:root {
  color-scheme: light;
  --background: #f8faf9;
  --ink: #1d2c32;
  --muted: #5d7077;
  --teal: #215d68;
  --line: #d9e3e3;
  --surface: #eff5f4;
  --negative: #9c4f4c;
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --mono: "SFMono-Regular", "DIN Alternate", "Roboto Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--background); color: var(--ink); font: 400 16px/1.8 var(--font); }
a { color: inherit; text-underline-offset: 3px; }
:focus-visible { outline: 2px solid var(--teal); outline-offset: 4px; }
::selection { background: var(--surface); color: var(--ink); }
.shell { width: min(100% - 48px, 1120px); margin-inline: auto; }
.skip-link { position: fixed; top: -80px; left: 16px; z-index: 10; padding: 7px 13px; background: var(--ink); color: white; }
.skip-link:focus { top: 12px; }
.site-header { border-bottom: 1px solid var(--line); }
.site-header__inner { min-height: 70px; display: flex; align-items: center; justify-content: space-between; gap: 25px; }
.brand { display: inline-flex; align-items: center; gap: 11px; font-size: 14px; font-weight: 650; letter-spacing: -.02em; text-decoration: none; white-space: nowrap; }
.brand__glyph { width: 31px; height: 31px; display: inline-flex; align-items: center; justify-content: center; border: 1px solid var(--teal); color: var(--teal); font: 700 13px/1 var(--mono); letter-spacing: -.14em; }
.brand__glyph span { padding-inline: 1px 3px; color: var(--line); font-weight: 400; }
.top-nav { display: flex; align-items: center; gap: clamp(14px, 2.5vw, 31px); color: var(--muted); font-size: 13px; font-weight: 550; }
.top-nav a { text-decoration: none; white-space: nowrap; }
.top-nav a:hover { color: var(--teal); }
.eyebrow { margin: 0; color: var(--teal); font: 650 12px/1.5 var(--mono); letter-spacing: .035em; }
.hero { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(360px, .85fr); gap: clamp(46px, 6vw, 76px); align-items: start; max-width: 1120px; padding-block: 92px 74px; }
.hero h1 { max-width: 770px; margin: 20px 0 22px; font-size: clamp(36px, 4.2vw, 49px); font-weight: 680; line-height: 1.35; letter-spacing: -.045em; }
.hero__lead { max-width: 680px; margin: 0; color: var(--muted); font-size: 17px; line-height: 1.9; }
.text-link { display: inline-block; margin-top: 27px; color: var(--teal); font-size: 14px; font-weight: 650; text-decoration-thickness: 1px; }
.hook-trace { align-self: center; border-top: 1px solid var(--teal); }
.hook-trace__heading { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; padding: 14px 0 8px; }
.hook-trace__heading > span { color: var(--teal); font-size: 12px; font-weight: 650; white-space: nowrap; }
.hook-trace h2 { margin: 0; color: var(--muted); font-size: 13px; font-weight: 500; }
.hook-trace ul { margin: 0; padding: 0; list-style: none; }
.hook-trace li { display: grid; grid-template-columns: minmax(0, 1fr) 20px; gap: 0 8px; padding: 14px 0 15px; border-bottom: 1px solid var(--line); }
.hook-trace code { color: var(--teal); font: 600 13px/1.55 var(--mono); }
.hook-trace li span { grid-column: 1; color: var(--ink); font-size: 13px; }
.hook-trace li a { grid-column: 2; grid-row: 1 / 3; align-self: center; color: var(--teal); font-size: 17px; text-align: right; text-decoration: none; }
.hook-trace > p { margin: 13px 0 0; color: var(--muted); font-size: 12px; }
.section-heading h2 { margin: 9px 0 0; font-size: clamp(25px, 2.7vw, 32px); font-weight: 660; letter-spacing: -.035em; line-height: 1.45; }
.section-heading > p:last-child:not(.eyebrow) { max-width: 650px; margin: 11px 0 0; color: var(--muted); font-size: 15px; }
.flow { padding-block: 40px 44px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.flow__steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin: 30px 0 0; padding: 0; list-style: none; }
.flow__steps li { position: relative; min-height: 83px; padding-top: 13px; border-top: 2px solid var(--teal); }
.flow__steps li:not(:last-child)::after { content: '→'; position: absolute; top: 0; right: -20px; color: var(--muted); font: 20px/1 var(--mono); }
.flow__steps span { display: block; font-weight: 650; }
.flow__steps small { display: block; margin-top: 3px; color: var(--muted); font-size: 13px; }
.flow__note { margin: 19px 0 0; color: var(--muted); font-size: 13px; }
.evidence-overview { padding-block: 83px 85px; }
.observation-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 32px; margin-top: 31px; }
.observation { display: flex; flex-direction: column; align-items: flex-start; min-height: 220px; padding: 22px 0 19px; border-top: 2px solid var(--teal); border-bottom: 1px solid var(--line); text-decoration: none; }
.observation--negative { border-top-color: var(--negative); }
.observation > span:first-child { color: var(--muted); font-size: 13px; }
.observation strong { margin-top: 13px; color: var(--teal); font-size: 33px; font-weight: 670; letter-spacing: -.045em; line-height: 1.3; }
.observation--negative strong { color: var(--negative); }
.observation p { max-width: 450px; margin: 7px 0 15px; color: var(--ink); font-size: 15px; }
.observation__link { margin-top: auto; color: var(--teal); font-size: 13px; font-weight: 650; }
.observation:hover .observation__link { text-decoration: underline; }
.evidence-overview__note { margin: 19px 0 0; color: var(--muted); font-size: 13px; }
.evidence-overview__note a { color: var(--teal); }
.catalog { padding-block: 63px 92px; border-top: 1px solid var(--line); }
.feature-group { display: grid; grid-template-columns: 210px minmax(0, 1fr); gap: 34px; padding-block: 44px 9px; border-bottom: 1px solid var(--line); }
.feature-group__heading h3 { margin: 0; color: var(--teal); font-size: 22px; font-weight: 650; }
.feature-group__heading p { max-width: 185px; margin: 6px 0 0; color: var(--muted); font-size: 13px; }
.feature-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 22px 26px; padding-bottom: 35px; }
.feature-card { display: block; min-width: 0; padding: 19px 20px 18px; border: 1px solid var(--line); background: rgba(255,255,255,.44); text-decoration: none; transition: border-color .18s ease, background .18s ease; }
.feature-card:hover { border-color: var(--teal); background: var(--surface); }
.feature-card__meta { display: flex; justify-content: space-between; align-items: center; gap: 8px; color: var(--teal); font-size: 13px; }
.feature-card h4 { margin: 11px 0 5px; font-size: 19px; font-weight: 670; letter-spacing: -.025em; line-height: 1.45; }
.feature-card p { min-height: 47px; margin: 0; color: var(--muted); font-size: 14px; line-height: 1.7; }
.feature-card__evidence { display: block; margin-top: 18px; padding-top: 12px; border-top: 1px solid var(--line); color: var(--ink); font-size: 13px; line-height: 1.65; }
.status { color: var(--teal); font-size: 12px; font-weight: 650; white-space: nowrap; }
.status::before { content: ''; display: inline-block; width: 5px; height: 5px; margin-right: 7px; border-radius: 50%; background: currentColor; vertical-align: .15em; }
.status--caution { color: var(--muted); }
.status--negative { color: var(--negative); }
.install { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; padding-block: 47px 92px; border-top: 1px solid var(--line); }
.install h2 { margin: 8px 0 17px; font-size: 28px; letter-spacing: -.035em; }
.install p:not(.eyebrow) { max-width: 540px; margin: 0; color: var(--muted); font-size: 15px; }
.install .install__note { margin-top: 14px !important; font-size: 13px !important; }
.install__address { align-self: start; padding: 18px 0; border-top: 2px solid var(--teal); border-bottom: 1px solid var(--line); }
.install__address span { display: block; color: var(--muted); font-size: 12px; }
.install__address code { display: block; margin: 9px 0 17px; color: var(--ink); font: 13px/1.7 var(--mono); overflow-wrap: anywhere; }
.install__address a { color: var(--teal); font-size: 13px; font-weight: 650; }
.site-footer { border-top: 1px solid var(--line); }
.site-footer__inner { display: flex; justify-content: space-between; gap: 22px; padding-block: 23px; color: var(--muted); font-size: 12px; }
.site-footer p { margin: 0; }
.site-footer a { text-decoration: none; }
.site-footer a:hover { color: var(--teal); }
.breadcrumbs { display: flex; align-items: center; flex-wrap: wrap; gap: 9px; padding-block: 33px 0; color: var(--muted); font-size: 12px; }
.breadcrumbs a { color: var(--teal); text-decoration: none; }
.breadcrumbs a:hover { text-decoration: underline; }
.detail { padding-bottom: 110px; }
.detail article { max-width: 800px; margin: 0 auto; }
.detail__header { padding: 58px 0 46px; border-bottom: 1px solid var(--line); }
.detail__meta { display: flex; gap: 19px; align-items: center; color: var(--muted); font-size: 12px; }
.detail h1 { margin: 16px 0 8px; font-size: clamp(35px, 4vw, 47px); font-weight: 680; letter-spacing: -.045em; line-height: 1.3; }
.detail__summary { margin: 0; font-size: 19px; font-weight: 550; line-height: 1.7; }
.detail__intro { max-width: 740px; margin: 23px 0 0; color: var(--muted); }
.mechanism { padding-block: 41px 50px; }
.mechanism .section-heading h2 { font-size: 23px; }
.mechanism__seams { display: flex; align-items: baseline; gap: 19px; margin-top: 20px; color: var(--muted); font-size: 12px; }
.mechanism__seams > span { flex: 0 0 auto; }
.mechanism__seams ul { display: flex; flex-wrap: wrap; gap: 5px 13px; margin: 0; padding: 0; list-style: none; }
.mechanism__seams li + li::before { content: '·'; margin-right: 13px; color: var(--muted); }
.mechanism__seams code { color: var(--teal); font: 600 12px/1.6 var(--mono); }
.mechanism__steps { margin: 22px 0 0; padding: 0; border-top: 1px solid var(--line); }
.mechanism__steps > div { display: grid; grid-template-columns: 120px 1fr; gap: 20px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.mechanism__steps dt { color: var(--teal); font-size: 13px; font-weight: 650; }
.mechanism__steps dd { margin: 0; color: var(--ink); font-size: 14px; line-height: 1.75; }
.mechanism__refs { margin: 13px 0 0; color: var(--muted); font-size: 12px; }
.mechanism__refs a { display: inline-block; margin-left: 8px; color: var(--teal); }
.case-list { border-top: 1px solid var(--line); }
.case { padding: 39px 0 43px; border-bottom: 1px solid var(--line); }
.case__kind { color: var(--teal); font-size: 12px; font-weight: 650; }
.case__heading h2 { max-width: 700px; margin: 6px 0 16px; font-size: clamp(23px, 2.6vw, 29px); line-height: 1.45; letter-spacing: -.035em; }
.case--lead .case__heading h2 { font-size: clamp(26px, 2.8vw, 32px); }
.case--lead .case__task { font-size: 17px; }
.case__task { margin: 0 0 18px; color: var(--ink); font-size: 16px; }
.case__probe { margin: 0 0 19px; color: var(--muted); font-size: 14px; }
.case__probe span { display: block; margin-bottom: 3px; color: var(--teal); font-size: 12px; font-weight: 650; }
.case__finding { padding: 16px 0 13px 18px; border-left: 2px solid var(--teal); }
.case__finding > span { color: var(--teal); font-size: 12px; font-weight: 650; }
.case__finding p { margin: 5px 0 0; font-size: 16px; font-weight: 550; }
.case__sources { display: block; margin-top: 11px; color: var(--muted); font-size: 12px; font-weight: 400; }
.case__sources a { margin-left: 8px; color: var(--teal); font-weight: 600; white-space: normal; }
.case__reading { margin: 18px 0 0; color: var(--muted); font-size: 14px; }
.detail-limits { display: grid; grid-template-columns: 130px 1fr; gap: 20px; padding: 25px 0; border-bottom: 1px solid var(--line); }
.detail-limits h2 { margin: 0; color: var(--muted); font-size: 13px; font-weight: 650; }
.detail-limits ul { margin: 0; padding-left: 1.1em; color: var(--muted); font-size: 13px; }
.detail-limits li + li { margin-top: 5px; }
.detail-next { display: flex; justify-content: space-between; gap: 20px; padding-top: 32px; font-size: 13px; font-weight: 650; }
.detail-next a { color: var(--teal); text-decoration: none; }
.detail-next a:hover { text-decoration: underline; }
.evidence-page { padding-bottom: 100px; }
.evidence-page header { max-width: 800px; padding: 60px 0 28px; }
.evidence-page h1 { margin: 8px 0 13px; font-size: clamp(30px, 3.7vw, 43px); letter-spacing: -.04em; line-height: 1.4; }
.evidence-page header p:not(.eyebrow) { color: var(--muted); font-size: 14px; }
.evidence-page header a { color: var(--teal); font-size: 13px; font-weight: 650; }
.evidence-text { max-width: 940px; overflow-x: auto; margin: 0; padding: 23px; border: 1px solid var(--line); background: white; color: var(--ink); font: 13px/1.85 var(--mono), var(--font); white-space: pre-wrap; overflow-wrap: anywhere; }

@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; gap: 44px; }
  .hook-trace { width: min(100%, 680px); }
  .feature-group { grid-template-columns: 140px 1fr; gap: 20px; }
  .feature-grid { gap: 15px; }
  .feature-card { padding: 17px; }
}

@media (max-width: 650px) {
  .shell { width: min(100% - 36px, 1120px); }
  .site-header__inner { align-items: flex-start; flex-direction: column; justify-content: center; gap: 8px; padding-block: 12px; }
  .top-nav { max-width: 100%; gap: 20px; overflow-x: auto; padding-bottom: 3px; font-size: 12px; }
  .hero { padding-block: 64px 55px; }
  .hero h1 { margin-block: 16px 19px; font-size: clamp(32px, 8.5vw, 36px); line-height: 1.4; }
  .hero__lead { font-size: 15px; }
  .hook-trace__heading { flex-direction: column; align-items: flex-start; gap: 0; }
  .flow { padding-block: 32px; }
  .flow__steps { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 17px 20px; margin-top: 23px; }
  .flow__steps li { min-height: 66px; }
  .flow__steps li::after { display: none; }
  .evidence-overview { padding-block: 62px; }
  .observation-grid { grid-template-columns: 1fr; gap: 20px; }
  .observation { min-height: 0; }
  .catalog { padding-block: 54px 70px; }
  .feature-group { display: block; padding-block: 31px 0; }
  .feature-group__heading p { max-width: none; }
  .feature-grid { grid-template-columns: 1fr; gap: 11px; padding-block: 20px 31px; }
  .feature-card p { min-height: 0; }
  .install { grid-template-columns: 1fr; gap: 29px; padding-block: 40px 72px; }
  .site-footer__inner { flex-direction: column; gap: 4px; }
  .detail { padding-bottom: 75px; }
  .detail__header { padding-block: 45px 35px; }
  .detail h1 { font-size: clamp(32px, 8.5vw, 36px); }
  .detail__summary { font-size: 17px; }
  .mechanism { padding-block: 36px 43px; }
  .mechanism__seams { align-items: flex-start; flex-direction: column; gap: 2px; }
  .mechanism__steps > div { grid-template-columns: 1fr; gap: 2px; padding-block: 12px; }
  .case { padding-block: 31px 35px; }
  .case__heading h2 { font-size: 23px; }
  .case--lead .case__heading h2 { font-size: 25px; }
  .detail-limits { grid-template-columns: 1fr; gap: 5px; }
  .detail-next { flex-direction: column; gap: 13px; }
  .evidence-page header { padding-top: 45px; }
  .evidence-text { padding: 16px; font-size: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .feature-card { transition: none; }
}