:root {
  --paper: #f7f7f3;
  --white: #ffffff;
  --ink: #171717;
  --muted: #62625e;
  --line: #cfcfc7;
  --wine: #990c2f;
  --green: #177245;
  --yellow: #f2c94c;
  --soft-green: #e4f1e9;
  --header-height: 72px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, Helvetica, sans-serif; line-height: 1.7; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }
button { font: inherit; }
.section-shell { padding-left: max(24px, calc((100% - 1180px) / 2)); padding-right: max(24px, calc((100% - 1180px) / 2)); }
.site-header { position: sticky; top: 0; z-index: 50; height: var(--header-height); display: flex; align-items: center; justify-content: space-between; padding: 0 max(24px, calc((100% - 1180px) / 2)); background: rgba(247, 247, 243, .96); border-bottom: 1px solid var(--ink); }
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 24px; font-weight: 800; letter-spacing: 0; }
.brand img { width: 34px; height: 34px; object-fit: contain; }
.site-nav { display: flex; align-items: center; gap: 28px; font-size: 14px; font-weight: 700; }
.site-nav a { position: relative; white-space: nowrap; }
.site-nav a:not(.nav-download)::after { content: ""; position: absolute; left: 0; right: 100%; bottom: -7px; height: 2px; background: var(--wine); transition: right .2s ease; }
.site-nav a:hover::after, .site-nav a.active::after { right: 0; }
.nav-download, .primary-button, .secondary-button { min-height: 44px; display: inline-flex; align-items: center; justify-content: center; padding: 10px 22px; border: 1px solid var(--ink); font-weight: 800; transition: transform .2s ease, box-shadow .2s ease; }
.nav-download, .primary-button { color: var(--white); background: var(--wine); }
.nav-download:hover, .primary-button:hover, .secondary-button:hover { transform: translate(-2px, -2px); box-shadow: 4px 4px 0 var(--ink); }
.menu-toggle { display: none; width: 44px; height: 44px; padding: 10px; background: transparent; border: 1px solid var(--ink); }
.menu-toggle span { display: block; height: 2px; margin: 5px 0; background: var(--ink); }

.hero { position: relative; min-height: min(730px, calc(100svh - 118px)); display: grid; grid-template-columns: minmax(0, 1.06fr) minmax(340px, .94fr); gap: 70px; align-items: center; padding-top: 42px; padding-bottom: 54px; overflow: hidden; border-bottom: 1px solid var(--ink); }
.hero-copy { max-width: 660px; }
.index-label { display: inline-block; color: var(--green); font-size: 12px; font-weight: 900; letter-spacing: 0; text-transform: uppercase; }
h1, h2, h3, p { margin-top: 0; }
h1 { max-width: 680px; margin-bottom: 22px; font-size: clamp(44px, 6vw, 86px); line-height: .98; letter-spacing: 0; }
.hero-copy > p { max-width: 650px; margin-bottom: 28px; color: #44443f; font-size: 17px; }
.hero-actions { display: flex; align-items: center; gap: 24px; flex-wrap: wrap; }
.text-link { font-weight: 800; border-bottom: 1px dotted var(--ink); }
.hero-ledger { display: grid; grid-template-columns: repeat(3, 1fr); max-width: 590px; margin: 38px 0 0; border-top: 1px dotted var(--ink); border-bottom: 1px dotted var(--ink); }
.hero-ledger div { display: flex; align-items: center; gap: 10px; padding: 11px 4px; }
.hero-ledger div + div { border-left: 1px dotted var(--ink); padding-left: 16px; }
.hero-ledger dt { color: var(--wine); font-size: 12px; font-weight: 900; }
.hero-ledger dd { margin: 0; font-size: 13px; font-weight: 800; }
.hero-media { position: relative; min-height: 590px; display: flex; align-items: center; justify-content: center; }
.hero-shot { position: relative; z-index: 2; width: min(290px, 76%); max-width: 400px; max-height: 535px; object-fit: cover; object-position: top; border: 1px solid var(--ink); box-shadow: 12px 12px 0 var(--yellow); }
.catalog-back { position: absolute; z-index: 1; width: 330px; height: 430px; padding: 25px; transform: translate(-36px, -24px) rotate(-3deg); background: var(--soft-green); border: 1px solid var(--ink); }
.catalog-back span { position: absolute; top: 20px; left: 20px; font-size: 11px; font-weight: 900; writing-mode: vertical-rl; }
.catalog-back strong { position: absolute; right: 18px; bottom: 10px; font-size: 64px; line-height: 1; color: var(--green); }
.image-tab { position: absolute; z-index: 3; right: 0; bottom: 52px; padding: 8px 14px; color: var(--white); background: var(--ink); font-size: 11px; font-weight: 900; }
.next-section-tab { position: absolute; left: 50%; bottom: 0; transform: translateX(-50%); padding: 7px 16px; color: var(--ink); background: var(--yellow); border: 1px solid var(--ink); border-bottom: 0; font-size: 12px; font-weight: 900; }

.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 20px; margin-bottom: 36px; }
.section-heading h2, .download-band h2, .support-route h2 { margin: 0; font-size: clamp(30px, 4vw, 54px); line-height: 1.05; letter-spacing: 0; }
.archive-index { padding-top: 88px; padding-bottom: 100px; }
.index-board { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--ink); }
.index-board article { min-height: 260px; padding: 24px; background: var(--white); }
.index-board article + article { border-left: 1px dotted var(--ink); }
.index-board span { color: var(--wine); font-size: 11px; font-weight: 900; }
.index-board h3 { margin: 48px 0 14px; font-size: 21px; line-height: 1.25; }
.index-board p { margin: 0; color: var(--muted); font-size: 14px; }

.showcase { padding-top: 86px; padding-bottom: 100px; color: var(--white); background: var(--ink); }
.light .index-label { color: var(--yellow); }
.contact-sheet { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; align-items: end; }
.contact-sheet figure { margin: 0; padding: 12px; border: 1px dotted #73736f; }
.contact-sheet figure:nth-child(even) { transform: translateY(28px); }
.contact-sheet figure > span { display: block; margin-bottom: 8px; color: var(--yellow); font-size: 10px; font-weight: 900; }
.contact-sheet img { width: 100%; max-width: 400px; max-height: 480px; object-fit: cover; object-position: top; background: #fff; }
.contact-sheet figcaption { padding-top: 10px; font-size: 13px; font-weight: 800; }

.features { padding-top: 110px; padding-bottom: 100px; }
.feature-list { border-top: 1px solid var(--ink); }
.feature-list article { display: grid; grid-template-columns: 170px 1fr; gap: 24px; padding: 28px 0; border-bottom: 1px dotted var(--ink); }
.feature-list article > span { align-self: start; width: fit-content; padding: 4px 10px; background: var(--yellow); border: 1px solid var(--ink); font-size: 12px; font-weight: 900; }
.feature-list h3 { margin-bottom: 6px; font-size: 24px; }
.feature-list p { max-width: 720px; margin: 0; color: var(--muted); }

.reading-route { display: grid; grid-template-columns: .9fr 1.1fr; gap: 80px; padding-top: 90px; padding-bottom: 90px; background: var(--soft-green); border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.route-intro h2 { margin: 12px 0 28px; font-size: clamp(36px, 5vw, 68px); line-height: 1; }
.route-links { display: grid; gap: 10px; }
.route-links a { padding: 16px 0; border-top: 1px dotted var(--ink); }
.route-links span { display: block; color: var(--muted); font-size: 13px; }
.route-steps { margin: 0; padding: 0; list-style: none; }
.route-steps li { display: grid; grid-template-columns: 70px 1fr; gap: 20px; padding: 22px 0; border-bottom: 1px dotted var(--ink); }
.route-steps li > span { display: grid; place-items: center; width: 48px; height: 48px; color: var(--white); background: var(--wine); font-weight: 900; }
.route-steps strong { font-size: 20px; }
.route-steps p { margin: 4px 0 0; color: var(--muted); }

.faq-preview { padding-top: 90px; padding-bottom: 100px; }
.faq-preview-grid { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--ink); }
.faq-preview-grid a { min-height: 160px; padding: 22px; background: var(--white); }
.faq-preview-grid a + a { border-left: 1px dotted var(--ink); }
.faq-preview-grid span { display: block; margin-bottom: 38px; color: var(--wine); font-size: 11px; font-weight: 900; }
.faq-preview-grid strong { display: block; line-height: 1.45; }
.download-band { display: flex; align-items: center; justify-content: space-between; gap: 30px; padding-top: 48px; padding-bottom: 48px; color: var(--white); background: var(--wine); }
.download-band .index-label { color: var(--yellow); }
.download-band p, .download-band .section-summary { margin: 10px 0 0; }
.primary-button.inverse { color: var(--ink); background: var(--yellow); }
.site-footer { display: grid; place-items: center; gap: 8px; padding: 42px 24px; text-align: center; background: var(--white); border-top: 1px solid var(--ink); }
.site-footer p { max-width: 860px; margin: 0; color: var(--muted); font-size: 13px; text-align: center; }
.footer-brand { margin-bottom: 8px; }

.inner-hero { min-height: 420px; display: grid; grid-template-columns: 1.15fr .85fr; gap: 80px; align-items: end; padding-top: 76px; padding-bottom: 66px; border-bottom: 1px solid var(--ink); }
.inner-hero h1 { margin: 10px 0 22px; font-size: clamp(46px, 6vw, 78px); }
.inner-hero p { max-width: 680px; margin: 0; color: var(--muted); font-size: 17px; }
.guide-index, .topic-grid { display: grid; border: 1px solid var(--ink); background: var(--white); }
.guide-index a, .topic-grid a { display: flex; justify-content: space-between; padding: 12px 16px; font-size: 13px; font-weight: 800; }
.guide-index a + a, .topic-grid a + a { border-top: 1px dotted var(--ink); }
.guide-section { display: grid; grid-template-columns: 270px 1fr; gap: 80px; padding-top: 80px; padding-bottom: 88px; }
.guide-section aside span, .faq-group-title > span { color: var(--wine); font-size: 12px; font-weight: 900; }
.guide-section aside h2, .faq-group-title h2 { margin: 8px 0 0; font-size: 30px; line-height: 1.2; }
.guide-content h3 { font-size: 30px; }
.guide-content > p { color: #3e3e3a; }
.check-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 28px 0; }
.check-grid div { padding: 18px; background: var(--white); border: 1px solid var(--ink); }
.check-grid p { margin: 8px 0 0; color: var(--muted); font-size: 13px; }
.muted-band { background: #eaeae4; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.numbered-list { margin: 28px 0 0; padding: 0; list-style: none; counter-reset: steps; border-top: 1px solid var(--ink); }
.numbered-list li { counter-increment: steps; display: grid; grid-template-columns: 1fr 1.6fr; gap: 20px; padding: 18px 0; border-bottom: 1px dotted var(--ink); }
.numbered-list li::before { content: "0" counter(steps); color: var(--wine); font-size: 12px; font-weight: 900; grid-column: 1 / -1; }
.numbered-list span { color: var(--muted); }
.flow-line { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 30px; border: 1px solid var(--ink); }
.flow-line div { min-height: 145px; padding: 18px; background: var(--white); }
.flow-line div + div { border-left: 1px dotted var(--ink); }
.flow-line b, .flow-line span { display: block; }
.flow-line span { margin-top: 34px; color: var(--muted); font-size: 13px; }
.dark-band { color: var(--white); background: var(--ink); }
.dark-band .guide-content > p, .dark-band a { color: #d4d4cc; }
.dark-band aside span { color: var(--yellow); }

.faq-hero { align-items: center; }
.topic-grid a span { color: var(--wine); }
.faq-group { display: grid; grid-template-columns: 270px 1fr; gap: 80px; padding-top: 78px; padding-bottom: 82px; }
.accordion-list { border-top: 1px solid var(--ink); }
.accordion-item { scroll-margin-top: 90px; border-bottom: 1px solid var(--ink); }
.accordion-item h3 { margin: 0; }
.accordion-item button { width: 100%; min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 18px 4px; text-align: left; color: var(--ink); background: transparent; border: 0; cursor: pointer; font-weight: 800; }
.accordion-item button b { flex: 0 0 32px; display: grid; place-items: center; width: 32px; height: 32px; color: var(--white); background: var(--wine); }
.accordion-panel { padding: 0 54px 22px 4px; color: var(--muted); }
.accordion-panel p { margin: 0; }
.support-route { display: flex; align-items: center; justify-content: space-between; gap: 30px; padding-top: 56px; padding-bottom: 56px; background: var(--yellow); border-top: 1px solid var(--ink); }
.support-route p { margin: 8px 0 0; }
.secondary-button { background: var(--white); }

@media (max-width: 900px) {
  :root { --header-height: 64px; }
  .menu-toggle { display: block; }
  .site-nav { position: fixed; top: var(--header-height); left: 0; right: 0; display: none; align-items: stretch; gap: 0; padding: 12px 20px 20px; background: var(--paper); border-bottom: 1px solid var(--ink); }
  .site-nav.open { display: grid; }
  .site-nav a { padding: 12px 4px; }
  .site-nav a::after { display: none; }
  .nav-download { margin-top: 8px; }
  .hero { min-height: calc(100svh - 104px); grid-template-columns: 1fr 310px; gap: 28px; }
  h1 { font-size: 52px; }
  .hero-media { min-height: 480px; }
  .index-board, .contact-sheet { grid-template-columns: repeat(2, 1fr); }
  .index-board article:nth-child(3) { border-left: 0; border-top: 1px dotted var(--ink); }
  .index-board article:nth-child(4) { border-top: 1px dotted var(--ink); }
  .contact-sheet figure:nth-child(even) { transform: none; }
  .reading-route, .inner-hero { grid-template-columns: 1fr; gap: 38px; }
  .guide-section, .faq-group { grid-template-columns: 190px 1fr; gap: 38px; }
  .check-grid { grid-template-columns: 1fr; }
}

@media (max-width: 680px) {
  .section-shell { padding-left: 18px; padding-right: 18px; }
  .site-header { padding: 0 18px; }
  .hero { min-height: calc(100svh - 82px); grid-template-columns: 1fr; align-content: center; gap: 18px; padding-top: 26px; padding-bottom: 36px; }
  .hero-copy { text-align: center; }
  h1 { margin: 8px auto 14px; font-size: 42px; }
  .hero-copy > p { margin: 0 auto 16px; font-size: 14px; line-height: 1.65; }
  .hero-actions { justify-content: center; gap: 16px; }
  .hero-ledger { margin-top: 18px; }
  .hero-ledger div { justify-content: center; padding: 8px 2px; }
  .hero-ledger div + div { padding-left: 2px; }
  .hero-ledger dd { font-size: 11px; }
  .hero-media { min-height: 245px; }
  .hero-shot { width: 142px; max-height: 238px; box-shadow: 7px 7px 0 var(--yellow); }
  .catalog-back { width: 175px; height: 206px; padding: 12px; transform: translate(-20px, -10px) rotate(-3deg); }
  .catalog-back span { top: 10px; left: 9px; font-size: 8px; }
  .catalog-back strong { right: 8px; bottom: 6px; font-size: 34px; }
  .image-tab { right: calc(50% - 115px); bottom: 8px; padding: 5px 8px; font-size: 8px; }
  .next-section-tab { font-size: 10px; white-space: nowrap; }
  .section-heading { align-items: start; flex-direction: column; gap: 8px; }
  .archive-index, .features, .faq-preview { padding-top: 64px; padding-bottom: 70px; }
  .index-board, .contact-sheet, .faq-preview-grid { grid-template-columns: 1fr; }
  .index-board article { min-height: 210px; }
  .index-board article + article { border-left: 0; border-top: 1px dotted var(--ink); }
  .contact-sheet { max-width: 330px; margin: 0 auto; }
  .contact-sheet img { max-height: 420px; }
  .feature-list article { grid-template-columns: 74px 1fr; gap: 14px; }
  .feature-list h3 { font-size: 19px; }
  .reading-route { grid-template-columns: 1fr; gap: 30px; padding-top: 64px; padding-bottom: 64px; }
  .faq-preview-grid a + a { border-left: 0; border-top: 1px dotted var(--ink); }
  .download-band, .support-route { align-items: flex-start; flex-direction: column; }
  .download-band .primary-button, .support-route .secondary-button { width: 100%; }
  .inner-hero { min-height: auto; grid-template-columns: 1fr; gap: 32px; padding-top: 50px; padding-bottom: 48px; }
  .inner-hero h1 { font-size: 43px; }
  .guide-section, .faq-group { grid-template-columns: 1fr; gap: 30px; padding-top: 58px; padding-bottom: 64px; }
  .flow-line { grid-template-columns: repeat(2, 1fr); }
  .flow-line div:nth-child(3) { border-left: 0; border-top: 1px dotted var(--ink); }
  .flow-line div:nth-child(4) { border-top: 1px dotted var(--ink); }
  .numbered-list li { grid-template-columns: 1fr; gap: 5px; }
}

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