/* ═══════════════════════════════════════════════════════
   History of the world — shared stylesheet
   Palette: "Excavation" — sand, ochre, lichen, umber
   ═══════════════════════════════════════════════════════ */

:root{
  --sand:#f5ead8;
  --surface:#ebddc5;
  --surface-2:#e2d2b4;
  --ink:#201e1d;
  --ochre:#c67139;
  --ochre-deep:#a2542a;
  --lichen:#7a8a5e;

  --turf:#d9c9a8;
  --loam:#c2a473;
  --clay:#a87c4f;
  --umber:#6b4a2f;
  --bedrock:#3a2a1d;

  --muted:#6a635c;
  --hair:rgba(32,30,29,.16);
  --hair-2:rgba(32,30,29,.08);
  --glow:rgba(198,113,57,.20);

  --display:'Cormorant Garamond',Georgia,'Times New Roman',serif;
  --body:'Figtree',-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;

  --shell:1240px;
  --gutter:40px;
}
@media(max-width:720px){:root{--gutter:22px}}

*{box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--sand)}
body{
  margin:0;background:var(--sand);color:var(--ink);
  font-family:var(--body);font-size:17px;line-height:1.7;
  -webkit-font-smoothing:antialiased;overflow-x:hidden;
}
a{color:inherit}
img{max-width:100%;display:block}
:focus-visible{outline:2px solid var(--ochre-deep);outline-offset:4px;border-radius:3px}

h1,h2,h3,.display{
  font-family:var(--display);font-weight:400;color:var(--ink);
  line-height:1.02;letter-spacing:-.01em;margin:0;
}
h1{font-size:clamp(52px,9vw,132px)}
h2{font-size:clamp(36px,5.4vw,74px)}
h3{font-size:clamp(22px,2.4vw,30px);line-height:1.15}

.shell{max-width:var(--shell);margin:0 auto;padding:0 var(--gutter)}
.skip{position:absolute;left:-9999px}
.skip:focus{left:16px;top:16px;z-index:999;background:var(--ink);color:var(--sand);padding:10px 18px;border-radius:6px}

/* ── motion: scroll-driven, CSS only ─────────────────── */
@keyframes fade-up{from{opacity:0;transform:translateY(38px)}to{opacity:1;transform:none}}
@keyframes drift-slow{to{transform:translateY(-70px)}}
@keyframes drift-mid{to{transform:translateY(-140px)}}
@keyframes drift-fast{to{transform:translateY(-220px)}}
@keyframes wipe{from{transform:scaleX(0)}to{transform:scaleX(1)}}
@keyframes lift{from{opacity:0;transform:translateY(60px) scale(.97)}to{opacity:1;transform:none}}

@supports (animation-timeline: view()){
  .rise{animation:fade-up linear both;animation-timeline:view();animation-range:entry 6% cover 32%}
  .rise-slow{animation:lift linear both;animation-timeline:view();animation-range:entry 2% cover 40%}
  .wipe{transform-origin:left;animation:wipe linear both;animation-timeline:view();animation-range:entry 18% cover 46%}
}
@supports (animation-timeline: scroll()){
  .px-far{animation:drift-slow linear both;animation-timeline:scroll();animation-range:0 100vh}
  .px-mid{animation:drift-mid linear both;animation-timeline:scroll();animation-range:0 100vh}
  .px-near{animation:drift-fast linear both;animation-timeline:scroll();animation-range:0 100vh}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *{animation:none!important;transition-duration:.01ms!important}
  .rise,.rise-slow,.wipe{opacity:1!important;transform:none!important}
}

/* ── shared bits ─────────────────────────────────────── */
.eyebrow{
  font-family:var(--body);font-size:12.5px;font-weight:600;letter-spacing:.16em;
  color:var(--ochre-deep);margin:0 0 18px;
}
.lede{font-size:clamp(18px,1.5vw,21px);max-width:56ch;color:#3d3733}
.muted{color:var(--muted)}
.rule{height:1px;background:var(--hair);border:0;margin:0}

.btn{
  display:inline-flex;align-items:center;gap:10px;text-decoration:none;
  font-weight:600;font-size:15.5px;padding:15px 32px;border-radius:999px;
  border:1.5px solid var(--ink);color:var(--ink);background:transparent;
  transition:background .25s,color .25s,border-color .25s;
}
.btn:hover{background:var(--surface)}
.btn-solid{background:var(--ink);color:var(--sand);border-color:var(--ink)}
.btn-solid:hover{background:var(--umber);border-color:var(--umber);color:var(--sand)}
.btn-quiet{border-color:var(--hair);color:var(--ink)}
.btn-quiet:hover{background:var(--surface);border-color:var(--hair)}

section{padding:130px 0}
@media(max-width:720px){section{padding:84px 0}}
.head{max-width:64ch;margin-bottom:64px}
.head h2{margin-bottom:22px}

/* ── masthead ────────────────────────────────────────── */
.mast{
  position:fixed;inset:0 0 auto 0;z-index:50;
  display:flex;align-items:center;gap:28px;
  padding:16px var(--gutter);
  background:linear-gradient(to bottom,rgba(245,234,216,.94),rgba(245,234,216,.72) 60%,rgba(245,234,216,0));
  backdrop-filter:blur(8px);
}
.mark{display:flex;align-items:center;gap:12px;text-decoration:none}
.mark img{width:40px;height:40px}
.mark span{font-family:var(--display);font-size:21px;color:var(--ink);letter-spacing:.01em}
.mast nav{margin-left:auto;display:flex;gap:30px;font-size:14.5px}
.mast nav a{text-decoration:none;color:#4a443e;padding-bottom:3px;border-bottom:1px solid transparent}
.mast nav a:hover{color:var(--ink);border-bottom-color:var(--ochre)}
@media(max-width:820px){.mast nav{display:none}}

/* ── hero ────────────────────────────────────────────── */
.hero{
  position:relative;min-height:100svh;display:flex;align-items:center;
  padding:130px 0 90px;overflow:hidden;isolation:isolate;
}
.sky{
  position:absolute;inset:-12% -5% 30%;z-index:-4;
  background:
    radial-gradient(ellipse 46% 40% at 76% 34%,rgba(198,113,57,.30),transparent 62%),
    radial-gradient(ellipse 70% 46% at 22% 18%,rgba(122,138,94,.12),transparent 68%),
    linear-gradient(to bottom,#fbf5e9 0%,#f5ead8 46%,#efe0c6 100%);
}
.haze{
  position:absolute;inset:auto 0 26%;height:34vh;z-index:-3;
  background:
    linear-gradient(to bottom,transparent,rgba(226,210,180,.55) 60%,rgba(226,210,180,.85));
}
.ridge{position:absolute;inset:auto 0 20%;z-index:-2;width:100%;height:auto;opacity:.55}
.skyline{position:absolute;inset:auto 0 0;z-index:-1;width:100%;height:auto}
.ground{
  position:absolute;inset:auto 0 0;height:22vh;z-index:-1;
  background:linear-gradient(to bottom,transparent,var(--sand) 70%);
}
.hero-inner{position:relative}
.hero h1{margin-bottom:26px}
@supports (animation-timeline: view()){
  .hero h1,.hero .lede,.hero .hero-cta,.hero .eyebrow{
    animation:fade-up .95s cubic-bezier(.2,.7,.25,1) backwards;
  }
  .hero .eyebrow{animation-delay:.05s}
  .hero h1{animation-delay:.18s}
  .hero .lede{animation-delay:.36s}
  .hero .hero-cta{animation-delay:.52s}
}
.hero .lede{font-size:clamp(19px,1.7vw,24px);max-width:38ch;color:#3d3733}
.hero-cta{display:flex;gap:16px;margin-top:44px;flex-wrap:wrap}
.scroll-hint{
  position:absolute;left:var(--gutter);bottom:34px;
  font-size:12px;letter-spacing:.16em;color:rgba(32,30,29,.42);
}

/* ── timeline ────────────────────────────────────────── */
.tl{position:relative;padding-left:34px}
.tl::before{
  content:"";position:absolute;left:5px;top:6px;bottom:6px;width:1px;
  background:linear-gradient(to bottom,transparent,var(--hair) 8%,var(--hair) 92%,transparent);
}
.era{border-bottom:1px solid var(--hair-2)}
.era summary{
  list-style:none;cursor:pointer;padding:30px 0;position:relative;
  display:grid;grid-template-columns:auto 1fr auto;gap:26px;align-items:baseline;
}
.era summary::-webkit-details-marker{display:none}
.era summary::before{
  content:"";position:absolute;left:-34px;top:44px;width:11px;height:11px;
  border-radius:50%;background:var(--sand);border:1.5px solid var(--clay);
  transition:background .3s,box-shadow .3s,border-color .3s;
}
.era[open] summary::before,.era summary:hover::before{
  background:var(--ochre);border-color:var(--ochre);box-shadow:0 0 0 5px var(--glow);
}
.era .yr{
  font-family:var(--body);font-size:13px;font-weight:600;letter-spacing:.1em;
  color:var(--ochre-deep);white-space:nowrap;min-width:9ch;
}
.era .name{font-family:var(--display);font-size:clamp(26px,3.4vw,44px);color:var(--ink);line-height:1.05;font-weight:400}
.era summary:hover .name{color:var(--ochre-deep)}
.era .plus{color:var(--clay);font-size:22px;line-height:1;transition:transform .35s}
.era[open] .plus{transform:rotate(45deg)}

.era .drawer{display:grid;grid-template-rows:0fr;transition:grid-template-rows .5s cubic-bezier(.3,.8,.3,1)}
.era[open] .drawer{grid-template-rows:1fr}
.era .drawer > div{overflow:hidden}
.era .panel{display:grid;grid-template-columns:1.1fr 1fr;gap:44px;padding:6px 0 44px}
.era .panel p{margin:0 0 22px;max-width:52ch;color:#3d3733}
.era .panel ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:14px}
.era .panel li{display:grid;grid-template-columns:auto 1fr;gap:16px;font-size:15.5px;line-height:1.55}
.era .panel li b{color:var(--ochre-deep);font-weight:600;font-size:13px;letter-spacing:.06em;white-space:nowrap;padding-top:2px}
.plate{
  border-radius:14px;border:1px solid var(--hair);min-height:260px;
  background:linear-gradient(150deg,var(--surface),var(--surface-2));
  display:flex;align-items:flex-end;padding:22px;
}
.plate span{font-size:12px;letter-spacing:.12em;color:rgba(32,30,29,.42)}
@media(max-width:900px){
  .era summary{grid-template-columns:1fr auto;gap:6px 20px}
  .era .yr{grid-column:1/-1;min-width:0}
  .era .panel{grid-template-columns:1fr;gap:28px}
}

/* ── civilisations ───────────────────────────────────── */
.grid-civ{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.civ{
  position:relative;border-radius:16px;overflow:hidden;text-decoration:none;
  border:1px solid var(--hair);min-height:330px;display:flex;flex-direction:column;
  justify-content:flex-end;padding:32px;isolation:isolate;
  transition:transform .5s cubic-bezier(.2,.8,.3,1),border-color .4s,box-shadow .5s;
}
.civ::before{
  content:"";position:absolute;inset:0;z-index:-2;
  background:linear-gradient(155deg,var(--surface),var(--surface-2));
}
.civ::after{
  content:"";position:absolute;inset:0;z-index:-1;opacity:0;
  background:radial-gradient(ellipse 82% 62% at 50% 100%,rgba(198,113,57,.28),transparent 70%);
  transition:opacity .5s;
}
.civ:hover{
  transform:perspective(1100px) rotateX(4deg) rotateY(-4deg) translateY(-10px);
  border-color:rgba(198,113,57,.55);
  box-shadow:0 26px 60px rgba(58,42,29,.18);
}
.civ:hover::after{opacity:1}
.civ .yr{font-size:12.5px;letter-spacing:.12em;color:var(--ochre-deep);margin:0 0 10px;font-weight:600}
.civ h3{margin-bottom:12px}
.civ p{margin:0;font-size:15px;color:#544d46;line-height:1.6}
@media(max-width:960px){.grid-civ{grid-template-columns:repeat(2,1fr)}}
@media(max-width:600px){.grid-civ{grid-template-columns:1fr}}

/* ── inventions rail ─────────────────────────────────── */
.rail{
  display:flex;gap:20px;overflow-x:auto;scroll-snap-type:x mandatory;
  padding:4px 0 30px;margin:0 calc(var(--gutter) * -1);padding-inline:var(--gutter);
  scrollbar-width:thin;scrollbar-color:var(--clay) transparent;
}
.rail::-webkit-scrollbar{height:5px}
.rail::-webkit-scrollbar-thumb{background:var(--clay);border-radius:3px}
.inv{
  flex:0 0 290px;scroll-snap-align:start;border:1px solid var(--hair);
  border-radius:14px;padding:30px 28px;background:var(--surface);
  transition:border-color .35s,background .35s,transform .35s;
}
.inv:hover{border-color:rgba(198,113,57,.5);background:var(--surface-2);transform:translateY(-4px)}
.inv .glyph{width:40px;height:40px;margin-bottom:22px;color:var(--ochre-deep)}
.inv .yr{font-size:12.5px;letter-spacing:.1em;color:var(--ochre-deep);font-weight:600;margin:0 0 8px}
.inv h3{font-size:23px;margin-bottom:10px}
.inv p{margin:0;font-size:15px;color:#544d46;line-height:1.6}

/* ── future block ────────────────────────────────────── */
.future{position:relative;overflow:hidden;isolation:isolate;background:var(--surface);
  border-top:1px solid var(--hair);border-bottom:1px solid var(--hair)}
.future::before{
  content:"";position:absolute;inset:0;z-index:-1;
  background:
    radial-gradient(ellipse 58% 68% at 78% 32%,rgba(122,138,94,.20),transparent 66%),
    radial-gradient(ellipse 70% 60% at 16% 72%,rgba(198,113,57,.16),transparent 66%);
}
.future-grid{display:grid;grid-template-columns:1fr 1fr;gap:70px;align-items:center}
.orb{
  width:min(360px,80%);aspect-ratio:1;border-radius:50%;margin:0 auto;
  background:radial-gradient(circle at 34% 28%,#a9b98d,#7a8a5e 46%,#4c5a3a 100%);
  box-shadow:0 26px 70px rgba(58,42,29,.24),inset -24px -24px 66px rgba(38,44,26,.45);
  position:relative;
}
.orb::after{
  content:"";position:absolute;inset:-11%;border-radius:50%;
  border:1px solid rgba(198,113,57,.42);
}
.stat-row{display:flex;gap:44px;margin-top:40px;flex-wrap:wrap}
.stat b{display:block;font-family:var(--display);font-size:46px;color:var(--ochre-deep);font-weight:400;line-height:1}
.stat span{font-size:13.5px;color:var(--muted)}
@media(max-width:860px){.future-grid{grid-template-columns:1fr;gap:44px}}

/* ── closing quote ───────────────────────────────────── */
.closing{
  text-align:center;padding:150px 0 160px;
  background:var(--bedrock);color:var(--sand);
}
.closing blockquote{
  font-family:var(--display);font-weight:400;font-size:clamp(34px,5.6vw,72px);
  line-height:1.08;color:var(--sand);margin:0 auto 30px;max-width:16ch;
}
.closing cite{font-style:normal;font-size:14px;letter-spacing:.14em;color:var(--ochre)}
.closing .btn{margin-top:52px;border-color:var(--ochre);color:var(--ochre)}
.closing .btn:hover{background:var(--ochre);color:#2a1608}

/* ── footer ──────────────────────────────────────────── */
footer{border-top:1px solid var(--hair-2);padding:64px 0 76px;font-size:15px}
.foot{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:40px}
.foot h4{font-family:var(--body);font-size:12.5px;font-weight:600;letter-spacing:.12em;color:var(--ochre-deep);margin:0 0 16px}
.foot ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:10px}
.foot a{text-decoration:none;color:#4a443e}
.foot a:hover{color:var(--ink)}
.foot-note{color:var(--muted);font-size:14px;max-width:32ch;margin:14px 0 0}
.colophon{
  margin-top:56px;padding-top:24px;border-top:1px solid var(--hair-2);
  color:var(--muted);font-size:13px;display:flex;gap:24px;flex-wrap:wrap;
}
@media(max-width:820px){.foot{grid-template-columns:1fr 1fr;gap:34px}}
@media(max-width:520px){.foot{grid-template-columns:1fr}}

/* ── period rows inside a timeline drawer ────────────── */
.rows{display:flex;flex-direction:column;border:1px solid var(--hair);border-radius:12px;overflow:hidden}
.row{
  display:grid;grid-template-columns:1fr auto auto;gap:20px;align-items:baseline;
  padding:18px 22px;text-decoration:none;background:var(--surface);
  border-top:1px solid var(--hair-2);
  transition:background .25s,padding-left .25s;
}
.row:first-child{border-top:0}
.row .nm{font-family:var(--display);font-size:23px;color:var(--ink);line-height:1.1}
.row .dt{font-size:13px;font-weight:600;letter-spacing:.06em;color:var(--muted);white-space:nowrap}
.row .go{
  font-size:12.5px;font-weight:600;letter-spacing:.08em;color:var(--ochre-deep);
  white-space:nowrap;min-width:5ch;text-align:right;
}
a.row:hover{background:var(--surface-2);padding-left:28px}
a.row:hover .nm{color:var(--ochre-deep)}
.row-off{opacity:.5;background:transparent}
.row-off .go{color:var(--muted)}
@media(max-width:560px){
  .row{grid-template-columns:1fr auto;gap:4px 16px;padding:16px 18px}
  .row .nm{grid-column:1}
  .row .go{grid-row:1;grid-column:2}
  .row .dt{grid-column:1/-1}
  a.row:hover{padding-left:22px}
}

/* ── chapter chips ───────────────────────────────────── */
.chips{display:flex;flex-wrap:wrap;gap:10px;margin:0 0 26px}
.chip{
  display:inline-flex;align-items:baseline;gap:9px;font-size:14.5px;font-weight:600;
  padding:9px 18px;border-radius:999px;border:1px solid var(--hair);
  color:var(--muted);text-decoration:none;background:transparent;
}
.chip em{font-style:normal;font-weight:500;font-size:12.5px;opacity:.72;white-space:nowrap}
.chip-on{
  background:var(--ochre);border-color:var(--ochre);color:#2a1608;
  transition:transform .2s,background .2s;
}
.chip-on:hover{background:#d8823f;transform:translateX(3px)}

/* ── theme sections on a chapter page ────────────────── */
.themes{display:flex;flex-direction:column;gap:0;margin-top:12px}
.theme{
  display:grid;grid-template-columns:200px 1fr;gap:44px;
  padding:44px 0;border-top:1px solid var(--hair-2);
}
.theme:first-child{border-top:1px solid var(--hair)}
.theme .label{position:sticky;top:96px;align-self:start}
.theme .label h2{font-size:clamp(24px,2.6vw,32px);margin:0 0 8px}
.theme .label p{font-size:13px;letter-spacing:.1em;color:var(--ochre-deep);margin:0;font-weight:600}
.theme .body p{margin:0 0 20px;color:#33302c}
.theme .body p:last-child{margin-bottom:0}
@media(max-width:820px){
  .theme{grid-template-columns:1fr;gap:18px;padding:34px 0}
  .theme .label{position:static}
}

/* ── key dates inset ─────────────────────────────────── */
.dates{
  background:var(--surface);border:1px solid var(--hair);border-radius:14px;
  padding:34px 36px;margin:56px 0;
}
.dates h3{font-size:24px;margin:0 0 22px}
.dates ol{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:16px;counter-reset:d}
.dates li{display:grid;grid-template-columns:auto 1fr;gap:20px;font-size:15.5px;line-height:1.55}
.dates li b{color:var(--ochre-deep);font-weight:600;font-size:13px;letter-spacing:.06em;white-space:nowrap;padding-top:3px;min-width:11ch}
@media(max-width:600px){
  .dates{padding:26px 22px}
  .dates li{grid-template-columns:1fr;gap:4px}
  .dates li b{min-width:0}
}

/* ── chapter pager ───────────────────────────────────── */
.pager{
  display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:74px;
  padding-top:34px;border-top:1px solid var(--hair);
}
.pager a,.pager span{
  border:1px solid var(--hair);border-radius:14px;padding:24px 26px;
  text-decoration:none;display:block;transition:border-color .3s,background .3s;
}
.pager a:hover{border-color:var(--ochre);background:var(--surface)}
.pager small{display:block;font-size:12.5px;letter-spacing:.1em;color:var(--ochre-deep);font-weight:600;margin-bottom:6px}
.pager strong{font-family:var(--display);font-size:23px;font-weight:400;color:var(--ink)}
.pager span{opacity:.5}
@media(max-width:600px){.pager{grid-template-columns:1fr}}

/* ── article page ────────────────────────────────────── */
.article{max-width:44rem;margin:0 auto;padding:170px var(--gutter) 40px}
.article h1{font-size:clamp(42px,6.4vw,80px);margin-bottom:24px}
.article .meta{font-size:13px;letter-spacing:.12em;color:var(--ochre-deep);margin-bottom:40px}
.article h2{font-size:clamp(28px,3.4vw,40px);margin:64px 0 20px}
.article p{margin:0 0 24px;color:#33302c}
.article .pull{
  font-family:var(--display);font-size:clamp(26px,3vw,38px);line-height:1.15;
  color:var(--ink);border-left:2px solid var(--ochre);padding-left:28px;margin:52px 0;
}
.article figure{margin:52px 0}
.article figcaption{font-size:13.5px;color:var(--muted);margin-top:14px}
.crumbs{font-size:13px;letter-spacing:.1em;color:var(--muted);margin-bottom:26px}
.crumbs a{text-decoration:none}
.crumbs a:hover{color:var(--ochre-deep)}