:root{--paper:#f5f3ec;--ink:#233d36;--muted:#626961;--line:#d8dacf;--accent:#925937;--white:#fcfbf7}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:28px}body{margin:0;background:var(--paper);color:var(--ink);font-family:'DM Sans',-apple-system,BlinkMacSystemFont,'Hiragino Kaku Gothic ProN','Yu Gothic',Meiryo,sans-serif;line-height:1.85;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}a:hover{text-decoration:underline;text-underline-offset:5px}button{font:inherit;cursor:pointer}a:focus-visible,button:focus-visible{outline:2px solid var(--accent);outline-offset:5px}img{max-width:100%;height:auto}h1,h2,h3,h4,p{margin-top:0}h2,h3,h4{font-weight:500}ul{padding-left:1.2em}[hidden]{display:none!important}.nav-inner,.container{width:min(1184px,calc(100% - 96px));margin-inline:auto}.nav-inner{min-height:104px;display:flex;align-items:center;gap:24px;border-bottom:1px solid var(--line)}.nav-logo{font-size:21px;font-weight:500;line-height:1.35;letter-spacing:-.5px;white-space:nowrap}.nav-logo span{display:block;font-size:10px;letter-spacing:2px;margin-top:6px;font-weight:400}.nav-links{display:flex;align-items:center;gap:20px;margin:0 0 0 auto;padding:0;list-style:none;font-size:11px}.lang-switch{display:flex;gap:12px;border-left:1px solid var(--line);padding-left:20px;font-size:11px}.lang-btn.active{border-bottom:1px solid var(--ink)}.nav-toggle{display:none}.eyebrow{font-size:10px;letter-spacing:1.8px;font-weight:600;margin-bottom:24px}.header-section{padding:74px 0 58px}.header-content{display:grid;grid-template-columns:1.08fr 1fr;gap:32px 80px}.hero-title h1{font:clamp(68px,7.3vw,100px)/1.04 'DM Serif Display',Georgia,serif;font-weight:400;letter-spacing:-3px;margin:0 0 30px}.hero-title h1 em{font-weight:400;color:var(--accent)}.hero-name{font-size:16px;letter-spacing:.04em;margin:0}.hero-intro{align-self:center;border-left:1px solid var(--line);padding-left:35px}.hero-tagline{font-size:20px;line-height:1.9;font-weight:500;margin-bottom:24px}.hero-sub{font-size:13px;line-height:2.1;color:var(--muted)}.hero-sub strong{color:var(--ink);font-weight:500}.text-link{display:inline-block;border-bottom:1px solid var(--ink);font-size:12px;padding:8px 0;margin-top:10px}.links{grid-column:1/-1;display:flex;flex-wrap:wrap;gap:14px 28px;border-top:1px solid var(--line);padding-top:25px;font-size:11px}.links a:after{content:' ↗';color:var(--accent)}.content,.section-alt{border-top:1px solid var(--line);padding:46px 0}.content-wrapper{width:100%}.content-wrapper>h2{font-size:25px;letter-spacing:.04em;margin:0 0 28px;line-height:1.45}.content-wrapper>h2:not(:first-child){margin-top:46px}.content-wrapper>.eyebrow+h2{margin-top:0}.content-wrapper>.eyebrow{color:var(--accent);margin-bottom:12px}#about{border-top-color:var(--ink)}#about .content-wrapper{display:grid;grid-template-columns:240px minmax(0,1fr);column-gap:70px}#about .eyebrow{grid-column:1;grid-row:1;align-self:start}#about h2{grid-column:1;grid-row:2;align-self:start;font:48px/1.1 'DM Serif Display',Georgia,serif;margin:0}#about .profile-info{grid-column:2;grid-row:1/4}#about .external-link-area{grid-column:2}.info-item{padding:17px 0;border-bottom:1px solid var(--line);font-size:13px;line-height:1.9}.info-item:first-child{padding-top:0}.info-item strong{display:block;font-size:10px;font-weight:500;color:var(--muted);margin-bottom:5px;letter-spacing:.06em}.info-item a{overflow-wrap:anywhere}.external-link-area{font-size:12px;margin:24px 0 0}.external-link-area a{border-bottom:1px solid #a6afa3;padding-bottom:3px;line-height:2}.news-item,.timeline-item{display:grid;grid-template-columns:190px minmax(0,1fr);gap:40px;padding:20px 0;border-bottom:1px solid var(--line);font-size:13px}.news-item:first-child,.timeline-item:first-child{padding-top:0}.news-item:last-child,.timeline-item:last-child{border-bottom:0}.news-date,.timeline-date{color:var(--muted);font-size:11px;letter-spacing:.02em;padding-top:3px}.news-content a,.timeline-content a{border-bottom:1px solid #a6afa3}.news-content strong{font-weight:500;color:var(--accent)}.tag{display:inline-block;font-size:11px;border-bottom:1px solid var(--line);padding:6px 0;margin:0 20px 12px 0;color:var(--muted)}.category-legend{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:22px;margin:24px 0 34px}.cat-badge{font-size:11px;line-height:1.9;border-top:1px solid var(--line);padding:15px 0}.cat-badge strong{color:var(--accent);font-size:14px;margin-right:10px}.cat-badge b{font-weight:500}.cat-badge span{display:block;color:var(--muted);margin-top:8px}.card-cat,.pub-cat{display:inline-block;font-size:10px;color:var(--accent);border:1px solid var(--line);padding:1px 6px;margin:0 8px 8px 0}.layer-row{display:grid;grid-template-columns:190px minmax(0,1fr);gap:40px;border-top:1px solid var(--line);padding:28px 0}.layer-row-label{font-size:13px}.layer-row-desc{display:block;font-size:10px;color:var(--muted);margin-top:5px}.layer-row-cards,.research-themes{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:28px}.theme-card h3{font-size:16px;line-height:1.6;margin:2px 0 10px}.theme-card p{font-size:12px;line-height:2;color:var(--muted);margin:0}.research-themes .theme-card{padding:22px 0;border-top:1px solid var(--line)}.research-tree-card{border:1px solid var(--line);padding:28px}.research-tree-link{display:grid;grid-template-columns:220px minmax(0,1fr);gap:36px}.research-tree-link:hover{text-decoration:none}.research-tree-thumbnail{background:var(--ink);color:var(--paper);display:flex;align-items:center;justify-content:center;min-height:200px;padding:25px}.thumbnail-content h4{font:28px/1.3 'DM Serif Display',Georgia,serif;margin-bottom:14px}.thumbnail-content p{font-size:11px;margin:0}.research-tree-content h4{font-size:18px;margin:0 0 14px}.research-tree-content p,.research-tree-content li{font-size:12px;line-height:1.9;color:var(--muted)}.research-tree-content ul{margin-bottom:24px}.external-link-button{font-size:12px;color:var(--accent)}.research-tree-link:hover .external-link-button{text-decoration:underline}.teaching-card h3{font-size:18px}.teaching-card>p{font-size:13px}.teaching-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px;margin:25px 0}.teaching-grid>div{border-top:1px solid var(--line);padding-top:20px}.teaching-grid strong{display:block;font-size:14px;font-weight:500;margin-bottom:10px}.teaching-grid span{font-size:12px;color:var(--muted)}.publications h3{font-size:17px;margin:32px 0 22px}.publications ul{list-style:none;padding:0;margin:0}.publications li{font-size:13px;line-height:1.95;border-top:1px solid var(--line);padding:23px 0;overflow-wrap:anywhere}.publications li strong{font-weight:500}.publications li>strong:first-of-type{font-size:16px;color:var(--ink)}.pub-link{font-size:11px;margin-top:12px;display:flex;flex-wrap:wrap;align-items:center;gap:14px}.pub-link a{border-bottom:1px solid var(--line)}.grant-note{font-size:11px;color:var(--muted);margin-top:5px}.data-cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:34px}.data-card{padding:24px 0;border-top:1px solid var(--line);min-width:0}.data-card h3{font:25px/1.3 'DM Serif Display',Georgia,serif;font-weight:400;margin-bottom:18px}.data-card p{font-size:12px;line-height:1.95;color:var(--muted)}.data-card-meta{display:flex;gap:12px;flex-wrap:wrap;font-size:10px;color:var(--muted);margin:16px 0}.data-badge,.data-card .social-link{display:inline-block;margin:8px 12px 8px 0;font-size:11px;overflow-wrap:anywhere}.data-theory-note{border-left:2px solid var(--line);padding-left:13px}#data-code>.content-wrapper>p{font-size:13px;color:var(--muted)}.contact-card>p{font-size:14px;line-height:2;max-width:800px}.contact-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:30px;margin-top:28px}.contact-item{font-size:12px;overflow-wrap:anywhere;border-top:1px solid var(--line);padding-top:20px}.contact-item strong{font-size:10px;color:var(--muted);font-weight:400}.footer{border-top:1px solid var(--ink);padding:30px 0}.footer p{font-size:10px;line-height:1.9;color:var(--muted);margin:0}.skip-link{position:absolute;top:-100px;left:20px;background:var(--ink);color:white;padding:15px;z-index:10}.skip-link:focus{top:10px}
/* The existing four-layer model and feedback arrow retain their structure. */
.scd-fw{background:#eaece2;border:1px solid var(--line);margin:24px 0 40px;padding:34px;container-type:inline-size}.scd-kicker{font-size:9px;letter-spacing:1.8px;color:var(--accent);text-transform:uppercase}.scd-title{font:34px/1.2 'DM Serif Display',Georgia,serif;margin:12px 0}.scd-lead{font-size:14px;line-height:1.8}.scd-lead em{display:block;font-style:normal;font-size:11px;color:var(--muted);margin-top:6px}.scd-flow{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:20px;margin-top:28px}.scd-rail,.scd-dot{display:none}.scd-card{border-top:1px solid #a6afa3;padding-top:17px}.scd-num{font-size:11px;color:var(--accent)}.scd-en{font-size:9px;letter-spacing:.09em;color:var(--muted);margin-top:10px}.scd-ja{font-size:17px;margin-top:5px}.scd-kw{font-size:11px;color:var(--muted);margin-top:8px}.scd-proj{border-top:1px solid var(--line);padding-top:12px;margin-top:14px}.scd-proj a{display:flex;gap:8px;font-size:11px;line-height:1.7;margin-bottom:8px}.scd-proj b{font-weight:500;color:var(--accent);min-width:20px}.scd-loop{margin-top:18px;position:relative;padding-top:50px}.scd-loop svg{position:absolute;top:0;width:100%;height:50px}.scd-loop svg path{stroke:var(--accent)}.scd-loop p{text-align:center;font-size:11px;color:var(--muted);margin:0}.scd-loop p b{color:var(--accent);font-weight:500}
@media(max-width:1050px){.nav-inner,.container{width:calc(100% - 48px)}.nav-links{gap:13px;font-size:10px}.nav-inner{gap:16px}.lang-switch{padding-left:12px}.header-content{gap:30px 40px}.hero-tagline{font-size:18px}.hero-intro{padding-left:25px}#about .content-wrapper{grid-template-columns:190px minmax(0,1fr);gap:0 40px}.scd-flow{grid-template-columns:repeat(2,minmax(0,1fr))}.scd-loop svg{display:none}.scd-loop{padding-top:0}.category-legend{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:760px){.nav-inner{flex-wrap:wrap;padding-block:20px;min-height:84px}.nav-logo{margin-right:auto}.nav-links{order:4;flex-basis:100%;display:flex;flex-wrap:wrap;margin:10px 0 0;font-size:12px;gap:0}.nav-links li{width:50%}.nav-links a{display:block;padding:10px 0}.js .nav-links{display:none}.js .nav-links.open{display:flex}.nav-toggle{display:block;background:transparent;border:1px solid var(--line);padding:9px 12px;font-size:11px;min-height:44px}.header-section{padding:45px 0 35px}.header-content{grid-template-columns:1fr;gap:30px}.hero-title h1{font-size:76px}.hero-title .eyebrow{font-size:8px;letter-spacing:1.3px}.hero-name{font-size:14px}.hero-intro{border-left:0;border-top:1px solid var(--line);padding:25px 0 0}.hero-tagline{font-size:17px}.hero-sub{font-size:12px}.links{gap:12px 22px}.content,.section-alt{padding:34px 0}.content-wrapper>h2{font-size:22px}.content-wrapper>h2:not(:first-child){margin-top:34px}#about .content-wrapper{display:block}#about h2{font-size:42px;margin:0 0 28px}.news-item,.timeline-item{grid-template-columns:1fr;gap:7px;padding:18px 0;font-size:12px}.info-item{font-size:12px}.research-tree-link{grid-template-columns:1fr;gap:24px}.research-tree-thumbnail{min-height:135px;justify-content:flex-start}.research-tree-card{padding:22px}.layer-row{grid-template-columns:1fr;gap:22px}.layer-row-cards,.research-themes{gap:22px}.teaching-grid,.data-cards,.contact-grid{grid-template-columns:1fr;gap:22px}.data-card h3{font-size:24px}.scd-fw{padding:23px}.scd-title{font-size:28px}.scd-flow{grid-template-columns:1fr;gap:22px}.scd-card{display:grid;grid-template-columns:30px minmax(0,1fr);column-gap:10px}.scd-num{grid-row:1/6}.scd-en{margin-top:0}.scd-ja,.scd-kw,.scd-proj{grid-column:2}.scd-lead{font-size:12px}.scd-proj{margin-top:12px}.publications li{font-size:12px}.publications li>strong:first-of-type{font-size:14px}.contact-card>p{font-size:12px}}
@media(max-width:440px){.nav-inner,.container{width:calc(100% - 40px)}.nav-logo{font-size:18px}.hero-title h1{font-size:66px;letter-spacing:-2px}.layer-row-cards,.research-themes,.category-legend{grid-template-columns:1fr}.hero-tagline br{display:none}.lang-switch{gap:10px;font-size:10px}.info-item a{font-size:12px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

/* Homepage hierarchy refinements, 2026-10-12. */
.header-section .hero-name {
  font-size: clamp(22px, 2.3vw, 30px);
  font-weight: 500;
  line-height: 1.55;
  letter-spacing: .015em;
  text-wrap: balance;
}
.hero-intro { min-width: 0; }
.hero-sub { max-width: 44ch; text-wrap: pretty; }
html[lang="ja"] .hero-sub { max-width: 32em; line-break: strict; }
.hero-sub .keep-phrase { white-space: nowrap; }
#research .tag {
  padding: 6px 12px;
  margin: 0 8px 10px 0;
  border: 1px solid #d8dacf;
  border-radius: 4px;
  background: #eaece2;
  color: #344a40;
  line-height: 1.6;
}
.scd-fw {
  background: #233d36;
  border-color: #233d36;
  color: #f5f3ec;
}
.scd-fw .scd-title, .scd-fw .scd-ja, .scd-fw .scd-proj a { color: #f5f3ec; }
.scd-fw .scd-lead, .scd-fw .scd-lead em,
.scd-fw .scd-en, .scd-fw .scd-kw, .scd-fw .scd-loop p { color: #d0d8ca; }
.scd-fw .scd-kicker, .scd-fw .scd-num,
.scd-fw .scd-proj b, .scd-fw .scd-loop p b { color: #e5c6a6; }
.scd-fw .scd-card, .scd-fw .scd-proj { border-color: #63796b; }
.scd-fw .scd-loop svg path { stroke: #e5c6a6; }
.scd-fw .scd-loop svg marker path { fill: #e5c6a6; }
.scd-fw a:focus-visible { outline-color: #e5c6a6; }
@media(max-width:760px) {
  .header-section .hero-name { font-size: 22px; }
  .hero-sub { max-width: none; }
}