:root {
  color-scheme: light;
  --paper: #f7f6f2;
  --ink: #242a29;
  --muted: #666b66;
  --line: #dedfd7;
  --accent: #be3e25;
  --track: #df4c31;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 28px; }
body { margin: 0; }
a { color: inherit; text-decoration: none; }
button, a, summary { -webkit-tap-highlight-color: transparent; }
a:focus-visible, summary:focus-visible { outline: 3px solid var(--accent); outline-offset: 6px; }
::selection { background: #f3c4ad; color: var(--ink); }
.container { width: min(1180px, calc(100% - 96px)); margin-inline: auto; }
.skip-link { position: fixed; top: -100px; left: 24px; z-index: 10; padding: 14px 24px; background: var(--ink); color: white; }
.skip-link:focus { top: 16px; }
.site-header { min-height: 104px; display: flex; align-items: center; justify-content: space-between; gap: 24px; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 11px; font-size: 17px; font-weight: 650; letter-spacing: .025em; }
.brand img { flex-shrink: 0; }
.brand small { display: block; margin-top: 5px; font-size: 8px; font-weight: 500; letter-spacing: .16em; color: var(--muted); }
nav { display: flex; align-items: center; gap: 34px; font-size: 13px; }
nav a { padding-block: 12px; }
nav a:hover, .text-link:hover, .back-link:hover, .site-footer a:hover { color: var(--accent); }
.nav-action { display: flex; gap: 20px; align-items: center; }
.nav-action span { font-size: 20px; }
.hero { display: grid; grid-template-columns: 1fr 1fr; gap: 58px; padding-block: 64px 76px; align-items: center; }
.eyebrow { display: flex; align-items: center; gap: 10px; font-size: 11px; font-weight: 600; letter-spacing: .12em; margin: 0 0 24px; }
.tiny-line { display: inline-block; height: 2px; width: 24px; background: var(--accent); }
h1, h2, h3, p { margin-top: 0; }
h1 { font-size: clamp(38px, 4.5vw, 61px); font-weight: 650; line-height: 1.3; letter-spacing: -.045em; margin-bottom: 24px; }
h1 > span { color: var(--accent); }
.hero-description { font-size: 15px; line-height: 1.95; color: var(--muted); margin-bottom: 30px; }
.hero-actions { display: flex; gap: 28px; align-items: center; flex-wrap: wrap; }
.button { min-height: 50px; display: inline-flex; align-items: center; justify-content: space-between; gap: 30px; padding: 14px 22px; border-radius: 5px; font-size: 14px; font-weight: 550; transition: background .18s, transform .18s; }
.button span { font-size: 20px; line-height: 1; }
.button:hover { transform: translateY(-2px); }
.button-primary { background: var(--accent); color: #fffaf2; }
.button-primary:hover { background: #a3321d; }
.button-dark { background: var(--ink); color: #fffaf2; }
.button-dark:hover { background: #414944; }
.text-link { display: inline-flex; gap: 16px; align-items: center; font-size: 13px; padding-block: 14px; }
.hero-note { display: flex; gap: 8px; align-items: center; font-size: 11px; color: var(--muted); margin: 24px 0 0; }
.note-dot { width: 5px; height: 5px; background: #758473; border-radius: 50%; }
.track-art { height: 508px; position: relative; overflow: hidden; background: var(--track); color: #fff4de; border-radius: 5px; }
.art-heading { position: absolute; inset: 26px 27px auto; display: flex; justify-content: space-between; font: 10px ui-monospace, "SFMono-Regular", Consolas, monospace; letter-spacing: .09em; z-index: 2; }
.track-lines { position: absolute; width: 590px; height: 790px; top: 68px; left: 35px; transform: rotate(-25deg); }
.lane { position: absolute; border: 2px solid #f9cdb1; border-radius: 260px 260px 0 0; border-bottom: 0; }
.lane-one { inset: 0; }
.lane-two { inset: 42px 42px 0; }
.lane-three { inset: 84px 84px 0; }
.lane-four { inset: 126px 126px 0; }
.lane-five { inset: 168px 168px 0; background: #c4432e; }
.start-line { position: absolute; left: -40px; top: 343px; width: 300px; height: 12px; background: #fff4de; transform: rotate(-25deg); }
.lane-numbers { position: absolute; top: 339px; left: 42px; display: flex; gap: 25px; transform: rotate(-25deg); font-size: 24px; font-weight: 600; }
.start-marker { position: absolute; right: 30px; top: 185px; display: flex; align-items: center; gap: 9px; font: 10px ui-monospace, monospace; letter-spacing: .06em; }
.start-marker span { display: block; width: 8px; height: 8px; background: #fff4de; border-radius: 50%; box-shadow: 0 0 0 6px #fff4de25; }
.art-caption { position: absolute; inset: auto 27px 25px; display: flex; align-items: center; justify-content: space-between; font-size: 11px; letter-spacing: .08em; }
.art-caption > span:last-child { font-size: 30px; }
.feature-section { border-top: 1px solid var(--line); padding-block: 43px 58px; }
.section-heading .eyebrow { color: var(--muted); margin-bottom: 12px; }
h2 { font-size: 27px; font-weight: 600; letter-spacing: -.03em; line-height: 1.4; margin-bottom: 0; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 38px; margin-top: 36px; }
.feature + .feature { border-left: 1px solid var(--line); padding-left: 38px; }
.feature-index { font: 10px ui-monospace, "SFMono-Regular", Consolas, monospace; letter-spacing: .1em; color: var(--accent); }
.feature h3 { font-size: 19px; font-weight: 600; margin: 18px 0 12px; }
.feature p { font-size: 13px; line-height: 1.9; color: var(--muted); margin-bottom: 0; max-width: 290px; }
.firmware-banner { background: #eceee6; border: 1px solid #e1e4d9; border-radius: 5px; padding: 34px; display: flex; align-items: center; gap: 28px; margin-bottom: 60px; }
.firmware-symbol { width: 64px; height: 64px; border: 1px solid #bbc4b4; border-radius: 50%; display: grid; place-items: center; font-size: 36px; color: #65745e; flex-shrink: 0; }
.banner-copy { flex: 1; }
.banner-copy .eyebrow { color: #53624b; font-size: 10px; margin-bottom: 10px; }
.banner-copy h2 { font-size: 23px; }
.banner-copy p:last-child { font-size: 12px; line-height: 1.8; color: var(--muted); margin: 10px 0 0; }
.firmware-banner .button { white-space: nowrap; }
.site-footer { border-top: 1px solid var(--line); padding-block: 25px 32px; display: flex; justify-content: space-between; gap: 24px; font-size: 11px; line-height: 1.8; color: var(--muted); }
.footer-dot { margin-inline: 12px; color: #a6aaa0; }
.site-footer a { white-space: nowrap; }
.firmware-main { padding-top: 29px; }
.back-link { font-size: 12px; color: var(--muted); }
.firmware-intro { margin-top: 42px; margin-bottom: 36px; }
.firmware-intro h1 { font-size: clamp(34px, 4vw, 48px); line-height: 1.4; margin-bottom: 17px; }
.firmware-intro > p:last-child { font-size: 15px; line-height: 1.8; color: var(--muted); }
.flasher-panel { display: grid; grid-template-columns: .85fr 1.15fr; border: 1px solid var(--line); border-radius: 6px; overflow: hidden; }
.flasher-primary { padding: 38px; background: #edece5; display: flex; align-items: flex-start; flex-direction: column; }
.desk-badge { font-size: 11px; color: #59634f; background: #dfe4d4; border-radius: 4px; padding: 7px 10px; margin-bottom: 32px; }
.flasher-primary h2 { font-size: 34px; letter-spacing: -.035em; }
.flasher-primary > p { font-size: 14px; line-height: 1.9; color: var(--muted); margin-block: 15px 27px; }
.flasher-primary .button { margin-top: auto; }
.flasher-primary .local-address { font-size: 11px; margin: 15px 0 0; line-height: 1.8; }
code { font-family: ui-monospace, "SFMono-Regular", Consolas, monospace; font-size: .9em; overflow-wrap: anywhere; }
.flasher-instructions { padding: 38px; }
.flasher-instructions .eyebrow { color: var(--muted); }
.steps { list-style: none; margin: 0; padding: 0; }
.steps li { display: flex; gap: 20px; }
.steps li + li { margin-top: 26px; }
.step-number { padding-top: 3px; color: var(--accent); font: 14px ui-monospace, monospace; }
.steps h3 { font-size: 15px; font-weight: 600; margin-bottom: 8px; }
.steps p { font-size: 12px; color: var(--muted); line-height: 1.9; margin-bottom: 0; }
.usage-note { display: flex; align-items: flex-start; gap: 14px; padding: 22px 0; }
.usage-note > span { color: var(--accent); font-size: 20px; }
.usage-note p { color: var(--muted); font-size: 12px; line-height: 1.9; margin-bottom: 0; }
.faq-section { margin: 44px 0 65px; display: grid; grid-template-columns: .85fr 1.15fr; gap: 38px; }
.faq-section h2 { font-size: 23px; max-width: 260px; }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list details:first-child { border-top: 1px solid var(--line); }
.faq-list summary { cursor: pointer; padding: 20px 0; font-size: 14px; list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary span { color: var(--accent); font-size: 21px; transition: transform .18s; }
.faq-list details[open] summary span { transform: rotate(45deg); }
.faq-list details p { font-size: 12px; line-height: 1.9; color: var(--muted); padding-right: 24px; margin-bottom: 20px; }
@media (min-width: 1500px) { .hero { padding-block: 80px 88px; } }
@media (max-width: 1050px) {
  .container { width: calc(100% - 64px); }
  .hero { gap: 32px; }
  .track-art { height: 472px; }
  .desktop-break { display: none; }
  .hero-actions { gap: 14px; }
  .firmware-symbol { display: none; }
  .flasher-primary, .flasher-instructions { padding: 28px; }
}
@media (max-width: 760px) {
  .container { width: calc(100% - 40px); }
  .site-header { min-height: 86px; gap: 12px; }
  .brand { font-size: 14px; gap: 8px; }
  .brand img { width: 32px; height: 32px; }
  .brand small { font-size: 6px; }
  .nav-overview { display: none; }
  .nav-action { gap: 8px; font-size: 12px; }
  .hero { grid-template-columns: 1fr; padding-block: 42px; gap: 34px; }
  h1 { font-size: clamp(38px, 8.5vw, 56px); }
  .hero-description { font-size: 14px; }
  .hero-actions { gap: 24px; }
  .track-art { height: 360px; }
  .track-lines { top: 46px; left: 50px; }
  .start-line { top: 261px; }
  .lane-numbers { top: 257px; }
  .start-marker { top: 133px; }
  .feature-section { padding-block: 32px 38px; }
  h2 { font-size: 24px; }
  .feature-grid { grid-template-columns: 1fr; gap: 25px; margin-top: 27px; }
  .feature + .feature { padding-left: 0; padding-top: 25px; border-left: 0; border-top: 1px solid var(--line); }
  .feature h3 { margin-top: 12px; }
  .feature p { max-width: none; }
  .firmware-banner { padding: 26px; flex-direction: column; align-items: flex-start; gap: 22px; margin-bottom: 38px; }
  .banner-copy h2 { font-size: 22px; }
  .site-footer { flex-wrap: wrap; gap: 12px; padding-block: 22px; }
  .footer-dot { margin-inline: 5px; }
  .firmware-intro { margin-top: 33px; }
  .firmware-intro h1 { font-size: clamp(30px, 7vw, 42px); }
  .flasher-panel, .faq-section { grid-template-columns: 1fr; }
  .flasher-primary, .flasher-instructions { padding: 26px; }
  .flasher-primary h2 { font-size: 32px; }
  .desk-badge { margin-bottom: 24px; }
  .flasher-primary .button { width: 100%; gap: 14px; }
  .faq-section { margin-block: 26px 42px; gap: 24px; }
  .faq-section h2 { max-width: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}