:root{
  --paper:#fcfbf9; --ink:#15181a; --ink-soft:#3c434a; --muted:#6c757d;
  --rule:#e2ded5; --line:#cdc7bb; --accent:#1d5a4b; --accent-ink:#12443a;
  --wash:#f4f1ea; --warn:#8a4a1f;
  --sans:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:ui-monospace,"SF Mono",Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
body{margin:0;background:var(--paper);color:var(--ink);font:16.5px/1.62 var(--sans);-webkit-font-smoothing:antialiased}
.wrap{max-width:60rem;margin:0 auto;padding:0 1.4rem}
a{color:var(--accent-ink);text-decoration:none;border-bottom:1px solid rgba(29,90,75,.28)}
a:hover{border-bottom-color:var(--accent-ink)}
header.top{border-bottom:1px solid var(--rule);background:#fff}
.top-in{max-width:60rem;margin:0 auto;padding:.95rem 1.4rem;display:flex;align-items:center;justify-content:space-between;gap:1rem;flex-wrap:wrap}
.logo{font:700 1.1rem/1 var(--sans);letter-spacing:-.01em;color:var(--ink);border:0}
.logo span{font:400 .62rem/1.5 var(--mono);letter-spacing:.14em;text-transform:uppercase;color:var(--muted);display:block;margin-top:.25rem}
nav.top-nav{display:flex;gap:1.2rem;flex-wrap:wrap}
nav.top-nav a{font:500 .82rem/1.6 var(--sans);color:var(--ink-soft);border:0}
nav.top-nav a:hover{color:var(--accent-ink)}
main{padding:2.2rem 0 3rem}
h1{font-size:clamp(1.7rem,3.4vw,2.25rem);line-height:1.18;letter-spacing:-.02em;margin:0 0 .8rem;text-wrap:balance}
h2{font-size:1.18rem;margin:2.4rem 0 .6rem;letter-spacing:-.01em}
h3{font-size:1rem;margin:1.5rem 0 .4rem}
p{margin:0 0 1rem;max-width:44rem;text-wrap:pretty;color:var(--ink-soft)}
ul,ol{max-width:44rem;padding-left:1.15rem;color:var(--ink-soft);margin:0 0 1rem}
li{margin-bottom:.35rem}
.crumbs{font:400 .72rem/1.6 var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:1.1rem}
.crumbs a{color:var(--muted);border:0}
.lede{font-size:1.08rem;color:var(--ink-soft);max-width:40rem}

/* ---- the tool ---- */
.tool{background:#fff;border:1px solid var(--line);border-radius:2px;padding:1.3rem 1.35rem 1.5rem;margin:0 0 1.6rem}
.tool .grid{display:grid;gap:.9rem 1.1rem;grid-template-columns:1fr}
@media(min-width:38rem){.tool .grid{grid-template-columns:1fr 1fr}}
.field label{display:block;font:500 .8rem/1.4 var(--sans);letter-spacing:.02em;margin-bottom:.3rem;color:var(--ink)}
.field .hint{font-size:.76rem;color:var(--muted);margin-top:.25rem}
.field input,.field select{width:100%;font:400 1rem/1.4 var(--sans);padding:.62rem .7rem;border:1px solid var(--line);background:#fff;color:var(--ink);border-radius:2px;min-height:44px}
.field input:focus,.field select:focus{outline:2px solid rgba(29,90,75,.35);outline-offset:1px;border-color:var(--accent)}
.result{margin-top:1.2rem;border-top:1px solid var(--rule);padding-top:1rem}
.result .label{font:400 .7rem/1 var(--mono);letter-spacing:.15em;text-transform:uppercase;color:var(--muted);margin-bottom:.45rem}
.result .big{font:600 2rem/1.1 var(--sans);letter-spacing:-.02em;color:var(--accent-ink)}
.result .big .unit{font:400 .95rem/1 var(--sans);color:var(--ink-soft);letter-spacing:0;margin-left:.2rem}
.result .secondary{margin-top:.7rem;display:flex;flex-wrap:wrap;gap:.5rem 1.6rem;font-size:.9rem;color:var(--ink-soft)}
.result .secondary b{font-weight:600;color:var(--ink)}
.result .note{margin-top:.8rem;font-size:.82rem;color:var(--muted);max-width:38rem}

/* ---- reserved ad slots: height fixed so nothing shifts when they fill ---- */
.ad-slot{border:1px dashed var(--rule);background:#faf8f4;margin:1.6rem 0;display:flex;align-items:center;justify-content:center;font:400 .66rem/1 var(--mono);letter-spacing:.16em;text-transform:uppercase;color:#b3ada2}
.ad-slot.inline{min-height:280px}
.ad-slot.leader{min-height:100px}
.ad-slot.footer{min-height:250px}
@media(max-width:36rem){.ad-slot.inline{min-height:250px}}

details{border-top:1px solid var(--rule);padding:.85rem 0}
details:last-of-type{border-bottom:1px solid var(--rule)}
summary{cursor:pointer;font-weight:600;font-size:.95rem;list-style:none}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";float:right;color:var(--muted);font-weight:400}
details[open] summary::after{content:"–"}
details p{margin:.6rem 0 0;font-size:.93rem}

.examples{display:grid;gap:1.1rem;margin:0 0 1.4rem}
@media(min-width:44rem){.examples{grid-template-columns:1fr 1fr}}
.example{border-left:2px solid var(--line);padding-left:.9rem}
.example h3{margin:.1rem 0 .3rem;font-size:.92rem}
.example p{font-size:.9rem;margin:0}

.related{display:grid;gap:.6rem;margin:.6rem 0 1.6rem}
@media(min-width:44rem){.related{grid-template-columns:1fr 1fr}}
.related a{display:block;border:1px solid var(--rule);background:#fff;padding:.7rem .85rem;font-size:.92rem;border-bottom:1px solid var(--rule)}
.related a:hover{border-color:var(--accent)}

.byline{font-size:.8rem;color:var(--muted);border-top:1px solid var(--rule);padding-top:.9rem;margin-top:2rem;max-width:44rem}
footer.site{border-top:1px solid var(--rule);background:#fff;margin-top:2rem;font-size:.8rem;color:var(--muted)}
.foot-in{max-width:60rem;margin:0 auto;padding:1.3rem 1.4rem 2.2rem;display:flex;gap:.6rem 2rem;flex-wrap:wrap;justify-content:space-between}
footer.site a{color:var(--muted);border-bottom-color:var(--rule)}

/* hub + home listings */
.cards{display:grid;gap:.9rem;margin:1.2rem 0 2rem}
@media(min-width:44rem){.cards{grid-template-columns:1fr 1fr}}
@media(min-width:60rem){.cards{grid-template-columns:1fr 1fr 1fr}}
.card{border:1px solid var(--rule);background:#fff;padding:.95rem 1rem}
.card h3{margin:.1rem 0 .3rem;font-size:.96rem}
.card p{font-size:.86rem;margin:0;color:var(--muted)}
.card a{border:0}

.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.note-box{background:var(--wash);border-left:3px solid var(--accent);padding:.9rem 1.1rem;margin:0 0 1.4rem;font-size:.9rem}
.note-box p{margin:0;font-size:.9rem}
@media print{.ad-slot{display:none}}