:root {
  color-scheme: light;
  --ink: #182b31;
  --muted: #657479;
  --line: #dde6e5;
  --teal: #0c756d;
  --teal-dark: #075e57;
  --page: #f5f8f7;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 28px; }
body { margin: 0; background: var(--page); color: var(--ink); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif; line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
a, summary { -webkit-tap-highlight-color: transparent; }
a:focus-visible, summary:focus-visible { outline: 3px solid #188f84; outline-offset: 5px; }
h1, h2, p { margin: 0; }
svg { display: block; width: 24px; height: 24px; flex-shrink: 0; }
.sr-only, .skip-link:not(:focus) { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.skip-link:focus { position: absolute; top: 8px; left: 8px; z-index: 5; padding: 10px 16px; background: #fff; color: var(--teal); }
.site-header { background: #fff; border-bottom: 1px solid #e7edeb; }
.header-inner { max-width: 1168px; min-height: 82px; margin: auto; padding: 16px 28px; display: flex; justify-content: space-between; align-items: center; gap: 24px; }
.brand { display: flex; align-items: center; gap: 11px; font-size: 17px; font-weight: 650; letter-spacing: -.45px; white-space: nowrap; }
.brand img { display: block; border-radius: 9px; }
.brand strong { font-weight: 450; color: var(--muted); }
.site-header nav { display: flex; align-items: center; gap: 28px; font-size: 13px; color: #506167; }
.site-header nav a { padding: 8px 0; }
.site-header nav a:hover { color: var(--teal); }
.site-header nav span { margin-left: 4px; }
.download-main { width: min(980px, calc(100% - 56px)); margin: 0 auto; }
.intro { padding: 62px 0 36px; }
.eyebrow { display: flex; align-items: center; gap: 9px; margin-bottom: 16px; color: var(--teal); font-size: 12px; font-weight: 650; letter-spacing: 2px; }
.eyebrow > span { width: 7px; height: 7px; border-radius: 50%; background: var(--teal); }
h1 { font-size: clamp(28px, 3.6vw, 42px); font-weight: 680; line-height: 1.25; letter-spacing: -1.2px; }
.title-dot { color: var(--teal); }
.intro-caption { margin-top: 15px; color: var(--muted); font-size: 15px; }
.platform-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.platform-card { min-width: 0; padding: 32px; border: 1px solid var(--line); border-radius: 20px; background: #fff; box-shadow: 0 6px 24px rgba(24, 43, 49, .025); scroll-margin-top: 28px; }
.windows-card { border-color: #bcd8d2; }
.card-top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 23px; }
.platform-icon { width: 55px; height: 55px; display: grid; place-items: center; border-radius: 14px; }
.platform-icon svg { width: 28px; height: 28px; }
.windows-icon { background: #e8f4f1; color: var(--teal); }
.mac-icon { background: #edf0f3; color: #384c5c; }
.version-tag { padding: 5px 11px; border: 1px solid #e4ebe8; border-radius: 7px; color: #526965; background: #fafcfb; font-size: 12px; font-weight: 600; font-variant-numeric: tabular-nums; }
.platform-card h2 { margin-bottom: 3px; font-size: 29px; line-height: 1.3; letter-spacing: -.6px; font-weight: 650; }
.edition-label { color: var(--muted); font-size: 13px; }
.edition-label > span { margin: 0 7px; color: #a1b1ad; }
.platform-specs { margin: 25px 0; padding-top: 18px; border-top: 1px solid #edf1ef; display: grid; gap: 8px; font-size: 13px; }
.platform-specs > div { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; }
.platform-specs dt { color: var(--muted); flex-shrink: 0; }
.platform-specs dd { margin: 0; text-align: right; font-variant-numeric: tabular-nums; }
.platform-specs dd > span { color: var(--muted); }
.download-button { display: flex; justify-content: center; align-items: center; gap: 10px; min-height: 52px; padding: 12px 16px; border-radius: 10px; background: var(--teal); color: #fff; font-size: 14px; font-weight: 650; transition: background .15s, transform .15s; }
.download-button svg { width: 19px; height: 19px; }
.download-button:hover { background: var(--teal-dark); transform: translateY(-1px); }
.mac-button { background: #263c49; }
.mac-button:hover { background: #192d39; }
.store-row { display: flex; align-items: center; gap: 16px; padding: 22px 28px; margin-top: 20px; border: 1px solid var(--line); border-radius: 14px; background: #fff; }
.store-icon { color: #6d807c; width: 40px; height: 40px; display: grid; place-items: center; flex-shrink: 0; }
.store-icon svg { width: 27px; height: 27px; }
.store-copy { flex: 1; }
.section-kicker { margin-bottom: 2px; color: var(--muted); font-size: 10px; font-weight: 550; letter-spacing: 1.1px; }
.store-copy h2 { font-size: 16px; font-weight: 600; }
.store-link { display: inline-flex; justify-content: center; align-items: center; gap: 15px; padding: 10px 16px; border: 1px solid #d4e1dd; border-radius: 8px; color: var(--teal-dark); font-size: 13px; font-weight: 600; }
.store-link:hover { background: #f0f7f4; }
.install-section { margin-top: 38px; }
.section-heading { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; margin-bottom: 15px; }
.section-heading h2 { font-size: 17px; font-weight: 600; }
.section-heading > span { font-size: 12px; color: var(--muted); }
.guide-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); align-items: start; gap: 24px; }
.install-guide { background: #fff; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.install-guide summary { display: flex; align-items: center; justify-content: space-between; gap: 15px; padding: 19px 22px; font-size: 13px; font-weight: 550; list-style: none; cursor: pointer; }
.install-guide summary::-webkit-details-marker { display: none; }
.install-guide summary:focus-visible { outline-offset: -4px; border-radius: 10px; }
.install-guide summary:hover { background: #f9fcfb; color: var(--teal); }
.expand-icon { width: 18px; height: 18px; position: relative; color: #78928b; flex-shrink: 0; }
.expand-icon::before, .expand-icon::after { content: ""; position: absolute; top: 8px; left: 3px; width: 12px; height: 1.5px; background: currentColor; }
.expand-icon::after { transform: rotate(90deg); transition: transform .15s; }
.install-guide[open] .expand-icon::after { transform: rotate(0); }
.install-guide ol { margin: 0; padding: 0 22px 23px; list-style: none; counter-reset: steps; }
.install-guide li { position: relative; padding: 14px 0 0 34px; counter-increment: steps; font-size: 12px; }
.install-guide li::before { content: counter(steps, decimal-leading-zero); position: absolute; top: 15px; left: 0; color: var(--teal); font-size: 11px; font-weight: 600; }
.install-guide li strong { display: block; font-size: 13px; font-weight: 600; margin-bottom: 3px; }
.install-guide li > span { display: block; color: var(--muted); overflow-wrap: anywhere; }
.download-footer { display: flex; justify-content: space-between; align-items: center; gap: 20px; margin-top: 30px; padding: 24px 0 34px; border-top: 1px solid var(--line); color: var(--muted); font-size: 12px; }
.download-footer a { display: inline-block; margin-left: 8px; color: var(--teal-dark); padding: 4px 0; }
.download-footer a:hover { text-decoration: underline; }
.download-footer > span { letter-spacing: .3px; color: #788883; }
@media (max-width: 740px) {
  .header-inner { min-height: 74px; padding: 14px 22px; }
  .brand { font-size: 15px; }
  .brand img { width: 32px; height: 32px; }
  .site-header nav { gap: 16px; font-size: 12px; }
  .download-main { width: calc(100% - 40px); max-width: 540px; }
  .intro { padding: 40px 0 28px; }
  h1 { font-size: clamp(27px, 5vw, 34px); }
  .platform-grid, .guide-grid { grid-template-columns: 1fr; gap: 16px; }
  .platform-card { padding: 27px; border-radius: 16px; }
  .card-top { margin-bottom: 20px; }
  .store-row { padding: 22px; flex-wrap: wrap; gap: 12px; }
  .store-link { width: 100%; margin-top: 5px; min-height: 45px; }
  .store-copy { flex-basis: calc(100% - 56px); }
  .install-section { margin-top: 28px; }
}
@media (max-width: 420px) {
  .header-inner { padding: 14px 18px; gap: 15px; flex-wrap: wrap; }
  .brand { font-size: 14px; gap: 8px; }
  .site-header nav { gap: 18px; }
  .download-main { width: calc(100% - 32px); }
  .intro { padding-top: 32px; }
  .eyebrow { margin-bottom: 13px; }
  .platform-card { padding: 23px; }
  .platform-specs { font-size: 12px; }
  .platform-specs > div { gap: 8px; }
  .download-footer { flex-wrap: wrap; gap: 8px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}