:root {
      --ink: #071b33;
      --ink-soft: #435269;
      --paper: #ffffff;
      --wash: #f2f6fa;
      --line: #d7e0e9;
      --blue: #0957a4;
      --red: #d13f32;
      --max: 1160px;
      --serif: "Yu Mincho", "Hiragino Mincho ProN", "Noto Serif JP", Georgia, serif;
      --sans: Inter, "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      margin: 0;
      color: var(--ink);
      background: var(--paper);
      font-family: var(--sans);
      font-size: 16px;
      line-height: 1.8;
      -webkit-font-smoothing: antialiased;
    }
    a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: .22em; }
    a:hover { color: var(--blue); }
    button, a { -webkit-tap-highlight-color: transparent; }
    :focus-visible { outline: 3px solid #80bfff; outline-offset: 4px; }
    .skip-link {
      position: fixed;
      top: 12px;
      left: 12px;
      z-index: 100;
      transform: translateY(-160%);
      padding: 8px 14px;
      color: #fff;
      background: var(--ink);
    }
    .skip-link:focus { transform: translateY(0); }
    .wrap { width: min(calc(100% - 48px), var(--max)); margin-inline: auto; }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 20;
      border-bottom: 1px solid rgba(215, 224, 233, .9);
      background: rgba(255, 255, 255, .94);
      backdrop-filter: blur(14px);
    }
    .header-inner {
      min-height: 72px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 24px;
    }
    .brand {
      display: inline-flex;
      align-items: center;
      gap: 12px;
      text-decoration: none;
      font-family: var(--serif);
      font-size: 1rem;
      font-weight: 700;
      letter-spacing: .04em;
    }
    .monogram {
      width: 34px;
      height: 34px;
      display: grid;
      place-items: center;
      overflow: hidden;
      color: #fff;
      background: var(--ink);
      font-family: Georgia, serif;
      font-size: .95rem;
      letter-spacing: .06em;
    }
    .monogram img {
      display: block;
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .nav-group { display: flex; align-items: center; gap: 28px; }
    .main-nav { display: flex; gap: 24px; }
    .main-nav a {
      color: var(--ink-soft);
      font-size: .88rem;
      font-weight: 700;
      text-decoration: none;
      white-space: nowrap;
    }
    .main-nav a:hover { color: var(--blue); }
    .lang-switch {
      display: inline-flex;
      border: 1px solid var(--line);
      padding: 3px;
    }
    .lang-switch button {
      min-width: 42px;
      border: 0;
      padding: 5px 8px;
      color: var(--ink-soft);
      background: transparent;
      font: 700 .76rem/1.4 var(--sans);
      cursor: pointer;
    }
    .lang-switch button[aria-pressed="true"] { color: #fff; background: var(--ink); }

    .hero {
      position: relative;
      overflow: hidden;
      padding: clamp(72px, 12vw, 150px) 0 84px;
      color: #fff;
      background: var(--ink);
    }
    .hero::after {
      content: "税";
      position: absolute;
      right: max(-.15em, calc((100vw - var(--max)) / 2 - 80px));
      bottom: -.42em;
      color: rgba(255, 255, 255, .035);
      font-family: var(--serif);
      font-size: clamp(15rem, 40vw, 35rem);
      font-weight: 700;
      line-height: 1;
      pointer-events: none;
    }
    html[lang="en"] .hero::after { content: "TAX"; font-size: clamp(10rem, 28vw, 25rem); }
    .hero-grid {
      position: relative;
      z-index: 1;
      display: grid;
      grid-template-columns: minmax(0, 1.6fr) minmax(250px, .65fr);
      gap: clamp(48px, 9vw, 120px);
      align-items: end;
    }
    .eyebrow {
      display: flex;
      align-items: center;
      gap: 12px;
      margin: 0 0 24px;
      color: #9ccfff;
      font-size: .78rem;
      font-weight: 800;
      letter-spacing: .14em;
      text-transform: uppercase;
    }
    .eyebrow::before { content: ""; width: 34px; height: 2px; background: var(--red); }
    h1 {
      margin: 0;
      font-family: var(--serif);
      font-size: clamp(3.3rem, 8vw, 6.9rem);
      font-weight: 600;
      letter-spacing: -.045em;
      line-height: 1.02;
    }
    h1 span { display: block; margin-top: 14px; font: 500 clamp(1.1rem, 2.2vw, 1.55rem)/1.3 Georgia, serif; letter-spacing: .035em; }
    .hero-copy { border-left: 1px solid rgba(255, 255, 255, .25); padding-left: 28px; }
    .hero-copy p { margin: 0; font-family: var(--serif); font-size: clamp(1.12rem, 2vw, 1.4rem); line-height: 1.9; }
    .hero-role { margin-top: 24px !important; color: #aebfd0; font: 500 .88rem/1.75 var(--sans) !important; }

    .topic-band { border-bottom: 1px solid var(--line); background: var(--wash); }
    .topics { display: grid; grid-template-columns: repeat(3, 1fr); }
    .topic { padding: 22px 26px; border-left: 1px solid var(--line); }
    .topic:last-child { border-right: 1px solid var(--line); }
    .topic small { display: block; color: var(--blue); font-size: .7rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
    .topic strong { font-family: var(--serif); font-size: 1rem; font-weight: 600; }

    .section { padding: clamp(76px, 10vw, 126px) 0; }
    .section.alt { background: var(--wash); }
    .section-head {
      display: grid;
      grid-template-columns: 170px minmax(0, 1fr);
      gap: 40px;
      margin-bottom: 54px;
      align-items: start;
    }
    .section-kicker { margin: 4px 0 0; color: var(--blue); font-size: .76rem; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
    h2 { margin: 0; font-family: var(--serif); font-size: clamp(2rem, 4vw, 3.25rem); font-weight: 600; letter-spacing: -.025em; line-height: 1.35; }
    .section-intro { max-width: 720px; margin: 18px 0 0; color: var(--ink-soft); font-size: 1.03rem; }

    .research-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 2px solid var(--ink); }
    .research-card { min-height: 280px; padding: 30px 28px 34px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
    .research-card:first-child { border-left: 1px solid var(--line); }
    .research-number { color: var(--red); font: 700 .75rem/1 Georgia, serif; letter-spacing: .08em; }
    h3 { margin: 54px 0 14px; font-family: var(--serif); font-size: 1.35rem; line-height: 1.45; }
    .research-card p { margin: 0; color: var(--ink-soft); font-size: .94rem; }
    .research-card .research-note { font-size: .84rem; }

    .publication-list { border-top: 2px solid var(--ink); }
    .publication {
      display: grid;
      grid-template-columns: 100px minmax(0, 1fr) 34px;
      gap: 24px;
      align-items: start;
      padding: 26px 6px;
      border-bottom: 1px solid var(--line);
      text-decoration: none;
    }
    .publication:hover { color: inherit; background: rgba(255, 255, 255, .55); }
    .pub-year { color: var(--blue); font: 700 1rem/1.5 Georgia, serif; }
    .pub-title { margin: 0 0 5px; font-family: var(--serif); font-size: 1.05rem; font-weight: 700; line-height: 1.65; }
    .pub-meta { margin: 0; color: var(--ink-soft); font-size: .86rem; }
    .arrow { color: var(--blue); font-size: 1.5rem; line-height: 1; transition: transform .2s ease; }
    .publication:hover .arrow, .resource-link:hover .arrow { transform: translate(4px, -2px); }
    .all-link { display: inline-flex; align-items: center; gap: 10px; margin-top: 28px; color: var(--blue); font-weight: 800; }
    .publication-links { display: flex; flex-wrap: wrap; gap: 0 32px; }

    .split { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(50px, 9vw, 110px); }
    .split h2 { margin-bottom: 26px; }
    .split p { color: var(--ink-soft); }
    .course-heading { margin-top: 38px; font-size: clamp(1.25rem, 2.5vw, 1.65rem); }
    .course-list { margin: 18px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
    .course-list li { display: flex; justify-content: space-between; gap: 20px; padding: 15px 0; border-bottom: 1px solid var(--line); }
    .course-list span:first-child { min-width: 0; }
    .course-list span:last-child { color: var(--ink-soft); font-size: .84rem; text-align: right; }
    .timeline { margin: 28px 0 0; padding: 0; list-style: none; }
    .timeline li { display: grid; grid-template-columns: 64px 1fr; gap: 18px; padding: 0 0 22px; }
    .timeline time { color: var(--blue); font: 700 .9rem/1.65 Georgia, serif; }
    .timeline span { color: var(--ink-soft); }

    .resources { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
    .resource-link {
      display: grid;
      grid-template-columns: minmax(0, 1fr) 30px;
      min-height: 154px;
      padding: 26px;
      border: 1px solid var(--line);
      background: #fff;
      text-decoration: none;
    }
    .resource-link:hover { color: inherit; border-color: #8db8e2; box-shadow: 0 12px 35px rgba(7, 27, 51, .08); }
    .resource-label { color: var(--blue); font-size: .7rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
    .resource-title { align-self: end; margin: 30px 0 0; font-family: var(--serif); font-size: 1.15rem; font-weight: 700; }
    .resource-link .arrow { grid-row: 1 / 3; grid-column: 2; justify-self: end; }

    footer { padding: 42px 0; color: #b6c6d7; background: var(--ink); }
    .footer-inner { display: flex; justify-content: space-between; gap: 32px; align-items: end; }
    .footer-name { margin: 0 0 6px; color: #fff; font-family: var(--serif); font-size: 1.12rem; }
    .footer-copy, .footer-note { margin: 0; font-size: .78rem; }
    .footer-note { max-width: 420px; text-align: right; }

    [data-lang="en"] { display: none; }
    html[lang="en"] [data-lang="ja"] { display: none; }
    html[lang="en"] [data-lang="en"] { display: revert; }

    @media (max-width: 860px) {
      .main-nav { display: none; }
      .hero-grid, .section-head { grid-template-columns: 1fr; }
      .hero-copy { max-width: 560px; border-left: 0; border-top: 1px solid rgba(255, 255, 255, .25); padding: 24px 0 0; }
      .section-head { gap: 12px; }
      .research-grid { grid-template-columns: 1fr; }
      .research-card { min-height: auto; border-left: 1px solid var(--line); }
      h3 { margin-top: 30px; }
      .split { grid-template-columns: 1fr; }
    }

    @media (max-width: 620px) {
      .wrap { width: min(calc(100% - 32px), var(--max)); }
      .header-inner { min-height: 64px; }
      .brand > span:last-child { display: none; }
      .nav-group { gap: 10px; }
      .hero { padding-top: 72px; }
      .topics { grid-template-columns: 1fr; padding: 8px 0; }
      .topic, .topic:last-child { padding: 13px 0; border: 0; border-bottom: 1px solid var(--line); }
      .topic:last-child { border-bottom: 0; }
      .publication { grid-template-columns: 58px minmax(0, 1fr) 22px; gap: 12px; }
      .resources { grid-template-columns: 1fr; }
      .footer-inner { display: block; }
      .footer-note { margin-top: 20px; text-align: left; }
    }

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

/* Shared navigation and standalone content pages. */
.main-nav a[aria-current="page"] { color: var(--blue); text-decoration: underline; }
.reading-page { max-width: 820px; }
.reading-page > p:not(.section-kicker) { color: var(--ink-soft); }
.reading-page h1, .section-head h1 { margin: 0; color: var(--ink); font-family: var(--serif); font-size: clamp(1.8rem, 3.5vw, 2.65rem); line-height: 1.45; letter-spacing: -.025em; }
@media (max-width: 1100px) {
  .header-inner { flex-wrap: wrap; gap: 12px; padding-block: 12px; }
  .nav-group { width: 100%; justify-content: space-between; }
  .main-nav { display: flex; flex-wrap: wrap; gap: 8px 20px; }
}
@media (max-width: 620px) {
  .nav-group { flex-wrap: wrap; }
  .main-nav { width: 100%; gap: 4px 16px; }
  .main-nav a { padding-block: 8px; }
  .course-list li { display: block; }
  .course-list span { display: block; }
  .course-list span:last-child { margin-top: 6px; text-align: left; }
}
.reading-page h1 span, .section-head h1 span { margin: 0; font: inherit; letter-spacing: inherit; }

/* Stage 2: readable archives within the established site design. */
.archive-content { max-width: 960px; padding-bottom: 72px; overflow-wrap: anywhere; }
.archive-content h1 { margin: 20px 0; font: 600 clamp(1.75rem, 4vw, 2.8rem)/1.4 var(--serif); letter-spacing: -.025em; }
.archive-content h2 { margin: 0 0 20px; font-size: clamp(1.4rem, 3vw, 2rem); line-height: 1.5; }
.archive-content h3 { margin: 28px 0 12px; font-size: 1.15rem; }
.archive-content p { color: var(--ink-soft); }
.archive-content a { color: var(--blue); }
.archive-content li { margin-block: 12px; }
.archive-block { padding-top: 42px; margin-top: 36px; border-top: 1px solid var(--line); }
.archive-detail section { margin-block: 36px; }
.archive-nav { display: flex; flex-wrap: wrap; gap: 10px 22px; margin: 24px 0; }
.archive-nav a, .archive-back { font-size: .95rem; }
.archive-source, .archive-meta { font-size: .9rem; }
.archive-source { margin-top: 36px; }
.bibliography { padding-left: 1.5rem; }
.bibliography li { padding: 12px 0 18px 8px; border-bottom: 1px solid var(--line); }
.archive-content details { margin: 16px 0; border: 1px solid var(--line); }
.archive-content summary { cursor: pointer; padding: 16px 20px; font-weight: 700; background: var(--wash); }
.archive-detail, .region-body { padding: 8px 22px 20px; }
.resource-page { padding-top: 48px; }
.archive-content .box { padding: 20px; margin: 22px 0; background: var(--wash); }
.archive-content .pillbar { display: flex; gap: 20px; }
.archive-content .tag { display: inline-block; margin-left: 6px; color: var(--ink-soft); font-size: .875rem; }
.archive-content[id], .archive-content [id], .publication-list[id] { scroll-margin-top: 190px; }
.main-nav a[aria-current="location"] { color: var(--blue); text-decoration: underline; }
.naomi-links .archive-detail > section { padding-bottom: 18px; border-bottom: 1px solid var(--line); }
.naomi-links .archive-detail > section:last-child { border-bottom: 0; }
.naomi-links h3 { margin-top: 22px; color: var(--ink); }
.reading-page .subheading { margin-top: 34px; font-size: clamp(1.25rem, 2.5vw, 1.65rem); }
.archive-content blockquote { margin: 24px 0; padding: 12px 20px; border-left: 3px solid var(--blue); background: var(--wash); }
@media (max-width: 620px) {
  .archive-detail, .region-body { padding-inline: 14px; }
  .bibliography { padding-left: 1.2rem; }
  .archive-content[id], .archive-content [id], .publication-list[id] { scroll-margin-top: 220px; }
}
@media print { .archive-content details > * { display: block !important; } }

/* Stage 3: ordinary links between static language editions. */
.lang-switch a { display: inline-flex; align-items: center; justify-content: center; min-width: 42px; min-height: 36px; padding: 5px 8px; color: var(--ink-soft); font: 700 .76rem/1.4 var(--sans); text-decoration: none; }
.lang-switch a[aria-current="page"] { color: #fff; background: var(--ink); }
.lang-switch { flex-shrink: 0; }
.hero h1 { overflow-wrap: normal; }
html[lang="en"] .hero h1 { font-size: clamp(3.1rem, 7vw, 6rem); }
.resource-title { grid-column: 1; }

/* Stage 4: current research and the role of J-TaxNotes. */
#current-research { background: var(--wash); border-bottom: 1px solid var(--line); padding-block: 64px; scroll-margin-top: 210px; }
#current-research .m-current-head { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 20px; margin-bottom: 20px; }
#current-research .m-current-head a { color: var(--blue); font-size: .875rem; font-weight: 700; }
#current-research .m-topics { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 24px; }
#current-research .m-topics h3, #current-research .m-detail h3 { font-size: 1.125rem; line-height: 1.5; margin: 0; }
#current-research .m-detail { display: grid; grid-template-columns: 54px minmax(0,1fr); gap: 20px; padding: 28px 0; border-top: 1px solid var(--line); }
#current-research .m-number { color: var(--red); font: 700 .8125rem/1.8 Georgia,serif; }
#current-research .m-note { margin-top: 24px; padding: 28px; border-left: 3px solid var(--blue); background: #fff; }
#current-research .m-note h3 { margin: 0 0 12px; }
#current-research .m-kicker { color: var(--blue); font-size: .8125rem; font-weight: 700; letter-spacing: .1em; margin: 0 0 12px; }
#current-research .m-note p:not(.m-kicker) { color: var(--ink-soft); }
#current-research .m-note a { color: var(--blue); }
.resource-description { grid-column: 1; margin: 12px 0 0; font-size: .875rem; color: var(--ink-soft); }
@media(max-width:720px) {
 #current-research { padding-block: 42px; }
 #current-research .m-topics { grid-template-columns: 1fr; gap: 26px; }
 #current-research .m-detail { grid-template-columns: 28px minmax(0,1fr); gap: 12px; }
}

/* Tax treaty access page. */
.treaty-page { max-width: 960px; }
.treaty-page .treaty-toc,
.treaty-page .treaty-section {
  margin-top: 28px;
  padding: 24px 28px;
  border: 1px solid var(--line);
  background: var(--paper);
}
.treaty-page .treaty-toc { background: var(--wash); }
.treaty-page .treaty-toc p { margin-top: 0; }
.treaty-page .treaty-toc ul { margin-bottom: 0; }
.treaty-page .treaty-section h2 { margin-bottom: 14px; }
.treaty-page .treaty-section > ul { margin-bottom: 0; }
.treaty-page .treaty-badge {
  display: inline-block;
  margin-right: 8px;
  padding: 2px 9px;
  border: 1px solid var(--line);
  color: var(--ink);
  background: var(--wash);
  font-size: .82rem;
  font-weight: 700;
  line-height: 1.6;
}
.treaty-page .treaty-links { display: flex; flex-wrap: wrap; gap: 2px 12px; align-items: baseline; }
.treaty-page .treaty-links > div:first-child { flex-basis: 100%; }
.treaty-page .treaty-note { margin-bottom: 0; font-size: .9rem; }
@media (max-width: 620px) {
  .treaty-page .treaty-toc,
  .treaty-page .treaty-section { padding: 20px 18px; }
  .treaty-page .treaty-links { display: block; }
  .treaty-page .treaty-links a { display: inline; }
}