:root {
  color-scheme: light;
  --ink: #172233;
  --muted: #68768a;
  --blue: #2368f4;
  --blue-deep: #1550ce;
  --line: #dfe8f1;
  --paper: #f7fbff;
  font-family: "Microsoft YaHei UI", "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { min-width: 320px; margin: 0; color: var(--ink); background: var(--paper); }
a { color: inherit; text-decoration: none; }
.shell { width: min(1120px, calc(100% - 48px)); margin-inline: auto; }
:focus-visible { outline: 3px solid #88b4ff; outline-offset: 3px; }
.skip-link { position: absolute; z-index: 20; top: -80px; left: 16px; padding: 10px 14px; border-radius: 8px; color: #fff; background: var(--blue-deep); }
.skip-link:focus { top: 12px; }

.site-header { height: 76px; border-bottom: 1px solid #e4edf5; background: #fff; }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; height: 100%; }
.brand { display: inline-flex; align-items: center; gap: 11px; flex: none; font-size: 20px; font-weight: 780; letter-spacing: -.04em; white-space: nowrap; }
.brand-mark { display: block; width: 36px; height: 36px; flex: none; border-radius: 11px; object-fit: cover; box-shadow: 0 5px 13px #2368f42e; }
.brand-accent { color: var(--blue); }
.site-header nav { display: flex; gap: 28px; color: #64758a; font-size: 14px; font-weight: 650; }
.site-header nav a:hover, .site-header nav a:focus-visible { color: var(--blue-deep); }

.hero { position: relative; overflow: hidden; padding: 48px 0 52px; border-bottom: 1px solid #dceaf7; background: linear-gradient(121deg, #f8fcff 10%, #eaf4ff 70%, #f7fcff); }
.hero::before { position: absolute; inset: 0; content: ""; opacity: .52; pointer-events: none; background-image: linear-gradient(#4c89be13 1px, transparent 1px), linear-gradient(90deg, #4c89be13 1px, transparent 1px); background-size: 64px 64px; }
.hero .shell { position: relative; }
.back-link { display: inline-block; margin-bottom: 27px; color: #56718e; font-size: 14px; font-weight: 650; }
.back-link:hover { color: var(--blue-deep); }
.eyebrow { margin: 0 0 16px; color: #2766ad; font-size: 12px; font-weight: 760; letter-spacing: .08em; }
.eyebrow span { margin-inline: 5px; color: #61a4e9; }
h1 { margin: 0; color: #183d6e; font-size: clamp(34px, 4.2vw, 50px); line-height: 1.18; font-weight: 800; letter-spacing: -.055em; }
.hero-description { max-width: 700px; margin: 18px 0 0; color: #64778b; font-size: 16px; line-height: 1.75; }
.download-tool { display: inline-flex; align-items: center; justify-content: center; margin-top: 22px; padding: 12px 22px; border-radius: 9px; color: #fff; background: linear-gradient(135deg, #2368f4, #1550ce); box-shadow: 0 8px 18px #2368f43d; font-size: 16px; font-weight: 800; transition: transform .2s ease, box-shadow .2s ease; }
.download-tool:hover, .download-tool:focus-visible { transform: translateY(-2px); box-shadow: 0 11px 22px #2368f452; }

.content-wrap { padding-top: 36px; padding-bottom: 88px; }
.guide { padding: 30px 34px 38px; border: 1px solid var(--line); border-radius: 16px; color: #53677d; background: #fff; box-shadow: 0 9px 28px #31567a0b; font-size: 14px; line-height: 1.8; }
.requirement { margin: 0 0 28px; padding: 15px 19px; border: 1px solid #f2ad87; border-left: 5px solid #df4a21; border-radius: 10px; color: #9a3412; background: #fff3ed; font-size: 20px; font-weight: 800; line-height: 1.5; }
.precheck { margin-bottom: 32px; padding: 22px 22px 26px; border: 1px solid #d8e6f3; border-radius: 12px; background: #f8fbff; }
.precheck h2 { margin: 0 0 15px; color: #294d72; font-size: 18px; font-weight: 800; line-height: 1.5; }
.precheck-item + .precheck-item { margin-top: 22px; padding-top: 20px; border-top: 1px solid #e5eef7; }
.precheck p { display: flex; align-items: flex-start; gap: 9px; margin: 0; color: #53677d; }
.precheck-number { display: grid; flex: none; width: 23px; height: 23px; place-items: center; border-radius: 50%; color: var(--blue-deep); background: #e7f1ff; font: 700 12px/1 system-ui, sans-serif; }
.source a { color: var(--blue-deep); font-weight: 700; text-decoration: underline; text-underline-offset: 3px; }
.source a:hover { color: #103da1; }
.steps { margin: 0; padding: 0; list-style: none; }
.steps li + li { margin-top: 30px; padding-top: 26px; border-top: 1px solid #edf1f6; }
.steps h2 { display: flex; align-items: center; gap: 11px; margin: 0 0 9px; color: #294d72; font-size: 16px; font-weight: 750; line-height: 1.5; }
.step-number { display: grid; flex: none; width: 27px; height: 27px; place-items: center; border-radius: 50%; color: var(--blue-deep); background: #edf5ff; font: 700 12px/1 system-ui, sans-serif; }
.steps p { margin: 0; color: #64758a; }
.steps kbd { padding: 2px 6px; border: 1px solid #e2eaf2; border-radius: 5px; color: #31506e; background: #f5f8fc; font-family: Consolas, "Microsoft YaHei UI", monospace; font-size: .92em; }
figure { width: fit-content; max-width: 100%; margin: 18px auto 0; }
figure img { display: block; max-width: 100%; height: auto; margin-inline: auto; border: 1px solid var(--line); border-radius: 10px; background: #f7f9fc; }
figcaption { margin-top: 7px; color: #8a9bad; font-size: 12px; text-align: center; }
.steps .source { margin-top: 12px; }

.site-footer { border-top: 1px solid #e2eaf3; background: #fff; }
.footer-inner { display: flex; align-items: center; gap: 22px; min-height: 98px; color: #8a9bad; font-size: 12px; }
.footer-inner span:first-child { flex: none; color: #526a83; font-weight: 750; }
.footer-inner span:nth-child(2) { margin-right: auto; }
.footer-inner a { flex: none; color: #5577a6; font-weight: 680; }
.footer-inner a:hover { color: var(--blue-deep); }

@media (max-width: 680px) {
  .shell { width: min(100% - 32px, 1120px); }
  .site-header { height: 64px; }
  .brand { font-size: 18px; }
  .brand-mark { width: 32px; height: 32px; }
  .site-header nav { gap: 12px; font-size: 12px; }
  .site-header nav [aria-current] { display: none; }
  .hero { padding: 36px 0 38px; }
  .back-link { margin-bottom: 22px; font-size: 13px; }
  h1 { font-size: 34px; }
  .hero-description { margin-top: 14px; font-size: 14px; }
  .download-tool { margin-top: 17px; padding: 11px 18px; font-size: 15px; }
  .content-wrap { padding-top: 24px; padding-bottom: 60px; }
  .guide { padding: 22px 17px 26px; font-size: 13px; }
  .requirement { padding: 13px 15px; font-size: 17px; }
  .precheck { padding: 18px 15px 21px; }
  .steps h2 { font-size: 15px; }
  .footer-inner { flex-wrap: wrap; align-content: center; gap: 6px 15px; padding-block: 22px; }
  .footer-inner span:nth-child(2) { flex-basis: 100%; order: 2; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}