:root {
  color-scheme: light;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --canvas: #f7f8fc;
  --panel: #fff;
  --ink: #1f2024;
  --secondary: #5b5d66;
  --muted: #747784;
  --accent: #6d5ae6;
  --accent-dark: #5743cf;
  --soft: #eeebfd;
  --edge: #e6e7ee;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 28px; }
body { margin: 0; background: var(--canvas); color: var(--ink); font-family: var(--font); -webkit-font-smoothing: antialiased; line-height: 1.6; }
body::before { content: ""; position: absolute; inset: 0 0 auto; height: 660px; z-index: -1; background: radial-gradient(ellipse at 52% 0, #e9e4ff88, transparent 68%); pointer-events: none; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button { cursor: pointer; }
button:disabled { cursor: default; }
button:focus-visible, a:focus-visible, [tabindex]:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
img { display: block; max-width: 100%; }
::selection { color: #352777; background: #e4defc; }
[hidden] { display: none !important; }
.page-width { width: min(1360px, calc(100% - 88px)); margin-inline: auto; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.js-only { display: none !important; }
.js .js-only { display: flex !important; }
.skip-link { position: fixed; left: 20px; top: -70px; z-index: 10; border-radius: 8px; background: var(--ink); color: white; padding: 10px 18px; }
.skip-link:focus { top: 14px; }

.site-header { min-height: 96px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 11px; font-size: 20px; font-weight: 700; letter-spacing: -.6px; line-height: 1.35; }
.brand-mark { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 13px; background: linear-gradient(135deg, #7c5cff, #5b4bd6); box-shadow: 0 4px 10px #6d5ae628, inset 0 1px 1px #ffffff40; flex-shrink: 0; }
.brand-mark img { object-fit: contain; }
.brand-subtitle { display: block; color: var(--muted); font-size: 10px; letter-spacing: .6px; font-weight: 500; margin-top: 3px; }
.header-actions { display: flex; align-items: center; gap: 24px; }
.language-switch { gap: 2px; padding: 3px; background: #eeeff5; border: 1px solid #e6e7ee; border-radius: 10px; }
.language-switch button { min-height: 34px; min-width: 42px; border: 0; border-radius: 7px; background: transparent; font-size: 12px; font-weight: 600; color: var(--secondary); }
.language-switch button[aria-pressed="true"] { color: var(--ink); background: white; box-shadow: 0 1px 4px #24233a10; }
.header-repo { display: flex; align-items: center; gap: 14px; font-size: 13px; font-weight: 600; padding-block: 11px; }
.header-repo:hover, .text-link:hover, .site-footer a:hover { color: var(--accent-dark); }
.intro { padding-top: 33px; padding-bottom: 40px; text-align: center; }
.eyebrow { display: flex; align-items: center; justify-content: center; gap: 8px; color: var(--accent-dark); font-size: 12px; font-weight: 600; letter-spacing: .4px; }
.status-dot { width: 6px; height: 6px; background: var(--accent); border-radius: 50%; }
.eyebrow-divider { width: 1px; height: 12px; margin-inline: 5px; background: #d9d6e8; }
.eyebrow-secondary { color: var(--muted); font-weight: 400; }
h1 { margin: 20px 0 18px; font-size: clamp(36px, 3.6vw, 52px); line-height: 1.35; letter-spacing: -1.8px; font-weight: 700; }
.accent-text { color: var(--accent); }
.intro-description { max-width: 585px; margin: 0 auto; color: var(--secondary); font-size: 15px; line-height: 1.95; }
.demo-notice { display: inline-flex; align-items: center; gap: 8px; margin: 19px 0 0; padding: 7px 12px; border-radius: 8px; color: var(--muted); background: #eeedf6a8; font-size: 11px; line-height: 1.6; }
.demo-notice > span:first-child { color: var(--accent); font-size: 15px; }

.tour { outline: none; }
.tour-layout { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 30px; align-items: start; }
.preview-column { min-width: 0; }
.preview-window { margin: 0; overflow: hidden; border: 1px solid #dddfe9; border-radius: 16px; background: white; box-shadow: 0 16px 48px -22px #35305535, 0 2px 7px #25203305; }
.window-bar { height: 37px; display: flex; align-items: center; justify-content: space-between; padding: 0 14px; gap: 12px; border-bottom: 1px solid var(--edge); background: #fdfdff; }
.window-dots { display: flex; gap: 5px; }
.window-dots span { width: 7px; height: 7px; border-radius: 50%; background: #dddde7; }
.window-dots span:first-child { background: #b9aeee; }
.window-title { font-size: 10px; color: var(--muted); letter-spacing: .25px; }
.static-label { font-size: 9px; color: var(--accent-dark); background: #efedfa; padding: 2px 6px; border-radius: 4px; }
.screen-stage { aspect-ratio: 8 / 5; position: relative; display: flex; align-items: center; justify-content: center; background: #f5f5fb; overflow: hidden; }
.screen-image { width: 100%; height: 100%; object-fit: contain; }
.screen-caption { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 9px 14px; border-top: 1px solid var(--edge); color: var(--muted); font-size: 10px; }
.screen-caption a { color: var(--secondary); display: inline-flex; align-items: center; gap: 5px; min-height: 26px; white-space: nowrap; }
.screen-caption a:hover { color: var(--accent-dark); }
.screen-stage.is-citation { flex-direction: column; gap: 28px; padding: 35px; background: radial-gradient(ellipse at 60% 0, #e8e3ff80, transparent 80%), #fafaff; }
.citation-intro { text-align: center; }
.small-label { color: var(--accent-dark); font-size: 10px; font-weight: 500; letter-spacing: .5px; }
.citation-intro h3 { margin: 11px 0 0; font-size: clamp(17px, 1.6vw, 23px); letter-spacing: -.5px; font-weight: 600; line-height: 1.5; }
.is-citation .screen-image { width: min(540px, 100%); height: auto; padding: 18px; border: 1px solid #e6e2f5; border-radius: 14px; box-shadow: 0 12px 25px -20px #4e3d7a55; background: #f7f8fd; }
.citation-outro { max-width: 440px; margin: 0; font-size: 11px; line-height: 1.9; color: var(--secondary); text-align: center; }
.step-nav { margin-top: 16px; width: 100%; }
.step-nav ol { width: 100%; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 12px; margin: 0; padding: 0; list-style: none; }
.step-nav li { min-width: 0; }
.step-nav button { width: 100%; padding: 5px; background: transparent; border: 1px solid transparent; border-radius: 9px; color: var(--secondary); text-align: left; transition: background .15s, border-color .15s; }
.step-nav button:hover { background: #f0eef9; }
.step-nav button[aria-current="step"] { background: white; border-color: #bfb4f4; color: var(--accent-dark); box-shadow: 0 2px 6px #4d388d08; }
.step-thumbnail { display: flex; aspect-ratio: 8 / 4.4; align-items: center; justify-content: center; overflow: hidden; background: #f3f2fa; border-radius: 5px; }
.step-thumbnail img { width: 100%; height: 100%; object-fit: cover; object-position: center top; opacity: .72; }
.step-nav button[aria-current="step"] .step-thumbnail img, .step-nav button:hover .step-thumbnail img { opacity: 1; }
.citation-thumbnail img { object-fit: contain; padding: 6px; }
.step-nav-label { display: flex; align-items: baseline; gap: 7px; padding: 8px 2px 2px; font-size: 11px; font-weight: 500; }
.step-number { font-size: 9px; color: #858393; font-variant-numeric: tabular-nums; }

.step-details { display: flex; flex-direction: column; min-width: 0; padding: 15px 0 0; }
.step-detail-top { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.section-kicker { color: var(--accent-dark); font-size: 11px; font-weight: 600; letter-spacing: .75px; }
.step-count { font-size: 14px; font-weight: 650; font-variant-numeric: tabular-nums; }
.step-count span { color: #a0a1ae; font-size: 11px; font-weight: 400; }
.progress-track { display: flex; gap: 4px; margin: 13px 0 24px; }
.progress-track span { flex: 1; height: 3px; border-radius: 3px; background: #e6e4f0; }
.progress-track span.is-complete { background: var(--accent); }
.step-details h2 { margin: 0 0 14px; font-size: 25px; font-weight: 650; line-height: 1.45; letter-spacing: -.7px; }
.step-description { color: var(--secondary); font-size: 13px; line-height: 1.9; margin: 0; }
.step-points { display: grid; gap: 13px; margin: 23px 0 26px; padding: 0; list-style: none; color: #50515d; font-size: 12px; line-height: 1.8; }
.step-points li { position: relative; padding-left: 15px; }
.step-points li::before { content: ""; position: absolute; top: .65em; left: 0; width: 5px; height: 5px; border-radius: 50%; background: #b5a9ef; }
.detail-note { display: flex; align-items: flex-start; gap: 9px; padding: 12px 13px; border-radius: 10px; background: #eeecf7; color: #655e82; }
.note-mark { display: flex; align-items: center; justify-content: center; flex-shrink: 0; width: 14px; height: 14px; margin-top: 3px; border: 1px solid #a49abd; border-radius: 50%; font-size: 9px; font-family: Georgia, serif; font-weight: 700; }
.detail-note p { margin: 0; font-size: 11px; line-height: 1.8; }
.tour-controls { gap: 10px; margin-top: 25px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 10px; min-height: 44px; padding: 11px 17px; border-radius: 10px; border: 1px solid transparent; font-size: 12px; font-weight: 600; line-height: 1.5; text-align: center; transition: background .15s, box-shadow .15s; }
.button-primary { color: white; background: var(--accent); box-shadow: 0 4px 10px -5px #6d5ae670; }
.button-primary:hover { background: var(--accent-dark); box-shadow: 0 5px 14px -5px #6d5ae680; }
.button-secondary { color: var(--secondary); background: white; border-color: var(--edge); }
.button-secondary:hover:enabled { background: #f1effb; }
.button-secondary:disabled { color: #9fa1ab; border-color: #e9e9f0; background: #f4f4f9; }
.tour-controls .button { flex: 1; }
.keyboard-hint { margin: 12px 0 0; gap: 7px; align-items: center; justify-content: center; font-size: 9px; color: var(--muted); }
.keyboard-hint > span:first-child { display: flex; gap: 3px; }
kbd { min-width: 16px; height: 15px; display: inline-flex; align-items: center; justify-content: center; border: 1px solid #dedee8; border-radius: 3px; font-family: var(--font); font-size: 9px; background: #fcfcfe; }
.noscript-note { padding: 15px; border: 1px solid var(--edge); border-radius: 10px; font-size: 13px; }
.noscript-note a { color: var(--accent-dark); text-decoration: underline; }

.next-step { margin-top: 62px; padding: 31px 34px; display: flex; align-items: center; justify-content: space-between; gap: 45px; border: 1px solid var(--edge); border-radius: 16px; background: linear-gradient(110deg, #fff 50%, #f0edfd); }
.next-step-copy { max-width: 720px; }
.next-step h2 { margin: 8px 0 9px; font-size: 25px; line-height: 1.5; font-weight: 650; letter-spacing: -.7px; }
.next-step p { margin: 0; color: var(--secondary); font-size: 12px; line-height: 1.9; }
.next-step-actions { display: flex; flex-direction: column; align-items: center; gap: 12px; flex-shrink: 0; }
.next-step-actions .button { min-width: 196px; }
.text-link { display: inline-flex; align-items: center; gap: 7px; font-size: 11px; color: var(--secondary); min-height: 28px; }
.data-boundary { display: flex; gap: 16px; padding-block: 20px 28px; color: var(--muted); font-size: 10px; line-height: 1.8; }
.boundary-label { white-space: nowrap; font-weight: 600; color: #646374; }
.data-boundary p { margin: 0; }
.site-footer { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px 24px; padding-block: 20px 26px; border-top: 1px solid var(--edge); color: var(--muted); font-size: 10px; }
.site-footer p { margin: 0; }
.footer-dot { margin-inline: 6px; color: #b9b5ca; }
.site-footer a { min-height: 30px; display: inline-flex; align-items: center; }

@media (min-width: 1500px) {
  .tour-layout { grid-template-columns: minmax(0, 1fr) 314px; gap: 38px; }
  .step-details { padding-top: 25px; }
  .step-details h2 { margin-top: 7px; }
  .step-description { font-size: 14px; }
  .step-points { font-size: 13px; margin-block: 25px 30px; }
}

@media (max-width: 1080px) {
  .page-width { width: calc(100% - 48px); }
  .tour-layout { grid-template-columns: minmax(0, 1fr) 265px; gap: 24px; }
  .step-details { padding-top: 3px; }
  .step-details h2 { font-size: 23px; }
  .step-points { margin-block: 17px; gap: 10px; }
  .step-nav ol { gap: 5px; }
  .step-nav-label { gap: 4px; font-size: 10px; }
  .step-number { font-size: 8px; }
  .screen-stage.is-citation { padding: 22px; gap: 20px; }
  .is-citation .screen-image { padding: 12px; }
  .citation-outro { font-size: 10px; }
  .next-step { padding: 26px; gap: 25px; }
}

@media (max-width: 820px) {
  .site-header { min-height: 84px; }
  .intro { padding-top: 24px; padding-bottom: 30px; }
  h1 { font-size: 40px; }
  .intro-description { font-size: 14px; max-width: 540px; }
  .tour-layout { grid-template-columns: minmax(0, 1fr); gap: 26px; }
  .step-details { padding: 25px; background: white; border: 1px solid var(--edge); border-radius: 14px; }
  .step-nav ol { gap: 12px; }
  .step-nav-label { font-size: 11px; gap: 7px; }
  .step-number { font-size: 9px; }
  .step-details h2 { font-size: 25px; }
  .progress-track { margin-bottom: 18px; }
  .step-points { font-size: 13px; margin-block: 17px 22px; }
  .tour-controls { margin-top: 22px; }
  .keyboard-hint { display: none !important; }
  .js .keyboard-hint { display: none !important; }
  .screen-stage.is-citation { padding: 35px; gap: 28px; }
  .citation-intro h3 { font-size: 24px; }
  .citation-outro { font-size: 12px; }
  .next-step { margin-top: 30px; }
  .next-step h2 { font-size: 22px; }
  .next-step-actions .button { min-width: 166px; }
}

@media (max-width: 560px) {
  .page-width { width: calc(100% - 32px); }
  .site-header { min-height: 76px; gap: 10px; }
  .brand { font-size: 17px; gap: 8px; }
  .brand-mark { width: 35px; height: 35px; border-radius: 10px; }
  .brand-mark img { width: 24px; height: 24px; }
  .brand-subtitle { font-size: 8px; letter-spacing: .2px; }
  .header-actions { gap: 10px; }
  .header-repo { font-size: 11px; gap: 4px; }
  .header-repo > span:last-child { display: none; }
  .language-switch { padding: 2px; gap: 0; }
  .language-switch button { min-width: 32px; min-height: 32px; font-size: 10px; }
  .intro { padding-top: 23px; }
  .eyebrow { font-size: 10px; gap: 7px; }
  h1 { font-size: clamp(30px, 7.9vw, 39px); letter-spacing: -1px; margin-block: 20px 15px; }
  .intro-description { max-width: 390px; font-size: 12px; line-height: 1.95; padding-inline: 9px; }
  .demo-notice { font-size: 9px; margin-top: 15px; gap: 6px; padding: 7px 9px; }
  .preview-window { border-radius: 10px; }
  .window-bar { height: 30px; padding-inline: 9px; gap: 6px; }
  .window-dots { gap: 3px; }
  .window-dots span { width: 5px; height: 5px; }
  .window-title { font-size: 8px; }
  .static-label { font-size: 8px; }
  .screen-caption { padding: 5px 9px; font-size: 9px; }
  .screen-stage.is-citation { padding: 17px; gap: 16px; min-height: 300px; aspect-ratio: auto; }
  .citation-intro h3 { font-size: 18px; }
  .small-label { font-size: 9px; }
  .is-citation .screen-image { padding: 9px; border-radius: 10px; }
  .citation-outro { font-size: 10px; }
  .step-nav { margin-top: 12px; }
  .step-nav ol { gap: 4px; }
  .step-nav button { padding: 4px; border-radius: 7px; min-height: 69px; }
  .step-nav-label { font-size: 9px; gap: 3px; justify-content: center; padding-top: 7px; }
  .step-number { display: none; }
  .step-thumbnail { aspect-ratio: 8 / 5; }
  .citation-thumbnail img { padding: 3px; }
  .tour-layout { gap: 18px; }
  .step-details { padding: 20px; border-radius: 12px; }
  .step-details h2 { font-size: 24px; }
  .step-description { font-size: 13px; }
  .step-points { font-size: 12px; }
  .next-step { flex-direction: column; align-items: stretch; gap: 21px; padding: 25px 21px; margin-top: 25px; border-radius: 12px; }
  .next-step h2 { font-size: 23px; }
  .next-step p { font-size: 11px; }
  .next-step-actions { align-items: stretch; gap: 8px; }
  .next-step-actions .text-link { justify-content: center; min-height: 34px; }
  .data-boundary { flex-direction: column; gap: 5px; padding-block: 18px 23px; font-size: 10px; }
  .site-footer { justify-content: center; gap: 5px; text-align: center; font-size: 9px; }
  .site-footer > p { width: 100%; }
  .site-footer > a { margin-top: 3px; }
  html[lang="en"] .brand-subtitle { font-size: 7px; letter-spacing: 0; }
  html[lang="en"] .header-repo { font-size: 10px; }
  html[lang="en"] .step-nav-label { font-size: 8px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

@media (forced-colors: active) {
  .button, .language-switch button, .step-nav button { border: 1px solid ButtonText; }
  .step-nav button[aria-current="step"] { outline: 2px solid Highlight; }
  .progress-track span.is-complete { background: Highlight; }
}