/* ============================================================
   AI 20/20 — pillar pages (/ai-vendors, /enterprise-ai)
   Loads AFTER ai2020.css and only adds the long-form article
   components the application subpages never needed. Tokens come
   from ai2020.css; nothing here redefines them. Every size and
   line-height sits on the 4px grid, per brand-guide.md section 6.
   Synced to brand-guide.md 2026-08-25.
   ============================================================ */

/* ---- reading layout: article + sticky rail ---------------- */
.pillar-page{
  padding:0 0 96px;
  display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:56px;
  align-items:start;
}
.pillar-main{grid-column:1 / span 3;min-width:0}
.pillar-side{grid-column:4;position:sticky;top:88px}

.pillar-side .toc a{
  display:block;
  font-family:var(--mono);font-size:11px;line-height:16px;
  letter-spacing:.14em;text-transform:uppercase;color:var(--muted);
  padding:8px 0 8px 16px;position:relative;
  transition:color .2s ease;
}
.pillar-side .toc a::before{
  content:"";position:absolute;left:0;top:15px;
  width:8px;height:1px;background:var(--line-strong);
  transition:background .2s ease,width .2s ease;
}
.pillar-side .toc a:hover{color:var(--paper)}
.pillar-side .toc a:hover::before{background:var(--orange);width:12px}

/* ---- prose ------------------------------------------------ */
.prose{max-width:68ch}
.prose p{font-size:17px;line-height:28px;color:var(--dim);margin:0 0 24px}
.prose p b,.prose p strong{color:var(--paper);font-weight:600}
.prose a{
  color:var(--paper);
  border-bottom:1px solid var(--line-strong);
  transition:color .18s ease,border-color .18s ease;
}
.prose a:hover{color:var(--orange);border-color:var(--orange)}
.prose .num{font-family:var(--mono)}

.pillar-sec{padding-top:64px}
.pillar-sec .sec-head{margin-bottom:40px}
.pillar-sec .sec-head h2{font-size:40px;line-height:36px}

/* the compiled line under the hero lede */
.compiled{
  margin-top:24px;
  font-family:var(--mono);font-size:10px;line-height:16px;
  letter-spacing:.18em;text-transform:uppercase;color:var(--muted);
}
.compiled b{color:var(--orange);font-weight:500}

/* ---- question blocks (/ai-vendors) ------------------------ */
.qa{
  border-top:1px solid var(--line);
  padding:32px 0 40px;
}
.qa .qn{
  font-family:var(--mono);font-size:11px;line-height:16px;
  letter-spacing:.18em;color:var(--orange);
}
.qa h3{font-size:28px;line-height:28px;margin:12px 0 20px}
.qa .why{font-size:15px;line-height:24px;color:var(--dim);max-width:64ch;margin:0 0 24px}
.qa-pair{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}
.qa-pair .ans{
  border:1px solid var(--line);
  background:var(--black-2);
  padding:24px;
}
.qa-pair .ans .lab{
  font-family:var(--mono);font-size:10px;line-height:16px;
  letter-spacing:.18em;text-transform:uppercase;
  margin-bottom:12px;
}
.qa-pair .real .lab{color:var(--orange)}
.qa-pair .dodge .lab{color:var(--muted)}
.qa-pair .dodge{background:var(--black)}
.qa-pair .ans p{font-size:15px;line-height:24px;color:var(--dim);margin:0}
.qa-pair .ans p em{font-style:normal;color:var(--paper)}

/* ---- failure-mode ledger ---------------------------------- */
.fm{border-top:1px solid var(--line)}
.fm-line{
  border-bottom:1px solid var(--line);
  padding:28px 0;
  display:grid;grid-template-columns:56px minmax(0,1fr);gap:24px;
  align-items:baseline;
}
.fm-line .k{
  font-family:var(--mono);font-size:11px;line-height:16px;
  letter-spacing:.18em;color:var(--orange);
}
.fm-line h3{font-size:24px;line-height:24px;margin:0 0 8px}
.fm-line p{font-size:15px;line-height:24px;color:var(--dim);max-width:64ch;margin:0}

/* ---- case dossiers (/enterprise-ai) ----------------------- */
.dossier{
  position:relative;
  border:1px solid var(--line);
  background:var(--black-2);
  padding:36px;
  margin-bottom:24px;
}
.dossier::before,.dossier::after{
  content:"";position:absolute;width:20px;height:20px;
  border-color:var(--orange);border-style:solid;border-width:0;
}
.dossier::before{top:-1px;left:-1px;border-top-width:2px;border-left-width:2px}
.dossier::after{bottom:-1px;right:-1px;border-bottom-width:2px;border-right-width:2px}
.dossier .tc{
  font-family:var(--mono);font-size:11px;line-height:16px;
  letter-spacing:.18em;text-transform:uppercase;color:var(--orange);
}
.dossier h3{font-size:32px;line-height:32px;margin:12px 0 24px}
.d-row{
  display:grid;grid-template-columns:120px minmax(0,1fr);gap:24px;
  border-top:1px solid var(--line);
  padding:16px 0;
}
.d-row .lab{
  font-family:var(--mono);font-size:10px;line-height:16px;
  letter-spacing:.16em;text-transform:uppercase;color:var(--muted);
  padding-top:4px;
}
.d-row p{font-size:15px;line-height:24px;color:var(--dim);margin:0}
.d-row p em{font-style:normal;color:var(--paper)}
.d-row .num{font-family:var(--mono)}
.d-src{
  border-top:1px solid var(--line);
  padding-top:16px;
  display:flex;flex-wrap:wrap;gap:8px 24px;
}
.d-src .lab{
  font-family:var(--mono);font-size:10px;line-height:16px;
  letter-spacing:.16em;text-transform:uppercase;color:var(--muted);
}
.d-src a{
  font-family:var(--mono);font-size:10px;line-height:16px;
  letter-spacing:.14em;text-transform:uppercase;color:var(--dim);
  border-bottom:1px solid var(--line-strong);
  transition:color .18s ease,border-color .18s ease;
}
.d-src a:hover{color:var(--orange);border-color:var(--orange)}

/* ---- pattern list ----------------------------------------- */
.pattern{border-top:1px solid var(--line)}
.pattern-line{
  border-bottom:1px solid var(--line);
  padding:24px 0;
  display:grid;grid-template-columns:56px minmax(0,1fr);gap:24px;
  align-items:baseline;
}
.pattern-line .k{
  font-family:var(--mono);font-size:11px;line-height:16px;
  letter-spacing:.18em;color:var(--orange);
}
.pattern-line p{font-size:17px;line-height:28px;color:var(--dim);max-width:64ch;margin:0}
.pattern-line p b{color:var(--paper);font-weight:600}

/* ---- the room CTA ----------------------------------------- */
.room-cta{
  margin-top:64px;
  border:1px solid var(--line);
  background:var(--black-2);
  padding:48px 36px;
  position:relative;
}
.room-cta::before{
  content:"";position:absolute;left:0;top:0;bottom:0;width:3px;
  background:var(--orange);
}
.room-cta h2{font-size:40px;line-height:36px;margin:12px 0 16px}
.room-cta p{font-size:17px;line-height:28px;color:var(--dim);max-width:60ch;margin:0 0 28px}
.room-cta .cta-row{display:flex;flex-wrap:wrap;gap:16px}

/* ---- sibling cluster block -------------------------------- */
.siblings{margin-top:64px}
.siblings .sec-head{margin-bottom:32px}
.sib-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}
.sib{
  display:flex;flex-direction:column;gap:12px;
  border:1px solid var(--line);
  background:var(--black);
  padding:24px;
  transition:background .25s ease,border-color .25s ease;
}
.sib:hover{background:var(--black-3);border-color:var(--line-strong)}
.sib .tc{
  font-family:var(--mono);font-size:10px;line-height:16px;
  letter-spacing:.18em;text-transform:uppercase;color:var(--orange);
}
.sib h3{font-size:24px;line-height:24px}
.sib p{font-size:15px;line-height:24px;color:var(--dim);flex:1;margin:0}
.sib .go{
  font-family:var(--mono);font-size:11px;line-height:16px;
  letter-spacing:.14em;text-transform:uppercase;color:var(--paper);
}
.sib:hover .go{color:var(--orange)}

/* ---- responsive ------------------------------------------- */
@media (max-width:900px){
  .pillar-page{grid-template-columns:1fr;gap:48px}
  .pillar-main,.pillar-side{grid-column:1}
  .pillar-side{position:static;order:-1}
  .qa-pair{grid-template-columns:1fr}
  .sib-grid{grid-template-columns:1fr}
  .d-row{grid-template-columns:1fr;gap:8px}
  .dossier{padding:28px 24px}
  .room-cta{padding:36px 24px}
  .pillar-sec .sec-head h2{font-size:32px;line-height:32px}
}
@media (min-width:760px){
  .pillar-sec .sec-head h2{font-size:48px;line-height:44px}
  .room-cta h2{font-size:48px;line-height:44px}
}