@font-face {
  font-family: "Sora";
  src: url("fonts/Sora.ttf") format("truetype");
  font-style: normal;
  font-weight: 100 800;
  font-display: swap;
}

:root {
  color-scheme: light;
  --paper: #faf8f2;
  --violet: #34265e;
  --lime: #d5f36b;
  --ink: #211a33;
  --muted: #625b70;
  --paper-line: #e8e3d8;
  --page-width: 1200px;
  --gutter: clamp(22px, 5vw, 72px);
  font-family: "Sora", sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; background: var(--paper); }
body { margin: 0; color: var(--ink); background: var(--paper); }
button, a { font: inherit; }
a { color: inherit; }
a:focus-visible, button:focus-visible { outline: 3px solid var(--violet); outline-offset: 4px; }
button { color: inherit; }
img { display: block; max-width: 100%; }
[hidden] { display: none !important; }
::selection { color: var(--ink); background: var(--lime); }

.skip-link {
  position: fixed; z-index: 20; top: 12px; left: 12px; transform: translateY(-160%);
  padding: 12px 16px; color: var(--paper); background: var(--violet); border-radius: 8px;
}
.skip-link:focus { transform: translateY(0); }
.site-header {
  position: relative; z-index: 2; display: flex; align-items: center; gap: 38px;
  width: min(var(--page-width), 100%); min-height: 96px; margin: 0 auto; padding: 14px var(--gutter);
}
.brand { display: flex; min-height: 44px; align-items: center; width: 220px; flex: 0 1 220px; }
.brand img { width: 100%; height: auto; }
.main-nav { display: flex; align-items: center; gap: clamp(20px, 3vw, 42px); margin-left: auto; }
.main-nav a { display: inline-flex; min-height: 44px; align-items: center; }
.main-nav a, .header-action, .premium-link, .site-footer a {
  text-decoration-thickness: 1px; text-underline-offset: 4px;
}
.main-nav a { color: var(--muted); font-size: 14px; text-decoration: none; }
.main-nav a:hover, .premium-link:hover, .site-footer a:hover { text-decoration: underline; }
.header-action { display: inline-flex; min-height: 46px; align-items: center; gap: 12px; padding: 0 18px; border: 1px solid var(--violet); border-radius: 12px; color: var(--violet); font-size: 14px; font-weight: 600; text-decoration: none; white-space: nowrap; }
.header-action:hover { color: var(--paper); background: var(--violet); }

.hero {
  position: relative; display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(340px, .9fr); align-items: center;
  gap: clamp(44px, 7vw, 100px); width: min(var(--page-width), 100%); min-height: 650px; margin: 0 auto; padding: 60px var(--gutter) 112px;
}
.hero-copy { position: relative; z-index: 1; max-width: 700px; }
.eyebrow { margin: 0 0 22px; color: var(--muted); font-size: 14px; font-weight: 600; line-height: 1.5; }
h1, h2, h3, p { margin-top: 0; }
.hero h1 { max-width: 720px; margin-bottom: 25px; font-size: clamp(48px, 5.3vw, 64px); font-weight: 700; letter-spacing: -.045em; line-height: 1.15; }
h1 em, h2 em { color: var(--violet); font-style: normal; }
.hero-description { max-width: 450px; margin-bottom: 27px; color: var(--muted); font-size: clamp(16px, 1.55vw, 19px); line-height: 1.75; }
.button { display: inline-flex; min-height: 54px; align-items: center; justify-content: center; gap: 20px; padding: 0 24px; border: 0; border-radius: 12px; font-size: 16px; font-weight: 600; text-decoration: none; transition: transform .18s ease, background-color .18s ease; }
.button:hover { transform: translateY(-2px); }
.button-dark { color: var(--paper); background: var(--violet); }
.button-dark:hover { background: #493579; }
.hero-note { margin: 13px 0 0 4px; color: var(--muted); font-size: 14px; }
.hero-page-mark { position: absolute; right: 0; bottom: 0; width: min(26vw, 300px); height: min(17vw, 195px); opacity: .8; background: var(--lime); clip-path: polygon(0 0, 100% 0, 100% 100%, 26% 100%); }
.hero-page-mark::after { position: absolute; inset: 0 0 0 26%; content: ""; background: var(--paper); clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%, 24% 53%); }

.practice-wrap { position: relative; z-index: 1; width: min(100%, 455px); justify-self: end; padding: 22px 0 0 22px; }
.practice-wrap::before { position: absolute; top: 0; left: 0; width: 70%; height: 78%; content: ""; background: #eee9dc; clip-path: polygon(0 0, 82% 0, 100% 22%, 100% 100%, 0 100%); }
.practice-card { position: relative; isolation: isolate; overflow: hidden; min-height: 366px; padding: clamp(26px, 4vw, 40px); background: var(--paper); border: 1px solid var(--paper-line); border-radius: 16px; box-shadow: 0 18px 55px rgb(33 26 51 / 8%); }
.practice-topline { display: flex; align-items: center; justify-content: space-between; gap: 18px; padding-bottom: 16px; border-bottom: 1px solid var(--paper-line); }
.practice-label { color: var(--violet); font-size: 14px; font-weight: 600; }
.practice-count { color: var(--muted); font-size: 14px; font-variant-numeric: tabular-nums; }
.practice-context { margin: 29px 0 9px; color: var(--muted); font-size: 14px; }
.practice-card h2 { max-width: 280px; margin-bottom: 21px; font-size: 21px; font-weight: 600; letter-spacing: -.035em; line-height: 1.4; }
.practice-prompt { min-height: 76px; margin-bottom: 12px; color: var(--violet); font-size: clamp(20px, 2vw, 25px); font-weight: 600; letter-spacing: -.04em; line-height: 1.4; }
.translation-toggle { display: inline-flex; min-height: 44px; align-items: center; gap: 12px; padding: 0; border: 0; background: transparent; color: var(--muted); cursor: pointer; font-size: 14px; text-align: left; text-decoration: underline; text-underline-offset: 4px; }
.translation-toggle span { color: var(--violet); font-size: 19px; text-decoration: none; }
.practice-translation { margin: 2px 0 11px; color: var(--muted); font-size: 14px; line-height: 1.6; }
.practice-rule { height: 5px; margin: 12px 0 10px; background: #eee9dc; }
.practice-rule span { display: block; width: 16.666%; height: 100%; background: var(--lime); transition: width .2s ease; }
.practice-controls { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.practice-controls button { display: grid; width: 46px; min-height: 46px; place-items: center; border: 1px solid var(--paper-line); border-radius: 50%; background: transparent; color: var(--violet); cursor: pointer; font-size: 20px; }
.practice-controls button:hover:not(:disabled) { background: var(--lime); border-color: var(--lime); }
.practice-controls button:disabled { color: #9892a0; cursor: not-allowed; }
.control-hint { color: var(--muted); font-size: 14px; text-align: center; }
.fold-corner { position: absolute; z-index: -1; top: 0; right: 0; width: 58px; height: 58px; background: var(--lime); clip-path: polygon(0 0, 100% 100%, 100% 0); }
.practice-caption { position: relative; margin: 12px 0 0 4px; color: var(--muted); font-size: 14px; line-height: 1.5; }

.learning { position: relative; isolation: isolate; overflow: hidden; color: var(--paper); background: var(--violet); }
.learning-body { position: relative; isolation: isolate; overflow: hidden; padding: clamp(64px, 9vw, 116px) var(--gutter) clamp(72px, 9vw, 120px); }

/* Video panel: full screen on landscape displays, a full-width 16:9 player with its controls underneath elsewhere. */
.learning-stage { display: flex; flex-direction: column; background: #13100d; }
.learning-video { display: block; width: 100%; aspect-ratio: 16 / 9; background: #13100d; object-fit: contain; }
.stage-controls { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 10px; padding: 12px var(--gutter) 16px; }
.stage-controls button { min-height: 44px; padding: 0 18px; border: 1px solid rgb(250 248 242 / 32%); border-radius: 12px; color: var(--paper); background: rgb(19 16 13 / 78%); cursor: pointer; font-size: 14px; font-weight: 600; transition: background-color .18s ease; }
.stage-controls button:hover { background: rgb(19 16 13 / 94%); }
.stage-controls button:focus-visible { outline-color: var(--lime); }
@media (min-aspect-ratio: 8 / 5) {
  .learning-stage { position: relative; display: block; height: 100vh; height: 100svh; }
  .learning-video { height: 100%; aspect-ratio: auto; }
  .stage-controls { position: absolute; z-index: 1; right: var(--gutter); bottom: clamp(18px, 7%, 64px); padding: 0; }
}
.learning-stage:fullscreen { position: relative; display: block; width: 100%; height: 100%; }
.learning-stage:fullscreen .learning-video { height: 100%; aspect-ratio: auto; object-fit: contain; }
.learning-stage:fullscreen .stage-controls { position: absolute; z-index: 1; right: var(--gutter); bottom: clamp(18px, 4%, 40px); padding: 0; }
/* 16:10 to 19:10 screens: fill the screen; the cropped edge is at most 5%, so the logo and the progress bar drawn inside the video stay visible. Any other shape shows every pixel. */
@media (min-aspect-ratio: 8 / 5) and (max-aspect-ratio: 19 / 10) {
  .learning-video { object-fit: cover; }
}
.learning-heading, .learning-layout { width: min(var(--page-width), 100%); margin-inline: auto; }
.eyebrow-light { color: #c9c1d8; }
.learning h2, .practice-note h2, .closing h2 { margin-bottom: 18px; font-size: clamp(37px, 5vw, 64px); font-weight: 600; letter-spacing: -.07em; line-height: 1.04; }
.learning h2 em { color: var(--lime); }
.learning-intro { max-width: 560px; margin-bottom: 52px; color: #d6d0e1; font-size: 16px; line-height: 1.75; }
.learning-layout { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(220px, .7fr); align-items: center; gap: clamp(50px, 10vw, 145px); }
.learning-steps { margin: 0; padding: 0; list-style: none; }
.learning-steps li { display: grid; grid-template-columns: 50px 1fr; gap: 14px; padding: 24px 0 28px; border-top: 1px solid rgb(250 248 242 / 25%); }
.step-number { padding-top: 3px; color: var(--lime); font-size: 14px; font-weight: 700; letter-spacing: .1em; }
.learning-steps h3 { margin-bottom: 8px; font-size: 19px; font-weight: 600; letter-spacing: -.035em; }
.learning-steps p { max-width: 465px; margin: 0; color: #d6d0e1; font-size: 16px; line-height: 1.7; }
.app-preview { width: min(100%, 250px); margin: 0 auto; }
.app-preview img { width: 100%; height: auto; border: 1px solid rgb(250 248 242 / 25%); border-radius: 12px; }
.app-preview figcaption { margin-top: 11px; color: #d6d0e1; font-size: 14px; line-height: 1.5; }
.learning-fold { position: absolute; z-index: -1; top: -10px; right: 0; width: min(30vw, 350px); aspect-ratio: 1.5; background: rgb(213 243 107 / 9%); clip-path: polygon(0 0, 100% 0, 100% 100%, 29% 100%); }

.practice-note { display: grid; grid-template-columns: 88px minmax(250px, .9fr) minmax(250px, .8fr); align-items: center; gap: clamp(26px, 6vw, 78px); width: min(var(--page-width), 100%); margin: 0 auto; padding: clamp(70px, 10vw, 124px) var(--gutter); }
.practice-note .eyebrow { margin-bottom: 16px; font-size: 10px; }
.practice-note h2 { margin: 0; font-size: clamp(32px, 4vw, 49px); }
.practice-note h2 em { color: var(--violet); }
.note-symbol { width: 78px; }
.note-symbol img { width: 100%; height: auto; }

.note-copy { max-width: 420px; margin: 0; color: var(--muted); font-size: 15px; line-height: 1.8; }

.examples { width: min(var(--page-width), 100%); margin: 0 auto; padding: clamp(8px, 2vw, 24px) var(--gutter) clamp(70px, 10vw, 112px); }
.examples h2 { max-width: 720px; margin-bottom: 14px; font-size: clamp(28px, 3.6vw, 44px); font-weight: 600; letter-spacing: -.06em; line-height: 1.1; }
.examples-intro { max-width: 600px; margin-bottom: 30px; color: var(--muted); font-size: 16px; line-height: 1.75; }
.example-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 340px), 1fr)); gap: 0 clamp(32px, 6vw, 80px); margin: 0; padding: 0; list-style: none; }
.example-list li { padding: 18px 0 20px; border-top: 1px solid var(--paper-line); }
.example-list .en { display: block; margin-bottom: 4px; color: var(--violet); font-size: 19px; font-weight: 600; letter-spacing: -.035em; line-height: 1.4; }
.example-list .id { color: var(--muted); font-size: 14px; line-height: 1.6; }

.info { width: min(var(--page-width), 100%); margin: 0 auto; padding: clamp(64px, 9vw, 112px) var(--gutter) 0; }
.info-faq { padding-top: clamp(8px, 2vw, 24px); }
.info-head { max-width: 760px; margin-bottom: clamp(26px, 4vw, 44px); }
.info h2 { margin-bottom: 16px; font-size: clamp(30px, 4vw, 48px); font-weight: 600; letter-spacing: -.06em; line-height: 1.1; }
.info-lead { margin: 0; color: var(--muted); font-size: 16px; line-height: 1.8; }
.info-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr)); gap: 0 clamp(28px, 5vw, 64px); }
.info-grid-two { grid-template-columns: repeat(auto-fit, minmax(min(100%, 340px), 1fr)); }
.info-grid article, .faq-list > div { padding: 22px 0 26px; border-top: 1px solid var(--paper-line); }
.info h3 { margin-bottom: 8px; color: var(--violet); font-size: 19px; font-weight: 600; letter-spacing: -.035em; line-height: 1.35; }
.info-grid p, .faq-list p { max-width: 520px; margin: 0; color: var(--muted); font-size: 15px; line-height: 1.75; }
.faq-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 420px), 1fr)); gap: 0 clamp(28px, 5vw, 64px); }
.faq-list p { max-width: 560px; }

.doc { width: min(840px, 100%); margin: 0 auto; padding: clamp(28px, 5vw, 64px) var(--gutter) clamp(56px, 8vw, 104px); }
.crumbs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 28px; color: var(--muted); font-size: 14px; }
.crumbs a { color: var(--muted); text-underline-offset: 4px; }
.doc h1 { margin-bottom: 18px; font-size: clamp(34px, 5vw, 54px); font-weight: 700; letter-spacing: -.05em; line-height: 1.12; }
.doc-lead { max-width: 680px; margin-bottom: clamp(36px, 5vw, 56px); color: var(--muted); font-size: clamp(16px, 1.6vw, 19px); line-height: 1.75; }
.doc section { margin-bottom: clamp(36px, 5vw, 56px); }
.doc h2 { margin-bottom: 16px; font-size: clamp(24px, 3vw, 32px); font-weight: 600; letter-spacing: -.045em; line-height: 1.2; }
.doc h3 { margin: 0 0 6px; color: var(--violet); font-size: 18px; font-weight: 600; letter-spacing: -.03em; line-height: 1.4; }
.doc p, .doc li, .doc dd { color: var(--muted); font-size: 16px; line-height: 1.8; }
.doc p { max-width: 680px; margin-bottom: 14px; }
.doc a { color: var(--violet); text-underline-offset: 4px; }
.doc-steps { margin: 0; padding: 0; list-style: none; counter-reset: step; }
.doc-steps li { position: relative; padding: 20px 0 22px 56px; border-top: 1px solid var(--paper-line); counter-increment: step; }
.doc-steps li::before { position: absolute; top: 22px; left: 0; content: counter(step, decimal-leading-zero); color: var(--violet); font-size: 14px; font-weight: 700; letter-spacing: .1em; }
.doc-steps p { margin: 0; }
.doc-list { max-width: 680px; margin: 0 0 14px; padding-left: 22px; }
.doc-list li { margin-bottom: 8px; }
.doc-faq > div { padding: 18px 0 20px; border-top: 1px solid var(--paper-line); }
.doc-faq p { margin: 0; }
.doc-links { display: flex; flex-wrap: wrap; gap: 8px 24px; margin: 0; padding: 0; list-style: none; }
.doc-links a { display: inline-flex; min-height: 44px; align-items: center; }
.doc-contact { margin: 0 0 18px; }
.doc-contact > div { padding: 16px 0; border-top: 1px solid var(--paper-line); }
.doc-contact dt { margin-bottom: 2px; color: var(--violet); font-size: 14px; font-weight: 600; }
.doc-contact dd { max-width: 620px; margin: 0; }
.doc-cta { margin: clamp(40px, 6vw, 64px) 0 28px; padding: clamp(24px, 4vw, 40px); color: var(--paper); background: var(--violet); border-radius: 16px; }
.doc-cta p { max-width: 560px; margin-bottom: 20px; color: #d6d0e1; font-size: 18px; line-height: 1.6; }
.doc-cta .button { background: var(--lime); color: var(--ink); }
.doc-cta .button:hover { background: #e0f78f; }
.doc-cta .button:focus-visible { outline-color: var(--paper); }
.doc-updated { margin: 0; color: var(--muted); font-size: 14px; }
.doc .example-list { margin-bottom: 8px; }
.footer-topics { grid-column: 1 / -1; display: flex; flex-wrap: wrap; justify-content: flex-start; gap: 4px 22px; padding-top: 8px; border-top: 1px solid var(--paper-line); }
.footer-topics a { display: inline-flex; min-height: 44px; align-items: center; color: var(--muted); font-size: 14px; text-decoration: none; }
.more-link { display: inline-flex; min-height: 44px; align-items: center; margin-top: 4px; color: var(--violet); font-size: 14px; font-weight: 600; text-underline-offset: 4px; }

.closing { padding: clamp(70px, 9vw, 112px) var(--gutter); color: var(--paper); background: var(--ink); text-align: center; }
.closing .eyebrow { justify-content: center; color: #c9c1d8; }
.closing h2 { margin-bottom: 30px; font-size: clamp(40px, 5vw, 64px); }
.closing h2 em { color: var(--lime); }
.closing-actions { display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 18px 28px; }
.button-paper { color: var(--ink); background: var(--lime); }
.button-paper:hover { background: #e0f78f; }
.premium-link { min-height: 44px; display: inline-flex; align-items: center; gap: 10px; color: var(--paper); font-size: 14px; text-decoration: none; }

.site-footer { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 22px; width: min(var(--page-width), 100%); min-height: 100px; margin: 0 auto; padding: 20px var(--gutter); }
.footer-brand { display: flex; min-height: 44px; align-items: center; width: 142px; }
.footer-brand img { width: 100%; height: auto; }
.site-footer p { margin: 0; color: var(--muted); font-size: 14px; }
.credit-link { text-decoration: underline; text-underline-offset: .15em; }
.site-footer nav { display: flex; justify-content: flex-end; flex-wrap: wrap; gap: 9px 20px; }
.site-footer nav a { display: inline-flex; min-height: 44px; align-items: center; color: var(--muted); font-size: 14px; text-decoration: none; }
.closing a:focus-visible { outline-color: var(--paper); }

@media (min-width: 1440px) {
  .hero-page-mark { right: 0; }
}

@media (max-width: 800px) {
  .site-header { min-height: 80px; gap: 18px; }
  .brand { width: 190px; flex-basis: 190px; }
  .main-nav { gap: 18px; }
  .main-nav a { font-size: 14px; }
  .header-action { min-height: 44px; padding-inline: 13px; font-size: 14px; }
  .hero { grid-template-columns: minmax(0, 1fr) minmax(280px, .8fr); gap: 30px; min-height: 590px; padding-top: 55px; }
  .hero h1 { font-size: clamp(40px, 6vw, 56px); }
  .practice-wrap { padding-left: 14px; }
  .practice-card { min-height: 350px; padding: 24px; }
  .practice-prompt { min-height: 84px; font-size: 21px; }
  .learning-layout { grid-template-columns: minmax(0, 1fr) 230px; gap: 35px; }
  .practice-note { grid-template-columns: 65px minmax(200px, .9fr) minmax(210px, .8fr); gap: 24px; }
  .note-symbol { width: 62px; }
}

@media (max-width: 600px) {
  :root { --gutter: 22px; }
  .site-header { min-height: 76px; justify-content: space-between; gap: 12px; }
  .brand { width: 168px; flex-basis: 168px; }
  .site-header { flex-wrap: wrap; }
  .main-nav { order: 3; flex: 1 0 100%; justify-content: center; gap: 24px; margin: 0; }
  .header-action { min-height: 44px; gap: 7px; padding-inline: 12px; font-size: 14px; }
  .hero { grid-template-columns: 1fr; gap: 43px; min-height: 0; padding-top: 50px; padding-bottom: 94px; }
  .hero .eyebrow { margin-bottom: 20px; }
  .hero h1 { max-width: 520px; margin-bottom: 19px; font-size: clamp(32px, 10vw, 40px); }
  .hero-description { max-width: 460px; margin-bottom: 22px; font-size: 16px; }
  .hero-page-mark { right: 0; bottom: 0; width: 42vw; height: 28vw; }
  .practice-wrap { width: min(100%, 440px); justify-self: center; padding: 14px 0 0 12px; }
  .practice-card { min-height: 350px; padding: 25px 22px; }
  .practice-context { margin-top: 23px; }
  .practice-card h2 { margin-bottom: 16px; font-size: 19px; }
  .practice-prompt { min-height: 78px; font-size: 21px; }
  .control-hint { font-size: 10px; }
  .learning-body { padding-top: 69px; padding-bottom: 78px; }
  .learning h2 { font-size: clamp(32px, 8vw, 40px); }
  .learning-intro { margin-bottom: 32px; font-size: 16px; }
  .learning-layout { grid-template-columns: 1fr; gap: 35px; }
  .learning-steps li { grid-template-columns: 36px 1fr; gap: 10px; padding: 20px 0 23px; }
  .learning-steps h3 { font-size: 17px; }
  .learning-steps p { font-size: 16px; }
  .app-preview { width: min(78%, 280px); }
  .practice-note { grid-template-columns: 54px 1fr; gap: 20px; padding-block: 70px; }
  .note-symbol { width: 52px; }
  .practice-note .eyebrow { font-size: 9px; }
  .practice-note h2 { font-size: clamp(29px, 8vw, 42px); }
  .note-copy { grid-column: 2; font-size: 16px; }
  .closing { padding-block: 72px; }
  .closing h2 { font-size: clamp(32px, 8vw, 40px); }
  .closing-actions { flex-direction: column; gap: 9px; }
  .site-footer { grid-template-columns: 1fr; justify-items: center; gap: 10px; padding-block: 23px; text-align: center; }
  .footer-brand { width: 130px; }
  .site-footer nav { justify-content: center; }
  .footer-topics { justify-content: center; }
  .doc-steps li { padding-left: 44px; }
}

@media (max-width: 360px) {
  :root { --gutter: 18px; }
  .site-header { gap: 8px; }
  .brand { width: 138px; flex-basis: 138px; }
  .header-action { min-height: 44px; padding-inline: 9px; font-size: 10px; }
  .hero h1 { font-size: 36px; }
  .practice-card { padding-inline: 18px; }
  .practice-prompt { font-size: 19px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}