:root { color-scheme: light; --ink: #182230; --muted: #667085; --paper: #f4f6f8; --panel: #fff; --line: #dfe4ea; --blue: #1769aa; --blue-soft: #edf6fc; --dark: #172b3b; }
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: Inter, "Segoe UI", "Microsoft YaHei", sans-serif; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
h1, h2, h3, p { margin-top: 0; }
.tutorial-shell { min-height: 100vh; }
.tutorial-main, .site-footer { width: min(1180px, calc(100% - 32px)); margin-right: auto; margin-left: auto; }
.tutorial-main { margin-top: 20px; margin-bottom: 72px; }
.eyebrow { margin: 0 0 14px; color: var(--blue); font-size: 11px; font-weight: 800; letter-spacing: .12em; }
.tutorial-hero { display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 42px; align-items: stretch; margin-bottom: 18px; padding: 44px; border: 1px solid var(--line); border-radius: 6px; background: var(--panel); }
.hero-copy { align-self: center; }
.hero-copy h1 { max-width: 760px; margin-bottom: 18px; font-size: 44px; line-height: 1.12; letter-spacing: 0; }
.hero-copy > p:not(.eyebrow) { max-width: 680px; margin-bottom: 0; color: var(--muted); font-size: 16px; line-height: 1.75; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 28px; }
.hero-actions a { display: inline-flex; min-height: 42px; align-items: center; justify-content: center; padding: 0 17px; border-radius: 5px; font-size: 14px; font-weight: 700; transition: transform 160ms ease, box-shadow 160ms ease; }
.hero-actions a:hover { transform: translateY(-2px); }
.primary-action { color: #fff; background: var(--blue); }
.secondary-action { border: 1px solid var(--line); background: #fff; }
.route-card { padding: 24px; border: 1px solid #314a5e; border-radius: 6px; color: #fff; background: var(--dark); }
.route-card > span { color: #4e9dcc; font-size: 10px; font-weight: 800; letter-spacing: .12em; }
.route-card ol { margin: 18px 0 0; padding: 0; list-style: none; counter-reset: route; }
.route-card li { position: relative; padding: 12px 0 12px 38px; border-top: 1px solid rgba(255, 255, 255, .13); counter-increment: route; }
.route-card li::before { position: absolute; left: 0; color: #4e9dcc; content: "0" counter(route); font-size: 11px; font-weight: 800; }
.route-card a { display: block; font-weight: 700; }
.route-card small { display: block; margin-top: 3px; color: rgba(255, 255, 255, .64); line-height: 1.5; }
.before-start, .tutorial-step { padding: 54px 0; border-top: 1px solid var(--line); }
.check-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.check-grid article { min-height: 210px; padding: 24px; border: 1px solid var(--line); border-radius: 6px; background: var(--panel); }
.check-grid strong { color: #4e9dcc; font-size: 12px; }
.check-grid h2 { margin: 48px 0 10px; font-size: 23px; letter-spacing: 0; }
.check-grid p { margin-bottom: 0; color: var(--muted); line-height: 1.7; }
code { padding: 2px 5px; color: #12633e; background: #eaf5ef; font-family: Consolas, monospace; }
.tutorial-step { scroll-margin-top: 76px; }
.step-heading { display: flex; gap: 18px; align-items: flex-start; margin-bottom: 28px; }
.step-number { display: grid; width: 48px; height: 48px; flex: 0 0 48px; place-items: center; border-radius: 6px; color: #fff; background: var(--blue); font-size: 13px; font-weight: 800; }
.step-heading .eyebrow { margin: 2px 0 6px; }
.step-heading h2 { margin-bottom: 0; font-size: 32px; line-height: 1.2; letter-spacing: 0; }
.step-copy { max-width: 900px; margin: 0 0 28px 66px; }
.step-copy p, .step-copy li { color: var(--muted); font-size: 16px; line-height: 1.75; }
.step-copy strong { color: var(--ink); }
.step-copy ul { display: grid; gap: 7px; margin: 20px 0 0; padding-left: 20px; }
.step-copy h3 { margin-bottom: 8px; font-size: 23px; }
.success-copy { margin-top: 42px; }
.screen-card { margin: 0 0 0 66px; overflow: hidden; border: 1px solid var(--line); border-radius: 6px; background: var(--panel); box-shadow: 0 10px 24px rgba(16, 24, 40, .07); }
.screen-card img { width: 100%; height: auto; background: #102033; }
.screen-card figcaption { display: flex; gap: 14px; padding: 16px 18px; color: var(--muted); font-size: 13px; line-height: 1.55; }
.screen-card figcaption span { flex: 0 0 auto; color: var(--blue); font-weight: 800; }
.two-column-copy { display: grid; max-width: none; grid-template-columns: 1.05fr .95fr; gap: 42px; }
.two-column-copy dl { margin: 0; }
.two-column-copy dl div { display: grid; grid-template-columns: 110px 1fr; gap: 12px; padding: 11px 0; border-top: 1px solid var(--line); }
.two-column-copy dt { color: var(--blue); font-weight: 800; }
.two-column-copy dd { margin: 0; color: var(--muted); line-height: 1.6; }
.notice { padding: 16px; border-left: 3px solid var(--blue); background: var(--blue-soft); }
.wide-screen img { aspect-ratio: 2552 / 1390; object-fit: cover; }
.update-screen img { aspect-ratio: 1308 / 1175; object-fit: contain; }
.action-list { display: grid; margin: 26px 0 0; padding: 0; border-top: 1px solid var(--line); list-style: none; }
.action-list li { display: grid; grid-template-columns: 140px 1fr; gap: 24px; padding: 13px 0; border-bottom: 1px solid var(--line); }
.action-list span { color: var(--muted); }
.problem-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; margin-left: 66px; }
.problem-grid article { min-height: 190px; padding: 24px; border: 1px solid var(--line); border-radius: 6px; background: var(--panel); }
.problem-grid h3 { margin-bottom: 10px; font-size: 21px; }
.problem-grid p { margin-bottom: 0; color: var(--muted); line-height: 1.7; }
.problem-grid a { display: inline-block; margin-top: 20px; color: var(--blue); font-weight: 800; }
.finish-card { margin: 10px 0 70px; padding: 44px; border: 1px solid #314a5e; border-radius: 6px; color: #fff; background: var(--dark); }
.finish-card .eyebrow { color: #4e9dcc; }
.finish-card h2 { max-width: 700px; margin-bottom: 16px; font-size: 32px; letter-spacing: 0; }
.finish-card > p:not(.eyebrow) { max-width: 680px; margin-bottom: 0; color: rgba(255, 255, 255, .68); line-height: 1.75; }
.finish-card .primary-action { color: #fff; background: var(--blue); }
.finish-card .secondary-action { color: #fff; border-color: rgba(255, 255, 255, .28); background: rgba(255, 255, 255, .06); }
.site-footer { display: flex; justify-content: space-between; gap: 16px; padding: 22px 0 34px; border-top: 1px solid var(--line); color: var(--muted); font-size: 12px; }
.site-footer a { color: var(--blue); }
@media (max-width: 900px) { .tutorial-hero { grid-template-columns: 1fr; } .route-card { max-width: 560px; } .check-grid { grid-template-columns: 1fr; } .check-grid article { min-height: auto; } .check-grid h2 { margin-top: 22px; } .two-column-copy { grid-template-columns: 1fr; gap: 20px; } }
@media (max-width: 760px) { .tutorial-main, .site-footer { width: min(100% - 20px, 1180px); } .tutorial-hero { padding: 30px 24px; } .hero-copy h1 { font-size: 36px; } .before-start, .tutorial-step { padding: 42px 0; } .step-copy, .screen-card, .problem-grid { margin-left: 0; } .problem-grid { grid-template-columns: 1fr; } .screen-card figcaption { display: block; } .screen-card figcaption span { display: block; margin-bottom: 4px; } }
@media (max-width: 480px) { .hero-actions a { width: 100%; } .action-list li, .two-column-copy dl div { grid-template-columns: 1fr; gap: 4px; } .finish-card { padding: 30px 24px; } }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } .hero-actions a { transition: none; } }