:root {
  --bg: #f4f4f0;
  --bg-panel: #ffffff;
  --bg-panel-2: #1c1a19;
  --border: #e2e1db;
  --border-strong: #cfcdc6;
  --accent: #1b5cf5;
  --accent-dark: #1443b8;
  --accent-soft: #e6ecfd;
  --text: #1e1d1b;
  --text-muted: #64625d;
  --text-faint: #a6a49d;
  --success: #1f8a5b;
  --warn: #d9653b;
  --error: #c33a2e;
  --on-accent: #ffffff;
  --on-dark: #f4f4f0;
  --on-dark-muted: #aaa69f;
  --dark-card: #262321;
  --dark-line: #3a3633;
  --bezel-edge: #3b3835;
  --veil: rgba(30, 29, 27, .32);

  --font-display: "Inter","Noto Sans SC","Noto Sans JP","Noto Sans KR",-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans","Apple SD Gothic Neo",sans-serif;
  --font-body: "Inter","Noto Sans SC","Noto Sans JP","Noto Sans KR",-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Microsoft YaHei",sans-serif;
  --font-mono: "JetBrains Mono",ui-monospace,"SF Mono",Menlo,Consolas,monospace;
  --weight-regular: 400;
  --weight-medium: 500;
  --size-body: 16px;
  --size-small: 14px;
  --size-fine: 12.5px;
  --size-lead: 17px;
  --size-h1: clamp(34px, 3.35vw, 48px);
  --size-h2: clamp(26px, 2.4vw, 34px);
  --size-h3: 22px;
  --tracking-title: -.02em;
  --line-body: 1.6;

  --radius-xs: 6px;
  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 32px;
  --radius-pill: 999px;
  --radius-logo: 28%;
  --radius-round: 50%;
  --radius-tablet: 3cqw;
  --radius-tablet-screen: 1.8cqw;
  --radius-phone: 4.6cqw;
  --radius-phone-screen: 3.7cqw;
  --radius-share: 1.2cqw;
  --radius-highlight: .6cqw;

  --shadow-back: 0 1px 2px rgba(30,29,27,.10),0 30px 64px -22px rgba(30,29,27,.24);
  --shadow-front: 0 2px 4px rgba(30,29,27,.16),0 40px 72px -22px rgba(30,29,27,.36);
  --shadow-btn: 0 1px 2px rgba(20,67,184,.28),0 8px 18px -8px rgba(27,92,245,.50);
  --shadow-soft: 0 1px 2px rgba(30,29,27,.06);
  --ring-focus: 0 0 0 3px rgba(27,92,245,.28);
  --header-h: 72px;
  --peek: 44px;
  --tab-w: 88px;
  --gutter: 64px;
  --width-page: 1440px;
  --width-reading: 880px;
  --section-space: 104px;
  --ease: cubic-bezier(.22,.7,.2,1);
  --duration-fast: .2s;
  --duration-slide: .38s;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 24px); }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--size-body);
  line-height: var(--line-body);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}
[hidden] { display: none !important; }
a { color: var(--accent); text-underline-offset: .22em; }
a:hover { color: var(--accent-dark); }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button, a { -webkit-tap-highlight-color: var(--accent-soft); }
img, svg { max-width: 100%; }
svg { flex-shrink: 0; }
img { height: auto; }
button svg, a svg { pointer-events: none; }
::selection { background: var(--accent-soft); color: var(--text); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; box-shadow: var(--ring-focus); border-radius: var(--radius-xs); }
h1, h2, h3, h4 { font-family: var(--font-display); font-weight: var(--weight-regular); text-wrap: balance; }
h1 { font-size: var(--size-h1); line-height: 1.15; letter-spacing: var(--tracking-title); }
h2 { font-size: var(--size-h2); line-height: 1.25; letter-spacing: var(--tracking-title); }
h3 { font-size: var(--size-h3); line-height: 1.4; }
p { margin-block: 0 1em; }
strong { font-weight: var(--weight-medium); }
code, pre, kbd { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 24px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-size: var(--size-small);
  line-height: 1.85;
  overscroll-behavior-inline: contain;
}
pre code { overflow-wrap: normal; word-break: normal; white-space: pre; }
hr { border: 0; border-top: 1px solid var(--border); margin-block: 32px; }
.wrap { width: 100%; max-width: var(--width-page); margin-inline: auto; padding-inline: var(--gutter); }
.reading { max-width: var(--width-reading); }
.section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
.section--white { background: var(--bg-panel); color: var(--text); border-radius: var(--radius-xl); }
.section--dark { background: var(--bg-panel-2); color: var(--on-dark); }
.section--dark p { color: var(--on-dark-muted); }
.section--dark a:not(.btn) { color: var(--on-dark); }
.grid-two { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 24px; }
.grid-two > *, .hero__grid > *, .store__inner > *, .footer__grid > *, .feature-panel > * { min-width: 0; }
.nowrap { white-space: nowrap; }
.muted { color: var(--text-muted); }
.text-link { font-weight: var(--weight-medium); text-decoration-thickness: 1px; }
.fine { margin: 12px 0 0; font-size: var(--size-fine); color: var(--text-muted); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; clip-path: inset(50%); overflow: hidden; white-space: nowrap; }
.skip-link { position: fixed; top: 8px; left: 16px; z-index: 100; padding: 12px 18px; background: var(--bg-panel); color: var(--accent); transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }
.prose { min-width: 0; }
.prose h2 { margin-top: 64px; margin-bottom: 24px; }
.prose h3 { margin-top: 36px; }
.prose p, .prose li { line-height: 1.85; }
.prose li + li { margin-top: 10px; }
.prose :is(ul,ol) { padding-left: 1.5em; }
.prose :is(h2,h3,[id]) { scroll-margin-top: calc(var(--header-h) + 24px); }

.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 52px; padding: 12px 22px; max-width: 100%;
  border: 1px solid transparent; border-radius: var(--radius-md);
  font-size: var(--size-body); font-weight: var(--weight-medium); letter-spacing: -.005em;
  text-decoration: none; text-align: center; line-height: 1.5;
  transition: background-color var(--duration-fast) var(--ease), border-color var(--duration-fast) var(--ease), transform var(--duration-fast) var(--ease);
}
.btn svg { width: 18px; height: 18px; }
.btn:hover { transform: translateY(-1px); }
.btn--primary { background: var(--accent); color: var(--on-accent); box-shadow: var(--shadow-btn); }
.btn--primary:hover, .btn--primary.is-hover { background: var(--accent-dark); color: var(--on-accent); }
.btn--ghost { background: var(--bg-panel); color: var(--text); border-color: var(--border-strong); box-shadow: var(--shadow-soft); }
.btn--ghost:hover { color: var(--text); border-color: var(--text-muted); }
.btn:active, .btn.is-active { transform: translateY(1px); box-shadow: var(--shadow-soft); }
.btn.is-focus { outline: 2px solid var(--accent); outline-offset: 3px; box-shadow: var(--ring-focus); }
.btn:disabled, .btn[aria-disabled="true"] { background: var(--border); color: var(--text-muted); border-color: var(--border-strong); box-shadow: none; cursor: not-allowed; transform: none; }
.card, .panel { padding: 32px; background: var(--bg-panel); color: var(--text); border: 1px solid var(--border); border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); min-width: 0; }
.card h3, .panel h3 { margin-top: 0; }
.card > :last-child, .panel > :last-child { margin-bottom: 0; }
.panel--quiet { background: var(--bg); color: var(--text); }
.reveal { opacity: 1; transform: none; }
.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(16px); }
.reveal-ready .reveal { transition: opacity .6s var(--ease), transform .6s var(--ease); }

.masthead {
  position: sticky; top: 0; z-index: 40; height: var(--header-h);
  background: var(--bg-panel); color: var(--text); border-bottom: 1px solid var(--border);
}
.masthead__row {
  max-width: min(100%, calc(1280px + var(--gutter) * 2)); height: 100%;
  margin-inline: auto; padding-inline: var(--gutter);
  display: flex; align-items: center; gap: 40px;
}
.brand {
  display: inline-flex; align-items: center; gap: 12px; flex-shrink: 0;
  text-decoration: none; color: var(--text); font-size: 17px;
  font-weight: var(--weight-medium); letter-spacing: -.012em; white-space: nowrap;
}
.brand:hover { color: var(--text); }
.brand__mark { display: block; width: 34px; height: 34px; flex: none; border-radius: var(--radius-logo); background: var(--bg-panel); color: var(--text); border: 1px solid var(--border-strong); box-shadow: var(--shadow-soft); }
.brand__tail { color: var(--text-muted); font-weight: var(--weight-regular); }
.tabs { position: relative; margin-left: auto; height: 100%; min-width: 0; }
.tabs__list { display: flex; align-items: center; height: 100%; list-style: none; margin: 0; padding: 0; }
.tabs__list li { width: var(--tab-w); height: 100%; flex-shrink: 0; }
.tabs__list a { height: 100%; min-height: 44px; display: flex; align-items: center; justify-content: center; padding-inline: 8px; font-size: 15px; color: var(--text-muted); text-decoration: none; white-space: nowrap; transition: color var(--duration-fast) var(--ease); }
.tabs__list a:hover, .tabs__list a[aria-current="page"] { color: var(--text); }
.tabs__bar { position: absolute; bottom: -1px; left: calc((var(--tab-w) - 28px) / 2); width: 28px; height: 2px; border-radius: var(--radius-pill); background: var(--accent); color: var(--on-accent); transition: transform var(--duration-slide) var(--ease); pointer-events: none; }
.tabs:has(li:nth-child(2) a[aria-current]) .tabs__bar { transform: translateX(var(--tab-w)); }
.tabs:has(li:nth-child(3) a[aria-current]) .tabs__bar { transform: translateX(calc(var(--tab-w) * 2)); }
.tabs:has(li:nth-child(4) a[aria-current]) .tabs__bar { transform: translateX(calc(var(--tab-w) * 3)); }
.tabs:has(li:nth-child(5) a[aria-current]) .tabs__bar { transform: translateX(calc(var(--tab-w) * 4)); }
.tabs:has(li:nth-child(6) a[aria-current]) .tabs__bar { transform: translateX(calc(var(--tab-w) * 5)); }
.tabs:has(li:nth-child(1) a:is(:hover,:focus-visible)) .tabs__bar { transform: translateX(0); }
.tabs:has(li:nth-child(2) a:is(:hover,:focus-visible)) .tabs__bar { transform: translateX(var(--tab-w)); }
.tabs:has(li:nth-child(3) a:is(:hover,:focus-visible)) .tabs__bar { transform: translateX(calc(var(--tab-w) * 2)); }
.tabs:has(li:nth-child(4) a:is(:hover,:focus-visible)) .tabs__bar { transform: translateX(calc(var(--tab-w) * 3)); }
.tabs:has(li:nth-child(5) a:is(:hover,:focus-visible)) .tabs__bar { transform: translateX(calc(var(--tab-w) * 4)); }
.tabs:has(li:nth-child(6) a:is(:hover,:focus-visible)) .tabs__bar { transform: translateX(calc(var(--tab-w) * 5)); }
.header-tools { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.language { position: relative; }
.lang { display: inline-flex; align-items: center; gap: 8px; min-height: 36px; padding: 7px 14px; font-size: var(--size-small); color: var(--text); background: var(--bg-panel); border: 1px solid var(--border); border-radius: var(--radius-pill); white-space: nowrap; }
.lang:hover { border-color: var(--border-strong); }
.lang svg { width: 16px; height: 16px; color: var(--text-muted); }
.lang__caret { color: var(--text-muted); font-size: 11px; }
.lang__short { display: none; }
.language__menu { position: absolute; right: 0; top: calc(100% + 12px); width: 200px; padding: 8px; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--bg-panel); color: var(--text); box-shadow: var(--shadow-back); }
.language__menu a { display: flex; align-items: center; min-height: 44px; padding: 10px 14px; color: var(--text); text-decoration: none; border-radius: var(--radius-xs); }
.language__menu a:hover, .language__menu a[aria-current] { background: var(--accent-soft); color: var(--accent-dark); }
.menu-toggle { display: none; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; padding: 10px; background: var(--bg-panel); color: var(--text); border: 1px solid var(--border); border-radius: var(--radius-sm); }
.menu-toggle svg { width: 22px; height: 22px; }
.menu-toggle[aria-expanded="true"] .menu-toggle__closed, .menu-toggle[aria-expanded="false"] .menu-toggle__opened { display: none; }
.mobile-drawer { position: absolute; inset: 100% 0 auto; z-index: 3; max-height: calc(100dvh - var(--header-h)); overflow-y: auto; overscroll-behavior: contain; padding: 16px var(--gutter) 24px; background: var(--bg-panel); color: var(--text); border-bottom: 1px solid var(--border); }
.mobile-drawer ul { list-style: none; padding: 0; margin: 0; }
.mobile-drawer a { display: flex; align-items: center; width: 100%; min-height: 48px; padding: 12px 16px; color: var(--text); text-decoration: none; border-radius: var(--radius-xs); }
.mobile-drawer a:hover, .mobile-drawer a[aria-current] { background: var(--accent-soft); color: var(--accent-dark); }
.mobile-drawer__label { margin: 20px 16px 8px; color: var(--text-muted); font-size: var(--size-small); }
.menu-veil { position: fixed; inset: var(--header-h) 0 0; z-index: 1; border: 0; background: var(--veil); color: var(--text); }
.mobile-drawer, .header-tools, .brand, .tabs { position: relative; z-index: 2; }
.mobile-drawer { position: absolute; z-index: 3; }

.hero { position: relative; overflow-x: clip; }
.hero__grid {
  max-width: var(--width-page); margin-inline: auto; padding: 40px var(--gutter);
  min-height: clamp(640px, calc(100svh - var(--header-h) - var(--peek)), 880px);
  display: grid; grid-template-columns: minmax(0,5fr) minmax(0,7fr); column-gap: 48px; align-items: center;
}
.hero__copy { max-width: 540px; position: relative; z-index: 3; }
.kicker { display: inline-flex; align-items: center; gap: 12px; margin: 0; font-size: 13px; letter-spacing: .02em; color: var(--text-muted); }
.kicker::before { content: ""; width: 22px; flex-shrink: 0; border-top: 1px solid var(--text); }
.hero__title { margin: 22px 0 0; font-size: var(--size-h1); line-height: 1.15; }
.hero__title-sub { display: block; color: var(--text-muted); }
.lead { margin: 24px 0 0; max-width: 30em; font-size: var(--size-lead); line-height: 1.78; color: var(--text-muted); }
.lead strong { color: var(--text); }
.devices { margin: 40px 0 0; padding: 22px 0 0; border-top: 1px solid var(--border); display: flex; flex-wrap: wrap; align-items: center; gap: 10px 20px; list-style: none; }
.devices__item { display: inline-flex; align-items: center; gap: 8px; font-size: var(--size-small); color: var(--text-muted); text-decoration: none; white-space: nowrap; }
.devices__item svg { width: 18px; height: 18px; color: var(--text); }
.devices__sep { width: 1px; height: 18px; flex-shrink: 0; background: var(--border-strong); color: var(--text); }
.cap { display: inline-flex; align-items: center; gap: 6px; min-height: 28px; padding: 3px 12px; max-width: 100%; font-size: 13px; color: var(--text); background: var(--bg-panel); border: 1px solid var(--border-strong); border-radius: var(--radius-pill); text-decoration: none; overflow-wrap: anywhere; }
.cap svg { width: 12px; height: 12px; }
.devices__gap { margin-left: -8px; }

.store { background: var(--bg-panel-2); color: var(--on-dark); }
.store__inner { max-width: var(--width-page); margin-inline: auto; padding: 104px var(--gutter) 112px; display: grid; grid-template-columns: minmax(0,5fr) minmax(0,7fr); column-gap: 48px; align-items: start; }
.store__kicker { margin: 0; font-size: 13px; letter-spacing: .02em; color: var(--on-dark-muted); }
.store__title { margin: 16px 0 0; font-size: var(--size-h2); line-height: 1.22; }
.store__text { margin: 18px 0 0; max-width: 30em; color: var(--on-dark-muted); line-height: 1.78; }
.store__link { display: inline-flex; align-items: center; gap: 8px; margin-top: 28px; color: var(--on-dark); text-decoration: none; font-weight: var(--weight-medium); border-bottom: 1px solid var(--on-dark-muted); padding-bottom: 2px; }
.store__link:hover { color: var(--on-dark); border-bottom-color: var(--on-dark); }
.store__cards { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 16px; }
.store__card { padding: 28px; background: var(--dark-card); color: var(--on-dark); border: 1px solid var(--dark-line); border-radius: var(--radius-lg); }
.store__icons { display: flex; gap: 10px; }
.store__icons svg { width: 22px; height: 22px; }
.store__card h3 { margin: 22px 0 0; font-size: 18px; font-weight: var(--weight-medium); }
.store__card p { margin: 10px 0 0; font-size: 15px; line-height: 1.72; color: var(--on-dark-muted); }

.site-footer { background: var(--bg-panel); color: var(--text); border-top: 1px solid var(--border); padding-top: 72px; padding-bottom: 32px; }
.footer__grid { display: grid; grid-template-columns: minmax(0,1.5fr) minmax(0,.8fr) minmax(0,1.3fr); gap: 56px; }
.footer__intro { margin-top: 22px; max-width: 28em; color: var(--text-muted); }
.footer__heading { margin: 0 0 18px; font-size: var(--size-body); font-weight: var(--weight-medium); }
.footer__list { list-style: none; padding: 0; margin: 0; }
.footer__list a { display: inline-block; padding-block: 7px; color: var(--text-muted); text-decoration: none; overflow-wrap: anywhere; }
.footer__list a:hover { color: var(--accent); }
.footer__languages { display: flex; flex-wrap: wrap; gap: 8px 24px; margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--border); }
.footer__languages a { display: inline-flex; align-items: center; min-height: 44px; color: var(--text-muted); text-decoration: none; }
.footer__languages a[aria-current] { color: var(--text); text-decoration: underline; }
.footer__bottom { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px 24px; margin-top: 24px; font-size: var(--size-small); color: var(--text-muted); }
.footer__bottom p { margin: 0; }
.footer__legal { display: flex; flex-wrap: wrap; gap: 20px; }
.footer__legal a { color: var(--text-muted); }

@media (max-width: 1180px) {
  :root { --gutter: 40px; --tab-w: 80px; }
  .masthead__row { gap: 24px; }
}
@media (max-width: 1280px) {
  html:not([lang="zh-CN"]):not([lang="zh-TW"]) .masthead .tabs { display: none; }
  html:not([lang="zh-CN"]):not([lang="zh-TW"]) .header-tools { margin-left: auto; }
  html:not([lang="zh-CN"]):not([lang="zh-TW"]) .menu-toggle { display: inline-flex; }
}
@media (max-width: 960px) {
  :root { --gutter: 20px; --tab-w: 78px; --section-space: 72px; }
  .masthead__row { gap: 12px; }
  .masthead .tabs { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: inline-flex; }
  .hero__grid { grid-template-columns: minmax(0,1fr); min-height: 0; padding-top: 36px; padding-bottom: 56px; row-gap: 44px; }
  .hero__title { font-size: clamp(26px,7vw,30px); }
  .lead { font-size: var(--size-body); }
  .store__inner { grid-template-columns: minmax(0,1fr); row-gap: 36px; padding-top: 72px; padding-bottom: 80px; }
  .store__cards { grid-template-columns: minmax(0,1fr); }
  .footer__grid { grid-template-columns: minmax(0,1fr) minmax(0,1fr); gap: 32px; }
  .footer__brand { grid-column: 1 / -1; }
  .preview-masthead { height: auto; }
  .preview-masthead .masthead__row { flex-wrap: wrap; padding-top: 12px; }
  .preview-masthead .brand { height: 48px; }
  .preview-masthead .tabs { display: block; order: 3; width: 100%; height: 48px; margin-left: 0; overflow-x: auto; scrollbar-width: none; }
  .preview-masthead .tabs__list { width: max-content; }
}
@media (max-width: 768px) {
  h1 { font-size: clamp(24px,6.4vw,30px); }
}
@media (max-width: 640px) {
  :root { --gutter: 20px; }
  .grid-two, .footer__grid { grid-template-columns: minmax(0,1fr); }
  .card, .panel { padding: 24px; }
  .tilt, [data-tilt] { transform: none !important; }
  .footer__brand { grid-column: auto; }
  .brand { gap: 8px; font-size: 15px; }
  .brand__mark { width: 30px; height: 30px; }
  .header-tools { gap: 6px; margin-left: auto; }
  .lang { padding-inline: 10px; min-height: 44px; }
  .lang__full { display: none; }
  .lang__short { display: inline; }
  .lang svg { display: none; }
  pre { padding: 18px; }
}
@media (max-width: 420px) {
  .actions .btn { width: 100%; }
  .masthead__row { gap: 8px; }
  .devices { gap: 10px 16px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
  .btn:hover { transform: none; }
}