/* Postcards from the Past — English site only. */
.postcards-intro{max-width:980px;margin:0 0 1.5rem;font-size:1.08rem;line-height:1.65}
.postcard-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1.4rem;margin:1.2rem 0 2.5rem}
.postcard-link{display:block;text-decoration:none;color:inherit;border:1px solid #c9984e;background:rgba(255,250,235,.76);box-shadow:0 9px 24px rgba(84,51,21,.08);transition:transform .18s ease,box-shadow .18s ease}
.postcard-link:hover,.postcard-link:focus-visible{transform:translateY(-3px);box-shadow:0 13px 30px rgba(84,51,21,.16);outline:none}
.postcard-thumb{display:block;width:100%;aspect-ratio:1.75/1;object-fit:cover;border-bottom:1px solid rgba(154,105,48,.38)}
.postcard-copy{padding:1rem 1.1rem 1.15rem}
.postcard-copy small{display:block;text-transform:uppercase;letter-spacing:.14em;color:#966326;font-size:.72rem;margin-bottom:.35rem}
.postcard-copy h2{margin:.15rem 0 .45rem;font-size:1.48rem}
.postcard-copy p{margin:0;line-height:1.48}
.more-activities-head{margin-top:2.2rem;padding-top:1.5rem;border-top:1px solid rgba(154,105,48,.35)}
.more-activities-head span{display:block;text-transform:uppercase;letter-spacing:.15em;color:#966326;font-size:.78rem;margin-bottom:.28rem}
.more-activities-head h2{margin:.1rem 0 1rem;font-size:2rem}

/* Standalone challenge pages reached by QR codes. */
body.postcard-detail{min-height:100vh}
.postcard-topbar{position:sticky;top:0;z-index:20;display:flex;align-items:center;justify-content:space-between;gap:1rem;padding:.8rem clamp(1rem,4vw,4rem);background:rgba(250,239,216,.96);border-bottom:1px solid rgba(154,105,48,.42);backdrop-filter:blur(8px)}
.postcard-topbar a{text-decoration:none;color:#3b2415;font-weight:700}
.postcard-topbar .postcard-series{font-family:Georgia,'Times New Roman',serif;color:#845721;font-weight:400;letter-spacing:.06em}
.postcard-article{max-width:1020px;margin:0 auto;padding:clamp(1.5rem,4vw,4rem) clamp(1rem,4vw,2.2rem) 4rem}
.postcard-hero{width:100%;display:block;border:1px solid #c9984e;box-shadow:0 12px 32px rgba(84,51,21,.13);margin:0 0 2rem}
.postcard-kicker{text-transform:uppercase;letter-spacing:.16em;color:#966326;font-size:.78rem;font-weight:700}
.postcard-article h1{font-family:Georgia,'Times New Roman',serif;font-size:clamp(2.3rem,5vw,4.4rem);line-height:1.04;margin:.35rem 0 1.1rem;color:#352116}
.postcard-lede{font-size:1.25rem;line-height:1.6;max-width:820px}
.postcard-section{margin:2.1rem 0}
.postcard-section h2{font-family:Georgia,'Times New Roman',serif;font-size:1.75rem;margin:0 0 .7rem;color:#412718}
.postcard-section p,.postcard-section li{font-size:1.06rem;line-height:1.7}
.postcard-section ul{padding-left:1.3rem}
.postcard-formula{font-family:Georgia,'Times New Roman',serif;font-size:1.25rem;text-align:center;margin:1.2rem 0;padding:1rem;border-top:1px solid rgba(154,105,48,.35);border-bottom:1px solid rgba(154,105,48,.35)}
.postcard-note{background:rgba(255,250,235,.78);border:1px solid rgba(154,105,48,.55);padding:1.15rem 1.25rem;margin:1.4rem 0}
.postcard-book-link{margin-top:2.7rem;padding:1.45rem 1.55rem;background:rgba(255,250,235,.78);border-left:4px solid #a97833}
.postcard-book-link h2{margin-top:0}
.postcard-bottom-nav{display:flex;flex-wrap:wrap;gap:.7rem;margin-top:2.2rem;padding-top:1.3rem;border-top:1px solid rgba(154,105,48,.35)}
.postcard-bottom-nav a{display:inline-block;text-decoration:none;color:#3b2415;border:1px solid #b88642;padding:.55rem .75rem;background:rgba(255,250,235,.7)}
@media(max-width:760px){.postcard-grid{grid-template-columns:1fr}.postcard-topbar{align-items:flex-start;flex-direction:column;gap:.35rem}.postcard-copy h2{font-size:1.35rem}}

/* Compact QR challenge pages and full site navigation. */
body.postcard-detail{padding-top:78px}
.postcard-site-header{display:flex!important}
.postcard-article{padding-top:1.35rem;padding-bottom:2.6rem}
.postcard-hero{margin-bottom:1.25rem}
.postcard-article h1{font-size:clamp(2.05rem,4.6vw,3.9rem);margin:.28rem 0 .7rem}
.postcard-lede{font-size:1.16rem;line-height:1.5;margin:.25rem 0 1.2rem}
.postcard-section{margin:1.35rem 0}
.postcard-section h2{font-size:1.58rem;margin:0 0 .42rem}
.postcard-section p,.postcard-section li{font-size:1rem;line-height:1.58;margin:.5rem 0}
.postcard-formula{font-size:1.18rem;margin:.85rem 0;padding:.72rem}
.postcard-note{padding:.85rem 1rem;margin:.85rem 0}
.postcard-book-link{margin-top:1.6rem;padding:1rem 1.25rem}
.postcard-book-link h2{font-size:1.48rem;margin-bottom:.35rem}
.postcard-book-link p{margin:.35rem 0;line-height:1.55}
.postcard-bottom-nav{margin-top:1.5rem;padding-top:1rem}
@media(max-width:1050px){body.postcard-detail{padding-top:78px}}
@media(max-width:650px){
  .postcard-article{padding:1rem 5% 2rem}
  .postcard-hero{margin-bottom:1rem}
  .postcard-section{margin:1.15rem 0}
  .postcard-bottom-nav a{padding:.48rem .62rem}
}
\n\n/* v3 — compact postcard detail pages. Keep the postcard as a visual\n   introduction; the readable challenge text follows immediately below. */\nbody.postcard-detail{padding-top:70px}\n.postcard-article{max-width:960px;padding:1rem clamp(1rem,3vw,1.8rem) 2.25rem}\n.postcard-hero{width:min(100%,900px);height:auto;object-fit:contain;margin:0 auto .9rem;box-shadow:0 9px 24px rgba(84,51,21,.11)}\n.postcard-kicker{font-size:.72rem;letter-spacing:.145em;margin-top:.1rem}\n.postcard-article h1{font-size:clamp(2rem,4.1vw,3.45rem);line-height:1.02;margin:.22rem 0 .5rem;max-width:880px}\n.postcard-lede{font-size:1.08rem;line-height:1.42;margin:.15rem 0 .85rem}\n.postcard-section{margin:1rem 0}\n.postcard-section h2{font-size:1.46rem;line-height:1.15;margin:0 0 .28rem}\n.postcard-section p,.postcard-section li{font-size:.98rem;line-height:1.5;margin:.32rem 0}\n.postcard-formula{font-size:1.12rem;margin:.62rem 0;padding:.55rem}\n.postcard-note{padding:.72rem .9rem;margin:.65rem 0}\n.postcard-book-link{margin-top:1.15rem;padding:.72rem 1rem}\n.postcard-book-link h2{font-size:1.34rem;margin:0 0 .2rem}\n.postcard-book-link p{font-size:.96rem;margin:.2rem 0;line-height:1.42}\n.postcard-bottom-nav{margin-top:1rem;padding-top:.8rem;gap:.55rem}\n.postcard-bottom-nav a{padding:.46rem .65rem}\n@media(max-width:760px){\n body.postcard-detail{padding-top:66px}\n .postcard-article{padding:.8rem 4.5% 1.8rem}\n .postcard-hero{margin-bottom:.75rem}\n .postcard-article h1{font-size:clamp(1.85rem,9vw,2.75rem)}\n .postcard-lede{font-size:1.02rem}\n .postcard-section{margin:.9rem 0}\n .postcard-section h2{font-size:1.35rem}\n}\n

/* v5 — approved compact detail-page proportions, shared by all postcards. */
body.postcard-detail .postcard-article{
  max-width:960px;
  padding-top:.75rem;
}
body.postcard-detail .postcard-hero{
  width:min(100%,780px);
  height:auto;
  display:block;
  object-fit:contain;
  margin:0 auto .55rem;
}
body.postcard-detail .postcard-kicker{
  margin-top:0;
  font-size:.70rem;
  letter-spacing:.14em;
}
body.postcard-detail .postcard-article h1{
  font-size:clamp(1.95rem,3.75vw,3.15rem);
  line-height:1.02;
  margin:.16rem 0 .38rem;
  max-width:820px;
}
body.postcard-detail .postcard-lede{
  margin:.1rem 0 .65rem;
  font-size:1.04rem;
  line-height:1.38;
}
@media(max-width:760px){
  body.postcard-detail .postcard-hero{width:100%;}
  body.postcard-detail .postcard-article h1{font-size:clamp(1.8rem,8.5vw,2.6rem);}
}

/* v6 — Eratosthenes final test: slightly smaller hero/title and tighter opening. */
body.postcard-detail .eratosthenes-page{
  max-width:940px;
  padding-top:.58rem;
}
body.postcard-detail .eratosthenes-page .postcard-hero{
  width:min(100%,735px);
  margin-bottom:.34rem;
}
body.postcard-detail .eratosthenes-page .postcard-kicker{
  margin-top:0;
  margin-bottom:0;
}
body.postcard-detail .eratosthenes-page h1{
  font-size:clamp(1.9rem,3.45vw,2.95rem);
  line-height:1.015;
  margin:.12rem 0 .28rem;
  max-width:790px;
}
body.postcard-detail .eratosthenes-page .postcard-lede{
  margin:.06rem 0 .48rem;
  font-size:1.02rem;
}
body.postcard-detail .eratosthenes-page .postcard-section:first-of-type{
  margin-top:.72rem;
}
@media(max-width:760px){
  body.postcard-detail .eratosthenes-page .postcard-hero{width:100%;}
  body.postcard-detail .eratosthenes-page h1{font-size:clamp(1.78rem,8vw,2.5rem);}
}

/* Version 1.5 — final compact English postcard detail pages. */
body.postcard-detail .postcard-article{
  max-width:940px;
  padding-top:.58rem;
  padding-bottom:2rem;
}
body.postcard-detail .postcard-hero{
  width:min(100%,735px);
  height:auto;
  display:block;
  object-fit:contain;
  margin:0 auto .34rem;
  border:1px solid #c9984e;
  box-shadow:0 9px 24px rgba(84,51,21,.11);
}
body.postcard-detail .postcard-kicker{
  margin:0;
  font-size:.70rem;
  letter-spacing:.14em;
}
body.postcard-detail .postcard-article h1{
  font-family:Georgia,'Times New Roman',serif;
  font-size:1.60rem;
  line-height:1.08;
  margin:.14rem 0 .28rem;
  max-width:820px;
  color:#352116;
}
body.postcard-detail .postcard-lede{
  margin:.05rem 0 .48rem;
  font-size:1rem;
  line-height:1.4;
}
body.postcard-detail .postcard-section{
  margin:.80rem 0;
}
body.postcard-detail .postcard-section h2{
  font-size:1.16rem;
  line-height:1.16;
  margin:0 0 .20rem;
}
body.postcard-detail .postcard-section p,
body.postcard-detail .postcard-section li{
  font-size:.98rem;
  line-height:1.48;
  margin:.25rem 0;
}
body.postcard-detail .postcard-formula{
  font-size:1.08rem;
  margin:.50rem 0;
  padding:.48rem;
}
body.postcard-detail .postcard-note{
  padding:.68rem .88rem;
  margin:.58rem 0;
}
body.postcard-detail .postcard-book-link{
  margin-top:.90rem;
  padding:.68rem .95rem;
}
body.postcard-detail .postcard-book-link h2{
  font-size:1.16rem;
  line-height:1.16;
  margin:0 0 .16rem;
}
body.postcard-detail .postcard-book-link p{
  font-size:.96rem;
  margin:.16rem 0;
  line-height:1.4;
}
body.postcard-detail .postcard-bottom-nav{display:none!important;}
@media(max-width:760px){
  body.postcard-detail .postcard-article{padding:.72rem 4.5% 1.6rem;}
  body.postcard-detail .postcard-hero{width:100%;margin-bottom:.30rem;}
  body.postcard-detail .postcard-article h1{font-size:1.48rem;}
  body.postcard-detail .postcard-lede{font-size:.98rem;}
  body.postcard-detail .postcard-section h2,
  body.postcard-detail .postcard-book-link h2{font-size:1.12rem;}
}

/* Version 1.6 — postcard finishing touches. */
body.postcard-detail .postcard-kicker{
  margin:0 0 .48rem;
}
body.postcard-detail .postcard-article h1{
  margin:0 0 .28rem;
}
body.postcard-detail .postcard-bottom-nav{
  display:flex!important;
  flex-wrap:wrap;
  gap:.7rem;
  margin-top:1.15rem;
  padding-top:.95rem;
  border-top:1px solid rgba(154,105,48,.35);
}
body.postcard-detail .postcard-bottom-nav a{
  display:inline-block;
  text-decoration:none;
  color:#3b2415;
  border:1px solid #b88642;
  padding:.5rem .78rem;
  background:rgba(255,250,235,.72);
}
body.postcard-detail .postcard-bottom-nav a:hover,
body.postcard-detail .postcard-bottom-nav a:focus-visible{
  background:rgba(255,250,235,.98);
}
@media(max-width:760px){
  body.postcard-detail .postcard-kicker{margin-bottom:.38rem;}
  body.postcard-detail .postcard-bottom-nav{gap:.55rem;}
}


/* Version 1.7 — preserve full Syracuse and Delos postcard titles in grid thumbnails. */
.postcard-thumb-contain{
  object-fit:contain;
  background:rgba(255,250,235,.76);
}