:root{
  --paper:#ece7da;
  --paper-2:#f7f3ea;
  --shell:#d8d3c7;
  --screen:#b8c28f;
  --screen-2:#a7b37c;
  --screen-ink:#2f3d31;
  --ink:#232623;
  --muted:#686d66;
  --line:rgba(35,38,35,.16);
  --plum:#632d58;
  --brick:#984255;
  --blue:#283e61;
  --white:#fffdf7;
  --shadow:0 24px 64px rgba(39,36,30,.14);
  --soft-shadow:0 12px 30px rgba(39,36,30,.09);
  --max:1180px;
  --article:760px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--ink);
  background:
    radial-gradient(circle at 8% 4%,rgba(99,45,88,.055),transparent 26%),
    radial-gradient(circle at 94% 12%,rgba(40,62,97,.05),transparent 30%),
    linear-gradient(180deg,var(--paper) 0%,var(--paper-2) 42%,var(--paper) 100%);
  font-family:-apple-system,BlinkMacSystemFont,"Hiragino Sans","Yu Gothic","YuGothic","Noto Sans JP",sans-serif;
  line-height:1.85;
  letter-spacing:.025em;
}
a{color:inherit;text-decoration:none}
button,input{font:inherit}
button{color:inherit}
img{display:block;max-width:100%;height:auto}
.container{width:min(calc(100% - 36px),var(--max));margin-inline:auto}
.skip-link{
  position:fixed;z-index:1000;left:12px;top:12px;padding:10px 14px;
  color:#fff;background:var(--ink);border-radius:10px;transform:translateY(-160%)
}
.skip-link:focus{transform:none}
.site-header{
  position:sticky;top:0;z-index:100;border-bottom:1px solid var(--line);
  background:rgba(236,231,218,.92);backdrop-filter:blur(14px)
}
.header-inner{min-height:72px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.brand{display:flex;flex-direction:column;line-height:1.16}
.brand strong{font-weight:950;letter-spacing:.1em}
.brand small{margin-top:5px;color:var(--muted);font-size:.62rem;font-weight:900;letter-spacing:.15em}
.nav{display:flex;align-items:center;gap:20px;font-size:.82rem;font-weight:850}
.nav a{position:relative;padding:9px 0}
.nav a::after{content:"";position:absolute;left:0;right:0;bottom:2px;height:3px;background:var(--plum);border-radius:3px;transform:scaleX(0);transform-origin:left;transition:transform .2s ease}
.nav a:hover::after,.nav a:focus-visible::after,.nav a[aria-current="page"]::after{transform:scaleX(1)}
.menu-button{display:none;border:1px solid var(--line);background:var(--paper-2);border-radius:999px;padding:9px 14px;font-weight:900}
.breadcrumb{display:flex;flex-wrap:wrap;gap:8px;color:var(--muted);font-size:.75rem;font-weight:850;letter-spacing:.06em}
.kicker,.eyebrow{color:var(--plum);font-size:.72rem;font-weight:950;letter-spacing:.18em;text-transform:uppercase}
.badge{
  display:inline-flex;align-items:center;min-height:28px;padding:0 10px;border:1px solid currentColor;
  border-radius:999px;font-size:.68rem;font-weight:950;letter-spacing:.1em
}
.badge.word{color:var(--plum)}
.badge.product{color:var(--blue)}
.badge.person{color:var(--brick)}
.badge.fact{color:#406242}
.badge.today{color:#79530c}
.text-link{display:inline-flex;align-items:center;gap:8px;font-weight:950}
.text-link::after{content:"→";transition:transform .2s ease}
.text-link:hover::after{transform:translateX(5px)}
.button{
  display:inline-flex;align-items:center;justify-content:center;min-height:48px;padding:0 20px;
  border:1px solid var(--ink);border-radius:999px;font-weight:900;transition:.2s ease
}
.button.primary{color:#fff;background:var(--ink)}
.button:hover{transform:translateY(-2px);box-shadow:var(--soft-shadow)}
.site-footer{margin-top:84px;padding:44px 0 52px;color:rgba(255,255,255,.78);background:var(--ink)}
.footer-grid{display:grid;grid-template-columns:1.2fr .8fr;gap:50px}
.footer-title{color:#fff;font-size:1.08rem;font-weight:950;letter-spacing:.08em}
.footer-copy{max-width:620px;font-size:.8rem}
.footer-nav{display:flex;justify-content:flex-end;align-items:flex-start;gap:18px;flex-wrap:wrap;font-size:.78rem;font-weight:850}
.footer-meta{margin-top:28px;padding-top:24px;border-top:1px solid rgba(255,255,255,.14);font-size:.72rem;line-height:1.8}

/* Research index */
.index-hero{padding:86px 0 76px;border-bottom:1px solid var(--line)}
.index-hero-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(360px,.72fr);gap:60px;align-items:center;margin-top:26px}
.index-hero h1{margin:14px 0 22px;font-size:clamp(3rem,7vw,6.6rem);line-height:1.02;letter-spacing:-.065em;font-weight:950}
.index-lead{max-width:700px;margin:0;font-size:clamp(1.05rem,1.5vw,1.28rem);font-weight:800;line-height:1.95}
.file-machine{
  position:relative;padding:30px;border:1px solid rgba(47,61,49,.28);border-radius:28px;
  background:linear-gradient(145deg,var(--screen),var(--screen-2));color:var(--screen-ink);
  box-shadow:inset 0 0 0 8px rgba(255,255,255,.14),var(--shadow)
}
.file-machine::after{content:"";position:absolute;inset:14px;border:1px solid rgba(47,61,49,.17);border-radius:18px;pointer-events:none}
.machine-top,.machine-bottom{position:relative;z-index:1;display:flex;justify-content:space-between;gap:20px;font-size:.68rem;font-weight:950;letter-spacing:.14em}
.machine-title{position:relative;z-index:1;margin:34px 0 28px;font-size:clamp(2rem,4vw,3.6rem);line-height:1.18;font-weight:950;letter-spacing:-.04em}
.machine-list{position:relative;z-index:1;display:grid;gap:8px;margin:0;padding:0;list-style:none;font-size:.79rem;font-weight:850}
.machine-list li{display:flex;align-items:center;gap:10px}
.machine-list li::before{content:"";width:8px;height:8px;border-radius:2px;background:var(--screen-ink)}
.index-section{padding:78px 0}
.index-section.alt{border-top:1px solid var(--line);border-bottom:1px solid var(--line);background:rgba(255,253,247,.38)}
.section-head{display:grid;grid-template-columns:1fr minmax(330px,.72fr);gap:45px;align-items:end;margin-bottom:36px}
.section-head h2{margin:9px 0 0;font-size:clamp(2.2rem,5vw,4rem);line-height:1.18;letter-spacing:-.045em}
.section-head p{margin:0;color:var(--muted)}
.filter-bar{display:flex;gap:9px;flex-wrap:wrap;margin-bottom:28px}
.filter-button{
  min-height:40px;padding:0 14px;border:1px solid var(--line);border-radius:999px;background:rgba(255,253,247,.64);
  font-size:.76rem;font-weight:900;cursor:pointer
}
.filter-button.active{color:#fff;background:var(--ink);border-color:var(--ink)}
.article-list{display:grid;grid-template-columns:repeat(12,1fr);gap:18px}
.research-card{
  grid-column:span 4;display:flex;flex-direction:column;min-height:330px;padding:25px;border:1px solid var(--line);
  border-radius:23px;background:rgba(255,253,247,.8);box-shadow:0 1px 0 rgba(255,255,255,.5);
  transition:transform .24s ease,box-shadow .24s ease,border-color .24s ease
}
.research-card.featured{grid-column:span 8;min-height:390px;background:linear-gradient(145deg,rgba(184,194,143,.93),rgba(167,179,124,.86));color:var(--screen-ink)}
.research-card:hover{transform:translateY(-5px);box-shadow:var(--soft-shadow);border-color:rgba(99,45,88,.35)}
.research-card[hidden]{display:none}
.card-top{display:flex;align-items:center;justify-content:space-between;gap:18px}
.card-no{font-size:.68rem;font-weight:950;letter-spacing:.14em}
.card-state{color:var(--muted);font-size:.68rem;font-weight:900}
.research-card.featured .card-state{color:var(--screen-ink)}
.research-card h3{margin:36px 0 14px;font-size:clamp(1.55rem,2.5vw,2.55rem);line-height:1.35;letter-spacing:-.035em}
.research-card p{margin:0;color:var(--muted);font-size:.92rem}
.research-card.featured p{color:var(--screen-ink)}
.card-bottom{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-top:auto;padding-top:30px}
.card-meta{font-size:.72rem;font-weight:850}
.card-arrow{display:flex;align-items:center;justify-content:center;width:48px;height:48px;border-radius:999px;color:#fff;background:var(--ink);font-size:1.2rem}
.research-card.coming{opacity:.72;cursor:default}
.research-card.coming:hover{transform:none;box-shadow:none}
.method-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.method-card{padding:26px;border:1px solid var(--line);border-radius:22px;background:var(--white)}
.method-no{display:flex;align-items:center;justify-content:center;width:42px;height:42px;border-radius:13px;color:var(--screen-ink);background:var(--screen);font-weight:950}
.method-card h3{margin:20px 0 8px;font-size:1.2rem}
.method-card p{margin:0;color:var(--muted);font-size:.9rem}
.serial-box{display:grid;grid-template-columns:.8fr 1.2fr;gap:48px;align-items:start;padding:34px;border:1px solid var(--line);border-radius:26px;background:var(--ink);color:#fff}
.serial-box h2{margin:10px 0 0;font-size:clamp(2rem,4vw,3.5rem);line-height:1.2}
.serial-box p{margin:0;color:rgba(255,255,255,.72)}
.serial-points{display:grid;gap:12px;margin:24px 0 0;padding:0;list-style:none}
.serial-points li{display:flex;gap:12px}
.serial-points li::before{content:"FILE";flex:none;color:var(--screen);font-size:.66rem;font-weight:950;letter-spacing:.12em}

/* Article */
.progress{position:fixed;z-index:150;left:0;top:0;width:100%;height:4px;transform-origin:left;background:var(--plum);transform:scaleX(0)}
.article-hero{padding:64px 0 72px;border-bottom:1px solid var(--line)}
.article-hero-inner{margin-top:25px;display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:56px;align-items:end}
.article-hero h1{margin:16px 0 22px;font-size:clamp(2.65rem,6.5vw,6rem);line-height:1.08;letter-spacing:-.06em;font-weight:950}
.article-deck{max-width:760px;margin:0;font-size:clamp(1.05rem,1.6vw,1.3rem);font-weight:800;line-height:1.95}
.article-meta{display:flex;align-items:center;gap:11px;flex-wrap:wrap;margin-top:26px;color:var(--muted);font-size:.76rem;font-weight:850}
.file-stamp{
  padding:24px;border:1px solid rgba(47,61,49,.3);border-radius:23px;background:linear-gradient(145deg,var(--screen),var(--screen-2));
  color:var(--screen-ink);box-shadow:inset 0 0 0 7px rgba(255,255,255,.14),var(--soft-shadow)
}
.file-stamp small{display:block;font-size:.66rem;font-weight:950;letter-spacing:.16em}
.file-stamp strong{display:block;margin-top:20px;font-size:2.4rem;line-height:1;font-weight:950}
.file-stamp p{margin:12px 0 0;font-size:.78rem;font-weight:850}
.article-layout{display:grid;grid-template-columns:240px minmax(0,var(--article));gap:56px;justify-content:center;align-items:start;padding:70px 0}
.toc{position:sticky;top:102px}
.toc-label{margin-bottom:14px;color:var(--plum);font-size:.66rem;font-weight:950;letter-spacing:.15em}
.toc ol{display:grid;gap:4px;margin:0;padding:0;list-style:none;border-left:1px solid var(--line)}
.toc a{display:block;padding:8px 0 8px 16px;color:var(--muted);font-size:.76rem;font-weight:800;line-height:1.45;border-left:3px solid transparent;margin-left:-2px}
.toc a.active{color:var(--ink);border-left-color:var(--plum)}
.article-body{min-width:0}
.article-body p{margin:0 0 1.55em;font-size:1.01rem}
.article-body h2{scroll-margin-top:100px;margin:4.2rem 0 1.3rem;font-size:clamp(2rem,4vw,3.15rem);line-height:1.28;letter-spacing:-.04em}
.article-body h3{scroll-margin-top:100px;margin:2.8rem 0 1rem;font-size:clamp(1.35rem,2.5vw,1.9rem);line-height:1.4;letter-spacing:-.025em}
.article-body h2:first-child{margin-top:0}
.dropcap::first-letter{float:left;margin:.14em .13em 0 0;color:var(--plum);font-size:4.8rem;font-weight:950;line-height:.72}
.summary-panel{
  margin:0 0 3.2rem;padding:28px 30px;border-left:8px solid var(--plum);border-radius:0 20px 20px 0;background:rgba(255,253,247,.78)
}
.summary-panel strong{display:block;margin-bottom:12px;color:var(--plum);font-size:.72rem;letter-spacing:.14em}
.summary-panel p{margin:0;font-size:1.12rem;font-weight:850}
.idea-formula{display:grid;grid-template-columns:1fr auto 1fr auto 1fr;gap:12px;align-items:center;margin:34px 0}
.idea-formula span{display:flex;align-items:center;justify-content:center;min-height:104px;padding:18px;text-align:center;border:1px solid var(--line);border-radius:18px;background:var(--white);font-weight:950}
.idea-formula b{color:var(--plum);font-size:1.5rem}
.source-note,.analysis-note{
  margin:30px 0;padding:22px 24px;border:1px solid var(--line);border-radius:19px;background:rgba(255,253,247,.72)
}
.source-note{border-top:5px solid var(--blue)}
.analysis-note{border-top:5px solid var(--plum)}
.note-label{display:block;margin-bottom:8px;font-size:.68rem;font-weight:950;letter-spacing:.13em}
.source-note .note-label{color:var(--blue)}
.analysis-note .note-label{color:var(--plum)}
.source-note p,.analysis-note p{margin:0;font-size:.92rem}
.case-study{margin:3.2rem 0 4rem;padding-top:2rem;border-top:1px solid var(--line)}
.case-heading{display:grid;grid-template-columns:66px 1fr;gap:18px;align-items:start}
.case-number{display:flex;align-items:center;justify-content:center;width:58px;height:58px;border-radius:17px;color:#fff;background:var(--ink);font-size:1.25rem;font-weight:950}
.case-heading h3{margin:0}
.figure{margin:24px 0 28px;padding:10px;border:1px solid var(--line);border-radius:21px;background:var(--shell);box-shadow:var(--soft-shadow)}
.figure img{display:block;width:100%;height:auto;aspect-ratio:1400 / 788;object-fit:contain;border-radius:14px;background:#fff}
.figure figcaption{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;padding:12px 5px 2px;color:var(--muted);font-size:.72rem}
.flow{display:grid;grid-template-columns:1fr auto 1fr;gap:12px;align-items:center;margin:26px 0}
.flow div{padding:17px;border:1px solid var(--line);border-radius:15px;background:var(--white);font-weight:850;text-align:center}
.flow b{color:var(--plum)}
.pullquote{margin:3.4rem 0;padding:34px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);font-size:clamp(1.65rem,4vw,3rem);font-weight:950;line-height:1.45;letter-spacing:-.035em}
.pullquote em{color:var(--plum);font-style:normal}
.key-list{display:grid;gap:12px;margin:24px 0 34px;padding:0;list-style:none}
.key-list li{display:grid;grid-template-columns:42px 1fr;gap:14px;align-items:start;padding:18px;border:1px solid var(--line);border-radius:16px;background:rgba(255,253,247,.68)}
.key-list b{display:flex;align-items:center;justify-content:center;width:38px;height:38px;border-radius:11px;color:var(--screen-ink);background:var(--screen)}
.sources{margin-top:4rem;padding-top:2.4rem;border-top:1px solid var(--line)}
.sources h2{margin-top:0;font-size:1.65rem}
.sources ol{margin:0;padding-left:1.25rem;color:var(--muted);font-size:.82rem}
.article-end{margin-top:4rem;padding:28px;border:1px solid var(--line);border-radius:22px;background:var(--ink);color:#fff}
.article-end small{font-size:.68rem;font-weight:950;letter-spacing:.14em;color:var(--screen)}
.article-end h2{margin:12px 0 10px;font-size:1.7rem}
.article-end p{margin:0;color:rgba(255,255,255,.7)}
.article-nav{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:18px}
.article-nav a,.article-nav span{display:block;padding:18px;border:1px solid rgba(255,255,255,.16);border-radius:16px}
.article-nav small{display:block;margin-bottom:6px;color:rgba(255,255,255,.55)}
.article-nav strong{font-size:.91rem}
.article-nav .disabled{opacity:.45}
.share-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:20px}
.share-button{min-height:42px;padding:0 15px;border:1px solid var(--line);border-radius:999px;background:var(--white);font-size:.76rem;font-weight:900;cursor:pointer}
.share-status{align-self:center;color:var(--muted);font-size:.74rem}

/* Template helper */
.template-note{margin:28px 0;padding:20px;border:2px dashed var(--brick);border-radius:16px;background:#fff8f1;color:#5c2d21;font-size:.86rem}

@media(max-width:920px){
  .nav{display:none;position:absolute;left:18px;right:18px;top:72px;padding:16px;border:1px solid var(--line);border-radius:18px;background:var(--paper-2);box-shadow:var(--soft-shadow)}
  .nav.open{display:grid}
  .menu-button{display:block}
  .index-hero-grid,.article-hero-inner,.section-head,.serial-box,.footer-grid{grid-template-columns:1fr}
  .footer-nav{justify-content:flex-start}
  .article-layout{grid-template-columns:1fr;gap:0;padding-top:38px}
  .toc{position:static;margin-bottom:34px;padding:18px;border:1px solid var(--line);border-radius:17px;background:rgba(255,253,247,.65)}
  .toc ol{grid-template-columns:repeat(2,1fr);display:grid;border-left:0}
  .toc a{border-left:0;margin-left:0;padding:7px}
  .toc a.active{border-left:0;color:var(--plum)}
  .research-card,.research-card.featured{grid-column:span 6}
}
@media(max-width:650px){
  .container{width:min(calc(100% - 24px),var(--max))}
  .index-hero{padding:56px 0 58px}
  .index-hero h1{font-size:3.15rem}
  .index-section{padding:60px 0}
  .research-card,.research-card.featured{grid-column:1/-1;min-height:310px}
  .method-grid{grid-template-columns:1fr}
  .article-hero{padding:44px 0 52px}
  .article-hero-inner{gap:32px}
  .article-hero h1{font-size:2.75rem}
  .file-stamp{max-width:280px}
  .toc ol{grid-template-columns:1fr}
  .article-body p{font-size:.98rem}
  .idea-formula{grid-template-columns:1fr}
  .idea-formula b{transform:rotate(90deg);text-align:center}
  .flow{grid-template-columns:1fr}
  .flow b{transform:rotate(90deg)}
  .case-heading{grid-template-columns:52px 1fr}
  .case-number{width:48px;height:48px;border-radius:14px}
  .article-nav{grid-template-columns:1fr}
  .summary-panel{padding:24px 22px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *{animation:none!important;transition:none!important}
}