/* Shared shell for archieapa.com — every page links this one file.
   Design tokens, header, sidebar layout, article styles, cards, citations,
   dark mode. Page-specific markup varies; the styles all live here. */

:root{
  --paper:#FAFAF7; --panel:#F2F1EB; --ink:#232830; --muted:#5D6470; --line:#E1DFD5;
  --proj:#B06A12; --xp:#2E6F8E; --prac:#5C5890; --ref:#57606B;
  --ea:#B06A12; --eq:#2E6F8E; --ss:#5C5890;
  --warn-bg:#FBF3E4; --fix-bg:#EAF2F6; --note-bg:#F1F0E9;
  --chip-bg:#ECEAE1;
  --card:#FFFFFF; --link:#1E5C7A; --link-hover:#123F55; --lede-ink:#3A404B; --ph:#9AA0AA;
  --display:'Space Grotesk',system-ui,sans-serif;
  --body:'Source Serif 4',Georgia,serif;
  --mono:'IBM Plex Mono',ui-monospace,Menlo,monospace;
  color-scheme:light;
}
[data-theme="dark"]{
  --paper:#1B1E24; --panel:#262A32; --ink:#E8E6DF; --muted:#99A0AB; --line:#3A3F49;
  --proj:#D99A45; --xp:#6FA3BE; --prac:#9B97C9; --ref:#98A0AB;
  --ea:#D99A45; --eq:#6FA3BE; --ss:#9B97C9;
  --warn-bg:#33291A; --fix-bg:#1C2B33; --note-bg:#262A32;
  --chip-bg:#343945;
  --card:#232830; --link:#7FB3CC; --link-hover:#A9CFE0; --lede-ink:#C6CAD1; --ph:#6A717C;
  color-scheme:dark;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto} .article{animation:none!important}}
body{background:var(--paper);color:var(--ink);font-family:var(--body);font-size:16.5px;line-height:1.66}
a{color:var(--link);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:2.5px}
a:hover{color:var(--link-hover)}
a:focus-visible,button:focus-visible,input:focus-visible{outline:2.5px solid var(--xp);outline-offset:2px;border-radius:2px}

/* Header with Kelvin strip signature */
header.site{position:sticky;top:0;z-index:50;background:var(--paper);border-bottom:1px solid var(--line)}
.kelvin{height:5px;background:linear-gradient(90deg,#B06A12 0%,#D99A45 18%,#EFE0BD 38%,#FAFAF7 50%,#CFE2EC 62%,#6FA3BE 82%,#2E6F8E 100%)}
.masthead{display:flex;align-items:baseline;gap:14px;padding:14px 22px;flex-wrap:wrap;max-width:1280px;margin:0 auto}
.masthead h1{font-family:var(--display);font-weight:700;font-size:19px;letter-spacing:.01em}
.masthead h1 .k{color:var(--muted);font-weight:500}
.masthead h1 a{color:inherit;text-decoration:none}
.masthead h1 a:hover{text-decoration:underline;text-decoration-thickness:1.5px;text-underline-offset:3px}
.masthead .logo{width:26px;height:26px;vertical-align:-7px;margin-right:9px}
.masthead .sub{font-family:var(--display);font-size:12.5px;color:var(--muted);letter-spacing:.04em;text-transform:uppercase}
#themetoggle,#headertoggle{align-self:center;font-family:var(--display);font-size:12px;font-weight:600;color:var(--muted);background:transparent;border:1px solid var(--line);border-radius:6px;padding:5px 10px;cursor:pointer;white-space:nowrap}
#themetoggle{margin-left:auto}
#themetoggle:hover,#headertoggle:hover{background:var(--panel);color:var(--ink)}
#headertoggle{display:none}

/* Layout: sidebar + main */
.layout{display:grid;grid-template-columns:288px 1fr;max-width:1280px;margin:0 auto;min-height:calc(100vh - 60px)}
nav.side{border-right:1px solid var(--line);padding:14px 0 48px;background:var(--paper)}
nav.side .inner{position:sticky;top:78px;max-height:calc(100vh - 96px);overflow-y:auto;padding:6px 16px 24px}
#navsearch{width:100%;font-family:var(--mono);font-size:12.5px;padding:8px 10px;border:1px solid var(--line);border-radius:6px;background:var(--card);color:var(--ink);margin-bottom:14px}
#navsearch::placeholder{color:var(--ph)}
.navgroup{margin-bottom:16px}
.navgroup h2{font-family:var(--display);font-size:11px;font-weight:600;letter-spacing:.09em;text-transform:uppercase;color:var(--muted);padding:0 8px;margin-bottom:5px}
.navgroup a{display:flex;align-items:center;gap:9px;padding:6px 8px;border-radius:6px;text-decoration:none;color:var(--ink);font-family:var(--display);font-weight:500;font-size:13.5px;line-height:1.35}
.navgroup a:hover{background:var(--panel)}
.navgroup a[aria-current="page"]{background:var(--panel);font-weight:600}
.navgroup .empty{font-family:var(--display);font-size:12.5px;color:var(--muted);padding:2px 8px;line-height:1.5}
.dot{width:8px;height:8px;border-radius:2px;flex:none}
.dot.proj,.dot.ea{background:var(--proj)} .dot.xp,.dot.eq{background:var(--xp)} .dot.prac,.dot.ss{background:var(--prac)} .dot.ref{background:var(--ref)}
#navtoggle{display:none}

/* Articles */
main{padding:34px 44px 90px;min-width:0}
.article{display:none;max-width:820px}
.article.active{display:block;animation:fadein .18s ease-out}
@keyframes fadein{from{opacity:0;transform:translateY(3px)}to{opacity:1;transform:none}}
.eyebrow{font-family:var(--display);font-size:11.5px;font-weight:600;letter-spacing:.11em;text-transform:uppercase;margin-bottom:10px;display:flex;align-items:center;gap:8px}
.eyebrow.proj,.eyebrow.ea{color:var(--proj)} .eyebrow.xp,.eyebrow.eq{color:var(--xp)} .eyebrow.prac,.eyebrow.ss{color:var(--prac)} .eyebrow.ref{color:var(--ref)}
.article h1{font-family:var(--display);font-weight:700;font-size:31px;line-height:1.15;letter-spacing:-0.01em;margin-bottom:18px}
.article h2{font-family:var(--display);font-weight:600;font-size:20px;margin:34px 0 12px;padding-top:18px;border-top:1px solid var(--line)}
.article h3{font-family:var(--display);font-weight:600;font-size:16px;margin:22px 0 8px}
.article p{margin:0 0 14px}
.article ul,.article ol{margin:0 0 16px 22px}
.article li{margin-bottom:8px}
.article li>ul{margin-top:8px}
.lede{font-size:18.5px;line-height:1.6;color:var(--lede-ink);margin-bottom:20px}

/* Chip — signature element */
.t{font-family:var(--mono);font-size:.83em;font-weight:500;background:var(--chip-bg);padding:1px 6px 2px;border-radius:4px;white-space:nowrap;font-variant-numeric:tabular-nums}

/* Infobox */
.infobox{float:right;width:290px;margin:4px 0 18px 26px;border:1px solid var(--line);border-top:3px solid var(--ref);border-radius:8px;background:var(--card);font-family:var(--display);font-size:12.5px;overflow:hidden}
.infobox.proj,.infobox.ea{border-top-color:var(--proj)} .infobox.xp,.infobox.eq{border-top-color:var(--xp)} .infobox.prac,.infobox.ss{border-top-color:var(--prac)}
.infobox h4{font-size:11px;font-weight:600;letter-spacing:.09em;text-transform:uppercase;color:var(--muted);padding:10px 14px 6px}
.infobox dl{padding:0 14px 12px}
.infobox dt{font-weight:600;font-size:11px;letter-spacing:.05em;text-transform:uppercase;color:var(--muted);margin-top:8px}
.infobox dd{margin:2px 0 0;line-height:1.45;font-weight:500}
.infobox dd a{font-family:var(--display)}
@media(max-width:980px){.infobox{float:none;width:100%;margin:0 0 20px}}

/* Callouts */
.callout{border:1px solid var(--line);border-left-width:4px;border-radius:6px;padding:13px 16px;margin:0 0 16px;font-size:15.5px}
.callout p:last-child{margin-bottom:0}
.callout .ct{font-family:var(--display);font-weight:600;font-size:12px;letter-spacing:.08em;text-transform:uppercase;display:block;margin-bottom:5px}
.callout.warn{background:var(--warn-bg);border-left-color:var(--proj)}
.callout.warn .ct{color:var(--proj)}
.callout.fix{background:var(--fix-bg);border-left-color:var(--xp)}
.callout.fix .ct{color:var(--xp)}
.callout.note{background:var(--note-bg);border-left-color:var(--ref)}
.callout.note .ct{color:var(--ref)}

/* Tables */
table{border-collapse:collapse;width:100%;margin:0 0 18px;font-size:14px;font-family:var(--display)}
th{font-size:11.5px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);text-align:left;padding:8px 10px;border-bottom:2px solid var(--ink)}
td{padding:9px 10px;border-bottom:1px solid var(--line);vertical-align:top;line-height:1.45}
tr:last-child td{border-bottom:none}
td .t{font-size:12px}
.tablewrap{overflow-x:auto;margin-bottom:18px}
.tablewrap table{margin-bottom:0;min-width:560px}

/* Glossary */
.gloss dt{font-family:var(--display);font-weight:600;font-size:15px;margin-top:18px}
.gloss dt .t{margin-left:6px}
.gloss dd{margin:4px 0 0}

/* Citations */
sup.cite{line-height:0;font-size:.72em;font-family:var(--display);font-weight:600;letter-spacing:.02em}
sup.cite a{text-decoration:none;padding:0 1px}
ol.refs{margin:0 0 16px 24px;font-family:var(--display);font-size:13.5px;line-height:1.55}
ol.refs li{margin-bottom:9px}
ol.refs li:target{background:var(--warn-bg);border-radius:4px;outline:2px solid var(--line);outline-offset:3px}
.article [id]{scroll-margin-top:90px}

/* Footer of article */
.artfoot{margin-top:44px;padding-top:14px;border-top:1px solid var(--line);font-family:var(--display);font-size:12.5px;color:var(--muted)}

/* Blog index: content column + post cards */
.content{max-width:820px}
.content>h1{font-family:var(--display);font-weight:700;font-size:31px;line-height:1.15;letter-spacing:-0.01em;margin-bottom:18px}
.post{border:1px solid var(--line);border-left:4px solid var(--prac);border-radius:8px;background:var(--card);padding:18px 20px 16px;margin-bottom:18px}
.post.wiki{border-left-color:var(--proj)}
.post .meta{font-family:var(--display);font-size:11.5px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);display:flex;align-items:center;gap:10px;margin-bottom:8px;flex-wrap:wrap}
.post .meta .kind{color:var(--prac)}
.post.wiki .meta .kind{color:var(--proj)}
.post .meta .tags{display:flex;gap:6px;letter-spacing:0;text-transform:none}
.post h2{font-family:var(--display);font-weight:700;font-size:21px;line-height:1.25;margin-bottom:8px}
.post h2 a{color:var(--ink);text-decoration:none}
.post h2 a:hover{color:var(--link-hover);text-decoration:underline;text-decoration-thickness:1.5px}
.post p{margin:0 0 6px;font-size:15.5px;color:var(--lede-ink)}
.post .more{font-family:var(--display);font-size:13px}
#noresults{font-family:var(--display);font-size:14px;color:var(--muted);border:1px dashed var(--line);border-radius:8px;padding:18px 20px}

/* Sidebar-less single page (plain blog posts) */
.single{max-width:868px;margin:0 auto;padding:34px 24px 90px}

/* Site footer */
footer.site{border-top:1px solid var(--line);font-family:var(--display);font-size:12px;color:var(--muted);text-align:center;padding:18px 22px 26px}

@media(max-width:900px){
  .masthead{position:relative;padding-right:100px}
  #themetoggle{position:absolute;top:12px;right:18px;margin-left:0;align-self:auto;padding:6px 10px;font-size:15px}
  #themetoggle .tlabel{display:none}
  #headertoggle{display:block;position:absolute;top:12px;right:60px;margin-left:0;align-self:auto;padding:6px 10px;font-size:15px;line-height:1}
  .masthead.collapsed .sub{display:none}
  .masthead.collapsed h1{min-width:0;flex:1 1 auto;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
  .layout{grid-template-columns:1fr}
  nav.side{border-right:none;border-bottom:1px solid var(--line);padding:10px 0}
  nav.side .inner{position:static;max-height:none;overflow:visible;display:none;padding:8px 16px 16px}
  nav.side.open .inner{display:block}
  #navtoggle{display:block;margin:0 16px;font-family:var(--display);font-weight:600;font-size:13px;padding:9px 14px;border:1px solid var(--line);border-radius:6px;background:var(--card);color:var(--ink);cursor:pointer;width:calc(100% - 32px);text-align:left}
  main{padding:26px 20px 70px}
  .article h1{font-size:26px}
  .content>h1{font-size:26px}
}