:root {
  --navy: #173f5f;
  --navy-2: #245b77;
  --teal: #129590;
  --teal-dark: #0b706c;
  --mint: #dff4f1;
  --ink: #15324d;
  --muted: #61798c;
  --line: #d3e1e8;
  --surface: #ffffff;
  --soft: #f2f6f8;
  --amber-bg: #fff3d8;
  --amber: #9d5700;
  --red-bg: #ffe9e7;
  --red: #bf3a31;
  --green-bg: #e5f6ed;
  --green: #16764a;
  --shadow: 0 18px 50px rgb(19 53 79 / 9%);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: #edf2f5;
  font: 16px/1.7 "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  text-rendering: optimizeLegibility;
}
a { color: var(--teal-dark); text-underline-offset: 3px; }
img { display: block; max-width: 100%; height: auto; }
code { padding: .12em .42em; border-radius: .35em; background: #e9f0f4; font-family: Consolas, monospace; }

.skip-link { position: fixed; left: 12px; top: -60px; z-index: 20; padding: 10px 14px; border-radius: 8px; background: #fff; }
.skip-link:focus { top: 12px; }

.hero { color: #fff; background: linear-gradient(128deg, var(--navy) 0 68%, #168b87 100%); }
.hero__inner { width: min(1180px, calc(100% - 40px)); margin: 0 auto; padding: 66px 0 58px; }
.brand { display: inline-flex; gap: .65em; align-items: baseline; color: #fff; font-size: 20px; font-weight: 800; text-decoration: none; }
.brand span { color: #9fe5df; font-size: 15px; }
.eyebrow, .kicker { margin: 0; color: #79d8d1; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.eyebrow { margin-top: 40px; }
.hero h1 { margin: 8px 0 14px; font-size: clamp(40px, 4vw, 58px); line-height: 1.12; letter-spacing: -.035em; white-space: nowrap; }
.hero__summary { max-width: 820px; margin: 0; color: #d6e9f1; font-size: 19px; }
.hero__facts { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 28px; }
.hero__facts span { padding: 7px 13px; border: 1px solid rgb(255 255 255 / 25%); border-radius: 999px; background: rgb(255 255 255 / 8%); font-size: 14px; }

.step-nav { position: sticky; top: 0; z-index: 10; border-bottom: 1px solid var(--line); background: rgb(255 255 255 / 94%); backdrop-filter: blur(12px); }
.step-nav__inner { display: flex; gap: 4px; width: min(1180px, calc(100% - 24px)); margin: 0 auto; padding: 9px 0; overflow-x: auto; scrollbar-width: thin; }
.step-nav a { flex: 0 0 auto; padding: 8px 11px; border-radius: 8px; color: var(--ink); font-size: 14px; font-weight: 700; text-decoration: none; }
.step-nav a:hover, .step-nav a:focus-visible { color: #fff; background: var(--teal-dark); }

.page-shell { width: min(1180px, calc(100% - 40px)); margin: 34px auto 70px; }
.section { scroll-margin-top: 78px; margin-top: 24px; padding: clamp(24px, 4vw, 46px); border: 1px solid var(--line); border-radius: 22px; background: var(--surface); box-shadow: var(--shadow); }
.section-heading { display: flex; gap: 16px; align-items: center; margin-bottom: 26px; }
.section-number { display: grid; flex: 0 0 52px; width: 52px; height: 52px; place-items: center; border-radius: 50%; color: #fff; background: var(--teal); font-size: 21px; font-weight: 800; }
.section-heading h2 { margin: 2px 0 0; font-size: clamp(27px, 3.5vw, 38px); line-height: 1.25; }
.kicker { color: var(--teal-dark); font-size: 13px; }
h3 { margin: 0 0 5px; font-size: 19px; }
p { margin: 0; }

.permission-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.permission-card { padding: 20px; border: 1px solid var(--line); border-radius: 15px; background: var(--soft); }
.permission-card > span { display: grid; width: 32px; height: 32px; margin-bottom: 12px; place-items: center; border-radius: 50%; color: #fff; background: var(--teal); font-weight: 800; }
.permission-card p, .mini-note p, .plain-steps, .timeline p, figcaption, .sources p { color: var(--muted); }

.instruction-grid { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(250px, .8fr); gap: 18px; align-items: start; }
.instruction-grid > div > h3:not(:first-child) { margin-top: 20px; }
.plain-steps { margin: 0; padding-left: 24px; }
.plain-steps li { padding: 5px 0 5px 5px; }
.plain-steps li::marker { color: var(--teal-dark); font-weight: 800; }
.mini-note { padding: 18px; border: 1px solid #badfdc; border-radius: 14px; background: var(--mint); }
.mini-note--amber { border-color: #f0c66b; background: var(--amber-bg); }
.mini-note--amber strong, .mini-note--amber p { color: var(--amber); }

.guide-image { margin: 24px 0 0; overflow: hidden; border: 1px solid var(--line); border-radius: 16px; background: #f8fafb; }
.guide-image img { width: 100%; }
.guide-image--wide img { aspect-ratio: 1320 / 802; object-fit: contain; }
.guide-image--portrait { max-width: 790px; }
.guide-image--portrait img { object-fit: contain; }
figcaption { padding: 11px 15px; border-top: 1px solid var(--line); background: #fff; font-size: 13px; }
.image-pair { display: grid; grid-template-columns: .9fr 1.1fr; gap: 16px; align-items: start; }
.image-pair--balanced { grid-template-columns: 1fr 1fr; }

.callout { display: grid; grid-template-columns: minmax(110px, .22fr) 1fr; gap: 18px; margin-top: 22px; padding: 18px 20px; border: 1px solid #edc56e; border-radius: 14px; background: var(--amber-bg); }
.callout strong, .callout p { color: var(--amber); }
.callout--danger { border-color: #ffaaa4; background: var(--red-bg); }
.callout--danger strong, .callout--danger p { color: var(--red); }
.callout--safe { border-color: #a6dcc0; background: var(--green-bg); }
.callout--safe strong, .callout--safe p { color: var(--green); }

.support-card { display: grid; grid-template-columns: 1fr auto; gap: 28px; align-items: center; margin-top: 22px; padding: 24px; border: 1px solid #8fd1ca; border-radius: 16px; background: var(--mint); }
.support-card__copy > span { display: inline-block; margin-bottom: 9px; padding: 4px 10px; border-radius: 999px; color: #fff; background: var(--teal); font-size: 13px; font-weight: 800; }
.support-card h3 { margin-bottom: 8px; font-size: 24px; }
.support-card__copy > p { color: var(--muted); }
.support-card__safety { margin-top: 12px; }
.support-card__qr { text-align: center; }
.support-card__qr img { width: 150px; margin: 0 auto 8px; border: 1px solid #8fd1ca; border-radius: 10px; background: #fff; }
.support-card__qr strong { display: block; color: var(--teal-dark); font-size: 13px; line-height: 1.45; }

.timeline { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 0; padding: 0; list-style: none; }
.timeline li { display: flex; gap: 12px; padding: 18px; border: 1px solid var(--line); border-radius: 14px; background: var(--soft); }
.timeline li > span { display: grid; flex: 0 0 34px; width: 34px; height: 34px; place-items: center; border-radius: 50%; color: #fff; background: var(--teal); font-weight: 800; }
.timeline strong { display: block; margin: 2px 0 5px; }

.plain-steps--cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; padding: 0; list-style: none; counter-reset: local-step; }
.plain-steps--cards li { position: relative; min-height: 90px; padding: 18px 18px 18px 58px; border: 1px solid var(--line); border-radius: 14px; background: var(--soft); counter-increment: local-step; }
.plain-steps--cards li::before { content: counter(local-step); position: absolute; left: 17px; top: 17px; display: grid; width: 28px; height: 28px; place-items: center; border-radius: 50%; color: #fff; background: var(--teal); font-weight: 800; }

.finish { color: #fff; background: var(--navy); }
.finish .kicker { color: #83ddd6; }
.finish-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.finish-grid > div { padding: 20px; border: 1px solid rgb(255 255 255 / 20%); border-radius: 14px; background: rgb(255 255 255 / 8%); }
.finish-grid strong { color: #8ce0da; font-size: 22px; }
.finish-grid p { margin-top: 8px; color: #dceaf1; }
.troubleshooting { margin-top: 20px; padding: 18px 20px; border-radius: 14px; color: var(--ink); background: #fff; }
.troubleshooting summary { cursor: pointer; font-weight: 800; }
.troubleshooting ul { margin-bottom: 0; }
.sources { box-shadow: none; }
.sources h2 { margin-top: 0; }
.sources ul { margin-bottom: 0; }

.site-footer { display: flex; justify-content: space-between; gap: 20px; padding: 25px max(24px, calc((100% - 1180px) / 2)); color: #cfe0e8; background: #102f49; }
.site-footer div { display: flex; gap: 12px; }
.site-footer p { color: #9db4c3; }

.copy-protected-guide { -webkit-user-select: none; user-select: none; }
.copy-protected-guide img { -webkit-user-drag: none; }

@media (max-width: 850px) {
  .hero h1 { white-space: normal; }
  .permission-grid, .timeline, .finish-grid { grid-template-columns: 1fr; }
  .instruction-grid, .image-pair, .image-pair--balanced { grid-template-columns: 1fr; }
  .guide-image--portrait { max-width: none; }
}

@media (max-width: 620px) {
  body { font-size: 15px; }
  .hero__inner, .page-shell { width: min(100% - 22px, 1180px); }
  .hero__inner { padding: 38px 0 34px; }
  .eyebrow { margin-top: 28px; }
  .brand { display: block; }
  .brand span { display: block; margin-top: 2px; }
  .hero h1 { font-size: 40px; }
  .hero__summary { font-size: 16px; }
  .section { padding: 22px 17px; border-radius: 16px; }
  .section-heading { align-items: flex-start; }
  .section-number { flex-basis: 42px; width: 42px; height: 42px; font-size: 18px; }
  .plain-steps--cards { grid-template-columns: 1fr; }
  .callout { grid-template-columns: 1fr; gap: 4px; }
  .support-card { grid-template-columns: 1fr; }
  .support-card__qr { display: flex; gap: 14px; align-items: center; text-align: left; }
  .support-card__qr img { width: 116px; margin: 0; }
  .site-footer { display: block; }
  .site-footer p { margin-top: 8px; }
}

@media print {
  body { background: #fff; }
  .step-nav, .skip-link { display: none; }
  .hero { color: #000; background: #fff; }
  .hero__inner { padding: 20px 0; }
  .brand, .hero h1 { color: #173f5f; }
  .hero__summary, .hero__facts span { color: #334; }
  .page-shell { width: 100%; margin: 0; }
  .section { break-inside: avoid; box-shadow: none; }
  .finish { color: #173f5f; background: #fff; }
  .finish-grid p { color: #334; }
}