:root {
  --paper: #eef5f4;
  --paper-deep: #dbe9e7;
  --ink: #13243a;
  --ink-soft: #526577;
  --clover: #2faf6a;
  --clover-dark: #177947;
  --brass: #d59a38;
  --blue: #8db8c4;
  --white: #fff;
  --line: rgba(19, 36, 58, .14);
  --shadow: 0 22px 55px rgba(19, 36, 58, .13);
  --display: ui-rounded, "Avenir Next", "Segoe UI", sans-serif;
  --body: "Avenir Next", "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body { margin: 0; overflow-x: hidden; color: var(--ink); background: var(--paper); font-family: var(--body); line-height: 1.65; }
a { color: inherit; }
button, input, textarea { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--brass); outline-offset: 3px; }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 99; padding: .7rem 1rem; background: var(--ink); color: white; border-radius: .4rem; }
.skip-link:focus { top: 1rem; }

.topbar { position: sticky; top: 0; z-index: 30; height: 72px; display: flex; align-items: center; justify-content: space-between; padding: 0 clamp(1rem, 4vw, 3.5rem); color: var(--ink); background: rgba(238, 245, 244, .9); border-bottom: 1px solid var(--line); backdrop-filter: blur(18px); }
.brand { display: inline-flex; align-items: center; gap: .75rem; font-family: var(--display); font-weight: 800; letter-spacing: .08em; text-decoration: none; line-height: 1.05; }
.brand small { display: block; margin-top: .28rem; color: var(--ink-soft); font: 600 .62rem/1 var(--body); letter-spacing: .16em; }
.brand-mark { width: 32px; height: 32px; position: relative; flex: 0 0 auto; transform: rotate(45deg); }
.brand-mark span { position: absolute; width: 13px; height: 13px; background: var(--clover); border-radius: 55% 55% 20% 55%; }
.brand-mark span:nth-child(1) { top: 0; left: 0; }
.brand-mark span:nth-child(2) { top: 0; right: 0; transform: rotate(90deg); }
.brand-mark span:nth-child(3) { bottom: 0; right: 0; transform: rotate(180deg); }
.brand-mark span:nth-child(4) { bottom: 0; left: 0; transform: rotate(270deg); }
.top-actions { display: flex; align-items: center; gap: 1.25rem; }
.quiet-link { color: var(--ink-soft); font-size: .88rem; font-weight: 700; text-decoration: none; }
.quiet-link:hover { color: var(--clover-dark); }
.lang-toggle { display: inline-grid; grid-template-columns: 1fr 1fr; padding: 3px; border: 1px solid var(--line); border-radius: 999px; background: var(--white); cursor: pointer; }
.lang-toggle span { min-width: 32px; padding: .25rem .5rem; border-radius: 999px; color: var(--ink-soft); font-size: .78rem; font-weight: 800; }
.lang-toggle span.active { color: white; background: var(--ink); }
.menu-toggle { display: none; border: 0; background: transparent; color: var(--ink); font-size: 1.5rem; cursor: pointer; }

.page-shell { display: grid; grid-template-columns: 238px minmax(0, 1fr); max-width: 1500px; margin: 0 auto; }
.rail { position: sticky; top: 72px; height: calc(100vh - 72px); padding: 3.5rem 1.75rem 2rem; border-right: 1px solid var(--line); }
.rail-label { margin: 0 0 1.25rem; color: var(--ink-soft); font-size: .72rem; font-weight: 800; letter-spacing: .18em; text-transform: uppercase; }
.rail nav { display: grid; gap: .3rem; }
.rail nav a { display: grid; grid-template-columns: 28px 1fr; align-items: center; gap: .65rem; padding: .65rem .75rem; border-radius: .55rem; color: var(--ink-soft); font-size: .88rem; font-weight: 700; text-decoration: none; transition: .18s ease; }
.rail nav a span:first-child { font: 600 .65rem/1 var(--mono); opacity: .58; }
.rail nav a:hover, .rail nav a.active { color: var(--ink); background: rgba(255,255,255,.72); transform: translateX(3px); }
.rail nav a.active { box-shadow: inset 3px 0 var(--clover); }
.rail-note { position: absolute; left: 1.75rem; right: 1.75rem; bottom: 2rem; display: flex; gap: .6rem; padding-top: 1.2rem; border-top: 1px solid var(--line); }
.rail-note p { margin: 0; color: var(--ink-soft); font-size: .72rem; }
.rail-note strong { color: var(--ink); font-family: var(--mono); }
.status-dot { width: 8px; height: 8px; margin-top: .45rem; border-radius: 50%; background: var(--clover); box-shadow: 0 0 0 5px rgba(47,175,106,.13); }

main { min-width: 0; }
.hero, .chapter, footer { max-width: 1160px; margin-inline: auto; padding-inline: clamp(2rem, 6vw, 6.5rem); }
.hero { min-height: 720px; display: grid; grid-template-columns: 1.04fr .96fr; align-items: center; gap: clamp(2rem, 6vw, 5rem); padding-block: 6rem 7rem; overflow: hidden; }
.hero-copy { min-width: 0; }
.eyebrow, .kicker { margin: 0 0 1rem; color: var(--clover-dark); font-size: .74rem; font-weight: 900; letter-spacing: .17em; text-transform: uppercase; }
.hero h1 { margin: 0; font: 800 clamp(3.1rem, 6vw, 6.6rem)/.94 var(--display); letter-spacing: -.065em; }
.hero h1 em { color: var(--clover-dark); font-style: normal; }
.lede { max-width: 590px; margin: 2rem 0 0; color: var(--ink-soft); font-size: clamp(1rem, 1.6vw, 1.22rem); }
.hero-actions, .code-actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 2rem; }
.button { display: inline-flex; min-height: 46px; align-items: center; justify-content: center; padding: .72rem 1.2rem; border: 1px solid transparent; border-radius: .55rem; font-weight: 800; text-decoration: none; cursor: pointer; transition: transform .18s ease, box-shadow .18s ease, background .18s ease; }
.button:hover { transform: translateY(-2px); }
.button.primary { color: white; background: var(--ink); box-shadow: 0 10px 25px rgba(19,36,58,.18); }
.button.primary:hover { background: var(--clover-dark); }
.button.secondary { color: var(--ink); background: rgba(255,255,255,.75); border-color: var(--line); }

.game-figure { position: relative; min-width: 0; max-width: 100%; padding: 12px; border: 1px solid rgba(19,36,58,.18); border-radius: 1.4rem; background: #cadcda; box-shadow: var(--shadow), inset 0 0 0 5px rgba(255,255,255,.4); transform: rotate(1.2deg); }
.game-screen { position: relative; min-height: 420px; overflow: hidden; border: 2px solid rgba(255,255,255,.16); border-radius: 1rem; background: radial-gradient(circle at 50% 44%, #315d65 0, #183549 47%, #101e31 82%); box-shadow: inset 0 0 45px rgba(4,13,25,.65); }
.game-screen::before { content: ""; position: absolute; inset: 0; opacity: .2; background-image: linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px); background-size: 100% 4px; pointer-events: none; }
.game-hud { position: absolute; z-index: 3; top: 1rem; left: 1rem; right: 1rem; display: flex; justify-content: space-between; }
.game-hud span { display: flex; flex-direction: column; padding: .5rem .7rem; border: 1px solid rgba(141,184,196,.42); border-radius: .45rem; color: white; background: rgba(9,22,36,.62); box-shadow: 0 4px 0 rgba(4,13,25,.35); }
.game-hud i { color: var(--blue); font: 800 .52rem/1 var(--mono); font-style: normal; letter-spacing: .12em; }
.game-hud strong { margin-top: .2rem; font: 900 1rem/1 var(--display); }
.hero-cat { position: absolute; z-index: 2; left: 50%; bottom: -8%; width: 112%; max-width: none; transform: translateX(-50%); filter: drop-shadow(0 18px 20px rgba(3,11,20,.35)); }
.key-pop { position: absolute; z-index: 3; display: grid; place-items: center; width: 44px; height: 44px; border: 1px solid rgba(255,255,255,.5); border-radius: .55rem; color: var(--ink); background: #f7faf8; box-shadow: 0 6px 0 var(--brass), 0 12px 25px rgba(0,0,0,.25); font: 900 1.05rem/1 var(--display); }
.key-g { left: 10%; top: 31%; transform: rotate(-9deg); }
.key-h { right: 10%; top: 39%; transform: rotate(8deg); }
.spark { position: absolute; z-index: 3; color: #f1bf58; filter: drop-shadow(0 0 8px rgba(241,191,88,.55)); }
.spark-a { top: 24%; left: 28%; font-size: 1.7rem; }
.spark-b { top: 22%; right: 28%; font-size: .9rem; }
.xp-track { position: absolute; z-index: 3; right: 1.1rem; bottom: 1rem; left: 1.1rem; height: 7px; overflow: hidden; border: 1px solid rgba(255,255,255,.35); border-radius: 99px; background: rgba(3,11,20,.65); }
.xp-track span { display: block; width: 78%; height: 100%; background: linear-gradient(90deg, var(--clover), #84e392); box-shadow: 0 0 12px rgba(79,221,131,.75); }
.pose-dock { display: flex; min-width: 0; max-width: 100%; gap: .45rem; padding: .7rem .2rem .1rem; overflow-x: auto; scrollbar-width: thin; }
.pose-dock span { flex: 0 0 auto; padding: .4rem .55rem; border: 1px solid rgba(19,36,58,.16); border-radius: .4rem; background: rgba(255,255,255,.65); font: 700 .58rem/1 var(--mono); }
.pose-dock b { margin-right: .3rem; color: var(--clover-dark); }

.chapter { padding-block: 6rem; border-top: 1px solid var(--line); }
.chapter-heading { display: flex; align-items: flex-start; gap: 1.25rem; margin-bottom: 3rem; }
.chapter-number { padding-top: .45rem; color: var(--brass); font: 800 .75rem/1 var(--mono); }
.chapter-heading .kicker { margin-bottom: .45rem; }
.chapter h2 { margin: 0; font: 800 clamp(2.15rem, 4vw, 3.8rem)/1 var(--display); letter-spacing: -.045em; }
.steps-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; overflow: hidden; border: 1px solid var(--line); border-radius: .8rem; background: var(--line); }
.steps-grid article { min-height: 250px; padding: 1.5rem; background: rgba(255,255,255,.68); }
.steps-grid article > span { display: grid; place-items: center; width: 30px; height: 30px; border: 1px solid var(--line); border-radius: 50%; color: var(--clover-dark); font: 800 .75rem/1 var(--mono); }
.steps-grid h3, .pose-card h3, .alignment-tip h3, .update-card h3, .platform-grid h3 { margin: 2rem 0 .55rem; font: 800 1rem/1.25 var(--display); }
.steps-grid p, .pose-card p, .alignment-tip p, .update-card p, .platform-grid p { margin: 0; color: var(--ink-soft); font-size: .88rem; }
.callout { position: relative; margin-top: 1.4rem; padding: 1.35rem 8rem 1.35rem 1.5rem; border-radius: .8rem; }
.callout.clover { color: white; background: var(--clover-dark); }
.callout.brass { color: var(--ink); background: #f5dfb4; }
.callout strong { display: block; margin-bottom: .2rem; font-size: .77rem; letter-spacing: .08em; text-transform: uppercase; }
.callout p { margin: 0; }
.copy-inline { position: absolute; top: 50%; right: 1.25rem; transform: translateY(-50%); padding: .5rem .8rem; color: inherit; border: 1px solid currentColor; border-radius: .45rem; background: transparent; cursor: pointer; }

.pose-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.pose-card { min-height: 340px; padding: 1.25rem; border: 1px solid var(--line); border-radius: .8rem; background: rgba(255,255,255,.55); }
.pose-card code { color: var(--ink-soft); font: 600 .68rem/1 var(--mono); }
.pose-card h3 { margin-top: 1rem; }
.pose-viewport { position: relative; height: 190px; display: grid; place-items: center; margin-bottom: 1rem; overflow: hidden; border-radius: .55rem; background: radial-gradient(circle at 50% 55%, #dff1ed, #bdd6d6); }
.pose-viewport::after { content: ""; position: absolute; right: 10%; bottom: 12px; left: 10%; height: 14px; border-radius: 50%; background: rgba(19,36,58,.14); filter: blur(7px); }
.pose-viewport img { position: relative; z-index: 1; width: 115%; max-width: none; }
.pose-viewport.celebrate { background: radial-gradient(circle at 50% 55%, #fff6d6, #ebc876); }
.pose-state { position: absolute; z-index: 2; top: .65rem; left: .65rem; padding: .28rem .45rem; border-radius: .32rem; color: white; background: var(--ink); box-shadow: 0 3px 0 rgba(0,0,0,.18); font: 800 .56rem/1 var(--mono); letter-spacing: .09em; }
.alignment-tip { display: grid; grid-template-columns: 210px 1fr; align-items: center; gap: 2rem; margin-top: 1rem; padding: 1.5rem; border: 1px dashed rgba(19,36,58,.3); border-radius: .8rem; }
.alignment-tip h3 { margin: 0 0 .5rem; }
.alignment-demo { position: relative; height: 120px; border: 1px solid var(--line); background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px); background-size: 20px 20px; }
.alignment-demo span { position: absolute; left: 50%; bottom: 19px; width: 58px; height: 68px; border-radius: 50% 50% 40% 40%; background: rgba(47,175,106,.25); border: 2px solid var(--clover-dark); transform: translateX(-50%); }
.alignment-demo span:nth-child(2) { transform: translateX(-55%) rotate(-8deg); opacity: .5; }
.alignment-demo span:nth-child(3) { transform: translateX(-45%) rotate(8deg); opacity: .5; }
.alignment-demo i { position: absolute; left: 10px; right: 10px; bottom: 18px; border-top: 2px solid var(--brass); }

.spec-board { display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(280px, .75fr); gap: 1rem; }
.spec-main { overflow-x: auto; border: 1px solid var(--line); border-radius: .8rem; background: rgba(255,255,255,.55); }
table { width: 100%; border-collapse: collapse; font-size: .84rem; }
th, td { padding: 1rem; text-align: left; border-bottom: 1px solid var(--line); vertical-align: top; }
th { color: var(--ink-soft); font-size: .68rem; letter-spacing: .1em; text-transform: uppercase; }
tbody tr:last-child td { border-bottom: 0; }
td:first-child { font-weight: 800; }
.header-spec { padding: 1.4rem; color: white; border-radius: .8rem; background: var(--ink); }
.official-badge { display: inline-block; padding: .25rem .48rem; border: 1px solid rgba(255,255,255,.25); border-radius: 999px; color: var(--blue); font-size: .6rem; font-weight: 900; letter-spacing: .12em; }
.header-ratio { height: 105px; display: grid; place-content: center; margin: 1.2rem 0; border: 1px dashed rgba(255,255,255,.28); background: linear-gradient(115deg, rgba(47,175,106,.22), transparent); text-align: center; }
.header-ratio span { font: 800 1.75rem/1 var(--mono); }
.header-ratio i { margin-top: .45rem; color: rgba(255,255,255,.62); font-size: .67rem; font-style: normal; letter-spacing: .12em; }
.header-spec h3 { margin: 0 0 .4rem; font-family: var(--display); }
.header-spec p { margin: 0; color: rgba(255,255,255,.7); font-size: .8rem; }
.header-links { display: grid; gap: .4rem; margin-top: 1.1rem; }
.header-links a { color: var(--blue); font-size: .72rem; font-weight: 800; }
.source-note { color: var(--ink-soft); font-size: .7rem; }

.builder { display: grid; grid-template-columns: .9fr 1.1fr; overflow: hidden; border: 1px solid var(--line); border-radius: .9rem; background: white; box-shadow: var(--shadow); }
#manifest-form { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; padding: 1.5rem; }
#manifest-form label { display: grid; align-content: start; gap: .35rem; color: var(--ink-soft); font-size: .73rem; font-weight: 800; }
#manifest-form .wide { grid-column: 1 / -1; }
#manifest-form input, #manifest-form textarea { width: 100%; padding: .68rem .75rem; color: var(--ink); border: 1px solid var(--line); border-radius: .45rem; background: var(--paper); font-size: .85rem; font-weight: 500; resize: vertical; }
#manifest-form input:focus, #manifest-form textarea:focus { border-color: var(--clover); outline: 2px solid rgba(47,175,106,.16); }
#manifest-form fieldset { display: grid; grid-template-columns: 1fr 1fr; gap: .75rem; margin: 0; padding: 1rem; border: 1px solid var(--line); border-radius: .55rem; }
#manifest-form legend { padding: 0 .45rem; color: var(--ink-soft); font-size: .7rem; font-weight: 800; }
.code-panel { display: flex; min-width: 0; flex-direction: column; padding: 1.15rem; color: white; background: #101d2d; }
.code-toolbar { display: flex; justify-content: space-between; color: var(--blue); font: 700 .7rem/1 var(--mono); }
.code-panel pre { flex: 1; min-height: 380px; margin: 1.3rem 0; overflow: auto; color: #d8e9e6; font: 500 .76rem/1.75 var(--mono); white-space: pre-wrap; overflow-wrap: anywhere; }
.code-panel .button.secondary { color: white; background: rgba(255,255,255,.06); border-color: rgba(255,255,255,.25); }
.reference, .faq { margin-top: 1rem; border: 1px solid var(--line); border-radius: .65rem; background: rgba(255,255,255,.48); }
.reference summary, .faq summary { padding: 1rem 1.2rem; font-weight: 800; cursor: pointer; }
.reference-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0 2rem; padding: 0 1.2rem 1rem; }
.reference-grid p { display: grid; grid-template-columns: 115px 1fr; gap: .75rem; margin: 0; padding: .7rem 0; border-top: 1px solid var(--line); color: var(--ink-soft); font-size: .8rem; }
.reference-grid code { color: var(--clover-dark); }

.timeline { margin: 0; padding: 0; list-style: none; }
.timeline li { display: grid; grid-template-columns: 70px 1fr; gap: 1rem; padding: 1.35rem 0; border-bottom: 1px solid var(--line); }
.timeline li > span { color: var(--brass); font: 800 .72rem/1.5 var(--mono); }
.timeline h3 { margin: 0 0 .35rem; font: 800 1.05rem/1.3 var(--display); }
.timeline p { margin: 0; color: var(--ink-soft); font-size: .88rem; }
.update-card { display: grid; grid-template-columns: 70px 1fr; gap: 1rem; margin-top: 1.25rem; padding: 1.5rem; border: 1px solid var(--line); border-radius: .8rem; background: white; }
.update-mark { display: grid; place-items: center; width: 48px; height: 48px; border-radius: 50%; color: white; background: var(--clover); font-size: 1.5rem; }
.update-card h3 { margin: 0 0 .45rem; }
.update-card > div > code { display: block; margin-top: 1rem; padding: .7rem; overflow-x: auto; color: var(--ink-soft); border-radius: .4rem; background: var(--paper); font-size: .68rem; }
.update-card code strong { color: var(--clover-dark); }

.checklist { display: grid; gap: .6rem; }
.checklist label { display: grid; grid-template-columns: 30px 1fr; align-items: start; gap: .65rem; padding: 1rem; border: 1px solid var(--line); border-radius: .65rem; background: rgba(255,255,255,.55); cursor: pointer; }
.checklist input { width: 20px; height: 20px; margin: .15rem 0 0; accent-color: var(--clover); }
.checklist input:checked + span { color: var(--ink-soft); text-decoration: line-through; }
.platform-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin: 1.5rem 0; }
.platform-grid article { position: relative; min-height: 170px; padding: 1.3rem 1.3rem 1.3rem 5rem; border-radius: .7rem; background: var(--paper-deep); }
.platform-grid article > span { position: absolute; left: 1.4rem; top: 1.25rem; color: var(--clover-dark); font-size: 2rem; }
.platform-grid h3 { margin: 0 0 .45rem; }
.faq { margin-top: .6rem; }
.faq p { margin: 0; padding: 0 1.2rem 1.1rem; color: var(--ink-soft); font-size: .86rem; }

footer { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 2rem; padding-block: 3rem; border-top: 1px solid var(--line); }
.footer-brand { font-size: .78rem; }
.footer-brand .brand-mark { width: 24px; height: 24px; transform: rotate(45deg) scale(.7); }
footer p { margin: 0; color: var(--ink-soft); font-size: .7rem; }
footer > div:last-child { display: flex; gap: 1rem; font-size: .72rem; font-weight: 800; }

html[lang="en"] .hero h1 { font-size: clamp(3rem, 5.2vw, 5.9rem); }

@media (max-width: 1050px) {
  .page-shell { grid-template-columns: 190px minmax(0, 1fr); }
  .rail { padding-inline: 1rem; }
  .rail-note { left: 1rem; right: 1rem; }
  .hero { grid-template-columns: 1fr; padding-top: 5rem; }
  .game-figure { width: min(100%, 520px); margin: 2rem auto 0; }
  .steps-grid, .pose-grid { grid-template-columns: 1fr 1fr; }
  .spec-board { grid-template-columns: 1fr; }
  .builder { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  html { scroll-padding-top: 70px; }
  .topbar { height: 64px; padding-inline: 1rem; }
  .brand small, .quiet-link { display: none; }
  .top-actions { gap: .5rem; }
  .menu-toggle { display: block; }
  .page-shell { display: block; }
  .rail { position: fixed; top: 64px; right: 0; bottom: 0; left: auto; z-index: 25; width: min(82vw, 320px); height: auto; padding: 2rem 1.2rem; transform: translateX(105%); transition: transform .22s ease; background: var(--paper); box-shadow: -20px 0 45px rgba(19,36,58,.16); }
  .rail.open { transform: translateX(0); }
  .rail-note { left: 1.2rem; right: 1.2rem; }
  .hero, .chapter, footer { padding-inline: 1.15rem; }
  .hero { min-height: auto; padding-block: 4.5rem 5rem; }
  .hero h1 { font-size: clamp(2.75rem, 14vw, 4.5rem); overflow-wrap: anywhere; }
  .game-figure { transform: none; }
  .game-screen { min-height: 380px; }
  .chapter { padding-block: 4.5rem; }
  .chapter-heading { margin-bottom: 2rem; }
  .steps-grid, .pose-grid, .platform-grid { grid-template-columns: 1fr; }
  .steps-grid article { min-height: auto; }
  .pose-card { min-height: auto; }
  .callout { padding-right: 1.5rem; }
  .copy-inline { position: static; margin-top: 1rem; transform: none; }
  .alignment-tip { grid-template-columns: 1fr; }
  .spec-main { margin-inline: -1.15rem; border-radius: 0; }
  table { min-width: 610px; }
  #manifest-form { grid-template-columns: 1fr; padding: 1.1rem; }
  #manifest-form label, #manifest-form .wide { grid-column: 1; }
  #manifest-form fieldset { grid-template-columns: 1fr; }
  .reference-grid { grid-template-columns: 1fr; }
  .timeline li, .update-card { grid-template-columns: 45px 1fr; }
  footer { grid-template-columns: 1fr; gap: 1rem; }
}

@media (max-width: 430px) {
  .game-screen { min-height: 330px; }
  .game-hud strong { font-size: .85rem; }
  .hero-cat { bottom: -3%; width: 122%; }
  .key-pop { width: 38px; height: 38px; }
  .hero-actions .button { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}