/* ────────────────────────────────────────────────────────────────
   river.io — The Dark Factory (blog)

   Same flat Swiss system as /software/: neo-grotesque, hard 1px
   rules, no shadows, no gradients, no radii. Light and dark are both
   first-class. One stylesheet for the index and every post, so a new
   post is a single HTML file with no styling of its own.
   ──────────────────────────────────────────────────────────────── */
:root{
  --bg:#ffffff; --surface:#fafafa; --surface-2:#f2f2f4;
  --ink:#0a0a0b; --ink-2:#3f3f46; --muted:#84848c;
  --line:#e0e0e4; --line-strong:#0a0a0b;
  --brand:#1f4fd8;
  --sans:"Helvetica Neue",Helvetica,"Archivo",Arial,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,"SF Mono",Menlo,Consolas,monospace;
  --maxw:1180px; --measure:70ch; --gut:32px;
}
@media (prefers-color-scheme:dark){
  :root{
    --bg:#08080a; --surface:#0f0f12; --surface-2:#16161a;
    --ink:#f4f4f6; --ink-2:#b4b4bd; --muted:#6f6f78;
    --line:#26262c; --line-strong:#f4f4f6;
    --brand:#5b87ff;
  }
}
:root[data-theme="dark"]{
  --bg:#08080a; --surface:#0f0f12; --surface-2:#16161a;
  --ink:#f4f4f6; --ink-2:#b4b4bd; --muted:#6f6f78;
  --line:#26262c; --line-strong:#f4f4f6;
  --brand:#5b87ff;
}
:root[data-theme="light"]{
  --bg:#ffffff; --surface:#fafafa; --surface-2:#f2f2f4;
  --ink:#0a0a0b; --ink-2:#3f3f46; --muted:#84848c;
  --line:#e0e0e4; --line-strong:#0a0a0b;
  --brand:#1f4fd8;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--sans);
  font-size:16px;line-height:1.5;-webkit-font-smoothing:antialiased}
a{color:inherit}
::selection{background:var(--brand);color:#fff}
:focus-visible{outline:2px solid var(--brand);outline-offset:2px}
img{display:block;max-width:100%;height:auto}
.in{max-width:var(--maxw);margin:0 auto;padding:0 var(--gut)}

/* ── top bar ──────────────────────────────────────────────────── */
.bar{position:sticky;top:0;z-index:50;background:var(--bg);border-bottom:1px solid var(--line)}
.bar .in{height:52px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.id{font-family:var(--mono);font-size:12px;font-weight:600;letter-spacing:.04em;
  text-transform:uppercase;text-decoration:none;white-space:nowrap}
.id span{color:var(--muted);font-weight:400}
.id b{color:var(--brand);font-weight:600;padding:0 .3em}
nav.top{display:flex;align-items:center}
nav.top a{font-family:var(--mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;
  color:var(--muted);text-decoration:none;padding:8px 14px;border-left:1px solid var(--line);
  transition:color .12s,background .12s}
nav.top a:hover{color:var(--ink);background:var(--surface-2)}
.toggle{font-family:var(--mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;
  color:var(--muted);background:transparent;border:0;border-left:1px solid var(--line);
  padding:8px 14px;cursor:pointer;transition:color .12s,background .12s}
.toggle:hover{color:var(--ink);background:var(--surface-2)}

/* ── masthead (index) ─────────────────────────────────────────── */
.masthead{border-bottom:1px solid var(--line)}
.masthead .in{padding:78px var(--gut) 0}
.kicker{font-family:var(--mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--muted);display:flex;flex-wrap:wrap;gap:18px;margin:0 0 40px}
.kicker b{color:var(--ink);font-weight:500}
h1.title{font-size:clamp(2.6rem,7vw,5.1rem);line-height:.94;letter-spacing:-.045em;
  font-weight:700;margin:0;max-width:16ch}
h1.title span{color:var(--muted);font-weight:400}
.standfirst{font-size:clamp(1rem,1.5vw,1.18rem);color:var(--ink-2);max-width:58ch;margin:30px 0 0}
.standfirst b{color:var(--ink);font-weight:600}
.strip{display:grid;grid-template-columns:repeat(4,1fr);margin:54px 0 0;
  border-top:1px solid var(--line-strong);border-left:1px solid var(--line)}
@media (max-width:720px){.strip{grid-template-columns:repeat(2,1fr)}}
.strip div{border-right:1px solid var(--line);border-bottom:1px solid var(--line);padding:16px 18px 18px}
.strip .n{font-size:2.1rem;line-height:1;letter-spacing:-.04em;font-weight:600;
  font-variant-numeric:tabular-nums;display:block;margin-bottom:9px}
.strip .l{font-family:var(--mono);font-size:10.5px;letter-spacing:.12em;text-transform:uppercase;
  color:var(--muted);display:block}

/* ── post list ────────────────────────────────────────────────── */
.list{border-bottom:1px solid var(--line)}
.post-row{border-bottom:1px solid var(--line);transition:background .12s}
.post-row:last-child{border-bottom:0}
.post-row:hover{background:var(--surface)}
.post-row .in{display:grid;grid-template-columns:96px minmax(0,1fr) 150px;gap:28px;
  padding:30px var(--gut) 34px;align-items:start}
@media (max-width:860px){
  .post-row .in{grid-template-columns:72px minmax(0,1fr);gap:20px}
  .post-row .when{grid-column:2;margin-top:4px}
}
@media (max-width:560px){
  .post-row .in{grid-template-columns:1fr;gap:10px}
  .post-row .when{grid-column:1}
}
.order{font-family:var(--mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;
  color:var(--muted);padding-top:6px;font-variant-numeric:tabular-nums}
.post-row h2{margin:0;font-size:1.55rem;line-height:1.14;letter-spacing:-.03em;font-weight:700;
  max-width:24ch}
.post-row h2 a{text-decoration:none}
.post-row h2 a:hover{color:var(--brand)}
.post-row .dek{margin:12px 0 0;color:var(--ink-2);font-size:.98rem;max-width:62ch}
.tags{display:flex;flex-wrap:wrap;gap:0;margin-top:16px;
  border-top:1px solid var(--line);border-left:1px solid var(--line);width:fit-content;max-width:100%}
.tags span{font-family:var(--mono);font-size:10.5px;letter-spacing:.04em;color:var(--muted);
  padding:5px 10px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);white-space:nowrap}
.when{font-family:var(--mono);font-size:11px;letter-spacing:.06em;color:var(--muted);
  text-transform:uppercase;padding-top:6px}
.when b{display:block;color:var(--ink-2);font-weight:400}

/* ── article ──────────────────────────────────────────────────── */
.article-head{border-bottom:1px solid var(--line)}
.article-head .in{padding:70px var(--gut) 0;max-width:var(--maxw)}
.article-head .meta{font-family:var(--mono);font-size:11px;letter-spacing:.14em;
  text-transform:uppercase;color:var(--muted);display:flex;flex-wrap:wrap;gap:16px;margin:0 0 34px}
.article-head .meta b{color:var(--brand);font-weight:500}
.article-head h1{font-size:clamp(2.2rem,5.2vw,3.7rem);line-height:1.0;letter-spacing:-.04em;
  font-weight:700;margin:0;max-width:20ch}
.article-head .dek{font-size:clamp(1.05rem,1.6vw,1.24rem);color:var(--ink-2);
  max-width:58ch;margin:26px 0 0}
.article-head .rule{margin:44px 0 0;border-top:1px solid var(--line-strong);padding-bottom:0}
article.post{padding:0 0 20px}
article.post .in{max-width:var(--maxw);padding:54px var(--gut) 0}
article.post p,article.post ul,article.post ol,article.post blockquote,article.post h2,article.post h3,article.post .note,article.post figure,article.post table,article.post pre{max-width:var(--measure)}
article.post p{margin:0 0 24px;font-size:1.06rem;line-height:1.68;color:var(--ink-2)}
article.post p strong,article.post li strong{color:var(--ink);font-weight:600}
article.post h2{font-size:1.65rem;letter-spacing:-.03em;font-weight:700;margin:56px 0 16px;color:var(--ink)}
article.post h3{font-size:1.16rem;letter-spacing:-.02em;font-weight:600;margin:40px 0 12px;color:var(--ink)}
article.post ul,article.post ol{margin:0 0 24px;padding-left:22px}
article.post li{margin:9px 0;font-size:1.06rem;line-height:1.62;color:var(--ink-2)}
article.post a{color:var(--brand);text-decoration:none;border-bottom:1px solid var(--line)}
article.post a:hover{border-color:var(--brand)}
article.post blockquote{margin:0 0 26px;padding:20px 24px;background:var(--surface);
  border-left:2px solid var(--brand)}
article.post blockquote p{margin:0;color:var(--ink);font-size:1.06rem}
article.post code{font-family:var(--mono);font-size:.88em;background:var(--surface-2);padding:2px 6px}
article.post pre{background:var(--surface);border:1px solid var(--line);padding:18px 20px;
  overflow-x:auto;margin:0 0 26px}
article.post pre code{background:none;padding:0;font-size:.84rem;line-height:1.6}
article.post hr{border:0;border-top:1px solid var(--line);margin:48px 0}
article.post .lede-cap::first-letter{font-size:3.1rem;line-height:.86;font-weight:700;
  float:left;margin:6px 10px 0 0;color:var(--ink)}

/* a bordered aside for definitions and asides */
article.post .note{border:1px solid var(--line);padding:20px 22px 22px;margin:0 0 30px;background:var(--surface)}
article.post .note .k{font-family:var(--mono);font-size:10.5px;letter-spacing:.14em;text-transform:uppercase;
  color:var(--muted);margin-bottom:11px}
article.post .note p:last-child{margin:0}

/* data tables — the factory keeps records, so posts show them */
article.post table{border-collapse:collapse;width:100%;margin:0 0 28px;font-size:.9rem}
article.post th,article.post td{border-top:1px solid var(--line);padding:9px 12px;text-align:left;
  color:var(--ink-2)}
article.post thead th{border-top:1px solid var(--line-strong);border-bottom:1px solid var(--line);
  font-family:var(--mono);font-size:10.5px;letter-spacing:.1em;text-transform:uppercase;
  color:var(--muted);font-weight:500}
article.post td.num,article.post th.num{text-align:right;font-variant-numeric:tabular-nums}
.table-wrap{overflow-x:auto;max-width:var(--measure)}

/* ── article footer ───────────────────────────────────────────── */
.article-foot{border-top:1px solid var(--line);margin-top:56px}
.article-foot .in{padding:30px var(--gut) 60px;display:flex;flex-wrap:wrap;gap:14px 26px;
  justify-content:space-between;align-items:baseline}
.article-foot a{font-family:var(--mono);font-size:11px;letter-spacing:.08em;text-transform:uppercase;
  color:var(--muted);text-decoration:none}
.article-foot a:hover{color:var(--brand)}

/* ── page footer ──────────────────────────────────────────────── */
footer{border-top:1px solid var(--line)}
footer .in{padding:26px var(--gut) 58px;display:flex;flex-wrap:wrap;gap:12px 28px;
  justify-content:space-between;font-family:var(--mono);font-size:11px;letter-spacing:.06em;
  text-transform:uppercase;color:var(--muted)}
footer a{color:var(--ink-2);text-decoration:none}
footer a:hover{color:var(--brand)}