/* Jugami Geometry: drafting-paper theme. Blueprint navy, pencil graphite, warm compass-brass accent. */
:root{
  --navy:#1d3557; --navy2:#27466e; --blue:#3f6ea5; --graphite:#33373d; --pencil:#5b616a;
  --paper:#fbf8ef; --paper2:#f3eedf; --grid:rgba(63,110,165,.10); --grid2:rgba(63,110,165,.20);
  --accent:#e08a3c; --accent-ink:#9a4a0e; --good:#2f7d4f; --bad:#b23a2e;
  --radius:8px; --serif:"Iowan Old Style","Palatino Linotype",Palatino,"Book Antiqua",Georgia,serif;
  --sans:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --mono:ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
[hidden]{display:none!important}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;color:var(--graphite);font-family:var(--sans);font-size:18px;line-height:1.65;
  background-color:var(--paper);
  background-image:linear-gradient(var(--grid2) 1px,transparent 1px),linear-gradient(90deg,var(--grid2) 1px,transparent 1px),
    linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  background-size:100px 100px,100px 100px,20px 20px,20px 20px}
a{color:var(--accent-ink);text-underline-offset:2px}
a:hover{color:var(--navy)}
img,svg{max-width:100%;height:auto}
h1,h2,h3{font-family:var(--serif);color:var(--navy);line-height:1.2}
h2{font-size:1.75rem;margin:2.4em 0 .4em;scroll-margin-top:12px}
h2::after{content:"";display:block;width:64px;height:3px;background:var(--accent);margin-top:.35em}
h3{font-size:1.2rem;margin:1.4em 0 .3em}
.skip{position:absolute;left:-999px;top:8px}
.skip:focus{left:8px;background:var(--navy);color:#fff;padding:8px 12px;z-index:10}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
.visually-hidden{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.wrap{max-width:1040px;margin:0 auto;padding:0 18px}
.prose{max-width:40rem}
/* header */
.site-head{background:var(--navy);color:#fff;border-bottom:4px solid var(--accent)}
.site-head .bar{display:flex;align-items:center;gap:14px;flex-wrap:wrap;padding:10px 18px}
.brand{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font-family:var(--serif);font-size:1.3rem;letter-spacing:.03em}
.brand img{width:36px;height:36px}
.brand:hover{color:#ffd9b3}
.head-nav{margin-left:auto;display:flex;flex-wrap:wrap;gap:6px}
.head-nav a{color:#fff;text-decoration:none;font-size:.9rem;padding:5px 11px;border:1px solid rgba(255,255,255,.35);border-radius:999px}
.head-nav a:hover,.head-nav a:focus-visible{background:var(--accent);border-color:var(--accent);color:var(--navy)}
.crumbs{font-size:.9rem;color:var(--pencil);margin:14px 0 0}
.crumbs a{color:var(--pencil)}
/* hero */
.hero{display:grid;grid-template-columns:1.2fr 1fr;gap:28px;align-items:center;padding:24px 0 8px}
.hero h1{font-size:clamp(2.1rem,5.5vw,3.3rem);margin:.1em 0 .2em}
.tagline{font-family:var(--serif);font-style:italic;font-size:1.25rem;color:var(--blue);margin:0 0 .6em}
.hero figure{margin:0}
.sheet{background:var(--paper);border:1px solid #cfd8e3;border-radius:var(--radius);box-shadow:0 2px 0 #d9d2bd,0 8px 24px rgba(29,53,87,.10);padding:16px 20px}
.btns{display:flex;flex-wrap:wrap;gap:10px;margin:14px 0}
.btn,button{font:inherit;font-size:1rem;cursor:pointer;border-radius:999px;padding:8px 16px;border:2px solid var(--navy);background:var(--navy);color:#fff;text-decoration:none;display:inline-block}
.btn.ghost,button.ghost{background:transparent;color:var(--navy)}
.btn:hover,button:hover{background:var(--navy2);color:#fff}
button.ghost:hover{background:var(--paper2);color:var(--navy)}
button:disabled{opacity:.5;cursor:not-allowed}
/* toc + cards */
.toc{display:flex;flex-wrap:wrap;gap:8px;list-style:none;padding:0;margin:12px 0}
.toc a{display:block;padding:4px 12px;border:1px dashed var(--blue);border-radius:6px;text-decoration:none;color:var(--navy);background:rgba(255,255,255,.6);font-size:.95rem}
.toc a:hover{border-style:solid;background:#fff}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:16px;list-style:none;padding:0;margin:16px 0}
.card{position:relative;background:#fff;border:1px solid #cfd8e3;border-radius:var(--radius);padding:16px 18px;height:100%}
.card h3{margin:.3em 0 .25em}
.card p{margin:.2em 0;font-size:.98rem}
.card svg{display:block;width:72px;height:72px}
.card.live{border:2px solid var(--navy);box-shadow:4px 4px 0 var(--accent)}
.card.live a::after{content:"";position:absolute;inset:0}
.card.soon{opacity:.82;background:rgba(255,255,255,.7)}
.tag{display:inline-block;font-size:.75rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;padding:2px 8px;border-radius:4px;background:var(--paper2);color:var(--pencil)}
.tag.on{background:var(--accent);color:var(--navy)}
/* math + callouts */
.formula{font-family:var(--serif);font-size:clamp(1.8rem,5vw,2.6rem);text-align:center;color:var(--navy);margin:.4em 0;letter-spacing:.04em}
.m{font-family:var(--serif);font-style:italic;white-space:nowrap}
.callout{border-left:5px solid var(--accent);background:#fff;padding:12px 16px;border-radius:0 var(--radius) var(--radius) 0;margin:16px 0}
.callout.blue{border-left-color:var(--blue)}
.callout h3{margin-top:.1em}
.two{display:grid;grid-template-columns:1fr 1fr;gap:22px;align-items:start}
.steps{counter-reset:s;list-style:none;padding:0}
.steps li{counter-increment:s;position:relative;padding-left:2.2em;margin:.35em 0}
.steps li::before{content:counter(s);position:absolute;left:0;top:.15em;width:1.6em;height:1.6em;border-radius:50%;background:var(--navy);color:#fff;font-size:.85rem;display:grid;place-items:center}
table.data{border-collapse:collapse;background:#fff;margin:10px 0;font-size:.98rem}
table.data th,table.data td{border:1px solid #cfd8e3;padding:6px 12px;text-align:center}
table.data th{background:var(--paper2);color:var(--navy)}
.mistake{display:grid;grid-template-columns:auto 1fr;gap:4px 12px;background:#fff;border:1px solid #cfd8e3;border-radius:var(--radius);padding:12px 14px;margin:10px 0}
.mistake .x{color:var(--bad);font-weight:700}.mistake .ok{color:var(--good);font-weight:700}
/* widgets */
.widget{background:#fff;border:2px solid var(--navy);border-radius:var(--radius);padding:16px 18px;margin:16px 0;box-shadow:5px 5px 0 rgba(29,53,87,.15)}
.widget .help{color:var(--pencil);font-size:.95rem;margin-top:0}
.explorer{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:18px;align-items:start}
.explorer svg{width:100%;touch-action:none;background:var(--paper)}
.explorer .handle{cursor:grab}
.explorer .handle:focus{outline:none}
.explorer .handle:focus circle{stroke:var(--accent);stroke-width:4}
.ctrl{margin:8px 0}
.ctrl label{display:flex;justify-content:space-between;font-weight:600;color:var(--navy)}
.ctrl input[type=range]{width:100%;accent-color:var(--accent)}
.readout{font-family:var(--mono);font-size:1rem;background:var(--paper);border:1px dashed var(--blue);border-radius:6px;padding:10px 12px;line-height:1.8}
.readout b{color:var(--navy)}
.sq-a{fill:rgba(63,110,165,.22);stroke:var(--blue)}
.sq-b{fill:rgba(224,138,60,.22);stroke:var(--accent-ink)}
.sq-c{fill:rgba(47,125,79,.16);stroke:var(--good)}
.practice .q{font-family:var(--serif);font-size:1.2rem;color:var(--navy);min-height:2.4em}
.practice form{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.practice input[type=text]{font:inherit;font-size:1.1rem;width:9em;padding:6px 10px;border:2px solid var(--pencil);border-radius:6px}
.feedback{min-height:1.6em;font-weight:600;margin:.5em 0}
.feedback.good{color:var(--good)}.feedback.bad{color:var(--bad)}
.hint{color:var(--pencil);font-style:italic;min-height:1.2em}
.stats{display:flex;flex-wrap:wrap;gap:8px 18px;font-size:.95rem;color:var(--pencil);border-top:1px dashed #cfd8e3;padding-top:8px;margin-top:10px}
.stats b{color:var(--navy);font-size:1.05rem}
noscript p,.noscript{background:var(--paper2);border:1px dashed var(--pencil);padding:10px 14px;border-radius:6px}
/* pager + footer */
.pager{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;margin:40px 0 10px;padding:14px 0;border-top:2px solid var(--navy)}
.pager a{text-decoration:none;font-weight:600;color:var(--navy)}
.pager a:hover{color:var(--accent-ink)}
.sources li{margin:.3em 0}
.site-foot{margin-top:40px;background:var(--navy);color:#e8edf4;font-size:.95rem;padding:18px 0 22px}
.site-foot a{color:#ffd9b3}
.jugami-more{margin-top:8px}
.jugami-more span{font-weight:700;margin-right:4px}
@media (max-width:760px){.hero,.two,.explorer{grid-template-columns:1fr}body{font-size:17px}.head-nav{display:none}}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}