:root {
  color-scheme: dark;
  --bg: #080a0d;
  --text: #f2f3f5;
  --muted: #929ba6;
  --blue: #bdd9e9;
  --line: rgb(202 216 230 / 11%);
  --cycle: 12s;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-synthesis: none;
  background: var(--bg);
  color: var(--text);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 36px; }
body { margin: 0; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button:focus-visible, a:focus-visible { outline: 2px solid var(--blue); outline-offset: 6px; }
::selection { background: var(--blue); color: var(--bg); }
.shell { max-width: 1120px; width: calc(100% - 96px); margin-inline: auto; }
.header { height: 76px; display: flex; align-items: center; justify-content: space-between; }
.wordmark { display: inline-flex; gap: 4px; align-items: baseline; font-size: 22px; font-weight: 620; letter-spacing: -1px; }
.brand-dot { width: 3px; height: 3px; border-radius: 50%; background: var(--blue); margin-left: 1px; }
.language-switch { display: flex; align-items: center; gap: 13px; font-size: 12px; }
.language-switch > span { color: #3d424a; }
.language-switch button { padding: 10px 2px; background: none; border: 0; color: #8c949f; cursor: pointer; }
.language-switch button[aria-pressed="true"], .language-switch button:hover { color: var(--text); }
.hero { padding-top: 12px; }
.hero-copy { text-align: center; position: relative; z-index: 1; }
.eyebrow { font-size: 13px; font-weight: 450; letter-spacing: .2px; line-height: 1.6; margin: 0; color: var(--muted); }
.platform-label { color: #b3c0cc; font-size: 14px; }
h1 { margin: 20px 0 22px; font-size: clamp(62px, 6vw, 70px); font-weight: 530; line-height: 1.06; letter-spacing: -4.6px; }
h1 > span { display: block; }
.headline-second { color: #b6c6d3; }
.hero-description { max-width: 540px; font-size: 16px; line-height: 1.8; color: #a4adb8; margin: 0 auto; text-wrap: pretty; }
.hero-status { margin: 18px 0 0; color: #91a9bb; font-size: 11px; line-height: 1.7; }
.streaming-demo { margin: 30px auto 0; max-width: 980px; }
.device-scene { display: block; width: 100%; height: auto; overflow: visible; }
.stream-brand { fill: #8fa3b4; font: 500 10px -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; letter-spacing: 2px; }
.streaming-labels { display: grid; grid-template-columns: 46% 54%; text-align: center; margin-top: 4px; }
.streaming-labels > div { display: flex; flex-direction: column; gap: 8px; }
.streaming-labels strong { color: #d4dbe2; font-size: 13px; font-weight: 450; letter-spacing: .1px; }
.streaming-labels span { color: #838e9a; font-size: 11px; line-height: 1.6; }
.scene-caption { display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 12px 0 0; margin-top: 8px; color: #76818d; font-size: 10px; line-height: 1.6; }
.motion-toggle { display: inline-flex; align-items: center; gap: 7px; padding: 10px 0 10px 10px; border: 0; background: none; color: #9ba7b3; cursor: pointer; font-size: 10px; flex-shrink: 0; }
.motion-toggle:hover { color: var(--text); }
.play-icon { display: none; }
.animation-paused .pause-icon { display: none; }
.animation-paused .play-icon { display: block; }
.animation-paused *, .animation-paused *::before, .animation-paused *::after { animation-play-state: paused !important; }
.source-scan { opacity: 0; animation: source-scan var(--cycle) ease-in-out infinite; }
.flow-frame { opacity: 0; animation: frame-transfer var(--cycle) cubic-bezier(.35, 0, .3, 1) infinite; }
.packet-light { stroke-dasharray: 24 300; opacity: 0; animation: packet-light var(--cycle) ease-in-out infinite; }
.home-scene { opacity: .85; animation: home-view var(--cycle) ease-in-out infinite; mix-blend-mode: screen; }
.received-scene { opacity: 0; animation: receive-world var(--cycle) ease-in-out infinite; mix-blend-mode: screen; }
/* Forward motion is projected from world depth in script.js, never played in reverse. */
.flight-attitude { transform-origin: 143px 167px; animation: flight-trim 20s ease-in-out infinite; }
.flight-yoke { transform-origin: 69px 189px; animation: yoke-trim 20s ease-in-out infinite; }
.flight-needle { transform-origin: 56px 159px; animation: instrument-needle 12s ease-in-out infinite; }
@keyframes flight-trim { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-.25px); } }
@keyframes yoke-trim { 0%, 100% { transform: rotate(-.25deg); } 50% { transform: rotate(.25deg); } }
@keyframes instrument-needle { 0%, 100% { transform: rotate(-1deg); } 50% { transform: rotate(1deg); } }
/* A complete story: prepare, transmit, then hold the internal game view. */
@keyframes source-scan {
  0%, 2% { transform: translateX(0); opacity: 0; }
  5% { opacity: .35; }
  17% { transform: translateX(335px); opacity: .35; }
  20%, 100% { transform: translateX(335px); opacity: 0; }
}
@keyframes frame-transfer {
  0%, 15% { transform: translateX(0); opacity: 0; }
  20% { opacity: .8; }
  38% { transform: translateX(130px); opacity: .8; }
  44%, 100% { transform: translateX(167px); opacity: 0; }
}
@keyframes packet-light {
  0%, 15% { stroke-dashoffset: 24; opacity: 0; }
  21%, 38% { opacity: .4; }
  44%, 100% { stroke-dashoffset: -167; opacity: 0; }
}
@keyframes home-view { 0%, 44%, 100% { opacity: .85; } 50%, 93% { opacity: 0; } }
@keyframes receive-world { 0%, 45%, 100% { opacity: 0; } 52%, 92% { opacity: .95; } }
.features { margin-top: 80px; padding: 83px 0 94px; border-top: 1px solid var(--line); }
.section-heading { margin-bottom: 60px; }
.section-heading h2 { max-width: 640px; margin: 16px 0 0; font-size: clamp(32px, 3.8vw, 48px); font-weight: 450; letter-spacing: -1.7px; line-height: 1.2; text-wrap: balance; }
.development { padding: 90px 0 100px; text-align: center; border-top: 1px solid var(--line); }
.status { display: flex; justify-content: center; align-items: center; gap: 8px; color: #9aafc0; margin: 0 0 23px; font-size: 12px; }
.status > span:first-child { width: 4px; height: 4px; background: #bad6e9; border-radius: 50%; }
.development h2 { font-size: clamp(30px, 3.6vw, 45px); line-height: 1.25; font-weight: 450; letter-spacing: -1.5px; margin: 0 0 24px; }
.development > p:last-child { max-width: 470px; margin: auto; font-size: 15px; line-height: 1.9; color: var(--muted); }
.footer { border-top: 1px solid var(--line); min-height: 104px; display: flex; align-items: center; gap: 30px; }
.footer-wordmark { font-size: 18px; }
.footer p, .footer-note { font-size: 11px; color: #75818d; margin: 0; }
.footer-note { margin-left: auto; }
html[lang="zh-CN"] h1 { font-size: clamp(44px, 5.1vw, 70px); letter-spacing: -2px; line-height: 1.2; }
html[lang="zh-CN"] .hero-description { max-width: 510px; line-height: 1.95; }
html[lang="zh-CN"] .section-heading h2, html[lang="zh-CN"] .development h2 { letter-spacing: -.5px; }
@media (max-width: 900px) {
  .shell { width: calc(100% - 64px); }
  .header { height: 82px; }
  .hero { padding-top: 32px; }
  h1 { font-size: 64px; letter-spacing: -3.5px; }
  .streaming-demo { width: calc(100% + 32px); margin-inline: -16px; }
  .scene-caption { margin-inline: 16px; }
  .feature-grid, .controller-note { gap: 50px; }
  .features { margin-top: 60px; padding-block: 65px; }
  .feature p { font-size: 14px; }
}
@media (max-width: 600px) {
  .shell { width: calc(100% - 44px); }
  .header { height: 78px; }
  .wordmark { font-size: 20px; }
  .hero { padding-top: 33px; }
  .platform-label { font-size: 12px; }
  h1 { font-size: clamp(39px, 10.5vw, 60px); letter-spacing: -2px; line-height: 1.1; margin: 22px 0 24px; }
  .hero-description { font-size: 14px; line-height: 1.85; max-width: 360px; }
  .streaming-demo { margin-top: 38px; }
  .streaming-labels { margin-top: 3px; }
  .streaming-labels strong { font-size: 11px; }
  .streaming-labels span { font-size: 9px; }
  .streaming-labels > div { gap: 5px; }
  .scene-caption { padding-top: 20px; margin-top: 12px; font-size: 8px; gap: 12px; }
  .motion-toggle { font-size: 9px; gap: 4px; }
  .features { margin-top: 36px; padding-block: 46px 53px; }
  .section-heading { margin-bottom: 37px; }
  .section-heading h2 { font-size: 33px; line-height: 1.2; letter-spacing: -1px; margin-top: 13px; }
  .eyebrow { font-size: 12px; }
  .feature-grid { grid-template-columns: 1fr; gap: 37px; }
  .feature + .feature { border-top: 1px solid var(--line); padding-top: 34px; }
  .feature h3 { font-size: 31px; margin-bottom: 16px; }
  .feature p { font-size: 14px; }
  .feature-top { margin-bottom: 13px; }
  .feature-type, .feature-footnote, .text-link { font-size: 11px; }
  .controller-note { grid-template-columns: 1fr; gap: 18px; margin-top: 35px; padding-top: 30px; }
  .controller-note h3 { font-size: 25px; }
  .controller-note > p { font-size: 13px; }
  .desktop-note { margin-top: 35px; padding-top: 27px; gap: 12px; align-items: flex-start; }
  .desktop-note p { font-size: 12px; gap: 3px; }
  .desktop-note p > span { flex-basis: 100%; }
  .development { padding-block: 60px 66px; }
  .development h2 { font-size: 29px; letter-spacing: -.8px; }
  .development > p:last-child { font-size: 13px; }
  .status { font-size: 11px; }
  .footer { flex-wrap: wrap; gap: 15px 22px; padding-block: 28px; }
  .footer p, .footer-note { font-size: 10px; }
  .footer-note { flex-basis: 100%; margin: 0; }
  html[lang="zh-CN"] h1 { font-size: clamp(31px, 8.6vw, 50px); letter-spacing: -1px; line-height: 1.28; }
  html[lang="zh-CN"] .section-heading h2 { font-size: 28px; }
}
@media (min-width: 901px) and (max-height: 850px) {
  .header { height: 68px; }
  .hero { padding-top: 10px; }
  h1 { font-size: 60px; margin-block: 16px 18px; }
  .hero-description { font-size: 15px; }
  .streaming-demo { max-width: 840px; margin-top: 16px; }
  html[lang="zh-CN"] h1 { font-size: 60px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .source-scan, .flow-frame, .packet-light { opacity: 0; }
  .home-scene { opacity: 0; }
  .received-scene { opacity: .75; }
  .motion-toggle { display: none; }
}

/* Product details: quiet surfaces, generous spacing and a single interactive figure. */
.experience-heading { display: grid; grid-template-columns: 1.1fr 1fr; gap: 80px; align-items: end; margin-bottom: 44px; }
.section-intro { font-size: 15px; line-height: 1.9; color: #a4adb8; margin: 0 0 3px; max-width: 410px; }
.technical-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.tech-card { padding: 34px 36px; background: #0d1116; border: 1px solid #1c242d; border-radius: 18px; }
.feature-icon { display: block; width: 26px; height: 26px; fill: none; stroke: #a7c6db; stroke-width: 1.3; stroke-linecap: round; stroke-linejoin: round; margin-bottom: 25px; }
.tech-card h3 { font-size: 23px; font-weight: 480; line-height: 1.3; letter-spacing: -.6px; margin: 0 0 16px; text-wrap: balance; }
.tech-card p { color: #a5afbb; font-size: 14px; line-height: 1.85; margin: 0; text-wrap: pretty; }
.tech-card p + p { margin-top: 15px; }
.tech-card .card-note { font-size: 12px; line-height: 1.8; color: #8fa8bc; }
.clarity-card, .panel-card { grid-column: 1 / -1; display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; padding-block: 42px; }
.density-demo { margin: 0; min-width: 0; }
.density-controls { display: flex; width: fit-content; padding: 4px; margin: 0 auto 22px; border: 1px solid #25303a; border-radius: 30px; gap: 4px; }
.density-controls button { background: transparent; border: 0; border-radius: 24px; padding: 8px 16px; font-size: 12px; cursor: pointer; color: #8d9da9; }
.density-controls button[aria-pressed="true"] { background: #24313c; color: #e0edf5; }
.density-controls button:hover { color: #fff; }
.density-plot { display: block; width: 100%; }
.density-points circle { transition: cx .55s ease, cy .55s ease, fill .55s ease; }
.density-demo figcaption { display: flex; justify-content: space-between; gap: 12px; color: #8a9ba8; font-size: 10px; line-height: 1.7; margin-top: 12px; }
.density-demo .density-explanation { font-size: 11px; text-align: center; margin-top: 16px; color: #a6bbcb; min-height: 2em; }
.panel-preview { align-self: stretch; margin: 0; min-height: 240px; border: 1px dashed #303d49; border-radius: 12px; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 30px; text-align: center; }
.panel-preview > svg { width: 48px; height: 40px; stroke: #647b8d; fill: none; stroke-width: 1; margin-bottom: 22px; }
.panel-preview figcaption { display: grid; gap: 10px; }
.panel-preview strong { color: #b5c3ce; font-size: 14px; font-weight: 450; }
.panel-preview span { color: #7e909f; font-size: 11px; }
.just-works { display: grid; grid-template-columns: 1fr 2fr; gap: 40px; align-items: baseline; padding: 32px 0 0; }
.just-works > p:last-child { color: #a5afbb; line-height: 1.8; font-size: 14px; margin: 0; }
.just-works .eyebrow { color: #c1d1dc; font-size: 16px; }
.requirements { padding-block: 76px; border-top: 1px solid var(--line); }
.requirements .section-heading, .faq .section-heading { margin-bottom: 38px; }
.requirements-grid { display: grid; grid-template-columns: 1.3fr .9fr 1fr 1.2fr; gap: 36px; margin: 0; }
.requirements-grid dt { font-size: 14px; color: #e0e5eb; margin-bottom: 14px; }
.requirements-grid dd { margin: 0; font-size: 13px; line-height: 1.9; color: #97a4b0; }
.lan-note { margin: 32px 0 0; padding-top: 24px; border-top: 1px solid var(--line); color: #8fa8bc; font-size: 12px; line-height: 1.8; }
.faq { padding-block: 76px 90px; border-top: 1px solid var(--line); display: grid; grid-template-columns: 1fr 1.6fr; gap: 60px; }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { cursor: pointer; list-style: none; padding: 23px 32px 23px 0; position: relative; font-size: 15px; line-height: 1.5; color: #c8d1da; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: '+'; position: absolute; right: 2px; color: #8fa8bc; font-size: 20px; font-weight: 300; top: 20px; }
.faq-list details[open] summary::after { content: '−'; }
.faq-list summary:focus-visible { outline: 2px solid var(--blue); outline-offset: 4px; }
.faq-list details p { font-size: 14px; line-height: 1.8; margin: 0; padding: 0 28px 24px 0; color: #97a4b0; }
.footer { display: block; padding-block: 30px; }
.footer-top { display: flex; align-items: center; gap: 30px; }
.footer .trademarks { font-size: 10px; line-height: 1.8; margin-top: 24px; max-width: 900px; color: #84909c; }
html[lang="zh-CN"] .tech-card h3 { letter-spacing: 0; }
@media (max-width: 900px) {
  .experience-heading { gap: 36px; }
  .clarity-card, .panel-card { gap: 30px; }
  .tech-card { padding: 28px; }
  .requirements-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
  .faq { gap: 35px; }
}
@media (max-width: 600px) {
  .hero-status { font-size: 10px; margin-top: 15px; }
  .language-switch { gap: 6px; }
  .language-switch button { min-width: 44px; min-height: 44px; }
  .motion-toggle { min-height: 44px; }
  .experience-heading, .technical-grid, .clarity-card, .panel-card, .faq { grid-template-columns: 1fr; }
  .experience-heading { gap: 22px; margin-bottom: 28px; }
  .section-intro { font-size: 13px; }
  .technical-grid { gap: 12px; }
  .tech-card { padding: 27px 24px; border-radius: 14px; }
  .feature-icon { margin-bottom: 20px; width: 24px; height: 24px; }
  .tech-card h3 { font-size: 22px; letter-spacing: -.4px; }
  .tech-card p { font-size: 13px; }
  .tech-card .card-note { font-size: 11px; }
  .clarity-card, .panel-card { gap: 28px; }
  .density-controls button { min-height: 44px; padding: 8px 14px; font-size: 11px; }
  .density-demo figcaption { font-size: 8px; gap: 8px; }
  .density-demo .density-explanation { font-size: 10px; }
  .panel-preview { min-height: 200px; }
  .just-works { grid-template-columns: 1fr; gap: 12px; padding-top: 28px; }
  .just-works > p:last-child { font-size: 13px; }
  .requirements { padding-block: 48px; }
  .requirements-grid { gap: 28px 22px; }
  .requirements-grid dt { font-size: 13px; margin-bottom: 10px; }
  .requirements-grid dd { font-size: 12px; }
  .lan-note { font-size: 11px; }
  .faq { padding-block: 48px 55px; gap: 0; }
  .faq .section-heading { margin-bottom: 16px; }
  .faq-list summary { font-size: 14px; }
  .faq-list details p { font-size: 13px; }
  .footer-top { flex-wrap: wrap; gap: 15px 22px; }
  .footer .trademarks { font-size: 9px; }
}