/* ==========================================================================
   BLOG — shared stylesheet
   One file for every post so the writing surface can never drift from the
   site the way the old blog did. Tokens are copied verbatim from DESIGN.md;
   if a token changes there, change it here in the same commit.

   Visitor mode: READ. Structure for comprehension first, then make the
   reading itself worth staying in. Everything is subordinate to the measure.
   ========================================================================== */

:root{
  --bg:#212327; --bg-2:#292B30; --panel:#33363B; --panel-2:#3B3F45;
  --line:rgba(223,220,227,.10); --line-2:rgba(223,220,227,.20);
  --text:#DFDCE3; --text-2:#BFBCC6; --muted:#A29FAA;
  --blue:#368CBF; --blue-hover:#48A0D3; --blue-lift:#5FA9D6;
  --blue-soft:rgba(54,140,191,.15);
  --green:#7EBC59; --green-soft:rgba(126,188,89,.14);
  --on-accent:#1A1D21;

  --sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
          "Segoe UI Variable Display", "Segoe UI Variable Text", "Segoe UI",
          system-ui, Roboto, "Helvetica Neue", Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, "Menlo",
          "Cascadia Code", "Segoe UI Mono", "Roboto Mono", Consolas, monospace;

  --pad: clamp(20px,5vw,64px);
  --maxw: 1200px;
  --nav: 68px;
  --rail: clamp(92px,12vw,168px);
  --measure: 68ch;          /* the one number this whole surface serves */
}

*{margin:0;padding:0;box-sizing:border-box}
html{color-scheme:dark;scroll-behavior:smooth;-webkit-text-size-adjust:100%;scroll-padding-top:var(--nav)}
body{
  background:var(--bg);color:var(--text);
  font-family:var(--sans);font-size:17px;line-height:1.7;
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
  font-feature-settings:"kern" 1;font-optical-sizing:auto;font-synthesis:none;
  text-rendering:optimizeLegibility;overflow-x:clip;
}
a{color:inherit;text-decoration:none}
::selection{background:var(--blue);color:var(--on-accent)}
:focus-visible,button:focus-visible,summary:focus-visible{
  outline:2px solid var(--blue-lift);outline-offset:3px;border-radius:6px;
}
.skip{position:absolute;left:-9999px;top:0;background:var(--text);color:var(--bg);padding:10px 16px;z-index:300}
.skip:focus{left:0}
.sr-only{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.wrap{max-width:var(--maxw);margin:0 auto;padding-left:var(--pad);padding-right:var(--pad)}

/* ---------- nav: identical to the main site ---------- */
.nav{
  position:sticky;top:0;z-index:100;
  background:rgba(33,35,39,.72);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
  border-bottom:1px solid transparent;transition:border-color .3s ease,background .3s ease;
}
.nav.scrolled{border-bottom-color:var(--line);background:rgba(33,35,39,.92)}
.nav-row{display:flex;align-items:center;justify-content:space-between;gap:24px;height:var(--nav)}
.brand{font-size:15px;font-weight:600;letter-spacing:-0.02em;display:inline-flex;align-items:center;gap:9px}
.brand .bd{width:7px;height:7px;border-radius:50%;background:var(--green);box-shadow:0 0 0 4px var(--green-soft)}
.nav-links{display:flex;gap:28px}
.nav-links a{
  display:inline-flex;align-items:center;min-height:44px;
  font-size:14px;font-weight:500;color:var(--text-2);letter-spacing:-0.01em;transition:color .2s;
}
.nav-links a:hover,.nav-links a[aria-current="page"]{color:var(--text)}
.btn{
  display:inline-flex;align-items:center;gap:8px;
  background:var(--blue);color:var(--on-accent);
  border:1px solid var(--blue);border-radius:10px;
  padding:12px 18px;font-size:14px;font-weight:600;letter-spacing:-0.01em;
  transition:background .2s ease,transform .2s ease,border-color .2s ease;
  white-space:nowrap;cursor:pointer;
}
.btn:hover{background:var(--blue-hover);border-color:var(--blue-hover);transform:translateY(-1px)}
.btn .ar{transition:transform .2s ease;display:inline-block}
.btn:hover .ar{transform:translateX(3px)}
.btn-ghost{background:transparent;color:var(--text);border-color:var(--line-2)}
.btn-ghost:hover{background:rgba(223,220,227,.06);border-color:rgba(223,220,227,.34)}

/* reading progress — the same readout device as the main site */
.prog{
  position:absolute;left:0;bottom:-1px;height:2px;width:100%;
  transform:scaleX(var(--p,0));transform-origin:left center;
  background:linear-gradient(90deg,var(--blue),var(--blue-lift));
  opacity:0;transition:opacity .35s ease;pointer-events:none;
}
.nav.scrolled .prog{opacity:1}

/* ---------- the dossier header, same grammar as the site ---------- */
.post-head{
  padding:clamp(44px,8vh,88px) 0 clamp(28px,4vh,44px);
  display:grid;grid-template-columns:minmax(0,var(--rail)) minmax(0,1fr);
  column-gap:clamp(18px,4vw,64px);align-items:start;
}
.post-meta{grid-column:1;grid-row:1;display:flex;flex-direction:column;gap:10px;padding-top:.5em}
.post-meta span{
  font:600 10px/1.4 var(--sans);letter-spacing:.11em;text-transform:uppercase;color:var(--muted);
}
.post-meta .cat{color:var(--blue-lift)}
.post-head h1{
  grid-column:2;grid-row:1;
  font-size:clamp(30px,4.6vw,54px);font-weight:600;line-height:1.08;letter-spacing:-0.038em;
  max-width:20ch;
}
.post-head .dek{
  grid-column:2;grid-row:2;margin-top:22px;max-width:58ch;
  font-size:clamp(17px,1.6vw,20px);line-height:1.6;letter-spacing:-0.011em;color:var(--text-2);
}

/* ---------- the article body ---------- */
.post{
  display:grid;
  grid-template-columns:minmax(0,var(--rail)) minmax(0,1fr);
  column-gap:clamp(18px,4vw,64px);
  border-top:1px solid var(--line);
  padding-top:clamp(30px,5vh,52px);
  padding-bottom:clamp(48px,8vh,96px);
}
/* everything in the body lands in the wide column by default … */
.post > *{grid-column:2;max-width:var(--measure)}
/* … and these opt into the margin rail */
.post > .rail{grid-column:1;max-width:none}

.post h2{
  margin:clamp(38px,6vh,64px) 0 0;
  font-size:clamp(22px,2.4vw,30px);font-weight:600;letter-spacing:-0.025em;line-height:1.25;
  max-width:24ch;
}
.post h2 + p{margin-top:14px}
.post h3{
  margin:clamp(28px,4vh,40px) 0 0;
  font-size:clamp(18px,1.9vw,21px);font-weight:600;letter-spacing:-0.02em;line-height:1.35;
}
.post h3 + p{margin-top:10px}
.post p{margin-top:20px;color:var(--text-2)}
.post p strong{color:var(--text);font-weight:600}
.post a:not(.btn){
  color:var(--text);text-decoration:underline;
  text-decoration-color:var(--line-2);text-underline-offset:3px;
  transition:text-decoration-color .2s ease,color .2s ease;
}
.post a:not(.btn):hover{color:var(--blue-lift);text-decoration-color:var(--blue-lift)}

.post ul,.post ol{margin-top:20px;padding-left:0;list-style:none}
.post li{position:relative;padding-left:22px;margin-top:10px;color:var(--text-2)}
.post ul li::before{
  content:"";position:absolute;left:2px;top:.62em;width:5px;height:1px;background:var(--muted);
}
.post ol{counter-reset:li}
.post ol li{counter-increment:li;padding-left:30px}
.post ol li::before{
  content:counter(li,decimal-leading-zero);position:absolute;left:0;top:.1em;
  font:600 10px/1.9 var(--sans);letter-spacing:.09em;color:var(--muted);
}

/* section rule — the site's device, reused to break long reads */
.post hr{
  border:0;height:1px;background:var(--line);
  margin:clamp(38px,6vh,64px) 0 0;max-width:none;
}

/* ---------- margin notes: the reason the rail exists ---------- */
.post > .rail.note{
  font-size:12.5px;line-height:1.5;color:var(--muted);
  padding-top:6px;border-top:1px solid var(--line);
  margin-top:clamp(24px,4vh,38px);
}
.post > .rail.note b{
  display:block;font:600 9.5px/1.6 var(--sans);letter-spacing:.11em;
  text-transform:uppercase;color:var(--blue-lift);
}

/* ---------- pull quote ---------- */
.post blockquote{
  margin:clamp(34px,5vh,52px) 0 0;padding:0 0 0 20px;
  border-left:1px solid var(--blue);
  font-size:clamp(19px,2vw,24px);font-weight:600;line-height:1.4;letter-spacing:-0.024em;
  color:var(--text);max-width:30ch;
}
.post blockquote cite{
  display:block;margin-top:12px;font-style:normal;
  font:500 12px/1.5 var(--sans);letter-spacing:.02em;color:var(--muted);
}

/* ---------- callout: neutral, because green means system state ---------- */
.post .callout{
  margin-top:clamp(30px,4.5vh,44px);
  border:1px solid var(--line);border-radius:12px;background:var(--bg-2);
  padding:22px 24px;
}
.post .callout h4{
  font:600 10px/1 var(--sans);letter-spacing:.11em;text-transform:uppercase;
  color:var(--blue-lift);margin-bottom:12px;
}
.post .callout p{margin-top:0}
.post .callout p + p{margin-top:12px}

/* ---------- code: mono because it IS code, never as decoration ---------- */
.post pre{
  margin-top:24px;overflow-x:auto;
  border:1px solid var(--line);border-radius:12px;background:var(--bg-2);
  padding:18px 20px;
  font:400 13px/1.65 var(--mono);color:var(--text-2);
  -webkit-overflow-scrolling:touch;
}
.post pre code{white-space:pre}
.post :not(pre) > code{
  font:400 .88em/1 var(--mono);color:var(--text);
  background:var(--bg-2);border:1px solid var(--line);border-radius:4px;
  padding:.16em .38em;
}

/* ---------- figures: numbered, like the site's diagrams ---------- */
.post figure{margin-top:clamp(30px,4.5vh,44px)}
.post figure img,.post figure svg{
  display:block;width:100%;height:auto;
  border:1px solid var(--line);border-radius:12px;background:var(--bg-2);
}
.post figcaption{
  margin-top:11px;
  font:500 11.5px/1.5 var(--sans);letter-spacing:.01em;color:var(--muted);
}
.post figcaption b{
  font:600 9.5px/1 var(--sans);letter-spacing:.13em;text-transform:uppercase;
  color:var(--muted);margin-right:8px;
}

/* ---------- foot of the article ---------- */
.post-foot{
  border-top:1px solid var(--line);
  padding:clamp(34px,5vh,56px) 0 clamp(48px,7vh,80px);
}
.post-foot .h{
  font-size:clamp(22px,2.6vw,32px);font-weight:600;letter-spacing:-0.03em;
  line-height:1.25;max-width:22ch;
}
.post-foot p{margin-top:16px;max-width:52ch;color:var(--text-2);font-size:16px}
.post-foot .acts{display:flex;gap:12px;flex-wrap:wrap;margin-top:26px}

.pager{
  display:grid;grid-template-columns:1fr 1fr;gap:1px;
  background:var(--line);border:1px solid var(--line);border-radius:16px;overflow:hidden;
  margin-top:clamp(34px,5vh,52px);
}
.pager a{
  background:var(--bg-2);padding:22px 24px;transition:background .25s ease;
  display:flex;flex-direction:column;gap:8px;min-height:96px;justify-content:center;
}
.pager a:hover{background:var(--panel)}
.pager a:last-child{text-align:right;align-items:flex-end}
.pager b{font:600 10px/1 var(--sans);letter-spacing:.11em;text-transform:uppercase;color:var(--muted)}
.pager span{font-size:15px;font-weight:600;letter-spacing:-0.02em;color:var(--text);line-height:1.35}
.pager a.empty{pointer-events:none;opacity:.4}

/* ---------- the index ---------- */
.idx-head{
  padding:clamp(48px,9vh,104px) 0 clamp(30px,4vh,48px);
  display:grid;grid-template-columns:minmax(0,var(--rail)) minmax(0,1fr);
  column-gap:clamp(18px,4vw,64px);align-items:start;
  border-bottom:1px solid var(--line);
}
.idx-head .eyebrow{
  grid-column:1;grid-row:1;padding-top:.4em;
  font:600 11.5px/1 var(--sans);letter-spacing:.085em;text-transform:uppercase;color:var(--blue-lift);
}
.idx-head h1{
  grid-column:2;grid-row:1;
  font-size:clamp(32px,5vw,58px);font-weight:600;line-height:1.06;letter-spacing:-0.042em;max-width:16ch;
}
.idx-head .dek{
  grid-column:2;grid-row:2;margin-top:20px;max-width:56ch;
  font-size:clamp(16px,1.5vw,19px);line-height:1.6;color:var(--text-2);letter-spacing:-0.011em;
}

/* each entry is an index row, not a card — the site's own device */
.posts{border-top:0}
.posts a{
  display:grid;grid-template-columns:var(--rail) minmax(0,1fr) auto;
  gap:clamp(18px,4vw,64px);align-items:baseline;
  padding:clamp(26px,3.6vh,34px) 8px clamp(26px,3.6vh,34px) 0;
  border-bottom:1px solid var(--line);
  transition:background .22s ease,padding-left .22s ease;
}
.posts a:hover{background:rgba(223,220,227,.035);padding-left:14px}
.posts .when{font:600 10px/1.6 var(--sans);letter-spacing:.11em;text-transform:uppercase;color:var(--muted)}
.posts .t{font-size:clamp(19px,2.1vw,25px);font-weight:600;letter-spacing:-0.026em;line-height:1.25;color:var(--text);transition:color .2s ease}
.posts a:hover .t{color:var(--blue-lift)}
.posts .d{display:block;margin-top:9px;font-size:14.5px;line-height:1.55;color:var(--text-2);max-width:60ch;font-weight:400;letter-spacing:-0.008em}
.posts .rt{font:500 11px/1.6 var(--sans);letter-spacing:.06em;text-transform:uppercase;color:var(--muted);white-space:nowrap}

/* ---------- footer ---------- */
.footer{border-top:1px solid var(--line);padding:44px 0 40px;margin-top:clamp(40px,6vh,72px)}
.foot-base{
  display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;
  font-size:13px;color:var(--muted);
}
.foot-base a{color:var(--text-2);transition:color .2s}
.foot-base a:hover{color:var(--text)}

@media (max-width:860px){
  :root{--nav:62px}
  .nav-links{display:none}
  .post-head,.post,.idx-head{grid-template-columns:1fr}
  .post-head h1,.post-head .dek,.idx-head h1,.idx-head .dek{grid-column:1;max-width:none}
  .post-head h1{grid-row:2}.post-head .dek{grid-row:3}
  .idx-head h1{grid-row:2}.idx-head .dek{grid-row:3}
  .post-meta{grid-row:1;flex-direction:row;flex-wrap:wrap;gap:14px;padding-top:0;margin-bottom:16px}
  .idx-head .eyebrow{grid-row:1;padding-top:0;margin-bottom:14px}
  .post > *{grid-column:1;max-width:none}
  .post > .rail{grid-column:1}
  .post > .rail.note{
    border-left:1px solid var(--line-2);border-top:0;
    padding:2px 0 2px 16px;margin-top:26px;
  }
  .posts a{grid-template-columns:1fr auto;gap:12px}
  .posts .when{grid-column:1/-1}
  .pager{grid-template-columns:1fr}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .posts a:hover{padding-left:0}
  .btn:hover{transform:none}
  .prog{transition:none}
}

@media print{
  .nav,.post-foot .acts,.pager{display:none}
  body{background:#fff;color:#000}
  .post > *{max-width:none}
}