:root {
  color-scheme: dark;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #eef3f7;
  background: #090d12;
  font-synthesis: none;
  --bg: #090d12;
  --panel: #111821;
  --panel-soft: #151e28;
  --line: #28333e;
  --line-soft: #1d2732;
  --text: #eef3f7;
  --muted: #9aa7b5;
  --muted-2: #718090;
  --cyan: #28e8df;
  --lime: #b7f45d;
  --amber: #ffbe55;
  --red: #ff7686;
}

* { box-sizing: border-box; }
html { min-width: 320px; scroll-behavior: smooth; background: var(--bg); }
body {
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 83% 0, rgba(40, 232, 223, .09), transparent 27rem),
    radial-gradient(circle at 8% 24rem, rgba(255, 190, 85, .06), transparent 24rem),
    var(--bg);
}
a { color: inherit; }
img { display: block; max-width: 100%; }
button, input { font: inherit; }
.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  padding: 10px 15px;
  border-radius: 8px;
  color: #07110f;
  background: var(--cyan);
  transform: translateY(-180%);
}
.skip-link:focus { transform: translateY(0); }
:focus-visible { outline: 3px solid var(--cyan); outline-offset: 3px; }

.site-header,
.site-footer,
.hero,
.guide-hero,
.content-section,
.guide-layout {
  width: min(1180px, calc(100% - 48px));
  margin-inline: auto;
}
.site-header {
  min-height: 86px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--line-soft);
}
.site-brand { display: flex; align-items: center; gap: 13px; text-decoration: none; }
.site-brand img { width: 48px; height: 48px; object-fit: cover; border: 1px solid #394551; border-radius: 12px; background: #fff; box-shadow: 0 9px 30px rgba(0,0,0,.3); }
.site-brand span { display: block; }
.site-brand strong { display: block; font-size: .9rem; letter-spacing: .02em; }
.site-brand small { display: block; margin-top: 4px; color: var(--muted-2); font-size: .58rem; font-weight: 800; letter-spacing: .14em; }
.site-nav { display: flex; align-items: center; gap: 4px; }
.site-nav a { min-height: 44px; display: grid; place-items: center; padding: 0 16px; border-radius: 9px; color: var(--muted); font-size: .8rem; font-weight: 700; text-decoration: none; transition: color .16s ease, background .16s ease; }
.site-nav a:hover { color: var(--text); background: var(--panel); }
.site-nav a[aria-current="page"] { color: #061311; background: var(--cyan); }

.eyebrow { margin: 0; color: var(--cyan); font-size: .72rem; font-weight: 900; letter-spacing: .17em; }
.hero { min-height: 600px; display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(340px, .75fr); align-items: center; gap: clamp(48px, 8vw, 106px); padding-block: 72px 84px; }
.hero h1, .guide-hero h1 { margin: 18px 0; font-size: clamp(2.8rem, 6vw, 5.4rem); line-height: .98; letter-spacing: -.065em; }
.hero-lead { max-width: 720px; margin: 0; color: var(--muted); font-size: 1.05rem; line-height: 1.85; }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-top: 34px; }
.hero-actions.centered { justify-content: center; }
.button { min-height: 52px; display: inline-flex; align-items: center; justify-content: center; gap: 11px; padding: 0 21px; border: 1px solid var(--line); border-radius: 10px; font-size: .83rem; font-weight: 850; text-decoration: none; transition: transform .16s ease, border-color .16s ease, background .16s ease; }
.button:hover { transform: translateY(-2px); }
.button.primary { color: #05110f; border-color: var(--cyan); background: var(--cyan); box-shadow: 0 14px 36px rgba(40,232,223,.13); }
.button.mac-button { color: #171006; border-color: var(--amber); background: var(--amber); box-shadow: 0 14px 36px rgba(255,190,85,.12); }
.button.secondary { color: #dfe7ed; background: var(--panel); }
.button.secondary:hover { border-color: #51606d; }
.windows-mark { width: 17px; height: 17px; display: grid; grid-template-columns: 1fr 1fr; grid-template-rows: 1fr 1fr; gap: 2px; transform: skewY(-4deg); }
.windows-mark i { display: block; background: currentColor; }
.apple-mark { width: 17px; height: 17px; display: grid; place-items: center; font-size: .85rem; }
.hero-guide-link { margin-top: 13px; }
.release-line { margin: 16px 0 0; color: var(--muted-2); font-size: .72rem; }
.platform-panel { padding: 24px; border: 1px solid var(--line); border-radius: 20px; background: linear-gradient(150deg, rgba(22,31,41,.98), rgba(12,18,25,.98)); box-shadow: 0 34px 90px rgba(0,0,0,.34); }
.platform-panel-head { display: flex; align-items: center; gap: 18px; padding-bottom: 22px; border-bottom: 1px solid var(--line); }
.platform-panel-head img { flex: 0 0 auto; width: 92px; height: 92px; object-fit: cover; border: 1px solid #495561; border-radius: 20px; background: #fff; }
.platform-panel-head span { color: var(--cyan); font-size: .62rem; font-weight: 900; letter-spacing: .12em; }
.platform-panel-head strong { display: block; margin-top: 6px; font-size: 1.18rem; }
.platform-panel-head p { margin: 7px 0 0; color: var(--muted-2); font-size: .68rem; line-height: 1.55; }
.platform-row { min-height: 76px; display: grid; grid-template-columns: 38px minmax(0, 1fr) auto; align-items: center; gap: 14px; border-bottom: 1px solid var(--line-soft); }
.platform-symbol { width: 34px; height: 34px; color: var(--cyan); }
.platform-row .apple-symbol { display: grid; place-items: center; color: var(--amber); font-size: 1rem; }
.platform-row strong { display: block; font-size: .82rem; }
.platform-row small { display: block; margin-top: 5px; color: var(--muted-2); font-size: .65rem; }
.platform-row b { color: var(--muted-2); font-size: .62rem; letter-spacing: .1em; }
.platform-note { margin-top: 18px; padding: 15px; border: 1px solid rgba(40,232,223,.14); border-radius: 10px; background: rgba(40,232,223,.045); }
.platform-note span { color: var(--cyan); font-size: .62rem; font-weight: 900; letter-spacing: .1em; }
.platform-note p { margin: 7px 0 0; color: var(--muted); font-size: .68rem; line-height: 1.6; }
.download-file-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
.release-card { padding: 24px; border: 1px solid var(--line); border-radius: 20px; background: linear-gradient(150deg, rgba(22,31,41,.98), rgba(12,18,25,.98)); box-shadow: 0 34px 90px rgba(0,0,0,.34); }
.release-card-head { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding-bottom: 22px; border-bottom: 1px solid var(--line); }
.release-card-head div { min-width: 0; }
.release-card-head span { display: block; color: var(--muted-2); font-size: .65rem; font-weight: 800; letter-spacing: .14em; }
.release-card-head strong { display: block; margin-top: 7px; font-size: 1.35rem; }
.release-card-head a { flex: 0 0 auto; min-height: 42px; display: inline-flex; align-items: center; padding: 0 14px; border: 1px solid rgba(40,232,223,.25); border-radius: 8px; color: var(--cyan); background: rgba(40,232,223,.06); font-size: .7rem; font-weight: 850; text-decoration: none; }
.release-card-head a:hover { color: #061311; background: var(--cyan); }
.release-facts { margin: 7px 0 0; }
.release-facts div { display: grid; grid-template-columns: 76px minmax(0, 1fr); gap: 14px; padding: 12px 0; border-bottom: 1px solid var(--line-soft); }
.release-facts dt { color: var(--muted-2); font-size: .7rem; }
.release-facts dd { min-width: 0; margin: 0; color: #d8e0e7; font-size: .72rem; text-align: right; overflow-wrap: anywhere; }
.hash-block { margin-top: 17px; padding: 15px; border: 1px solid rgba(40,232,223,.16); border-radius: 10px; background: rgba(40,232,223,.045); }
.hash-block span { display: block; margin-bottom: 8px; color: var(--cyan); font-size: .62rem; font-weight: 900; letter-spacing: .12em; }
.hash-block code { color: #aebbc6; font-size: .66rem; line-height: 1.65; overflow-wrap: anywhere; }

.content-section { padding-block: 80px; border-top: 1px solid var(--line-soft); }
.section-heading { max-width: 660px; margin-bottom: 34px; }
.section-heading h2, .notice-card h2 { margin: 10px 0; font-size: clamp(1.9rem, 3.8vw, 3rem); letter-spacing: -.045em; }
.section-heading > p:last-child, .notice-card > p:last-child { margin: 0; color: var(--muted); line-height: 1.75; }
.feature-grid { display: grid; gap: 14px; }
.feature-grid.three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.feature-grid.four { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.feature-card { min-height: 220px; padding: 24px; border: 1px solid var(--line); border-radius: 14px; background: rgba(17,24,33,.84); }
.feature-card > span { display: grid; place-items: center; width: 38px; height: 38px; border-radius: 9px; color: #061311; background: var(--cyan); font-size: .7rem; font-weight: 900; }
.feature-card.numbered:nth-child(2) > span { background: var(--lime); }
.feature-card.numbered:nth-child(3) > span { background: var(--amber); }
.feature-card .feature-icon { width: auto; min-width: 38px; display: inline-grid; padding: 0 8px; color: var(--cyan); border: 1px solid rgba(40,232,223,.22); background: rgba(40,232,223,.06); }
.feature-card h3 { margin: 42px 0 10px; font-size: 1.02rem; }
.feature-card p { margin: 0; color: var(--muted); font-size: .82rem; line-height: 1.75; }
.split-section { display: grid; grid-template-columns: minmax(260px, .72fr) minmax(0, 1.28fr); gap: 72px; }
.sticky-heading { align-self: start; position: sticky; top: 28px; }
.text-link { min-height: 44px; display: inline-flex; align-items: center; gap: 8px; margin-top: 20px; color: var(--cyan); font-size: .78rem; font-weight: 800; text-decoration: none; }
.step-list { display: grid; gap: 10px; margin: 0; padding: 0; list-style: none; }
.step-list li { min-height: 126px; display: flex; align-items: flex-start; gap: 18px; padding: 23px; border: 1px solid var(--line); border-radius: 13px; background: var(--panel); }
.step-list li > span { flex: 0 0 auto; width: 34px; height: 34px; display: grid; place-items: center; border-radius: 50%; color: #061311; background: var(--cyan); font-size: .72rem; font-weight: 900; }
.step-list h3 { margin: 4px 0 8px; font-size: .96rem; }
.step-list p { margin: 0; color: var(--muted); font-size: .8rem; line-height: 1.65; }
.notice-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }
.notice-card { min-height: 284px; padding: 32px; border: 1px solid var(--line); border-radius: 17px; background: var(--panel); }
.notice-card.safe { background: linear-gradient(145deg, rgba(40,232,223,.08), rgba(17,24,33,.96) 55%); }
.notice-card.warning { background: linear-gradient(145deg, rgba(255,190,85,.09), rgba(17,24,33,.96) 55%); }
.notice-card.warning .eyebrow { color: var(--amber); }

.guide-hero { max-width: 920px; padding: 102px 0 94px; text-align: center; }
.guide-hero h1 { font-size: clamp(3.1rem, 7.5vw, 6.4rem); }
.guide-hero > p:not(.eyebrow) { max-width: 670px; margin: 0 auto; color: var(--muted); font-size: 1.03rem; line-height: 1.8; }
.guide-layout { display: grid; grid-template-columns: 228px minmax(0, 1fr); align-items: start; gap: 56px; padding-bottom: 100px; }
.guide-index { position: sticky; top: 24px; padding: 20px; border: 1px solid var(--line); border-radius: 13px; background: rgba(15,22,31,.92); }
.guide-index > strong { font-size: .74rem; letter-spacing: .08em; }
.guide-index nav { display: grid; gap: 3px; margin: 14px 0 18px; }
.guide-index a { min-height: 42px; display: flex; align-items: center; gap: 10px; padding: 0 8px; border-radius: 7px; color: var(--muted); font-size: .73rem; text-decoration: none; }
.guide-index a:hover { color: var(--text); background: var(--panel-soft); }
.guide-index a span { color: var(--cyan); font-size: .6rem; font-weight: 900; }
.guide-index p { margin: 0; padding-top: 15px; border-top: 1px solid var(--line-soft); color: var(--muted-2); font-size: .68rem; line-height: 1.6; }
.guide-content { min-width: 0; }
.guide-section { scroll-margin-top: 30px; padding: 43px; border: 1px solid var(--line); border-radius: 17px; background: rgba(17,24,33,.9); }
.guide-section + .guide-section { margin-top: 14px; }
.guide-step { display: flex; align-items: center; gap: 18px; margin-bottom: 26px; }
.guide-step > span { flex: 0 0 auto; width: 52px; height: 52px; display: grid; place-items: center; border: 1px solid rgba(40,232,223,.2); border-radius: 13px; color: var(--cyan); background: rgba(40,232,223,.06); font-size: .8rem; font-weight: 900; }
.guide-step h2 { margin: 7px 0 0; font-size: clamp(1.45rem, 3vw, 2.05rem); letter-spacing: -.035em; }
.guide-section > p { margin: 0; color: #acb8c3; font-size: .9rem; line-height: 1.85; }
.callout { margin-top: 24px; padding: 19px 20px; border-left: 3px solid var(--cyan); border-radius: 0 10px 10px 0; background: rgba(40,232,223,.055); }
.callout strong { font-size: .82rem; }
.callout p { margin: 7px 0 0; color: var(--muted); font-size: .76rem; line-height: 1.7; }
.warning-callout { border-left-color: var(--amber); background: rgba(255,190,85,.055); }
.check-list { display: grid; gap: 10px; margin: 24px 0 0; padding: 0; list-style: none; }
.check-list li { position: relative; padding: 13px 16px 13px 43px; border: 1px solid var(--line-soft); border-radius: 9px; color: #aeb9c4; background: #0e151d; font-size: .78rem; line-height: 1.6; }
.check-list li::before { content: "✓"; position: absolute; left: 16px; top: 13px; color: var(--cyan); font-weight: 900; }
.sync-grid, .definition-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 11px; margin-top: 25px; }
.sync-grid article, .definition-grid > div, .dashboard-grid article { padding: 20px; border: 1px solid var(--line); border-radius: 11px; background: #0e151d; }
.sync-grid span { color: var(--cyan); font-size: .64rem; font-weight: 900; letter-spacing: .08em; }
.sync-grid h3, .dashboard-grid h3 { margin: 12px 0 7px; font-size: .92rem; }
.sync-grid p, .dashboard-grid p, .definition-grid p { margin: 0; color: var(--muted); font-size: .74rem; line-height: 1.7; }
.status-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); margin: 18px 0 0; overflow: hidden; border: 1px solid var(--line); border-radius: 11px; }
.status-list div { padding: 15px 18px; }
.status-list div:nth-child(odd) { border-right: 1px solid var(--line); }
.status-list div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
.status-list dt { color: #dce4eb; font-size: .74rem; font-weight: 800; }
.status-list dd { margin: 6px 0 0; color: var(--muted-2); font-size: .7rem; line-height: 1.55; }
.dashboard-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 11px; margin-top: 25px; }
.dashboard-grid article > span { color: var(--cyan); font-size: .64rem; font-weight: 900; }
.definition-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.definition-grid strong { font-size: .78rem; }
.definition-grid p { margin-top: 9px; }
.contrast-card { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 22px; margin-top: 24px; padding: 24px; border: 1px solid rgba(255,190,85,.2); border-radius: 13px; background: rgba(255,190,85,.045); }
.contrast-card span { display: block; color: var(--amber); font-size: .66rem; font-weight: 900; letter-spacing: .06em; }
.contrast-card strong { display: block; margin-top: 8px; font-size: .85rem; }
.contrast-card p { margin: 7px 0 0; color: var(--muted); font-size: .72rem; line-height: 1.6; }
.contrast-card i { color: var(--amber); font-size: 1.35rem; font-style: normal; font-weight: 900; }
.faq-section details { border-top: 1px solid var(--line); }
.faq-section details:last-child { border-bottom: 1px solid var(--line); }
.faq-section summary { min-height: 58px; display: flex; align-items: center; justify-content: space-between; gap: 20px; cursor: pointer; font-size: .83rem; font-weight: 750; list-style: none; }
.faq-section summary::-webkit-details-marker { display: none; }
.faq-section summary::after { content: "+"; color: var(--cyan); font-size: 1.1rem; }
.faq-section details[open] summary::after { content: "−"; }
.faq-section details p { margin: -3px 0 18px; color: var(--muted); font-size: .76rem; line-height: 1.7; }

.site-footer { min-height: 150px; display: flex; align-items: center; justify-content: space-between; gap: 24px; border-top: 1px solid var(--line-soft); }
.site-footer strong { font-size: .84rem; }
.site-footer p { margin: 7px 0 0; color: var(--muted-2); font-size: .7rem; }
.site-footer nav { display: flex; gap: 22px; }
.site-footer a { min-height: 44px; display: inline-flex; align-items: center; color: var(--muted); font-size: .74rem; text-decoration: none; }
.site-footer a:hover { color: var(--cyan); }

@media (max-width: 960px) {
  .hero { min-height: 0; grid-template-columns: 1fr; gap: 50px; }
  .hero-copy { max-width: 760px; }
  .release-card { max-width: 620px; }
  .feature-grid.four { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .guide-layout { grid-template-columns: 1fr; gap: 18px; }
  .guide-index { position: static; overflow-x: auto; }
  .guide-index nav { display: flex; width: max-content; max-width: none; }
  .guide-index a { padding-inline: 12px; }
  .guide-index p { display: none; }
}

@media (max-width: 720px) {
  .site-header, .site-footer, .hero, .guide-hero, .content-section, .guide-layout { width: min(100% - 30px, 1180px); }
  .site-header { min-height: 112px; align-items: flex-start; flex-direction: column; justify-content: center; gap: 10px; padding-block: 15px; }
  .site-nav { width: 100%; }
  .site-nav a { flex: 1; }
  .hero { padding-block: 56px 66px; }
  .hero h1, .guide-hero h1 { font-size: clamp(2.65rem, 15vw, 4.2rem); }
  .hero-actions, .hero-actions.centered { align-items: stretch; flex-direction: column; }
  .button { width: 100%; }
  .release-card { padding: 20px; }
  .download-file-grid { grid-template-columns: 1fr; }
  .download-file-grid .release-card { max-width: none; }
  .feature-grid.three, .feature-grid.four, .notice-grid, .split-section { grid-template-columns: 1fr; }
  .feature-card { min-height: 196px; }
  .sticky-heading { position: static; }
  .split-section { gap: 20px; }
  .content-section { padding-block: 62px; }
  .guide-hero { padding: 70px 0 64px; }
  .guide-section { padding: 26px 20px; }
  .guide-step { align-items: flex-start; }
  .sync-grid, .dashboard-grid, .definition-grid, .status-list { grid-template-columns: 1fr; }
  .status-list div:nth-child(odd) { border-right: 0; }
  .status-list div:nth-child(-n+3) { border-bottom: 1px solid var(--line); }
  .contrast-card { grid-template-columns: 1fr; gap: 15px; }
  .contrast-card i { transform: rotate(90deg); }
  .site-footer { min-height: 180px; align-items: flex-start; flex-direction: column; justify-content: center; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .001ms !important; animation-duration: .001ms !important; animation-iteration-count: 1 !important; }
}