:root {
  --blue: #1554f6;
  --blue-deep: #0b2d91;
  --lime: #d8ff63;
  --orange: #ff7044;
  --ink: #0e1320;
  --ink-soft: #303846;
  --muted: #667085;
  --paper: #f7f9fd;
  --white: #fff;
  --line: #dce2ec;
  --good: #087a63;
  --warn: #a84a12;
  --danger: #b42318;
  --shadow: 0 24px 70px rgba(21, 50, 120, .13);
  --radius: 22px;
  --shell: min(1200px, calc(100% - 40px));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(rgba(21, 84, 246, .045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(21, 84, 246, .045) 1px, transparent 1px),
    var(--paper);
  background-size: 72px 72px;
  font-family: "Avenir Next", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; }
a { color: inherit; }
button, input, select { font: inherit; }
button, a, input, select { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--lime); outline-offset: 3px; }
.shell { width: var(--shell); margin-inline: auto; }
.skip-link { position: fixed; inset-inline-start: 12px; top: -80px; z-index: 100; padding: 12px 18px; color: #fff; background: var(--ink); border-radius: 10px; }
.skip-link:focus { top: 12px; }

.site-header {
  position: sticky;
  z-index: 50;
  top: 0;
  background: rgba(247, 249, 253, .92);
  border-bottom: 1px solid rgba(14, 19, 32, .11);
  backdrop-filter: blur(16px);
}
.header-row { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { min-height: 44px; display: inline-flex; align-items: center; gap: 11px; font-size: 20px; font-weight: 900; letter-spacing: -.05em; text-decoration: none; }
.brand-mark { width: 30px; height: 30px; display: grid; place-items: center; color: var(--ink); background: var(--lime); border: 5px solid var(--blue); border-radius: 9px; font-size: 12px; font-weight: 950; box-shadow: 3px 3px 0 var(--ink); }
.main-nav { display: flex; align-items: center; gap: 28px; font-size: 14px; font-weight: 700; }
.main-nav a { position: relative; text-decoration: none; }
.main-nav a::after { position: absolute; right: 0; bottom: -8px; left: 0; height: 2px; content: ""; background: var(--blue); transform: scaleX(0); transition: transform .18s ease; }
.main-nav a:hover::after, .main-nav a[aria-current="page"]::after { transform: scaleX(1); }
.nav-note { padding: 8px 12px; color: var(--blue-deep); background: #e9efff; border-radius: 999px; font-size: 12px; }
.menu-button { display: none; min-width: 46px; min-height: 46px; border: 1px solid var(--line); border-radius: 12px; color: var(--ink); background: #fff; }

.home-hero { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(340px, .85fr); gap: clamp(42px, 7vw, 96px); align-items: center; min-height: 690px; padding: 70px 0 78px; }
.eyebrow { display: flex; align-items: center; gap: 11px; margin: 0 0 18px; color: var(--blue); font-size: 12px; font-weight: 900; letter-spacing: .12em; text-transform: uppercase; }
.eyebrow::before { width: 34px; height: 3px; content: ""; background: currentColor; }
.home-hero h1 { max-width: 780px; margin: 0; font-size: clamp(48px, 6.4vw, 86px); line-height: .98; letter-spacing: -.07em; text-wrap: balance; }
.hero-lede { max-width: 690px; margin: 28px 0 0; color: var(--ink-soft); font-size: clamp(17px, 1.5vw, 21px); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 13px; margin-top: 30px; }
.button { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; gap: 9px; padding: 0 18px; border: 1px solid var(--ink); border-radius: 11px; color: #fff; background: var(--ink); font-weight: 800; text-decoration: none; cursor: pointer; transition: transform .16s ease, box-shadow .16s ease, background .16s ease; }
.button:hover { background: var(--blue); box-shadow: 0 12px 26px rgba(21, 84, 246, .22); transform: translateY(-2px); }
.button.secondary { color: var(--ink); background: #fff; }
.button.secondary:hover { color: #fff; background: var(--ink); }

.invite-stage { position: relative; isolation: isolate; }
.invite-stage::before { position: absolute; z-index: -1; inset: -20px 24px 22px -22px; content: ""; background: var(--blue); border-radius: 34px; transform: rotate(-3deg); }
.invite-stage::after { position: absolute; z-index: -2; right: -32px; bottom: -42px; width: 140px; height: 140px; content: ""; background: var(--lime); border-radius: 50%; }
.invite-card { padding: clamp(26px, 4vw, 42px); background: #fff; border: 1px solid rgba(14, 19, 32, .15); border-radius: 28px; box-shadow: var(--shadow); }
.invite-card-top { display: flex; justify-content: space-between; gap: 16px; margin-bottom: 26px; color: var(--muted); font-size: 11px; font-weight: 850; letter-spacing: .1em; }
.invite-code { margin: 6px 0 0; font-size: clamp(42px, 5vw, 66px); font-weight: 950; line-height: 1; letter-spacing: -.05em; }
.copy-button { width: 100%; min-height: 52px; margin-top: 24px; border: 0; border-radius: 12px; color: #fff; background: var(--blue); font-weight: 850; cursor: pointer; }
.copy-button[data-copied="true"] { color: var(--ink); background: var(--lime); }
.benefit { margin: 24px 0 0; padding-top: 20px; border-top: 1px solid var(--line); font-size: 18px; font-weight: 850; }
.benefit strong { color: var(--blue); }
.microcopy { margin: 7px 0 0; color: var(--muted); font-size: 12px; }

.ticker-strip { border-block: 1px solid var(--ink); background: var(--lime); }
.ticker-inner { min-height: 48px; display: flex; align-items: center; justify-content: space-between; gap: 28px; overflow: hidden; font-size: 12px; font-weight: 850; letter-spacing: .06em; white-space: nowrap; }

.section { padding: 86px 0; }
.section.tight { padding: 56px 0; }
.section-heading { display: grid; grid-template-columns: minmax(0, 1fr) minmax(260px, 420px); gap: 36px; align-items: end; margin-bottom: 34px; }
.section-heading h2 { margin: 0; font-size: clamp(34px, 4vw, 56px); line-height: 1.03; letter-spacing: -.055em; }
.section-heading p { margin: 0; color: var(--muted); }

.feature-grid { display: grid; grid-template-columns: 1.25fr .75fr; gap: 18px; }
.feature-stack { display: grid; gap: 18px; }
.feature-card, .story-card, .tool-card, .legal-card { position: relative; overflow: hidden; padding: 28px; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: 0 10px 34px rgba(26, 45, 92, .06); }
.feature-card.main { min-height: 460px; display: flex; flex-direction: column; justify-content: flex-end; color: #fff; background: var(--ink); }
.feature-card.main::before { position: absolute; top: -90px; right: -80px; width: 340px; height: 340px; content: ""; background: var(--blue); border: 50px solid var(--lime); border-radius: 50%; opacity: .9; }
.feature-card > *, .story-card > *, .tool-card > * { position: relative; }
.feature-card .card-index { color: var(--lime); font-size: 12px; font-weight: 900; letter-spacing: .11em; }
.feature-card h3 { max-width: 680px; margin: 12px 0 0; font-size: clamp(28px, 4vw, 48px); line-height: 1.06; letter-spacing: -.045em; }
.feature-card p { max-width: 680px; margin: 14px 0 0; color: inherit; opacity: .78; }
.feature-card a, .story-card a, .tool-card a { display: inline-flex; min-height: 44px; align-items: center; margin-top: 18px; color: var(--blue); font-weight: 850; text-decoration-thickness: 2px; text-underline-offset: 5px; }
.feature-card.main a { color: var(--lime); }

.card-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
.story-card:nth-child(4n+2) { border-top: 6px solid var(--blue); }
.story-card:nth-child(4n+3) { border-top: 6px solid var(--orange); }
.story-card:nth-child(4n+4) { border-top: 6px solid var(--good); }
.story-meta { display: flex; flex-wrap: wrap; gap: 8px; color: var(--muted); font-size: 12px; }
.story-card h3, .tool-card h3 { margin: 14px 0 0; font-size: 23px; line-height: 1.25; letter-spacing: -.025em; }
.story-card p, .tool-card p { margin: 12px 0 0; color: var(--muted); }
.tool-card { min-height: 300px; display: flex; flex-direction: column; }
.tool-card .tool-symbol { width: 52px; height: 52px; display: grid; place-items: center; color: #fff; background: var(--blue); border-radius: 14px; font-size: 20px; font-weight: 900; transform: rotate(-4deg); }
.tool-card a { margin-top: auto; padding-top: 18px; }

.trust-band { color: #fff; background: var(--ink); }
.trust-grid { display: grid; grid-template-columns: .85fr 1.15fr; gap: 60px; align-items: start; }
.trust-grid h2 { margin: 0; color: var(--lime); font-size: clamp(34px, 4.3vw, 58px); line-height: 1.02; letter-spacing: -.055em; }
.trust-list { margin: 0; padding: 0; list-style: none; }
.trust-list li { padding: 22px 0; border-top: 1px solid rgba(255, 255, 255, .2); }
.trust-list strong { display: block; margin-bottom: 5px; font-size: 17px; }
.trust-list span { color: #b9c1d1; }

.page-hero { padding: 72px 0 46px; }
.breadcrumbs { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 22px; color: var(--muted); font-size: 13px; }
.breadcrumbs a { text-underline-offset: 4px; }
.page-hero-grid { display: grid; grid-template-columns: minmax(0, 1fr) 360px; gap: clamp(36px, 7vw, 88px); align-items: end; }
.page-hero h1 { margin: 0; font-size: clamp(42px, 6vw, 76px); line-height: 1.02; letter-spacing: -.06em; text-wrap: balance; }
.page-deck { margin: 24px 0 0; color: var(--ink-soft); font-size: 19px; }
.page-meta { margin: 18px 0 0; color: var(--muted); font-size: 13px; }
.hero-brief { padding: 24px; background: var(--lime); border: 1px solid var(--ink); border-radius: 18px; box-shadow: 8px 8px 0 var(--ink); }
.hero-brief strong { display: block; margin-bottom: 8px; }

.article-cover { margin: 0 auto 48px; }
.article-cover img { width: 100%; display: block; border: 1px solid var(--ink); border-radius: 22px; box-shadow: 12px 12px 0 var(--blue); }
.article-cover figcaption { margin-top: 14px; color: var(--muted); font-size: 12px; }
.article-layout { display: grid; grid-template-columns: minmax(0, 760px) minmax(220px, 300px); gap: clamp(38px, 7vw, 80px); align-items: start; padding-bottom: 90px; }
.article-body { min-width: 0; font-size: 17px; }
.article-body > :first-child { margin-top: 0; }
.article-body h2 { margin: 58px 0 18px; font-size: clamp(28px, 3.2vw, 39px); line-height: 1.2; letter-spacing: -.035em; scroll-margin-top: 92px; }
.article-body h3 { margin: 34px 0 13px; font-size: 22px; line-height: 1.28; }
.article-body p { margin: 0 0 20px; }
.article-body ul, .article-body ol { margin: 0 0 24px; padding-inline-start: 1.35em; }
.article-body li { margin: 8px 0; }
.article-body a { color: var(--blue-deep); font-weight: 750; text-underline-offset: 4px; }
.article-body blockquote, .note, .source-note, .warning, .answer-box { margin: 28px 0; padding: 20px 22px; border-left: 6px solid var(--blue); background: #edf2ff; border-radius: 0 14px 14px 0; }
.article-body blockquote p:last-child, .note p:last-child, .source-note p:last-child, .warning p:last-child, .answer-box p:last-child { margin-bottom: 0; }
.warning { border-left-color: var(--orange); background: #fff1e9; }
.answer-box { border-left-color: var(--good); background: #eaf8f2; font-size: 18px; }
.data-table { width: 100%; margin: 26px 0 32px; border-collapse: collapse; font-size: 15px; }
.data-table th, .data-table td { padding: 14px 13px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
.data-table th { color: #fff; background: var(--ink); }
.data-table tr:nth-child(even) td { background: #f0f4fb; }
.inline-shot { margin: 32px 0; }
.inline-shot img { width: 100%; border: 1px solid var(--line); border-radius: 16px; }
.inline-shot figcaption { margin-top: 10px; color: var(--muted); font-size: 12px; }
.disclosure-box { margin: 24px 0; padding: 18px 20px; border: 1px dashed var(--blue); border-radius: 12px; color: var(--ink-soft); background: #f7f9ff; font-size: 14px; }

.article-aside { position: sticky; top: 98px; }
.aside-card { margin-bottom: 16px; padding: 20px; background: #fff; border: 1px solid var(--line); border-radius: 16px; }
.aside-card h2 { margin: 0 0 12px; font-size: 15px; letter-spacing: .02em; }
.aside-card ol { margin: 0; padding-inline-start: 19px; color: var(--muted); font-size: 13px; }
.aside-card li { margin: 8px 0; }
.aside-card a { text-decoration: none; }
.aside-card a:hover { color: var(--blue); text-decoration: underline; }
.tag-list { display: flex; flex-wrap: wrap; gap: 7px; }
.tag { padding: 6px 9px; color: var(--blue-deep); background: #edf2ff; border-radius: 999px; font-size: 11px; font-weight: 800; }

.tool-shell { max-width: 840px; margin: 0 auto 48px; padding: clamp(22px, 4vw, 38px); background: #fff; border: 1px solid var(--ink); border-radius: 24px; box-shadow: 10px 10px 0 var(--blue); }
.tool-form { display: grid; gap: 18px; }
.tool-form fieldset { min-width: 0; margin: 0; padding: 0; border: 0; }
.tool-form legend { margin-bottom: 12px; font-weight: 850; }
.field-group { display: grid; gap: 7px; }
.field-group label { font-size: 13px; font-weight: 850; }
.field-group small { color: var(--muted); }
.field-group input, .field-group select { width: 100%; min-height: 48px; padding: 0 13px; border: 1px solid #aeb7c7; border-radius: 10px; color: var(--ink); background: #fff; }
.tool-submit, .tool-reset { min-height: 48px; padding: 0 18px; border-radius: 11px; font-weight: 850; cursor: pointer; }
.tool-submit { border: 1px solid var(--ink); color: #fff; background: var(--blue); }
.tool-reset { border: 1px solid var(--ink); color: var(--ink); background: #fff; }
.tool-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.field { display: grid; gap: 7px; }
.field label, .fieldset-title { font-size: 13px; font-weight: 850; }
.field input, .field select { width: 100%; min-height: 48px; padding: 0 13px; border: 1px solid #aeb7c7; border-radius: 10px; color: var(--ink); background: #fff; }
.check-list { display: grid; gap: 10px; margin: 18px 0; }
.check-row { min-height: 48px; display: flex; align-items: center; gap: 12px; padding: 10px 12px; border: 1px solid var(--line); border-radius: 10px; cursor: pointer; }
.check-row input { width: 20px; height: 20px; flex: 0 0 auto; accent-color: var(--blue); }
.tool-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 22px; }
.tool-result { min-height: 110px; margin-top: 6px; padding: 22px; color: #fff; background: var(--ink); border-radius: 17px; }
.tool-result p { margin: 0; }
.tool-result strong { display: block; color: var(--lime); font-size: clamp(28px, 5vw, 48px); line-height: 1.1; }
.tool-result[data-level="warn"] { background: #713a12; }
.tool-result[data-level="danger"] { background: #7a1b16; }
.tool-result[data-level="good"] { background: #075c4a; }
.tool-hint { color: var(--muted); font-size: 12px; }
details.guide-details { margin: 50px 0 0; border-block: 1px solid var(--line); }
details.guide-details > summary { min-height: 58px; display: flex; align-items: center; font-weight: 850; cursor: pointer; }

.legal-layout { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; padding-bottom: 88px; }
.legal-card h2 { margin-top: 0; font-size: 24px; }
.legal-card p:last-child { margin-bottom: 0; }
.legal-index { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; margin: 26px 0 0; }
.legal-index a { min-height: 60px; display: flex; align-items: center; padding: 12px; border: 1px solid var(--line); border-radius: 11px; background: #fff; font-size: 13px; font-weight: 800; text-decoration: none; }
.legal-index a:hover { border-color: var(--blue); color: var(--blue); }

.site-footer { color: #c4cada; background: var(--ink); }
.footer-grid { display: grid; grid-template-columns: 1.1fr .9fr .9fr; gap: 50px; padding: 56px 0 42px; }
.footer-brand { color: #fff; }
.footer-brand .brand-mark { box-shadow: 3px 3px 0 #fff; }
.footer-copy { max-width: 420px; margin: 18px 0 0; font-size: 13px; }
.footer-col h2 { margin: 0 0 13px; color: #fff; font-size: 14px; }
.footer-col a { display: block; min-height: 36px; font-size: 13px; text-decoration: none; }
.footer-col a:hover { color: var(--lime); }
.footer-bottom { display: flex; justify-content: space-between; gap: 28px; padding: 22px 0 34px; border-top: 1px solid rgba(255, 255, 255, .16); font-size: 12px; }
.footer-bottom p { margin: 0; }

.not-found { min-height: 70vh; display: grid; place-items: center; text-align: center; }
.not-found strong { display: block; color: var(--blue); font-size: clamp(90px, 17vw, 190px); line-height: .9; letter-spacing: -.09em; }
.not-found h1 { margin: 18px 0 8px; font-size: 34px; }
.not-found p { margin: 0 0 24px; color: var(--muted); }

@media (max-width: 960px) {
  .main-nav { position: fixed; top: 72px; right: 16px; left: 16px; display: none; padding: 18px; background: #fff; border: 1px solid var(--line); border-radius: 16px; box-shadow: var(--shadow); }
  .main-nav[data-open="true"] { display: grid; gap: 6px; }
  .main-nav a { min-height: 44px; display: flex; align-items: center; }
  .menu-button { display: inline-grid; place-items: center; }
  .home-hero { grid-template-columns: 1fr; padding-top: 54px; }
  .invite-stage { width: min(560px, 100%); }
  .feature-grid, .trust-grid, .page-hero-grid, .article-layout { grid-template-columns: 1fr; }
  .article-aside { position: static; order: -1; }
  .aside-card.toc-card { display: none; }
  .card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid > :first-child { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  :root { --shell: min(100% - 24px, 560px); }
  body { background-size: 48px 48px; }
  .header-row { min-height: 64px; }
  .main-nav { top: 64px; }
  .nav-note { display: none; }
  .home-hero { min-height: auto; gap: 48px; padding: 40px 0 66px; }
  .home-hero h1 { font-size: clamp(42px, 13vw, 60px); }
  .invite-stage::before { inset: -12px 14px 14px -9px; border-radius: 26px; }
  .invite-stage::after { right: -8px; bottom: -26px; width: 90px; height: 90px; }
  .ticker-strip { display: none; }
  .section { padding: 64px 0; }
  .section-heading { grid-template-columns: 1fr; gap: 15px; }
  .feature-grid, .card-grid, .tool-grid, .legal-layout, .footer-grid { grid-template-columns: 1fr; }
  .footer-grid > :first-child { grid-column: auto; }
  .feature-card.main { min-height: 390px; }
  .page-hero { padding-top: 48px; }
  .page-hero h1 { font-size: clamp(39px, 12vw, 56px); }
  .page-deck { font-size: 17px; }
  .breadcrumbs a { min-width: 44px; min-height: 44px; display: inline-flex; align-items: center; justify-content: center; margin-block: -11px; }
  .article-cover img { border-radius: 14px; box-shadow: 7px 7px 0 var(--blue); }
  .article-body { font-size: 16px; }
  .article-body h2 { margin-top: 46px; }
  .article-body > p a { min-height: 44px; display: inline-flex; align-items: center; vertical-align: middle; }
  .aside-card li a { min-height: 44px; display: flex; align-items: center; }
  .data-table { display: block; overflow-x: auto; }
  .legal-index { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .legal-card a { min-height: 44px; display: inline-flex; align-items: center; }
  .footer-col a { min-height: 44px; display: flex; align-items: center; }
  .footer-bottom { flex-direction: column; }
}

@media (max-width: 420px) {
  .home-hero { gap: 22px; padding: 24px 0 44px; }
  .home-hero h1 { font-size: clamp(36px, 11vw, 46px); }
  .home-hero .hero-lede, .home-hero .hero-actions { display: none; }
  .invite-card { padding: 18px 16px; }
  .invite-card-top { margin-bottom: 14px; }
  .invite-code { font-size: 38px; }
  .copy-button { min-height: 46px; margin-top: 16px; }
  .benefit { margin-top: 15px; padding-top: 14px; font-size: 15px; }
  .invite-card .microcopy { line-height: 1.45; }
}

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