:root{
  --bg:#ffffff;
  --panel:#f5f5f7;
  --divider-fill:#e8e8ed;
  --deep:#000000;
  --ink:#1d1d1f;
  --elevated:#3a3a3c;
  --muted:#6e6e73;
  --muted-2:#86868b;
  --line:rgb(0 0 0 / 8%);
  --line-strong:rgb(0 0 0 / 16%);
  --line-dark:rgb(255 255 255 / 16%);
  --signal:#1d1d1f;
  --pad:clamp(22px,5vw,76px);
  --max:1540px;
  --ease:cubic-bezier(.16,1,.3,1);
  --font-sans:-apple-system,BlinkMacSystemFont,"SF Pro Display","SF Pro Text","Helvetica Neue",Helvetica,Arial,sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--bg)}
body{min-width:320px;margin:0;color:var(--ink);background:var(--bg);font-family:var(--font-sans);line-height:1.5;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit}
.skip-link{position:fixed;z-index:20;top:12px;left:12px;padding:10px 14px;color:var(--bg);background:var(--ink);transform:translateY(-150%)}
.skip-link:focus{transform:none}

/* header + brand */
.site-header{position:relative;z-index:5;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;min-height:76px;padding:0 var(--pad);border-bottom:1px solid var(--line)}
.brand-lockup{display:flex;align-items:center;gap:11px}
.brand-lockup-small{display:flex;flex-direction:column;align-items:flex-start;gap:6px;color:var(--muted);font-size:10px;letter-spacing:.04em}
.brand-lockup-name{color:var(--ink);font-size:12px;font-weight:600;letter-spacing:-.01em}
.brand-lockup-role{color:var(--muted)}
.brandmark{flex:none;display:block}
.wordmark{font-size:16px;font-weight:600;letter-spacing:-.01em}
.wordmark span{font-weight:400;color:var(--muted)}
.header-status,.header-link{font-size:12px;color:var(--muted)}
.header-status{display:flex;gap:8px;align-items:center}
.header-status i,.signal-dot{display:inline-block;width:6px;height:6px;border-radius:50%;background:var(--ink)}
.header-link{justify-self:end;color:var(--ink);font-weight:500}
.header-link:hover{color:var(--signal)}
main{overflow:hidden}

/* shared label style — quiet operational voice, no mono/uppercase shouting */
.hero-meta,.eyebrow,.chapter-head>span,.hero-facts dt,.palette-group-label,.palette b,.palette span,.visual-notes span,.type-specimen>span,.type-specimen small,.architecture-card>span,.architecture-card>b,.stage-top,.rollout-list>b{font-size:12px;font-weight:500;letter-spacing:0;color:var(--muted)}

/* hero */
.hero,.chapter,.chapter-nav,.site-footer{width:min(100%,var(--max));margin-inline:auto}
.hero{position:relative;min-height:600px;padding:clamp(92px,13vw,190px) var(--pad) 70px}
.hero-meta{position:relative;display:flex;justify-content:space-between}
.eyebrow{position:relative;margin-top:clamp(85px,12vw,180px);color:var(--signal)}
h1,h2,h3,p{margin:0}
.hero h1{position:relative;margin-top:16px;font-size:clamp(64px,11vw,168px);font-weight:600;line-height:.98;letter-spacing:-.03em;color:var(--ink)}
.hero h1 em{color:var(--muted-2);font-style:normal;font-weight:600}
.chapter-head h2 em,.position-card em,.type-specimen p em{color:var(--muted-2);font-style:normal;font-weight:inherit}
.hero-bottom{position:relative;display:grid;grid-template-columns:1fr .52fr;gap:40px;margin-top:clamp(60px,8vw,110px);margin-left:25%}
.hero-lede{max-width:530px;font-size:clamp(18px,2vw,24px);line-height:1.35;color:var(--muted)}
.hero-facts{display:grid;gap:13px;align-content:end}
.hero-facts div{display:flex;justify-content:space-between;gap:12px;padding-top:8px;border-top:1px solid var(--line);font-size:13px}
.hero-facts dd{margin:0;color:var(--muted)}
.hero-facts dd:last-child{display:flex;gap:7px;align-items:center}

/* chapter nav + shell */
.chapter-nav{display:grid;grid-template-columns:repeat(6,1fr);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.chapter-nav a{display:grid;gap:25px;min-height:100px;padding:17px;border-right:1px solid var(--line);font-size:13px;color:var(--ink)}
.chapter-nav a:last-child{border-right:0}
.chapter-nav span{color:var(--signal);font-size:12px}
.chapter-nav a:hover{color:var(--signal)}
.chapter{padding:clamp(90px,12vw,170px) var(--pad)}
.chapter-paper{max-width:none;color:var(--ink);background:var(--panel)}
.chapter-ink{max-width:none;color:#ffffff;background:var(--deep)}
.chapter-ink .hero-meta,.chapter-ink .eyebrow{color:var(--muted-2)}
.chapter-head{display:grid;grid-template-columns:.68fr 1fr;gap:40px;margin-bottom:clamp(50px,7vw,100px)}
.chapter-head>span{color:var(--signal)}
.chapter-ink .chapter-head>span{color:var(--muted-2)}
.chapter-head h2{font-size:clamp(44px,6vw,98px);font-weight:600;line-height:.98;letter-spacing:-.025em}

/* position */
.position-grid{display:grid;grid-template-columns:1fr .8fr .65fr;gap:clamp(28px,5vw,90px);margin-left:23%}
.lead{font-size:clamp(21px,2.6vw,34px);line-height:1.2;letter-spacing:-.015em}
.prose{display:grid;gap:22px;color:var(--muted);font-size:15px}
.position-card{display:grid;align-content:space-between;min-height:300px;padding:26px;background:var(--panel);color:var(--ink)}
.position-card span,.position-card small{font-size:12px;font-weight:500;color:var(--muted)}
.position-card strong{font-size:clamp(22px,2.2vw,34px);font-weight:600;line-height:1.05;letter-spacing:-.02em}
.position-card em{color:var(--muted-2);font-style:normal}

/* principles */
.principle-list{display:grid;max-width:1080px;margin:0 0 0 23%;padding:0;list-style:none}
.principle-list li{display:grid;grid-template-columns:60px 1fr 1fr;gap:20px;padding:24px 0;border-top:1px solid var(--line)}
.principle-list li:last-child{border-bottom:1px solid var(--line)}
.principle-list>li>span{color:var(--muted);font-size:12px;font-weight:500}
.principle-list h3{font-size:clamp(20px,2.2vw,30px);font-weight:600;line-height:1.1;letter-spacing:-.015em}
.principle-list p{color:var(--muted);font-size:14px}

/* brandmark usage guide */
.mark-guide{display:flex;flex-wrap:wrap;gap:1px;margin-bottom:56px;border:1px solid var(--line);background:var(--line)}
.mark-guide-display{flex:0 0 260px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:18px;padding:40px;background:var(--panel)}
.mark-guide-frame{display:flex;align-items:center;justify-content:center;padding:28px;border:1px dashed var(--line-strong)}
.mark-guide-display small{color:var(--muted);font-size:12px;text-align:center}
.mark-guide-notes{flex:1 1 380px;padding:30px 32px;background:var(--panel)}
.mark-guide-notes>span{color:var(--muted)}
.mark-guide-notes h3{margin-top:14px;font-size:24px;font-weight:600;letter-spacing:-.015em}
.mark-guide-notes>p{margin-top:12px;max-width:56ch;color:var(--muted);font-size:14px}
.mark-rules{display:flex;flex-direction:column;gap:14px;margin-top:24px;padding-top:20px;border-top:1px solid var(--line);list-style:none}
.mark-rules li{display:flex;gap:16px}
.mark-rules b{flex:0 0 108px;font-size:12px;font-weight:600;color:var(--ink)}
.mark-rules span{color:var(--muted);font-size:13px;line-height:1.4}

/* colour system (greyscale) */
.palette{display:flex;flex-wrap:wrap;gap:1px;background:var(--line);border:1px solid var(--line)}
.palette-group{flex:1 1 230px;display:flex;flex-direction:column;background:var(--bg)}
.palette-group-label{padding:14px 20px 0;color:var(--muted)}
.swatch{display:grid;align-content:space-between;min-height:96px;padding:16px 20px;text-align:left;border:0;border-top:1px solid var(--line);cursor:pointer;transition:outline-color .15s var(--ease)}
.palette-group>.swatch:first-of-type{border-top:0;margin-top:14px}
.swatch.is-active{outline:2px solid var(--ink);outline-offset:-2px}
.swatch:hover{outline:1px solid var(--muted);outline-offset:-1px}
.swatch span{font-size:12px}

.visual-notes{display:flex;flex-wrap:wrap;gap:1px;margin-top:30px;border:1px solid var(--line);background:var(--line)}
.visual-notes article{flex:1 1 260px;min-height:210px;padding:22px;background:var(--bg)}
.visual-notes span{color:var(--muted)}
.visual-notes h3{margin-top:50px;font-size:22px;font-weight:600;letter-spacing:-.015em}
.visual-notes p{margin-top:12px;color:var(--muted);font-size:14px}

/* type specimen */
.type-specimen{display:grid;gap:18px;margin-top:90px;padding:30px;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.type-specimen p{font-size:clamp(30px,4.2vw,64px);line-height:1.08;letter-spacing:-.02em;font-weight:600}
.type-specimen small{color:var(--muted)}

.chapter-ink .chapter-head h2 em{color:var(--muted-2)}

/* architecture */
.architecture-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line-dark);border:1px solid var(--line-dark)}
.architecture-card{display:grid;min-height:260px;padding:22px;background:var(--deep);border-right:1px solid var(--line-dark)}
.architecture-card:nth-child(3n){border-right:0}
.architecture-card:nth-child(n+4){border-top:1px solid var(--line-dark)}
.architecture-card>span{color:var(--muted-2)}
.architecture-card h3{align-self:end;font-size:clamp(22px,2.6vw,36px);font-weight:600;line-height:1.02;letter-spacing:-.02em}
.architecture-card p{margin-top:12px;color:var(--muted-2);font-size:14px}
.architecture-card>b{align-self:end;margin-top:28px;color:#ffffff;font-weight:600}
.architecture-card-feature{background:#ffffff;color:var(--ink)}
.architecture-card-feature>span{color:var(--muted)}
.architecture-card-feature p{color:var(--muted)}
.architecture-card-feature>b{color:var(--ink)}

/* interaction */
.interaction-layout{display:grid;grid-template-columns:1.25fr .75fr;gap:1px;background:var(--line);border:1px solid var(--line)}
.interaction-stage{display:grid;min-height:480px;padding:28px;background:var(--deep);color:#ffffff;transition:background .35s var(--ease)}
.stage-top{display:flex;justify-content:space-between}
.stage-top span{color:var(--muted-2)}
.stage-center{position:relative;display:grid;place-items:center;min-height:230px}
.stage-center i{position:absolute;width:clamp(100px,15vw,230px);aspect-ratio:1;border:1px solid rgb(255 255 255 / 22%);border-radius:50%;animation:orbit 8s linear infinite}
.stage-center i:nth-child(2){width:65%;animation-direction:reverse;animation-duration:11s}
.stage-center i:nth-child(3){width:34%;animation-duration:5s}
.stage-center strong{position:relative;font-size:clamp(26px,3.6vw,52px);font-weight:600;letter-spacing:-.02em}
.interaction-stage p{max-width:460px;font-size:17px;line-height:1.35;color:var(--muted-2)}
.stage-action{justify-self:start;align-self:end;min-height:42px;padding:0 16px;border:1px solid #ffffff;border-radius:999px;background:transparent;color:#ffffff;cursor:pointer;font-size:13px;font-weight:500}
.stage-action:hover{color:var(--ink);background:#ffffff}
.interaction-list{display:grid;background:var(--bg)}
.interaction-item{display:grid;grid-template-columns:36px 1fr;gap:2px 12px;padding:18px;text-align:left;border:0;border-bottom:1px solid var(--line);background:transparent;cursor:pointer}
.interaction-item:last-child{border-bottom:0}
.interaction-item span{grid-row:span 2;color:var(--muted);font-size:12px}
.interaction-item b{font-size:17px;font-weight:600}
.interaction-item small{color:var(--muted)}
.interaction-item.is-active{color:var(--ink);background:var(--panel)}
.interaction-item.is-active span{color:var(--signal)}

/* rollout */
.rollout-list{display:grid;grid-template-columns:repeat(4,1fr);border-top:1px solid var(--line);border-left:1px solid var(--line)}
.rollout-list>div{display:grid;gap:16px;min-height:240px;padding:20px;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
.rollout-list span{color:var(--muted);font-size:12px;font-weight:500}
.rollout-list h3{font-size:22px;font-weight:600;line-height:1.1;letter-spacing:-.015em}
.rollout-list p{color:var(--muted);font-size:14px}
.rollout-list b{align-self:end;color:var(--ink);font-weight:600}

.site-footer{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:22px var(--pad);border-top:1px solid var(--line);color:var(--muted);font-size:12px}

@keyframes orbit{to{transform:rotate(360deg)}}

@media(max-width:900px){
  .site-header{grid-template-columns:1fr auto}
  .header-status{display:none}
  .hero{min-height:520px}
  .hero-bottom{grid-template-columns:1fr;margin-left:12%}
  .chapter-nav{grid-template-columns:repeat(3,1fr)}
  .chapter-nav a:nth-child(n+4){border-top:1px solid var(--line)}
  .chapter-head{grid-template-columns:1fr;gap:24px}
  .position-grid,.principle-list{margin-left:0}
  .position-grid{grid-template-columns:1fr 1fr}
  .position-card{grid-column:1/-1}
  .architecture-grid{grid-template-columns:1fr 1fr}
  .architecture-card:nth-child(3n){border-right:1px solid var(--line-dark)}
  .architecture-card:nth-child(2n){border-right:0}
  .architecture-card:nth-child(n+3){border-top:1px solid var(--line-dark)}
  .interaction-layout{grid-template-columns:1fr}
  .rollout-list{grid-template-columns:1fr 1fr}
  .rollout-list>div:nth-child(2n){border-right:0}
  .rollout-list>div:nth-child(n+3){border-top:1px solid var(--line)}
}

@media(max-width:600px){
  .site-header{min-height:64px}
  .wordmark{font-size:14px}
  .header-link{font-size:12px}
  .hero{min-height:auto;padding-top:72px}
  .hero h1{font-size:clamp(56px,17vw,96px)}
  .hero-bottom{margin-left:0}
  .chapter-nav{grid-template-columns:repeat(2,1fr)}
  .chapter-nav a{min-height:80px}
  .chapter{padding-top:76px;padding-bottom:76px}
  .position-grid{grid-template-columns:1fr}
  .position-card{grid-column:auto}
  .mark-guide-display{flex-basis:100%}
  .palette-group{flex:1 1 100%}
  .principle-list li{grid-template-columns:34px 1fr}
  .principle-list p{grid-column:2}
  .architecture-grid,.rollout-list{grid-template-columns:1fr}
  .architecture-card,.architecture-card:nth-child(3n),.architecture-card:nth-child(2n){border-right:0;border-top:0;border-bottom:1px solid var(--line-dark)}
  .architecture-card:last-child{border-bottom:0}
  .rollout-list>div,.rollout-list>div:nth-child(2n){border-right:0;border-top:0;border-bottom:1px solid var(--line)}
  .rollout-list>div:last-child{border-bottom:0}
  .site-footer{display:grid;gap:12px;text-align:left}
  .interaction-stage{min-height:400px}
  .stage-center{min-height:160px}
}

@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .stage-center i{animation:none}
}