/* CSSH AI in Teaching — shared design system */
:root{
  --red:#d41b2c; --red-dark:#a3141f; --black:#0d0d0d; --ink:#1c1c1c;
  --muted:#5c5c5c; --bg:#ffffff; --surface:#faf9f8; --line:#d9d4cf; --chip:#f4f1ee;
  --accent2:#2f6f5e; --note-bg:#fff8e6; --note-line:#e6c36a;
  /* filled surfaces that carry WHITE text */
  --red-btn:#d41b2c; --red-btn-hover:#a3141f;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --red:#ff6b70; --red-dark:#e06068; --black:#f4f2f0; --ink:#eceae8;
    --muted:#a7a19b; --bg:#141210; --surface:#1e1b18; --line:#3d3731; --chip:#26221e;
    --accent2:#6fbfa6; --note-bg:#2a2416; --note-line:#8a7336;
    /* deeper red so white button text keeps contrast in dark mode */
    --red-btn:#c62f3a; --red-btn-hover:#a3242e;
  }
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);
  font:17px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif}
img{max-width:100%}
a{color:var(--red)}
:focus-visible{outline:3px solid var(--red);outline-offset:3px;border-radius:4px}
a.big:focus-visible,.tab[aria-selected="true"]:focus-visible,.filters button[aria-pressed="true"]:focus-visible{outline-color:var(--black)}

/* skip link */
.skip{position:absolute;left:-9999px;top:0;z-index:100;background:var(--bg);color:var(--red);padding:.6em 1em;font-weight:700;border:2px solid var(--red);border-radius:8px}
.skip:focus{left:1rem;top:1rem}

/* top bar + nav (shared across pages) */
.topbar{background:#0d0d0d;color:#fff;padding:9px 20px;font-size:.82rem;letter-spacing:.02em;
  display:flex;flex-wrap:wrap;justify-content:space-between;gap:4px 16px}
.topbar b{color:#fff}
.topbar .note{color:#d0cbc6}
nav{position:sticky;top:0;z-index:10;background:var(--bg);border-bottom:2px solid var(--red);
  display:flex;flex-wrap:wrap;gap:4px;padding:10px 16px;align-items:center;justify-content:center}
nav a{color:var(--ink);text-decoration:none;font-weight:600;font-size:.95rem;padding:6px 12px;border-radius:6px}
nav a:hover,nav a[aria-current="page"]{background:var(--chip);color:var(--red)}

/* layout */
.wrap{max-width:900px;margin:0 auto;padding:0 max(16px,5vmin) 5vmin}
header.hero{text-align:center;padding:2.6em max(16px,5vmin) .6em;max-width:900px;margin:0 auto}
.eyebrow{color:var(--red);font-weight:700;letter-spacing:.1em;text-transform:uppercase;font-size:.8rem}
h1{font-size:clamp(2.1rem,6vw,3.2rem);line-height:1.05;margin:.15em 0 .3em;color:var(--black)}
.lede{color:var(--muted);font-size:clamp(1.05rem,2.6vw,1.25rem);max-width:60ch;margin:0 auto}

/* blocks */
.intro{background:var(--surface);border:1px solid var(--line);border-left:5px solid var(--red);border-radius:10px;padding:18px 24px;margin:2em 0}
.intro p{margin:.5em 0}
section{scroll-margin-top:72px}
h2{font-size:1.5rem;line-height:1.25;color:var(--black);margin:2.2em 0 .25em}
h3{line-height:1.3}
.sub{color:var(--muted);margin:0 0 1.1em}
.toc{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin:1.2em 0 0;padding:0;list-style:none}
.toc a{display:inline-block;background:var(--chip);color:var(--ink);text-decoration:none;font-weight:600;font-size:.9rem;padding:6px 14px;border-radius:999px}
.toc a:hover{color:var(--red)}

/* "what do you need?" paths */
.paths{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:16px}
.path{background:var(--surface);border:1px solid var(--line);border-top:4px solid var(--red);border-radius:12px;padding:18px 20px}
.path h3{margin:0 0 .2em;font-size:1.15rem;color:var(--black)}
.path p{margin:0 0 .6em;color:var(--muted);font-size:.95rem}
.path ol{margin:0;padding-left:1.3em}
.path li{margin:.35em 0}

/* cards */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:16px}
a.card{display:block;background:var(--surface);border:1px solid var(--line);border-radius:12px;
  padding:18px 20px;text-decoration:none;color:var(--ink);transition:.15s}
a.card.feature{border-left:5px solid var(--red)}
a.card:hover{border-color:var(--red);box-shadow:0 4px 18px rgba(0,0,0,.07)}
a.card b,a.card h3{display:block;color:var(--red);font-size:1.05rem;margin:0 0 .25em}
a.card span{color:var(--muted);font-size:.93rem;display:block}
a.card .meta{margin-top:.7em;font-size:.72rem;color:var(--muted);text-transform:uppercase;letter-spacing:.04em}
a.card .meta em{font-style:normal;background:var(--chip);border-radius:20px;padding:2px 9px;margin:0 5px 4px 0;color:var(--ink);display:inline-block}
a.big{display:block;background:var(--red-btn);color:#fff;border-radius:12px;padding:20px 24px;text-decoration:none}
a.big:hover{background:var(--red-btn-hover)}
a.big b{font-size:1.2rem;display:block;margin-bottom:.2em;color:#fff}
a.big span{opacity:.95;font-size:.98rem}

/* callouts, rules, copyable text */
.callout{background:var(--note-bg);border:1px solid var(--note-line);border-radius:12px;padding:16px 22px;margin:1.2em 0}
.callout h3{margin:.1em 0 .4em;font-size:1.05rem;color:var(--black)}
.callout ul{margin:.3em 0;padding-left:1.2em}
.callout li{margin:.4em 0}
.rules{list-style:none;padding:0;margin:0;counter-reset:r}
.rules li{counter-increment:r;position:relative;background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:14px 18px 14px 56px;margin:.6em 0}
.rules li::before{content:counter(r);position:absolute;left:16px;top:14px;width:26px;height:26px;border-radius:50%;background:var(--red-btn);color:#fff;font-weight:700;font-size:.85rem;display:flex;align-items:center;justify-content:center}
.rules b{color:var(--black)}
.copy{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:14px 18px;margin:.8em 0}
.copy .head{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:.3em}
.copy .head b{color:var(--black)}
.copy blockquote{margin:0;color:var(--ink);font-size:.97rem}
.copybtn{border:1px solid var(--line);background:var(--bg);color:var(--ink);font:inherit;font-size:.82rem;font-weight:600;padding:4px 12px;border-radius:999px;cursor:pointer;flex:none}
.copybtn:hover{border-color:var(--red);color:var(--red)}
.tablewrap{overflow-x:auto}
table.labels{border-collapse:collapse;width:100%;font-size:.95rem}
table.labels th,table.labels td{border-bottom:1px solid var(--line);padding:10px 12px;text-align:left;vertical-align:top}
table.labels th{white-space:nowrap}
.pill{display:inline-block;font-weight:700;font-size:.85rem;padding:2px 10px;border-radius:999px;background:var(--chip);color:var(--ink);border:1px solid var(--line)}
details.guide{margin-top:.7em;background:var(--bg);border:1px solid var(--line);border-radius:10px;padding:10px 16px;color:var(--ink)}
details.guide summary{cursor:pointer;font-weight:700;color:var(--red)}
details.guide h3{font-size:1rem;margin:1em 0 .3em;color:var(--black)}
details.guide li{margin:.3em 0}
@media print{details.guide{display:block}details.guide>*{display:block}}
.faq details{background:var(--surface);border:1px solid var(--line);border-radius:10px;margin:.6em 0;padding:0 18px}
.faq summary{cursor:pointer;font-weight:700;color:var(--black);padding:14px 0;list-style-position:outside}
.faq summary:hover{color:var(--red)}
.faq details[open] summary{border-bottom:1px solid var(--line);margin-bottom:.6em}
.faq details>p,.faq details>ul{margin:.6em 0}
.faq details>:last-child{margin-bottom:14px}
@media print{.faq details>*{display:block}}
.linklike{background:none;border:0;padding:0;font:inherit;color:var(--red);text-decoration:underline;cursor:pointer}
.todo{background:var(--note-bg);border:1px dashed var(--note-line);border-radius:6px;padding:0 6px;font-weight:600;color:var(--ink)}
.source{font-size:.88rem;color:var(--muted)}

/* filters (examples gallery) */
.filters{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 1em}
.filters button{border:1px solid var(--line);background:var(--bg);color:var(--ink);
  padding:7px 14px;border-radius:999px;cursor:pointer;font-size:.88rem;font-weight:600}
.filters button[aria-pressed="true"]{background:var(--red-btn);color:#fff;border-color:var(--red-btn)}
.filter-label{font-size:.75rem;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;align-self:center;margin-right:2px}

/* misc */
ul.involve{padding-left:0;list-style:none}
ul.involve li{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:12px 16px;margin:.5em 0}
ul.involve b{color:var(--red)}
.sources{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:18px 24px;font-size:.93rem}
.sources h3{margin:.2em 0 .5em;font-size:1rem;color:var(--black)}
.sources li{margin:.5em 0}
.sources .by{color:var(--muted)}
.saveqr{display:inline-flex;align-items:center;gap:14px;background:var(--surface);
  border:1px solid var(--line);border-radius:12px;padding:12px 18px;text-align:left}
.saveqr .box{width:84px;height:84px;background:#fff;border-radius:8px;padding:6px;flex:none}
.saveqr .box img{width:100%;height:100%;display:block}
.saveqr .t b{color:var(--red);display:block;font-size:.95rem}
.saveqr .t span{color:var(--muted);font-size:.85rem}
footer{border-top:2px solid var(--red);margin-top:3em;padding:1.4em max(16px,5vmin);text-align:center;color:var(--muted);font-size:.87rem;max-width:900px;margin-inline:auto}
footer a{color:var(--muted)}

/* toolkit tabs */
.tabs{display:flex;flex-wrap:wrap;gap:8px;margin:1.4em 0 18px}
.tab{border:1px solid var(--line);background:var(--surface);color:var(--ink);
  padding:9px 15px;border-radius:999px;cursor:pointer;font-size:.92rem;font-weight:600}
.tab[aria-selected="true"]{background:var(--red-btn);color:#fff;border-color:var(--red-btn)}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:22px 24px}
.panel h2{margin:0 0 .1em;font-size:1.35rem}
.panel .who{font-size:.85rem;color:var(--muted);margin-bottom:1em}
.lever{border-left:3px solid var(--accent2);padding:2px 0 2px 14px;margin:16px 0}
.lever b{color:var(--accent2)}
.lever .ex{font-size:.93rem;color:var(--muted);margin-top:3px}
.lever dl{margin:.4em 0 0;font-size:.93rem;display:grid;grid-template-columns:max-content 1fr;gap:2px 12px}
.lever dt{font-weight:700;color:var(--muted)}
.lever dd{margin:0}
.diag{background:var(--chip);border-radius:10px;padding:14px 18px 14px 36px;margin:4px 0 2px}
.diag li{margin:.35em 0}
.adapt{background:var(--surface);border:1px dashed var(--line);border-radius:10px;padding:14px 18px;font-size:.95rem}
.adapt b{color:var(--red)}
code{background:var(--chip);padding:.08em .4em;border-radius:5px;font-size:.9em}

/* small screens: non-sticky nav so it never covers headings */
@media (max-width:600px){
  nav{position:static;justify-content:flex-start}
  nav a{padding:6px 10px}
  .topbar{padding:8px 16px}
  .saveqr{display:none}
  .lever dl{grid-template-columns:1fr}
  .lever dd{margin-bottom:.4em}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *{transition:none!important}
}
@media print{
  nav,.topbar,.tabs,.saveqr,.skip,.copybtn,.filters{display:none!important}
  body{font-size:11pt;background:#fff;color:#000}
  .panel{display:block!important;break-inside:avoid;margin-bottom:1em;border-color:#999}
  .wrap a[href^="http"]::after{content:" (" attr(href) ")";font-size:.8em;color:#555;word-break:break-all}
  a.card,.path,.copy,.rules li{break-inside:avoid}
}