color: var(--ink); }
.landing-prototype .study-rhythm .hero-intro, .landing-prototype .study-rhythm h2 span { color: var(--muted); }
.landing-prototype .rhythm-copy > p { color: var(--muted); }
.landing-prototype .rhythm-heading { gap: 40px; }
.landing-prototype .rhythm-planner { background: #f5f5f3; border-radius: 32px; }
.landing-prototype .rhythm-life { background: white; }
.landing-prototype .rhythm-session { background: #eaf4ff; }
.landing-prototype .rhythm-day:nth-child(3) .rhythm-session { background: var(--progress); }
.landing-prototype .landing-plans article, .landing-prototype .landing-plans article.landing-plan-pro { background: white; border: 1px solid var(--line); color: var(--ink); border-radius: 28px; margin-top: 0; }
.landing-prototype .landing-plan-pro > p { color: var(--muted); }
.landing-prototype .landing-plan-pro li::before { color: #526b24; }
.landing-prototype .landing-button.light { background: white; border-color: var(--line); color: var(--ink); }
.landing-prototype .landing-button.light:hover { border-color: var(--ink); }
.landing-prototype .landing-finish { background: #eaf4ff; color: var(--ink); padding-block: 62px; }
.landing-prototype .landing-finish h2 { font-size: clamp(2rem, 3.5vw, 3rem); }
.landing-prototype .landing-finish p { color: var(--muted); }
.landing-prototype .landing-finish .landing-button { background: var(--ink); border-color: var(--ink); color: white; }
/* B changes hierarchy: centered promise, then a wide unobstructed product surface. */
.landing-prototype-B .study-hero { display: flex; flex-direction: column; gap: 38px; padding-top: 52px; }
.landing-prototype-B .hero-message { text-align: center; max-width: 780px; }
.landing-prototype-B .hero-message h1 { font-size: clamp(3rem, 4.7vw, 4.6rem); }
.landing-prototype-B .hero-description { margin-inline: auto; max-width: 52ch; }
.landing-prototype-B .landing-actions { justify-content: center; align-items: center; }
.landing-prototype-B .hero-product-scene { max-width: 980px; padding: 0; }
.landing-prototype-B .desktop-preview { width: 100%; height: 480px; padding: 12px; background: white; }
.landing-prototype-B .hero-device { display: none; }
/* C borrows the app's navigation rail and compact working canvas. */
.prototype-app-frame { display: grid; grid-template-columns: 64px minmax(0, 1fr); gap: 26px; padding: 28px; }
.prototype-rail { display: flex; flex-direction: column; align-items: center; gap: 22px; padding: 22px 8px; background: #080808; border-radius: 38px; }
.prototype-rail img { filter: invert(1); margin-bottom: 22px; }
.prototype-rail a { display: grid; place-items: center; color: white; width: 42px; height: 42px; border-radius: 50%; font-size: 22px; }
.prototype-rail a:first-of-type { background: white; color: #151515; }
.prototype-rail a:hover { background: #333; color: white; }
.landing-prototype-C .study-hero { padding: 22px 0; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 30px; }
.landing-prototype-C .hero-message h1 { font-size: clamp(2.6rem, 3.7vw, 3.6rem); }
.landing-prototype-C .hero-message { padding: 28px; border-radius: 30px; background: white; }
.landing-prototype-C .landing-actions { flex-direction: column; align-items: flex-start; }
.landing-prototype-C .desktop-preview { width: 100%; height: 520px; padding: 0; background: transparent; border: 0; }
.landing-prototype-C .preview-chrome, .landing-prototype-C .hero-device { display: none; }
.landing-prototype-C .hero-product-scene { padding: 0; }
.landing-prototype-C .desktop-preview > img { width: 112%; max-width: none; margin-left: -12%; }
.landing-prototype-switcher { position: fixed; z-index: 100; bottom: 18px; left: 50%; transform: translateX(-50%); display: flex; align-items: center; gap: 14px; max-width: calc(100% - 24px); border: 1px solid #444; border-radius: 22px; padding: 10px 14px; background: #151515; color: white; box-shadow: 0 4px 14px #0002; font-size: 13px; }
.landing-prototype-switcher button { flex-shrink: 0; width: 40px; height: 40px; border: 0; border-radius: 50%; background: #303030; color: white; cursor: pointer; font-size: 20px; }
.landing-prototype-switcher strong, .landing-prototype-switcher small { display: block; white-space: nowrap; }
.landing-prototype-switcher small { color: #ccc; font-size: 10px; }
.prototype-original { color: white; text-decoration: underline; padding: 10px; }
.landing-prototype-switcher :focus-visible { outline: 3px solid #d6fc76; outline-offset: 3px; }
@media (max-width: 900px) {
  .landing.landing-prototype { margin-inline: 16px; }
  .landing-prototype .study-hero { gap: 24px; }
  .landing-prototype .hero-message h1 { font-size: 3rem; }
  .landing-prototype .desktop-preview { height: 420px; }
  .prototype-app-frame { gap: 18px; padding: 22px; }
  .landing-prototype-C .study-hero { grid-template-columns: 1fr; }
  .landing-prototype-C .hero-message { padding: 26px; }
}
@media (max-width: 650px) {
  body:has(.landing-prototype) .site-header { padding: 14px 12px 0; }
  body:has(.landing-prototype) .site-header-inner { padding: 12px; border-radius: 22px; }
  body:has(.landing-prototype) .site-header .brand { font-size: 1rem; }
  .landing.landing-prototype { margin: 14px 8px 0; border-radius: 28px 28px 0 0; }
  .landing-prototype .landing-wrap { width: calc(100% - 36px); }
  .landing-prototype .study-hero { grid-template-columns: 1fr; padding: 34px 18px; gap: 30px; }
  .landing-prototype .hero-message h1 { font-size: clamp(2.6rem, 10vw, 3.4rem); }
  .landing-prototype .hero-description { font-size: .85rem; }
  .landing-prototype .hero-product-scene { width: 100%; }
  .landing-prototype .desktop-preview { height: 380px; }
  .landing-prototype .hero-device .phone-mockup { width: 120px; }
  .landing-prototype .hero-device .phone-screen { height: 246px; }
  .landing-prototype .hero-device { right: -3px; }
  .landing-prototype .landing-promise, .landing-prototype .landing-pocket, .landing-prototype .study-rhythm { padding: 40px 18px; }
  .landing-prototype .landing-section { padding-block: 40px; }
  .landing-prototype .journey-layout { gap: 30px; }
  .landing-prototype .example-topics { gap: 18px; }
  .landing-prototype .nova-stage { min-height: 360px; padding: 20px 16px; }
  .landing-prototype .rhythm-heading { gap: 24px; }
  .landing-prototype .rhythm-planner { padding: 18px; }
  .landing-prototype-B .study-hero { padding-top: 34px; }
  .landing-prototype-B .desktop-preview { height: 340px; }
  .prototype-app-frame { display: block; padding: 12px; }
  .prototype-rail { flex-direction: row; justify-content: space-between; padding: 10px 16px; border-radius: 22px; gap: 12px; }
  .prototype-rail img { margin: 0; width: 28px; height: 28px; }
  .prototype-rail a { width: 36px; height: 36px; }
  .landing-prototype-C .study-hero { padding: 16px 0 0; }
  .landing-prototype-C .hero-message { padding: 24px 18px; }
  .landing-prototype-C .desktop-preview { height: 350px; }
  .landing-prototype-switcher { gap: 8px; padding: 8px; bottom: 10px; }
  .landing-prototype-switcher strong { font-size: 12px; }
  .landing-prototype-switcher small { font-size: 9px; }
  .prototype-original { padding: 6px; font-size: 11px; }
}
@media print { .landing-prototype-switcher { display: none; } }
/* A: replace the topic tiles with one tangible lesson and quiet alternative links. */
.landing-prototype .prototype-lesson-glimpse { border-top: 1px solid var(--line); padding-block: 64px; }
.glimpse-layout { display: grid; grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr); gap: 76px; align-items: center; }
.landing-prototype .glimpse-introduction h2 { font-size: clamp(2rem, 3.1vw, 2.85rem); }
.glimpse-description { max-width: 37ch; margin-top: 24px; color: var(--muted); font-size: .95rem; line-height: 1.8; }
.glimpse-free { margin-top: 18px; font-size: .75rem; color: var(--muted); }
.glimpse-other-topics { margin-top: 42px; }
.glimpse-other-topics > p { font-size: .75rem; margin-bottom: 12px; }
.glimpse-other-topics a { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding-block: 16px; border-top: 1px solid var(--line); }
.glimpse-other-topics small, .glimpse-other-topics strong { display: block; }
.glimpse-other-topics small { font-size: .7rem; color: var(--muted); margin-bottom: 5px; }
.glimpse-other-topics strong { font-size: .9rem; font-weight: 700; }
.glimpse-other-topics a:hover strong { text-decoration: underline; text-underline-offset: 4px; }
.glimpse-lesson { min-width: 0; background: white; border-radius: 32px; padding: 30px; }
.glimpse-lesson-header { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 24px; color: var(--muted); font-size: .7rem; }
.glimpse-lesson-header span:last-child { background: #f5f5f3; border-radius: 999px; padding: 6px 10px; }
.landing-prototype .glimpse-lesson h3 { font-size: 1.5rem; line-height: 1.3; letter-spacing: -.035em; }
.glimpse-lesson > p { font-size: .85rem; margin-top: 12px; line-height: 1.7; }
.glimpse-diagram { margin: 22px 0; background: #f5f5f3; border-radius: 22px; }
.glimpse-diagram svg { display: block; width: 100%; height: auto; font-family: var(--font-sans); }
.glimpse-question > p { color: var(--muted); font-size: .7rem; margin-bottom: 8px; }
.glimpse-question h4 { font-size: 1rem; line-height: 1.5; font-weight: 700; letter-spacing: -.02em; }
.glimpse-question details { margin-top: 18px; }
.glimpse-question summary { display: flex; justify-content: space-between; align-items: center; gap: 20px; list-style: none; cursor: pointer; border-radius: 14px; padding: 14px 18px; background: #eaf4ff; color: var(--ink); font-size: .8rem; font-weight: 700; }
.glimpse-question summary::-webkit-details-marker { display: none; }
.glimpse-question summary > span { font-size: 1.2rem; line-height: 1; }
.glimpse-question details[open] summary > span { transform: rotate(45deg); }
.glimpse-question summary:hover { background: #dfedfa; }
.glimpse-explanation { margin-top: 12px; padding: 18px; background: #f1f5e9; border-radius: 14px; }
.glimpse-explanation strong { font-size: .85rem; }
.glimpse-explanation p { font-size: .8rem; line-height: 1.7; margin-top: 8px; }
.glimpse-full-lesson { display: flex; align-items: center; justify-content: space-between; border-top: 1px solid var(--line); margin-top: 24px; padding-top: 20px; font-size: .8rem; font-weight: 700; }
.glimpse-full-lesson:hover { text-decoration: underline; text-underline-offset: 4px; }
@media (max-width: 900px) { .glimpse-layout { gap: 32px; } }
@media (max-width: 650px) {
  .landing-prototype .prototype-lesson-glimpse { padding-block: 40px; }
  .glimpse-layout { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .glimpse-introduction { display: contents; }
  .glimpse-introduction > .hero-intro { margin: 0 0 -16px; }
  .glimpse-description { margin-top: -12px; }
  .glimpse-free { margin-top: -16px; }
  .glimpse-other-topics { grid-row: 6; margin-top: 4px; }
  .glimpse-lesson { padding: 22px; border-radius: 26px; }
  .glimpse-diagram svg text { font-size: 18px; }
  .landing-prototype .glimpse-lesson h3 { font-size: 1.3rem; }
}
.glimpse-choices { display: grid; gap: 10px; border: 0; padding: 0; margin: 0; min-width: 0; }
.glimpse-choices legend { font-size: 1rem; line-height: 1.5; font-weight: 700; letter-spacing: -.02em; padding: 0; margin-bottom: 16px; }
.glimpse-choices label { display: flex; align-items: center; gap: 12px; padding: 12px 16px; min-height: 46px; border: 1px solid var(--line); border-radius: 14px; font-size: .8rem; cursor: pointer; }
.glimpse-choices label:hover { background: #f5f5f3; }
.glimpse-choices label:has(:checked) { border-color: #151515; background: #f5f5f3; }
.glimpse-choices input { appearance: auto; width: 16px; height: 16px; flex-shrink: 0; margin: 0; padding: 0; accent-color: #151515; }
.glimpse-choices input:focus-visible { outline: 3px solid #668619; outline-offset: 4px; }
.glimpse-question .glimpse-feedback { margin: 14px 0 0; font-size: .8rem; line-height: 1.6; color: var(--ink); }