/* PowerPlan CD Platform: shared tokens and base styles ("Engineering handbook").
   Every page links this file. Theme: <html data-theme="light|dark">, stored in localStorage "cd-theme",
   default from prefers-color-scheme (see the inline script in each page head and site.js).
   Page-specific CSS should use these tokens only. */

:root{
  color-scheme:light;
  /* surfaces and text */
  --bg:#FFFFFF;          /* page */
  --panel:#F7F8FA;       /* side panels, code, table heads */
  --text:#1A2230;
  --muted:#5A6474;       /* secondary text, meets 4.5:1 on --bg and --panel */
  --border:#E3E6EB;
  /* brand */
  --accent:#0F7C7E;      /* links, active nav, focus ring */
  --accent-soft:#E7F3F3; /* tinted backgrounds */
  --on-accent:#FFFFFF;
  /* state */
  --built:#1A7346;   --built-bg:#E8F5EE; /* #1E7F4F on #E8F5EE is 4.45:1; darkened to pass 4.5 */
  --planned:#8A5A00; --planned-bg:#FFF4DB;
  --broken:#B42318;  --broken-bg:#FDECEA;
  /* secondary hues, for diagrams-like accents only (never for meaning) */
  --c-blue:#1F5FBF; --c-violet:#6B3FB8;
  /* type */
  --font-sans:"Segoe UI",system-ui,-apple-system,"Helvetica Neue",Arial,sans-serif;
  --font-mono:"Cascadia Code",Consolas,ui-monospace,monospace;
  --fs-sm:14px; --fs-base:16px; --fs-h3:20px; --fs-h2:25px; --fs-h1:32px; --fs-hero:40px;
  /* shape */
  --radius:8px; --container:1200px; --measure:720px;
}
[data-theme="dark"]{
  color-scheme:dark;
  --bg:#0F141C; --panel:#161C26; --text:#E6EAF0; --muted:#9AA4B2; --border:#2A3240;
  --accent:#3CC2C4; --accent-soft:#12292B; --on-accent:#0F141C;
  --built:#5CCB8F;   --built-bg:#112619;
  --planned:#E8B65A; --planned-bg:#2A2111;
  --broken:#F2877C;  --broken-bg:#2D1715;
  --c-blue:#7DA8F5; --c-violet:#B39AF2;
}

/* ---------- base ---------- */
*,*::before,*::after{box-sizing:border-box}
html{scroll-padding-top:72px;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font:var(--fs-base)/1.6 var(--font-sans);overflow-wrap:break-word}
img,svg,iframe{max-width:100%}
a{color:var(--accent);text-underline-offset:2px}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:4px}
h1,h2,h3,h4{line-height:1.25;font-weight:600;margin:0 0 .5em}
h1{font-size:var(--fs-h1)}
h2{font-size:var(--fs-h2)}
h3{font-size:var(--fs-h3)}
h4{font-size:var(--fs-base)}
p,ul,ol{margin:0 0 1em}
li{margin:.25em 0}
small,.small{font-size:var(--fs-sm)}
.muted{color:var(--muted)}
hr{border:0;border-top:1px solid var(--border);margin:48px 0}
code,kbd,samp{font-family:var(--font-mono);font-size:.875em;font-variant-ligatures:none}
:not(pre)>code{background:var(--panel);border:1px solid var(--border);border-radius:4px;padding:.05em .35em;overflow-wrap:anywhere}
pre{font:13.5px/1.6 var(--font-mono);background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);
  padding:14px 16px;overflow:auto;margin:0 0 1em;font-variant-ligatures:none;max-width:100%}
pre code{background:none;border:0;padding:0;font-size:inherit}
table{width:100%;border-collapse:collapse;margin:0 0 1.25em;font-size:15px}
.table-wrap{overflow-x:auto;margin:0 0 1.25em}
.table-wrap table{margin:0}
th,td{text-align:left;padding:9px 12px;border-bottom:1px solid var(--border);vertical-align:top}
th{font-weight:600;background:var(--panel);font-size:var(--fs-sm)}
details{border:1px solid var(--border);border-radius:var(--radius);padding:10px 14px;margin:0 0 12px;background:var(--bg)}
details>summary{cursor:pointer;font-weight:600}
details[open]>summary{margin-bottom:8px}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);border:0}
.skip{position:absolute;left:-999px;top:8px;background:var(--accent);color:var(--on-accent);padding:8px 12px;border-radius:var(--radius);z-index:100}
.skip:focus{left:8px}
.rv{opacity:1;transform:none} /* legacy reveal class: content is always visible */

/* ---------- header and nav ---------- */
.site-header{position:sticky;top:0;z-index:50;background:var(--bg);border-bottom:1px solid var(--border)}
.site-header .bar{max-width:var(--container);margin:0 auto;padding:0 24px;min-height:60px;display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:10px;font-weight:600;color:var(--text);text-decoration:none;white-space:nowrap}
.brand .mark{width:14px;height:14px;border-radius:3px;background:var(--accent)}
.site-nav{display:flex;align-items:center;gap:4px;margin-left:auto;flex-wrap:wrap}
.site-nav>a,.paths>summary{color:var(--muted);text-decoration:none;font-size:15px;padding:8px 10px;border-radius:6px;display:block}
.site-nav>a:hover,.paths>summary:hover{color:var(--text);background:var(--panel)}
.site-nav>a[aria-current="page"],.paths.current>summary{color:var(--text);box-shadow:inset 0 -2px 0 var(--accent);border-radius:0}
.paths{position:relative;border:0;padding:0;margin:0;background:none}
.paths>summary{list-style:none;cursor:pointer;font-weight:400}
.paths>summary::-webkit-details-marker{display:none}
.paths>summary::after{content:"";display:inline-block;margin-left:6px;border:4px solid transparent;border-top-color:currentColor;vertical-align:-1px}
.paths[open]>summary{margin:0}
.paths-menu{position:absolute;top:calc(100% + 6px);left:0;min-width:200px;background:var(--bg);border:1px solid var(--border);
  border-radius:var(--radius);padding:6px;box-shadow:0 8px 24px rgba(0,0,0,.12)}
.paths-menu a{display:block;padding:8px 10px;border-radius:6px;color:var(--text);text-decoration:none;font-size:15px}
.paths-menu a:hover{background:var(--panel)}
.paths-menu a[aria-current="page"]{color:var(--accent);font-weight:600}
.icon-btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:36px;min-width:36px;padding:0 8px;border:1px solid var(--border);
  border-radius:6px;background:var(--bg);color:var(--text);cursor:pointer;font:inherit;font-size:var(--fs-sm)}
.icon-btn:hover{background:var(--panel)}
.icon-btn svg{width:18px;height:18px}
.theme-btn .i-sun{display:none}
[data-theme="dark"] .theme-btn .i-sun{display:block}
[data-theme="dark"] .theme-btn .i-moon{display:none}
.menu-btn{display:none}

/* ---------- layout ---------- */
.container{max-width:var(--container);margin:0 auto;padding:0 24px}
.narrow{max-width:var(--measure)}
main{display:block}
.page{max-width:var(--container);margin:0 auto;padding:40px 24px 64px}
.page>section,.content>section{margin-top:56px}
.page-head{padding:16px 0 8px;max-width:820px}
.eyebrow{font-size:var(--fs-sm);font-weight:600;color:var(--accent);margin:0 0 8px}
.lead{font-size:19px;color:var(--muted);margin:0 0 16px;max-width:760px}
.meta{font-size:var(--fs-sm);color:var(--muted);display:flex;flex-wrap:wrap;gap:6px 14px;align-items:center}
.with-toc{display:grid;grid-template-columns:220px minmax(0,1fr);gap:48px}
.toc{position:sticky;top:76px;align-self:start;font-size:var(--fs-sm);padding-top:8px;max-height:calc(100vh - 90px);overflow:auto}
.toc b{display:block;font-weight:600;margin-bottom:8px}
.toc a{display:block;color:var(--muted);text-decoration:none;padding:4px 0 4px 12px;border-left:2px solid var(--border)}
.toc a.on,.toc a:hover{color:var(--text);border-left-color:var(--accent)}
.content{min-width:0;max-width:820px}
section h2{padding-top:8px}
.section-num{color:var(--muted);font-weight:400;margin-right:.4em}

/* ---------- components ---------- */
.hero{padding:56px 0 24px}
.hero h1{font-size:var(--fs-hero);line-height:1.15;max-width:860px;margin-bottom:16px}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px;margin:16px 0}
.card{border:1px solid var(--border);border-radius:var(--radius);padding:20px;background:var(--bg);display:flex;flex-direction:column;gap:6px;min-width:0}
.card h3{font-size:18px;margin:0}
.card p{margin:0;color:var(--muted);font-size:15px}
.card .more{margin-top:auto;padding-top:10px;font-weight:600;text-decoration:none;color:var(--accent)}
.card .more:hover{text-decoration:underline}
a.card{text-decoration:none;color:inherit}
a.card:hover{border-color:var(--accent)}
.card .tag{align-self:flex-start}
.tag{display:inline-block;font-size:12px;font-weight:600;color:var(--muted);border:1px solid var(--border);border-radius:999px;padding:1px 8px;background:var(--panel)}
.thumb{display:block;border:1px solid var(--border);border-radius:6px;background:var(--panel);aspect-ratio:16/10;width:100%;height:auto;object-fit:cover;object-position:top left}

/* state badges (canonical): built / built, not live / planned / broken.
   Legacy markup .bp.b, .bp.p and .planned is styled the same. */
.badge,.bp,.planned{display:inline-block;font:600 12px/1.6 var(--font-sans);letter-spacing:0;text-transform:none;border-radius:999px;padding:0 8px;vertical-align:1px;white-space:nowrap;border:1px solid transparent}
.badge-built,.bp.b{color:var(--built);background:var(--built-bg);border-color:color-mix(in srgb,var(--built) 30%,transparent)}
.badge-notlive{color:var(--c-blue);background:color-mix(in srgb,var(--c-blue) 10%,var(--bg));border-color:color-mix(in srgb,var(--c-blue) 30%,transparent)}
.badge-planned,.bp.p,.planned{color:var(--planned);background:var(--planned-bg);border-color:color-mix(in srgb,var(--planned) 30%,transparent)}
.badge-broken,.bp.x{color:var(--broken);background:var(--broken-bg);border-color:color-mix(in srgb,var(--broken) 30%,transparent)}

.callout{border:1px solid var(--border);border-left:4px solid var(--accent);border-radius:var(--radius);padding:14px 16px;margin:0 0 16px;background:var(--panel)}
.callout>:last-child{margin-bottom:0}
.callout h3,.callout h4{margin:0 0 4px;font-size:var(--fs-base)}
.callout-broken{border-left-color:var(--broken);background:var(--broken-bg)}
.callout-planned{border-left-color:var(--planned);background:var(--planned-bg)}
.callout-built{border-left-color:var(--built);background:var(--built-bg)}
.analogy{border:1px solid var(--border);border-radius:var(--radius);padding:12px 16px;margin:0 0 16px;background:var(--panel)}
.analogy b:first-child{display:block;font-size:var(--fs-sm);color:var(--muted);font-weight:600}

.status{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}
.status>div{border:1px solid var(--border);border-radius:var(--radius);padding:14px 16px;font-size:15px}
.status h3{font-size:var(--fs-base);margin:0 0 6px;display:flex;align-items:center;gap:8px}
.status ul{margin:0;padding-left:18px}

ol.steps{counter-reset:s;list-style:none;padding:0;margin:0 0 1em}
ol.steps>li{counter-increment:s;position:relative;padding:2px 0 12px 44px;margin:0}
ol.steps>li::before{content:counter(s);position:absolute;left:0;top:0;width:30px;height:30px;border-radius:50%;
  border:1px solid var(--border);background:var(--panel);font-weight:600;display:flex;align-items:center;justify-content:center;font-size:var(--fs-sm)}
ul.ticks{list-style:none;padding:0}
ul.ticks li{padding-left:26px;position:relative}
ul.ticks li::before{content:"";position:absolute;left:4px;top:.55em;width:12px;height:7px;border-left:2px solid var(--accent);border-bottom:2px solid var(--accent);transform:rotate(-45deg)}

.embed{border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;margin:0 0 8px;background:var(--panel)}
.embed iframe{display:block;width:100%;height:720px;border:0}
.embed-links{display:flex;flex-wrap:wrap;gap:8px 18px;font-size:var(--fs-sm);margin:0 0 16px}
.two{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
dl.gloss{display:grid;grid-template-columns:minmax(150px,220px) 1fr;gap:6px 18px;margin:0}
dl.gloss dt{font-weight:600}
dl.gloss dd{margin:0;color:var(--text)}
dl.gloss dd code{font-size:.8em}

.site-footer{border-top:1px solid var(--border);margin-top:64px}
.site-footer .container{padding-top:20px;padding-bottom:32px;font-size:var(--fs-sm);color:var(--muted);display:flex;flex-wrap:wrap;gap:8px 24px;justify-content:space-between}

/* ---------- responsive ---------- */
@media (max-width:900px){
  .js .menu-btn{display:inline-flex;margin-left:auto}
  .js .site-nav{display:none;width:100%;flex-direction:column;align-items:stretch;padding:0 0 12px}
  .js .site-nav.open{display:flex}
  .site-nav{margin-left:0;width:100%}
  .paths-menu{position:static;box-shadow:none;border:0;padding:0 0 0 12px}
  .site-nav>a[aria-current="page"],.paths.current>summary{box-shadow:inset 3px 0 0 var(--accent)}
  .with-toc{grid-template-columns:1fr;gap:0}
  .toc{display:none}
  .status,.two{grid-template-columns:1fr}
  dl.gloss{grid-template-columns:1fr}
  dl.gloss dd{margin-bottom:8px}
  .hero{padding:32px 0 16px}
  :root{--fs-hero:30px;--fs-h1:28px;--fs-h2:22px}
  .embed iframe{height:560px}
  table{display:block;overflow-x:auto;max-width:100%}
  .table-wrap table{display:table}
}
@media (max-width:480px){
  .site-header .bar,.container,.page{padding-left:16px;padding-right:16px}
  .brand{white-space:normal}
}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* ---------- print ---------- */
@media print{
  :root,[data-theme="dark"]{--bg:#fff;--panel:#f5f5f5;--text:#000;--muted:#333;--border:#ccc;--accent:#0b5c5d}
  .site-header,.toc,.menu-btn,.theme-btn,.skip,.no-print,.embed iframe{display:none!important}
  .embed::after{content:"Interactive view: open " attr(data-src) " in a browser.";display:block;padding:12px;font-size:12px}
  body{font-size:11pt}
  .page,.with-toc{display:block;padding:0}
  a{color:inherit}
  .content a[href^="http"]::after{content:" (" attr(href) ")";font-size:9pt;color:#555;overflow-wrap:anywhere}
  details{border:0;padding:0}
  details>*:not(summary){display:block!important}
  section,.card,.callout,table,pre{break-inside:avoid}
  pre{white-space:pre-wrap}
}