/* Beautiful Mathematics — "Byrne parchment" house style. Logical properties throughout (RTL-ready, §4). */
@font-face{font-family:"EB Garamond";src:url(/fonts/EBGaramond-400.woff2) format("woff2");font-weight:400;font-style:normal;font-display:swap}
@font-face{font-family:"EB Garamond";src:url(/fonts/EBGaramond-600.woff2) format("woff2");font-weight:600;font-style:normal;font-display:swap}
@font-face{font-family:"EB Garamond";src:url(/fonts/EBGaramond-Italic-400.woff2) format("woff2");font-weight:400;font-style:italic;font-display:swap}
@font-face{font-family:"Cinzel";src:url(/fonts/Cinzel-600.woff2) format("woff2");font-weight:600;font-display:swap}
@font-face{font-family:"Marcellus";src:url(/fonts/Marcellus-Regular.woff2) format("woff2");font-display:swap}
@font-face{font-family:"GFS Didot";src:url(/fonts/GFSDidot-Regular.woff2) format("woff2");font-display:swap}

:root{
  --ink:#2a1f16; --ink-soft:#4a3a2c; --red:#a32a18; --red-fig:#b5301c; --blue:#1f4e8f; --yellow:#d9a21b;
  --accent:#7d2614; --frame:#7a2a18; --parchment:#e6d6b2; --paper:#f3e8cc; --rule:#b89a6a;
  --measure:42rem; --wide:64rem;
  --serif:"EB Garamond",Georgia,"Times New Roman",serif; --display:"Cinzel","EB Garamond",serif;
  --label:"Marcellus","EB Garamond",serif; --math:"GFS Didot","EB Garamond",serif;
}
*,*::before,*::after{box-sizing:border-box}
html{font-size:112.5%;-webkit-text-size-adjust:100%}
body{margin:0;color:var(--ink);background:var(--parchment) url(/img/parchment.webp) repeat;font-family:var(--serif);line-height:1.6;font-variant-numeric:oldstyle-nums}
img,svg{max-inline-size:100%;block-size:auto}
a{color:var(--blue);text-decoration-thickness:.07em;text-underline-offset:.18em}
a:hover{color:var(--red)}
:focus-visible{outline:3px solid var(--blue);outline-offset:3px;border-radius:2px}
.wrap{max-inline-size:var(--wide);margin-inline:auto;padding-inline:1rem}
.skip{position:absolute;inset-inline-start:-999px;inset-block-start:0;background:var(--ink);color:var(--paper);padding:.5rem 1rem;z-index:10}
.skip:focus{inset-inline-start:1rem}
.band{block-size:24px;background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20.0' height='24.0'%3E%3Cpolyline points='0,22.0 0,20 0,4 16,4 16,16 8,16 8,12 12,12 12,8 4,8 4,20 20,20' fill='none' stroke='%237a2a18' stroke-width='1.9' stroke-linejoin='miter' stroke-linecap='square'/%3E%3C/svg%3E") repeat-x center;border-block:2px solid var(--frame);margin-block:.4rem}
.preview-banner{background:var(--red);color:#fff;text-align:center;font-family:var(--label);padding:.35rem;letter-spacing:.05em}

/* Header */
.header-row{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:.5rem 1.5rem;padding-block:.6rem}
.brand{display:flex;align-items:center;gap:.6rem;color:var(--ink);text-decoration:none}
.brand-mark{inline-size:2.1rem;color:var(--red-fig)}
.brand-name{font-family:var(--display);font-weight:600;letter-spacing:.06em;font-size:1.15rem;text-transform:uppercase}
.nav{display:flex;flex-wrap:wrap;gap:.25rem 1.2rem;list-style:none;margin:0;padding:0;font-family:var(--label)}
.nav a{color:var(--ink);text-decoration:none;padding-block:.3rem;display:inline-block}
.nav a:hover{color:var(--red);text-decoration:underline}

/* Text */
main{padding-block:1.5rem 3rem}
h1,h2,h3{line-height:1.2;color:var(--ink)}
h1{font-family:var(--display);font-weight:600;font-size:clamp(1.7rem,4.5vw,2.6rem);letter-spacing:.02em;margin-block:.4rem .8rem}
h2{font-weight:600;font-size:1.55rem;margin-block:2.2rem .6rem;padding-block-end:.25rem;border-block-end:1px solid var(--rule)}
h3{font-weight:600;font-size:1.2rem;margin-block:1.6rem .4rem}
.prose,.article-head,.sources,.credits-list,.related,.crumbs,.toc,.part-of,.report,.cta,.explore{max-inline-size:var(--measure)}
.article{margin-inline:auto;max-inline-size:var(--measure)}
.prose p,.prose li{hyphens:auto}
.lead,.answer{font-size:1.2rem}
.answer{background:var(--paper);border-inline-start:5px solid var(--red-fig);padding:.8rem 1rem;margin-block:1rem}
.meta{display:flex;flex-wrap:wrap;gap:.3rem 1.2rem;font-style:italic;color:var(--ink-soft);margin:0}
.crumbs{font-family:var(--label);font-size:.9rem;color:var(--ink-soft)}
.math,.prose .num{font-family:var(--math);font-variant-numeric:lining-nums}
blockquote{margin-inline:0;padding-inline-start:1rem;border-inline-start:3px solid var(--rule);font-style:italic}
table{border-collapse:collapse;inline-size:100%;margin-block:1rem;display:block;overflow-x:auto}
th,td{border:1px solid var(--rule);padding:.35rem .6rem;text-align:start}
th{background:var(--paper)}
hr{border:0;border-block-start:1px solid var(--rule);margin-block:2rem}

/* Boxes: fact / legend / modern visualisation (§6) */
.box{border:2px solid var(--ink);background:var(--paper);padding:.8rem 1rem;margin-block:1.4rem;border-radius:2px}
.box-label{font-family:var(--label);font-size:.85rem;letter-spacing:.06em;text-transform:uppercase;margin:0 0 .3rem}
.box-title{font-weight:600;margin:0 0 .3rem}
.box-fact{border-color:var(--blue)} .box-fact .box-label{color:var(--blue)}
.box-legend{border-color:var(--red);border-style:dashed} .box-legend .box-label{color:var(--red)}
.box-modern{border-color:var(--ink-soft)} .box-modern .box-label{color:var(--ink-soft)}
.box > :last-child{margin-block-end:0}

/* Figures and video facade */
.figure{margin:1.5rem 0;text-align:center}
.figure svg{max-inline-size:min(100%,26rem)}
figcaption{font-size:.95rem;color:var(--ink-soft);margin-block-start:.4rem}
.video{margin:1.5rem 0}
.video-facade{position:relative;display:block;border:3px solid var(--ink);background:var(--ink);aspect-ratio:16/9}
.video-short .video-facade{aspect-ratio:9/16;max-inline-size:20rem}
.video-facade img{display:block;inline-size:100%;block-size:100%;object-fit:cover}
.video iframe{display:block;inline-size:100%;aspect-ratio:16/9;border:3px solid var(--ink)}
.video-short iframe{aspect-ratio:9/16;max-inline-size:20rem}
.play{position:absolute;inset:0;margin:auto;inline-size:4.2rem;block-size:4.2rem;border-radius:50%;background:rgba(181,48,28,.92);box-shadow:0 2px 10px rgba(0,0,0,.4)}
.play::after{content:"";position:absolute;inset-block-start:50%;inset-inline-start:54%;transform:translate(-50%,-50%);border-block:.8rem solid transparent;border-inline-start:1.25rem solid #fff}
[dir=rtl] .play::after{transform:translate(50%,-50%)}
.video-facade:hover .play,.video-facade:focus-visible .play{background:var(--red)}

/* Cards, CTA, sources */
.cards{list-style:none;padding:0;display:grid;gap:.8rem;grid-template-columns:repeat(auto-fill,minmax(15rem,1fr))}
.cards a{display:flex;flex-direction:column;gap:.2rem;block-size:100%;padding:.8rem 1rem;background:var(--paper);border:2px solid var(--ink);color:var(--ink);text-decoration:none}
.cards a:hover{border-color:var(--red)}
.cards strong{font-size:1.1rem}
.cards span{color:var(--ink-soft);font-size:.95rem}
.button{display:inline-block;font-family:var(--label);background:var(--red);color:#fff;text-decoration:none;padding:.55rem 1.1rem;border:2px solid var(--ink);border-radius:2px}
.button:hover{background:var(--ink);color:var(--paper)}
.cta{margin-block:2.5rem 1rem;padding:1rem;border:2px solid var(--ink);background:var(--paper);display:flex;flex-wrap:wrap;align-items:center;gap:.6rem 1rem}
.cta p{margin:0;flex:1 1 16rem}
.sources ol,.credits-list ul{font-size:.95rem}
.report{font-size:.9rem;font-style:italic;color:var(--ink-soft)}
.toc{background:var(--paper);border:1px solid var(--rule);padding:.6rem 1rem;margin-block:1rem}
.toc-head{font-family:var(--label);margin:0}
.toc ol{margin:.3rem 0 0;padding-inline-start:1.2rem}
.footnotes{font-size:.95rem}

/* Home, construction */
.hero{max-inline-size:var(--measure);padding-block:1rem}
.construction{max-inline-size:var(--measure);margin-inline:auto;text-align:center;padding-block:2rem}
.construction-figure svg{inline-size:min(70%,16rem)}

/* Footer */
.site-footer{margin-block-start:2rem;font-size:.95rem}
.footer-grid{display:grid;gap:1rem 2rem;grid-template-columns:repeat(auto-fit,minmax(12rem,1fr));padding-block:1rem}
.site-footer ul{list-style:none;padding:0;margin:0}
.site-footer li{margin-block:.25rem}
.footer-brand{font-family:var(--display);font-weight:600;text-transform:uppercase;letter-spacing:.06em;margin:0}
.footer-tag{font-style:italic;margin:.2rem 0}
.footer-head{font-family:var(--label);margin:0 0 .2rem}
.copyright{color:var(--ink-soft);font-size:.85rem}
.legal .prose{max-inline-size:var(--measure)}

@media (max-width:30rem){html{font-size:106.25%}.band{block-size:18px;background-size:auto 100%}}
@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
@media print{.site-header nav,.cta,.band,.video-facade .play{display:none}body{background:#fff}}

/* Photos of historical objects */
.photo{margin:1.5rem 0}
.photo img{display:block;inline-size:100%;block-size:auto;border:2px solid var(--ink);background:var(--paper)}
.photo.pair{display:grid;grid-template-columns:1fr 1fr;gap:.6rem;align-items:start}
.photo.pair figcaption{grid-column:1/-1}
.math{white-space:nowrap}

/* Video shelf (home + construction page) */
.shelf{max-inline-size:var(--wide);margin-block:1rem 2.5rem}
.shelf h2{margin-block-start:.5rem}
.shelf-lead{margin-block:0 1rem;color:var(--ink-soft)}
.shelf-first{max-inline-size:46rem;margin:0 0 1.2rem}
.shelf-new{font-family:var(--label);color:var(--red);text-transform:uppercase;letter-spacing:.06em;font-size:.85rem}
.shelf-grid{list-style:none;padding:0;margin:0;display:grid;gap:1rem;grid-template-columns:repeat(auto-fill,minmax(14rem,1fr))}
.shelf-grid p{margin:.35rem 0 0;font-size:.95rem;line-height:1.35}
.shelf-grid .play{inline-size:3rem;block-size:3rem}
.shelf-grid .play::after{border-block-width:.55rem;border-inline-start-width:.9rem}
.shelf-grid iframe{aspect-ratio:16/9}
.shelf-note{margin-block-start:1rem}
.shelf-grid .play{inset:auto;inset-block-end:.5rem;inset-inline-start:.5rem;margin:0}

.math-block{font-family:var(--math);font-variant-numeric:lining-nums;text-align:center;font-size:1.25em;margin:1rem 0;overflow-x:auto}
.photo.portrait{max-inline-size:18rem;margin-inline:auto}