/* 1. Tokens */
:root{
  --paper:#fbfbf9;
  --box:#ffffff;
  --ink:#121212;
  --ink-2:#4f4f4c;
  --ink-3:#8a8983;
  --rule:#e0ded6;
  --rule-2:#c9c6bb;
  --mark:#1f45c4;
  --tint:#eef1fb;
  --tint-2:#d7def5;
  --fail:#c42b1c;

  --pad:48px;
  --top:84px;
}

/* 2. Base */
*{margin:0;padding:0;box-sizing:border-box}
html{-webkit-font-smoothing:antialiased;scroll-padding-top:70px}
body{
  background:var(--paper);color:var(--ink);
  font-family:'Source Serif 4',Georgia,serif;font-weight:400;
  font-size:18.5px;line-height:1.62;
}
::selection{background:var(--mark);color:#fff}
a{color:inherit}

.m{font-family:'IBM Plex Mono',monospace;font-size:.66rem;letter-spacing:.1em;text-transform:uppercase}

.wrap{max-width:1240px;margin:0 auto;padding:0 var(--pad)}

/* 3. Running head */
.top{position:sticky;top:0;z-index:40;background:var(--paper);border-bottom:2px solid var(--ink)}
.top .bar{max-width:1240px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;padding:13px var(--pad);font-family:'Archivo',sans-serif;font-size:.86rem;font-weight:500}
.top .bar b{font-weight:800}
.top nav a{text-decoration:none;margin-left:26px}
.top nav a:hover{color:var(--mark)}

/* 4. Opening and contents strip */
.open{padding:112px 0 0}
.open .where{color:var(--ink-3);margin-bottom:30px}
.open h1{font-family:'Archivo',sans-serif;font-weight:800;font-size:clamp(2.5rem,7vw,5.9rem);line-height:.95;letter-spacing:-.04em;max-width:13ch}
.open h1 span{color:var(--mark)}
.lede{display:grid;grid-template-columns:1fr 1fr;gap:56px;margin-top:60px}
.lede p{color:var(--ink-2);max-width:46ch}

.contents{display:grid;grid-template-columns:repeat(4,1fr);margin-top:84px;border:2px solid var(--ink);background:var(--box)}
.contents a{display:flex;flex-direction:column;text-decoration:none;padding:18px 20px 20px}
.contents a+a{border-left:2px solid var(--ink)}
.contents a:hover{background:var(--tint)}
.contents .n{display:inline-flex;align-items:center;justify-content:center;width:26px;height:26px;background:var(--mark);color:#fff;font-family:'Archivo',sans-serif;font-weight:800;font-size:.8rem}
.contents .t{font-family:'Archivo',sans-serif;font-weight:700;font-size:1.06rem;line-height:1.2;margin:14px 0 16px}
.contents svg{display:block;width:100%;height:40px;margin-top:auto}
.contents .k{color:var(--ink-3);margin-top:12px}
.thumb .ax{stroke:var(--rule);stroke-width:1.5;fill:none}
.thumb .ln{stroke:var(--ink);stroke-width:1.5;fill:none}
.thumb .bl{stroke:var(--mark);stroke-width:2;fill:none}
.thumb .dt{fill:var(--mark)}

/* 5. Project box */
.proj{background:var(--box);border:2px solid var(--ink);margin-top:96px}
.ph{display:flex;align-items:center;gap:22px;padding:30px 36px 28px}
.ph .n{flex:none;width:64px;height:64px;background:var(--mark);color:#fff;font-family:'Archivo',sans-serif;font-weight:800;font-size:2.1rem;letter-spacing:-.04em;display:flex;align-items:center;justify-content:center}
.ph .meta{margin-left:auto;color:var(--ink-3)}
.ph h2{font-family:'Archivo',sans-serif;font-weight:800;font-size:clamp(1.9rem,4.2vw,3.2rem);line-height:1;letter-spacing:-.035em}

.tb{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));border-top:2px solid var(--ink);border-bottom:2px solid var(--ink)}
.tb div{padding:10px 16px 12px;min-width:0}
.tb div+div{border-left:1px solid var(--ink)}
.tb .k{display:block;font-family:'IBM Plex Mono',monospace;font-size:.58rem;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3);margin-bottom:2px}
.tb .v{font-family:'Archivo',sans-serif;font-weight:500;font-size:.94rem;line-height:1.3}

.cols{
  display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);
  grid-template-areas:"text plate" "foot plate";grid-template-rows:auto 1fr;
  gap:0 64px;padding:48px 36px 52px;align-items:start;
}
.cols>.text{grid-area:text}
.cols>.foot{grid-area:foot}
.cols>.plate{grid-area:plate;position:sticky;top:var(--top)}

/* 6. Prose */
.sec+.sec{margin-top:34px}
.sec h3{font-family:'Archivo',sans-serif;font-weight:700;font-size:1.08rem;letter-spacing:-.005em;margin-bottom:8px;display:flex;gap:12px;align-items:baseline}
.sec h3 i{font-style:normal;color:var(--mark);font-size:.9rem;min-width:2.1em}
.sec p{max-width:58ch}
.sec p+p{margin-top:14px}

.notes{margin-top:36px;border-top:1px solid var(--rule)}
.notes div{display:grid;grid-template-columns:28px 1fr;gap:10px;padding:9px 0;border-bottom:1px solid var(--rule);font-family:'IBM Plex Mono',monospace;font-size:.7rem;line-height:1.55;color:var(--ink-2)}
.notes div b{color:var(--mark);font-weight:600}
.fn{font-family:'IBM Plex Mono',monospace;font-size:.6rem;font-weight:600;color:var(--mark);text-decoration:none;vertical-align:super;letter-spacing:.04em}

.tr{display:inline-flex;align-items:center;gap:8px;margin-top:28px;font-family:'Archivo',sans-serif;font-weight:700;font-size:.86rem;text-decoration:none;border:2px solid var(--ink);padding:8px 16px}
.tr:hover{border-color:var(--mark);color:var(--mark)}

/* 7. Plate: designer's note */
.dn{border:2px solid var(--ink)}
.dn .lb{font-family:'Archivo',sans-serif;font-weight:800;font-size:.74rem;letter-spacing:.14em;text-transform:uppercase;padding:10px 18px;background:var(--ink);color:#fff}
.dn p{padding:26px 26px 30px;font-size:clamp(1.3rem,2.2vw,1.7rem);line-height:1.3;font-style:italic;letter-spacing:-.01em}
.rig .dn{margin-top:18px}
.rig .dn p{font-size:1rem;line-height:1.5;font-style:normal;letter-spacing:0;padding:18px 22px 20px}

/* 8. Widgets ("rigs") */
.rig{background:var(--tint);border-top:4px solid var(--mark)}
.rig-h{display:flex;justify-content:space-between;align-items:center;gap:14px;padding:16px 22px 0}
.rig-h .t{font-family:'Archivo',sans-serif;font-weight:800;font-size:.74rem;letter-spacing:.14em;text-transform:uppercase;color:var(--mark)}
.rig-body{padding:14px 22px 22px}
.rig svg{width:100%;height:auto;display:block}
.rig-body>svg{background:var(--box);border:1px solid var(--tint-2)}

button.rr{
  font-family:'Archivo',sans-serif;font-weight:700;font-size:.74rem;letter-spacing:.02em;
  background:var(--box);border:2px solid var(--ink);color:var(--ink);padding:4px 12px;cursor:pointer;
}
button.rr:hover{border-color:var(--mark);color:var(--mark)}
button.rr:disabled{opacity:.45;cursor:default}

.ctrls{margin-top:16px}
.ct{display:flex;align-items:center;gap:14px;margin-bottom:10px}
.ct label{font-family:'Archivo',sans-serif;font-weight:700;font-size:.8rem;color:var(--ink);width:132px;flex:none;line-height:1.25}
.ct input[type=range]{flex:1;accent-color:var(--mark);cursor:pointer;min-width:0}
.ct .v{font-family:'Archivo',sans-serif;font-weight:800;font-size:.86rem;background:var(--mark);color:#fff;padding:2px 8px;min-width:56px;text-align:center;flex:none}
.ct.ct-off{opacity:.45}

.rnote{font-size:1rem;line-height:1.5;color:var(--ink);border-left:3px solid var(--ink);padding:2px 0 2px 16px;margin-top:18px;min-height:76px}
.rcap{font-family:'IBM Plex Mono',monospace;font-size:.64rem;line-height:1.6;color:var(--ink-3);margin-top:10px}

/* 9. Design models */
.models{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:10px}
.models button.rr[aria-selected="true"]{background:var(--mark);border-color:var(--mark);color:#fff}
button.rr.solve{background:var(--mark);border-color:var(--mark);color:#fff}
button.rr.solve:hover{background:var(--ink);border-color:var(--ink);color:#fff}

.rig .legend{display:flex;flex-wrap:wrap;gap:4px 16px;margin:10px 0 4px;font-family:'IBM Plex Mono',monospace;font-size:.6rem;letter-spacing:.04em;color:var(--ink-2)}
.rig .legend span{white-space:nowrap}
.rig .legend svg{display:inline-block;width:18px;height:6px;vertical-align:middle;margin-right:6px}

.btns{display:flex;flex-wrap:wrap;gap:6px;align-items:center;margin-top:16px}
.btns .lb{font-family:'Archivo',sans-serif;font-weight:800;font-size:.66rem;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3);margin-right:6px}

.checks{margin-top:18px;border-top:2px solid var(--ink)}
.chk{display:grid;grid-template-columns:1fr auto 52px;gap:12px;padding:7px 0;border-bottom:1px solid var(--tint-2);font-family:'IBM Plex Mono',monospace;font-size:.66rem;align-items:baseline}
.chk .nm{color:var(--ink)}
.chk .ms{color:var(--ink-3)}
.chk .st{text-align:right;letter-spacing:.1em;color:var(--ink-3)}
.chk.fail .st,.chk.fail .nm{color:var(--fail)}
.chk.fail .st{font-weight:600}
.chk.tight .st{color:var(--ink);font-weight:600}

/* 10. Earlier */
.earlier .grid{display:grid;grid-template-columns:repeat(3,1fr);border-top:2px solid var(--ink)}
.earlier .card{padding:22px 24px 26px}
.earlier .card+.card{border-left:1px solid var(--ink)}
.earlier .card .x{font-family:'Archivo',sans-serif;font-weight:800;font-size:.76rem;color:var(--mark)}
.earlier .card h3{font-family:'Archivo',sans-serif;font-weight:700;font-size:1.18rem;line-height:1.15;margin:8px 0 6px}
.earlier .card p{font-size:.95rem;color:var(--ink-2)}

/* 11. Footer */
.end{padding:112px 0 120px;display:grid;grid-template-columns:1fr 1fr;gap:56px}
.end h2{font-family:'Archivo',sans-serif;font-weight:800;font-size:clamp(2rem,4vw,3.2rem);letter-spacing:-.035em;line-height:1}
.end p{max-width:46ch;margin-bottom:18px}
.end a{color:var(--mark)}
.end .sig{color:var(--ink-3);margin-top:40px}

/* 12. Responsive */
@media(max-height:760px){
  .cols>.plate{position:static}
}
@media(max-width:880px){
  :root{--pad:20px}
  body{font-size:17.5px}
  .open{padding-top:64px}
  .lede,.end{grid-template-columns:1fr;gap:28px}
  .lede{margin-top:40px}
  .contents{grid-template-columns:1fr 1fr;margin-top:56px}
  .contents a+a{border-left:0}
  .contents a:nth-child(even){border-left:2px solid var(--ink)}
  .contents a:nth-child(n+3){border-top:2px solid var(--ink)}
  .proj{margin-top:56px}
  .ph{padding:22px 20px 20px;gap:16px}
  .ph .n{width:48px;height:48px;font-size:1.6rem}
  .tb{grid-template-columns:1fr 1fr}
  .tb div:nth-child(3){border-left:0}
  .tb div:nth-child(n+3){border-top:1px solid var(--ink)}
  .cols{grid-template-columns:1fr;grid-template-areas:"text" "plate" "foot";grid-template-rows:auto;padding:30px 20px 34px}
  .cols>.plate{position:static;margin-top:32px}
  .earlier .grid{grid-template-columns:1fr}
  .earlier .card+.card{border-left:0;border-top:1px solid var(--ink)}
  .end{padding:72px 0 88px}
  .top nav a{margin-left:16px}
}
@media(max-width:520px){
  .contents .t{font-size:.98rem}
  .contents svg{height:30px}
  .rig-h{padding:14px 14px 0}
  .rig .legend span{white-space:normal}
  .rig-body{padding:12px 14px 16px}
  .dn p{padding:20px}
  .ct{flex-wrap:wrap;gap:8px 14px}
  .ct label{width:100%}
  .chk{grid-template-columns:1fr 52px;row-gap:2px}
  .chk .nm{grid-column:1;grid-row:1}
  .chk .st{grid-column:2;grid-row:1}
  .chk .ms{grid-column:1;grid-row:2}
}

@media(prefers-reduced-motion:reduce){
  *{animation-duration:.001ms !important;transition-duration:.001ms !important}
}