@font-face{font-family:"Fraunces";src:url("fonts/Fraunces-display.woff2") format("woff2");font-weight:100 900;font-display:swap}
@font-face{font-family:"Atkinson";src:url("fonts/AtkinsonHyperlegibleNext.woff2") format("woff2");font-weight:100 900;font-display:swap}

/* Snow light and the grey of the pack ice by day; the polar night in the dark theme. The accent
   is the brown-gold of the varnished silk, the walking track is the red of a sledge flag, and
   the ice drift is sea blue. */
:root{
  --paper:#f4f2ec; --surface:#e9e6dd; --surface-2:#dedad0;
  --ink:#141c26; --ink-2:#2f3a47; --ink-3:#3a4552;
  --rule:#c9c4b6; --rule-strong:#9d978a;
  --silk:#6a4209; --silk-soft:#c7953f;
  --walk:#8a2418; --walk-soft:#c65a45;
  --drift:#1c4a6e; --drift-soft:#6f9dbf;
  --sea:#dde5e8; --ice:#eef2f3; --land:#d9d2c1; --grat:#b8c4ca;
  --photo-bg:#1a1c1f;
  --focus:#1b4a8a;
  --shadow:0 1px 2px rgba(20,28,38,.10),0 10px 28px rgba(20,28,38,.08);
  --maxw:76rem; --measure:36rem; --bar:3.25rem; --r:10px;
}
:root[data-theme="dark"]{
  --paper:#0b1017; --surface:#131a24; --surface-2:#1a2330;
  --ink:#eef1f4; --ink-2:#c6ced8; --ink-3:#a9b4c1;
  --rule:#2a3442; --rule-strong:#475466;
  --silk:#eab96a; --silk-soft:#b8863a;
  --walk:#f39a86; --walk-soft:#c65a45;
  --drift:#8fc1e6; --drift-soft:#4f7fa3;
  --sea:#0e1722; --ice:#1a2431; --land:#27303b; --grat:#26344a;
  --photo-bg:#05070a;
  --focus:#8fc0ff;
  --shadow:0 1px 2px rgba(0,0,0,.45),0 10px 28px rgba(0,0,0,.35);
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --paper:#0b1017; --surface:#131a24; --surface-2:#1a2330;
    --ink:#eef1f4; --ink-2:#c6ced8; --ink-3:#a9b4c1;
    --rule:#2a3442; --rule-strong:#475466;
    --silk:#eab96a; --silk-soft:#b8863a;
    --walk:#f39a86; --walk-soft:#c65a45;
    --drift:#8fc1e6; --drift-soft:#4f7fa3;
    --sea:#0e1722; --ice:#1a2431; --land:#27303b; --grat:#26344a;
    --photo-bg:#05070a;
    --focus:#8fc0ff;
    --shadow:0 1px 2px rgba(0,0,0,.45),0 10px 28px rgba(0,0,0,.35);
  }
}

*,*::before,*::after{box-sizing:border-box}
[hidden]{display:none !important}
/* Without scripts every reveal stays open: theme.js marks the document .js before first paint,
   so this override applies only when scripts never ran. It must outrank [hidden] above. */
html:not(.js) .beat-reveal[hidden],html:not(.js) .q-why[hidden],html:not(.js) .reveal-block[hidden]{display:block !important}
html{-webkit-text-size-adjust:100%}
body{
  margin:0; background:var(--paper); color:var(--ink);
  font-family:"Atkinson",system-ui,-apple-system,"Segoe UI",sans-serif;
  font-size:clamp(1rem,.96rem + .2vw,1.09rem); line-height:1.62;
  overflow-x:clip;
}
img{max-width:100%;height:auto;display:block}
a{color:var(--silk);text-underline-offset:.18em;text-decoration-thickness:1px}
a:hover{color:var(--walk)}
:focus-visible{outline:3px solid var(--focus);outline-offset:2px;border-radius:3px}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ---------- top bar ---------- */
.topbar{
  position:sticky;top:0;z-index:40;display:flex;align-items:center;gap:.6rem;
  min-height:var(--bar);padding:0 clamp(.75rem,2vw,1.4rem);line-height:1;
  background:color-mix(in srgb,var(--paper) 92%,transparent);
  backdrop-filter:blur(8px);border-bottom:1px solid var(--rule);
}
.topbar .home{font-family:"Fraunces",Georgia,serif;font-weight:600;color:var(--ink);
  text-decoration:none;white-space:nowrap;font-size:.95rem;display:flex;align-items:center;min-height:2.75rem}
.topnav{display:flex;gap:.85rem;overflow-x:auto;scrollbar-width:none;min-width:0}
.topnav::-webkit-scrollbar{display:none}
.topnav a{color:var(--ink-2);text-decoration:none;white-space:nowrap;font-size:.9rem;display:flex;align-items:center;min-height:2.75rem}
.topnav a:hover,.topnav a[aria-current="true"]{color:var(--walk)}
.topnav a[aria-current="true"]{box-shadow:inset 0 -2px 0 var(--walk)}
.spacer{flex:1 1 auto}
.chip{color:var(--ink-2);text-decoration:none;font-size:.85rem;white-space:nowrap;
  border:1px solid var(--rule);border-radius:999px;padding:.25rem .6rem;display:flex;align-items:center;min-height:2.75rem}
.chip:hover{border-color:var(--walk)}
.icon-btn{display:grid;place-items:center;width:2.1rem;height:2.1rem;flex:0 0 auto;
  border:1px solid var(--rule);border-radius:999px;background:transparent;color:var(--ink-2);cursor:pointer;position:relative}
.icon-btn::after{content:"";position:absolute;inset:-.6rem}
.icon-btn svg{display:block}
.icon-btn svg[hidden]{display:none}
.icon-btn:hover{color:var(--walk);border-color:var(--walk)}

/* ---------- reading rail ---------- */
.rail{display:none}
@media (min-width:88rem){
  .rail{display:flex;flex-direction:column;gap:.55rem;position:fixed;right:1.1rem;top:50%;transform:translateY(-50%);z-index:30}
  .rail a{display:flex;align-items:center;justify-content:flex-end;gap:.5rem;min-height:1.4rem;text-decoration:none;color:var(--ink-2);font-size:.78rem}
  .rail a span{opacity:0;transition:opacity .2s;background:var(--paper);padding:.1rem .35rem;border-radius:4px;white-space:nowrap}
  .rail a:hover span,.rail a:focus-visible span{opacity:1}
  .rail a i{display:block;width:6px;height:6px;border-radius:50%;background:var(--rule-strong);transition:transform .2s,background .2s}
  .rail a[aria-current="true"] i{background:var(--walk);transform:scale(1.45)}
}
@media print{.rail,.topbar{display:none}}

main{max-width:var(--maxw);margin:0 auto;padding:0 clamp(1rem,3vw,2rem)}
section,.hero{scroll-margin-top:calc(var(--bar) + 1rem)}

/* ---------- hero: the photograph develops ---------- */
.hero{display:grid;gap:clamp(1.2rem,3vw,2.4rem);padding:clamp(1.6rem,4vw,3.2rem) 0 clamp(1.2rem,3vw,2rem)}
@media (min-width:62rem){.hero{grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);align-items:center}}
.hero-text{max-width:40rem}
h1{font-family:"Fraunces",Georgia,serif;font-weight:600;line-height:1.08;
  font-size:clamp(2rem,1.25rem + 3.2vw,3.5rem);margin:0 0 1rem;letter-spacing:-.015em;text-wrap:balance}
.deck{font-size:clamp(1.06rem,1rem + .4vw,1.24rem);color:var(--ink-2);margin:0 0 1.2rem}
.stats{display:flex;flex-wrap:wrap;gap:clamp(1rem,3.5vw,2.2rem);border-top:1px solid var(--rule);padding-top:1rem}
.stat{display:flex;flex-direction:column;gap:.2rem;min-width:7.5rem;max-width:12rem}
.stat .n{font-family:"Fraunces",Georgia,serif;font-size:clamp(1.55rem,1.2rem + 1.4vw,2.3rem);font-weight:600;line-height:1;color:var(--ink)}
.stat .l{font-size:.82rem;color:var(--ink-3);line-height:1.35}
.hero-fig{margin:0}
.hero-fig .frame{position:relative;background:var(--photo-bg);border-radius:var(--r);overflow:hidden;box-shadow:var(--shadow)}
.hero-fig img{width:100%;height:auto}
figcaption{font-size:.84rem;color:var(--ink-3);line-height:1.45;margin-top:.55rem}
figcaption .cr{display:block;margin-top:.2rem}

/* The developing bath: the positive image starts as a thin, dark, blurred ghost and
   comes up to full density. The finished print is the default; the effect is added only
   when the script runs and motion is allowed. */
.dev img{transition:filter 4.2s cubic-bezier(.3,.1,.3,1),opacity 4.2s ease}
.js .dev.latent img{filter:brightness(.18) contrast(.6) blur(6px) sepia(.4);opacity:.55}
.js .dev.latent.done img{filter:none;opacity:1}

/* ---------- the story: sticky map beside the prose ---------- */
.story{display:grid;gap:clamp(1rem,3vw,2.5rem);margin:clamp(1rem,3vw,2rem) 0}
@media (min-width:62rem){.story{grid-template-columns:minmax(0,1fr) minmax(0,29rem);align-items:start}}
.stage-wrap{position:sticky;top:calc(var(--bar) + .5rem);z-index:20;background:var(--paper);padding-bottom:.4rem}
@media (min-width:62rem){.stage-wrap{order:2}.prose{order:1}}
.stage{position:relative;border:1px solid var(--rule);border-radius:var(--r);background:var(--sea);overflow:hidden;box-shadow:var(--shadow)}
.stage svg{display:block;width:100%;height:auto;aspect-ratio:1320/1560}
@media (min-width:62rem){.stage svg{max-height:calc(100svh - var(--bar) - 6rem)}}
/* On a phone the map sits on top and must not eat the screen. No rem floor (zoom 400 %). */
@media (max-width:61.99rem){
  .stage svg{height:34svh;aspect-ratio:auto}
  .legend{font-size:.72rem;gap:.1rem .7rem;margin-top:.3rem}
  .stage-note{font-size:.74rem;line-height:1.35;margin-top:.2rem}
  .hud{padding:.25rem .45rem}
}
.hud{position:absolute;left:.6rem;top:.55rem;display:flex;flex-direction:column;gap:.1rem;pointer-events:none;
  background:color-mix(in srgb,var(--paper) 88%,transparent);border-radius:8px;padding:.35rem .55rem}
.hud .d{font-family:"Fraunces",Georgia,serif;font-weight:600;font-size:clamp(.95rem,.85rem + .5vw,1.2rem);color:var(--ink);line-height:1.1}
.hud .k{font-size:.74rem;color:var(--ink-2)}
.legend{display:flex;flex-wrap:wrap;gap:.3rem .9rem;margin:.45rem 0 0;padding:0;list-style:none;font-size:.78rem;color:var(--ink-2)}
.legend li{display:flex;align-items:center;gap:.35rem}
.legend i{display:inline-block;width:1.2rem;height:0;border-top:3px solid}
.legend .lf i{border-color:var(--silk)}
.legend .lw i{border-color:var(--walk)}
.legend .lg i{border-color:var(--drift);border-top-style:dashed}
.stage-note{margin:.35rem 0 0;font-size:.82rem;color:var(--ink-3);min-height:1.2em}

.prose{max-width:var(--measure)}
.chapter{padding:clamp(1.6rem,5vw,3.2rem) 0;border-top:1px solid var(--rule)}
.chapter:first-child{border-top:0;padding-top:0}
.stamp{font-size:.76rem;letter-spacing:.09em;text-transform:uppercase;color:var(--silk);margin:0 0 .5rem;font-weight:700}
.chapter h2,.block h2{font-family:"Fraunces",Georgia,serif;font-weight:600;line-height:1.16;
  font-size:clamp(1.4rem,1.1rem + 1.2vw,2rem);margin:0 0 .8rem;letter-spacing:-.01em;text-wrap:balance}
h3{font-family:"Fraunces",Georgia,serif;font-weight:600;font-size:1.15rem;margin:0 0 .4rem;line-height:1.25}
.anchor{color:inherit;text-decoration:none;position:relative;display:inline-block}
.anchor::after{content:"";position:absolute;left:0;right:0;top:50%;height:2.75rem;transform:translateY(-50%)}
.anchor:hover{color:var(--walk)}
.chapter p{margin:0 0 1rem}
blockquote{margin:1.1rem 0;padding:.2rem 0 .2rem 1rem;border-left:3px solid var(--silk-soft);font-family:"Fraunces",Georgia,serif;font-size:1.08rem;color:var(--ink)}
blockquote p{margin:0 0 .3rem}
blockquote cite{display:block;font-family:"Atkinson",sans-serif;font-style:normal;font-size:.82rem;color:var(--ink-3)}
.count{font-family:"Fraunces",Georgia,serif;font-weight:600;font-size:clamp(1.9rem,1.4rem + 2vw,2.8rem);line-height:1;color:var(--silk);display:block;margin:1.2rem 0 .2rem;font-variant-numeric:tabular-nums}
.count-l{display:block;font-size:.86rem;color:var(--ink-3);margin-bottom:1.1rem}
.fig{margin:1.3rem 0}
.fig .frame{background:var(--photo-bg);border-radius:8px;overflow:hidden}

/* ---------- commit, then reveal ---------- */
.beat{margin:1.4rem 0 0;padding:1rem 1.1rem;background:var(--surface);border:1px solid var(--rule);border-left:3px solid var(--silk);border-radius:var(--r)}
.beat-q{margin:0 0 .6rem;font-weight:700;color:var(--ink)}
.beat-data{margin:0 0 .8rem;padding:0;list-style:none;font-size:.92rem;color:var(--ink-2)}
.beat-data li{padding:.25rem 0;border-bottom:1px dotted var(--rule-strong)}
.beat-data b{color:var(--ink)}
.opts{display:flex;flex-direction:column;gap:.45rem}
.opt{font:inherit;font-size:.95rem;text-align:left;cursor:pointer;min-height:2.75rem;padding:.55rem .8rem;border:1px solid var(--rule-strong);border-radius:8px;background:var(--paper);color:var(--ink)}
.opt:hover{border-color:var(--silk);color:var(--silk)}
.opt[aria-pressed="true"]{background:var(--surface-2);border-color:var(--silk);font-weight:700}
.opt.is-right{border-color:var(--silk);box-shadow:inset 3px 0 0 var(--silk)}
.opt.is-wrong{border-color:var(--walk);box-shadow:inset 3px 0 0 var(--walk)}
.beat-reveal{margin:.85rem 0 0;padding-top:.8rem;border-top:1px dashed var(--rule-strong);color:var(--ink-2)}
.beat-reveal p{margin:0 0 .6rem}

/* ---------- the drift slider ---------- */
.drift{margin:1.4rem 0 0;padding:1rem 1.1rem;background:var(--surface);border:1px solid var(--rule);border-radius:var(--r)}
.drift label{display:block;font-weight:700;margin-bottom:.3rem}
.drift input[type="range"]{width:100%;min-height:2.75rem;accent-color:var(--walk)}
.drift .ticks{display:flex;justify-content:space-between;font-size:.78rem;color:var(--ink-3)}
.drift-out{margin:.6rem 0 0;color:var(--ink);font-size:.95rem}
.drift-out b{font-family:"Fraunces",Georgia,serif}

/* ---------- blocks after the story ---------- */
.block{padding:clamp(1.8rem,5vw,3.2rem) 0;border-top:1px solid var(--rule)}
.lede{color:var(--ink-2);max-width:var(--measure)}

/* the plates */
.plates{display:grid;gap:1rem;margin-top:1.2rem}
@media (min-width:62rem){.plates{grid-template-columns:minmax(0,1.6fr) minmax(0,1fr);align-items:start}}
.plate-main{margin:0}
.plate-main .frame{position:relative;background:var(--photo-bg);border-radius:var(--r);overflow:hidden;aspect-ratio:3/2;display:grid;place-items:center}
.plate-main img{width:100%;height:100%;object-fit:contain}
.plate-list{display:grid;grid-template-columns:repeat(auto-fill,minmax(5.2rem,1fr));gap:.5rem;list-style:none;margin:0;padding:0}
.plate-list button{display:block;width:100%;padding:0;border:2px solid transparent;border-radius:6px;background:var(--photo-bg);cursor:pointer;aspect-ratio:1/1;overflow:hidden;min-height:2.75rem}
.plate-list button img{width:100%;height:100%;object-fit:cover;opacity:.8}
.plate-list button[aria-pressed="true"]{border-color:var(--silk)}
.plate-list button[aria-pressed="true"] img{opacity:1}
.plate-ctl{display:flex;flex-wrap:wrap;gap:.6rem;margin:.8rem 0}
.plate-side p{margin:0 0 .8rem;color:var(--ink-2)}

/* hypotheses */
.hyps{display:grid;gap:.8rem;margin-top:1.2rem;list-style:none;padding:0}
@media (min-width:48rem){.hyps{grid-template-columns:repeat(2,minmax(0,1fr))}}
.hyp{background:var(--surface);border:1px solid var(--rule);border-radius:var(--r);padding:1rem 1.1rem}
.hyp h3{margin-bottom:.3rem}
.hyp .who{font-size:.84rem;color:var(--ink-3);margin:0 0 .6rem}
.hyp dl{margin:0;font-size:.93rem}
.hyp dt{font-weight:700;color:var(--ink);margin-top:.45rem}
.hyp dd{margin:0;color:var(--ink-2)}
.verdict{margin-top:1.4rem;max-width:44rem;padding:1rem 1.1rem;border-left:3px solid var(--silk);background:var(--surface);border-radius:0 var(--r) var(--r) 0}
.verdict p{margin:0 0 .6rem}

/* numbers table */
.fig-table{width:100%;max-width:52rem;border-collapse:collapse;font-size:.94rem}
.fig-table th,.fig-table td{text-align:left;padding:.6rem .7rem;border-bottom:1px solid var(--rule);vertical-align:top}
.fig-table th{font-weight:400;color:var(--ink-2);width:58%}
.fig-table td{font-weight:700;color:var(--ink)}

/* game */
.qs{list-style:none;padding:0;margin:1.2rem 0 0;display:grid;gap:.9rem}
.q{background:var(--surface);border:1px solid var(--rule);border-radius:var(--r);padding:1rem 1.1rem;max-width:46rem}
.q-s{margin:0 0 .7rem;font-weight:600}
.q-btns{display:flex;gap:.5rem;flex-wrap:wrap}
.q-btns .opt{min-width:7rem;text-align:center}
.q-why{margin-top:.85rem;padding-top:.8rem;border-top:1px dashed var(--rule-strong);color:var(--ink-2)}
.q-why p{margin:0 0 .4rem}
.q-src{font-size:.85rem;color:var(--ink-3)}
.score{margin:1.2rem 0 0;font-family:"Fraunces",Georgia,serif;font-size:1.2rem;font-weight:600;min-height:1.6em}
.game-actions{display:flex;flex-wrap:wrap;gap:.6rem;margin-top:.9rem}
.btn{font:inherit;cursor:pointer;min-height:2.75rem;padding:.5rem 1rem;border:1px solid var(--rule-strong);border-radius:999px;background:var(--paper);color:var(--ink)}
.btn:hover{border-color:var(--walk);color:var(--walk)}
.btn.primary{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.btn.primary:hover{background:var(--walk);border-color:var(--walk);color:var(--paper)}

.limits,.srcs{max-width:46rem;padding-left:1.1rem;color:var(--ink-2)}
.limits li,.srcs li{margin:0 0 .6rem}
.block > p{max-width:var(--measure);color:var(--ink-2)}
.credits{font-size:.86rem}

.foot{max-width:var(--maxw);margin:0 auto;padding:2rem clamp(1rem,3vw,2rem) 3rem;border-top:1px solid var(--rule);color:var(--ink-3);font-size:.88rem}
.foot p{margin:.2rem 0}
.foot a,.srcs a{display:inline-block;padding-block:.65rem;position:relative}

/* ---------- the map's own marks ---------- */
.m-sea{fill:var(--sea)}
.m-land{fill:var(--land);stroke:var(--rule-strong);stroke-width:.8;vector-effect:non-scaling-stroke}
.m-grat{fill:none;stroke:var(--grat);stroke-width:.7;vector-effect:non-scaling-stroke}
.m-flight{fill:none;stroke:var(--silk);stroke-width:3;stroke-linejoin:round;stroke-linecap:round;vector-effect:non-scaling-stroke}
.m-walk{fill:none;stroke:var(--walk);stroke-width:3;stroke-linejoin:round;stroke-linecap:round;vector-effect:non-scaling-stroke}
.m-walk-unfixed{fill:none;stroke:var(--walk);stroke-width:2;stroke-dasharray:2 5;stroke-linecap:round;vector-effect:non-scaling-stroke}
.m-ghost{fill:none;stroke:var(--drift);stroke-width:2.4;stroke-dasharray:7 6;stroke-linecap:round;vector-effect:non-scaling-stroke}
.m-plan{fill:none;stroke:var(--ink-3);stroke-width:1.6;stroke-dasharray:3 7;stroke-linecap:round;vector-effect:non-scaling-stroke}
.m-fix{fill:var(--paper);stroke:var(--walk);stroke-width:1.8;vector-effect:non-scaling-stroke}
.m-ffix{fill:var(--paper);stroke:var(--silk);stroke-width:1.8;vector-effect:non-scaling-stroke}
.m-now{fill:var(--walk);stroke:var(--paper);stroke-width:2;vector-effect:non-scaling-stroke}
.m-now.air{fill:var(--silk)}
.m-ghost-now{fill:var(--paper);stroke:var(--drift);stroke-width:2.4;vector-effect:non-scaling-stroke}
.m-place{fill:var(--ink);stroke:var(--paper);stroke-width:1.5;vector-effect:non-scaling-stroke}
.m-label{fill:var(--ink);font-family:"Atkinson",sans-serif;font-weight:700;paint-order:stroke;stroke:var(--paper);stroke-width:3px;stroke-linejoin:round}
.m-label-sm{fill:var(--ink-2);font-family:"Atkinson",sans-serif;paint-order:stroke;stroke:var(--paper);stroke-width:2.5px;stroke-linejoin:round}
.m-grat-label{fill:var(--ink-3);font-family:"Atkinson",sans-serif;paint-order:stroke;stroke:var(--sea);stroke-width:2.5px;stroke-linejoin:round}
.m-scale{fill:none;stroke:var(--ink);stroke-width:2.2;vector-effect:non-scaling-stroke}

.nf{display:grid;place-items:center;min-height:100svh;text-align:center}
.nf main{padding:2rem}

/* ---------- motion ---------- */
.chapter{transition:opacity .35s ease}
@media (min-width:62rem){
  .story.ready .chapter{opacity:.8}
  .story.ready .chapter.is-live{opacity:1}
}
@media (prefers-reduced-motion:reduce){
  *{animation-duration:.01ms !important;transition-duration:.01ms !important}
  .story.ready .chapter,.story.ready .chapter.is-live{opacity:1}
  .js .dev.latent img{filter:none;opacity:1}
}
/* Short screens (a phone on its side, or 400 % zoom): the pinned map keeps only the map; the
   note stays readable to a screen reader, the legend waits for a taller screen. */
@media (max-width:61.99rem) and (max-height:34rem){
  .legend{display:none}
  .stage-note{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
  .stage svg{height:40svh}
  .hud .k{display:none}
}