:root {
  --canvas: #eef5ff;
  --paper: #fff;
  --ink: #0d2144;
  --muted: #50627d;
  --line: #c9d9ec;
  --blue: #075ee8;
  --violet: #6438dc;
  --mint: #138564;
  --amber: #8a5a00;
  --shadow: 0 18px 48px rgba(27, 69, 125, .12);
  color-scheme: light;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  color: var(--ink);
  background: linear-gradient(180deg, #f8fbff 0, var(--canvas) 44%, #f7fbff 100%);
  font-family: "HarmonyOS Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
:focus-visible { outline: 3px solid #ffad0a; outline-offset: 3px; }
.skip-link { position: fixed; z-index: 50; top: 12px; left: 12px; padding: 10px 14px; color: #fff; background: #083d92; transform: translateY(-180%); }
.skip-link:focus { transform: none; }

.guide-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1120px, calc(100% - 40px));
  min-height: 68px;
  margin: 0 auto;
  border-bottom: 1px solid rgba(132, 164, 201, .35);
}

.brand { min-height: 44px; display: inline-flex; align-items: center; color: #114eae; font-size: 20px; font-weight: 820; }
.brand i { color: var(--violet); }
.guide-header nav { display: flex; gap: 24px; }
.guide-header nav a { min-height: 44px; display: inline-flex; align-items: center; color: #244b7d; font-size: 15px; font-weight: 680; }
.guide-header nav a:hover { color: var(--blue); }

main { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }
.guide-intro { padding: 74px 0 58px; border-bottom: 1px solid var(--line); }
.eyebrow, .section-heading > p { margin: 0 0 8px; color: var(--violet); font-size: 14px; font-weight: 850; letter-spacing: .1em; }
.guide-intro h1 { max-width: 820px; margin: 0; color: #103b78; font-size: clamp(36px, 5vw, 60px); line-height: 1.12; letter-spacing: -.035em; text-wrap: balance; }
.lead { max-width: 780px; margin: 22px 0 0; color: var(--muted); font-size: 20px; line-height: 1.7; }
.intro-actions { display: flex; align-items: center; gap: 22px; margin-top: 30px; }
.primary-action { min-height: 52px; display: inline-flex; align-items: center; justify-content: center; padding: 10px 20px; border-radius: 11px; color: #fff; background: var(--blue); font-weight: 780; box-shadow: 0 12px 25px rgba(7, 94, 232, .2); }
.primary-action:hover { background: #054ab9; }
.text-action { min-height: 44px; display: inline-flex; align-items: center; color: #254f85; font-weight: 700; }
.prepare { display: flex; flex-wrap: wrap; gap: 10px 24px; margin-top: 34px; padding: 17px 0 0; border-top: 1px dashed #b6cae2; color: var(--muted); font-size: 15px; }
.prepare strong { color: #1b4478; }
.prepare span::before { content: "✓"; margin-right: 7px; color: var(--mint); font-weight: 900; }

.steps { padding: 72px 0 30px; }
.section-heading h2 { margin: 0; color: #123c75; font-size: 34px; line-height: 1.25; }
.step-rail { margin: 38px 0 0; padding: 0; list-style: none; }
.step-rail > li {
  position: relative;
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr) 250px;
  gap: 30px;
  padding: 0 0 48px;
}
.step-rail > li:not(:last-child)::before { content: ""; position: absolute; left: 35px; top: 58px; bottom: 8px; width: 2px; background: linear-gradient(#8eb4ec, #d7e4f3); }
.step-number { position: relative; z-index: 1; display: grid; place-items: center; width: 72px; height: 54px; border: 1px solid #9dbce4; border-radius: 14px; color: #fff; background: linear-gradient(135deg, #0a59d0, #6842dc); font-size: 18px; font-weight: 850; box-shadow: 0 10px 22px rgba(31, 88, 170, .18); }
.step-copy { min-width: 0; padding: 1px 0 0; }
.step-place { margin: 0 0 4px; color: var(--blue); font-size: 13px; font-weight: 820; letter-spacing: .07em; }
.step-copy h3 { margin: 0; color: #102f60; font-size: 23px; line-height: 1.35; }
.step-copy > p:not(.step-place) { margin: 10px 0 0; color: var(--muted); }
.step-copy > a, .step-links a { min-height: 44px; display: inline-flex; align-items: center; margin-top: 12px; color: #064fbf; font-weight: 760; text-decoration: underline; text-underline-offset: 4px; }
.step-links { display: flex; flex-wrap: wrap; gap: 8px 24px; }
.safety-note { padding: 11px 14px; border-left: 3px solid #e3a11a; color: #60471b !important; background: #fff8e7; }
.step-check { align-self: start; margin: 0; padding: 16px 18px; border: 1px solid #c9dfd5; border-radius: 12px; color: #315c50; background: #f1fbf7; font-size: 15px; }
.step-check strong { display: block; color: #176b51; font-size: 13px; letter-spacing: .05em; }
.step-check.is-finish { border-color: #adcaeb; color: #254f7d; background: #f1f7ff; }
.step-check.is-finish strong { color: #0753bc; }
code { padding: 2px 5px; border-radius: 5px; color: #4c2db4; background: #f0ebff; font: 700 .9em/1.5 ui-monospace, "Cascadia Code", Consolas, monospace; overflow-wrap: anywhere; }
.settings-path { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-top: 16px; }
.settings-path span { padding: 6px 10px; border: 1px solid #b9cde6; border-radius: 8px; color: #183e70; background: #fff; font-weight: 720; }
.settings-path b { color: #7b8ea7; }
blockquote { margin: 16px 0 0; padding: 15px 18px; border-left: 4px solid var(--violet); color: #263c66; background: #f3f0ff; font-size: 18px; font-weight: 750; }

.troubleshooting { margin: 34px 0 0; padding: 42px; border-radius: 18px; background: #102b54; box-shadow: var(--shadow); }
.troubleshooting .section-heading > p { color: #9ebcff; }
.troubleshooting .section-heading h2 { color: #fff; }
.troubleshooting dl { margin: 30px 0 0; border-top: 1px solid rgba(210, 228, 255, .22); }
.troubleshooting dl > div { display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 28px; padding: 20px 0; border-bottom: 1px solid rgba(210, 228, 255, .18); }
.troubleshooting dt { color: #fff; font-size: 17px; font-weight: 780; }
.troubleshooting dd { margin: 0; color: #d3e1f4; }
.leak-warning { margin: 24px 0 0; padding: 15px 17px; border-radius: 10px; color: #1f3d34; background: #dff5ec; }

.next-step { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 28px; align-items: center; margin: 56px 0; padding: 30px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.next-step p { margin: 0; color: var(--violet); font-size: 14px; font-weight: 850; }
.next-step h2 { margin: 3px 0 0; color: #123c75; font-size: 28px; }
.next-step span { color: var(--muted); }
.next-step > a { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; gap: 9px; padding: 10px 18px; border-radius: 10px; color: #fff; background: var(--violet); font-weight: 760; white-space: nowrap; }
.next-step > a span { color: inherit; }
.publisher-note { margin: 0 0 62px; padding-left: 18px; border-left: 3px solid #9ab4d4; color: var(--muted); font-size: 15px; }

footer { display: flex; align-items: center; gap: 24px; min-height: 74px; padding: 0 max(20px, calc((100vw - 1120px) / 2)); color: #60718a; background: #e6f0fb; font-size: 14px; }
footer a { min-height: 44px; display: inline-flex; align-items: center; }
footer a:first-child { color: var(--violet); font-weight: 800; }
footer span { margin-left: auto; }

@media (max-width: 820px) {
  .step-rail > li { grid-template-columns: 64px minmax(0, 1fr); gap: 20px; }
  .step-number { width: 62px; }
  .step-rail > li:not(:last-child)::before { left: 30px; }
  .step-check { grid-column: 2; }
  .troubleshooting dl > div { grid-template-columns: 1fr; gap: 5px; }
}

@media (max-width: 600px) {
  body { font-size: 16px; }
  .guide-header { width: calc(100% - 32px); min-height: 62px; }
  .guide-header nav a:first-child { display: none; }
  .brand { font-size: 18px; }
  main { width: calc(100% - 32px); }
  .guide-intro { padding: 48px 0 42px; }
  .guide-intro h1 { font-size: 37px; }
  .lead { margin-top: 16px; font-size: 18px; }
  .intro-actions { align-items: stretch; flex-direction: column; gap: 8px; }
  .text-action { justify-content: center; }
  .prepare { display: grid; gap: 7px; }
  .steps { padding-top: 50px; }
  .section-heading h2 { font-size: 28px; }
  .step-rail { margin-top: 30px; }
  .step-rail > li { grid-template-columns: 48px minmax(0, 1fr); gap: 14px; padding-bottom: 42px; }
  .step-number { width: 46px; height: 44px; border-radius: 11px; font-size: 15px; }
  .step-rail > li:not(:last-child)::before { left: 22px; top: 48px; }
  .step-copy h3 { font-size: 21px; }
  .step-check { grid-column: 1 / -1; }
  .settings-path { gap: 6px; }
  .settings-path span { padding: 5px 8px; font-size: 14px; }
  .troubleshooting { padding: 28px 22px; }
  .next-step { grid-template-columns: 1fr; }
  .next-step > a { width: 100%; }
  footer { flex-wrap: wrap; gap: 2px 18px; padding: 16px; }
  footer span { width: 100%; margin-left: 0; }
}

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