@font-face{font-family:"Literata";src:url(fonts/literata-latin.woff2) format("woff2");font-weight:200 900;font-display:swap;unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+2000-206F,U+2074,U+20AC,U+2122,U+2191-2199,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:"Literata";src:url(fonts/literata-latin-ext.woff2) format("woff2");font-weight:200 900;font-display:swap;unicode-range:U+0100-02AF,U+0304,U+0308,U+0329,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}
@font-face{font-family:"Plex";src:url(fonts/ibmplexsans-400-lat.woff2) format("woff2");font-weight:400;font-display:swap;unicode-range:U+0000-00FF,U+2000-206F,U+2190-2199}
@font-face{font-family:"Plex";src:url(fonts/ibmplexsans-400-ext.woff2) format("woff2");font-weight:400;font-display:swap;unicode-range:U+0100-02AF,U+1E00-1EFF}
@font-face{font-family:"Plex";src:url(fonts/ibmplexsans-600-lat.woff2) format("woff2");font-weight:600;font-display:swap;unicode-range:U+0000-00FF,U+2000-206F,U+2190-2199}
@font-face{font-family:"Plex";src:url(fonts/ibmplexsans-600-ext.woff2) format("woff2");font-weight:600;font-display:swap;unicode-range:U+0100-02AF,U+1E00-1EFF}
@font-face{font-family:"Plex";src:url(fonts/literata-latin.woff2) format("woff2");font-weight:400 600;font-display:swap;unicode-range:U+2212}

:root{
  --bg:#edf0f2;--paper:#f8fafb;--ink:#1d2733;--mut:#5a6a78;--line:#cfd8de;
  --clay:#a3401f;--heat:#b3372a;--frost:#1d5fa8;--frost-deep:#123f77;--warm:#b3611e;
  --sea:#d7e2e8;--focus:#1d5fa8;--bar:rgba(237,240,242,.92);
  --serif:"Literata",Georgia,serif;--sans:"Plex",system-ui,-apple-system,"Segoe UI",sans-serif;
  color-scheme:light;
}
:root[data-theme="dark"]{
  --bg:#141a21;--paper:#1c242e;--ink:#e9eef3;--mut:#a9b7c4;--line:#2e3a46;
  --clay:#f08a62;--heat:#ef7d6b;--frost:#7fb3e8;--frost-deep:#a9cdf2;--warm:#e5a75c;
  --sea:#1a232c;--focus:#8ec2ff;--bar:rgba(20,26,33,.92);
  color-scheme:dark;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#141a21;--paper:#1c242e;--ink:#e9eef3;--mut:#a9b7c4;--line:#2e3a46;
  --clay:#f08a62;--heat:#ef7d6b;--frost:#7fb3e8;--frost-deep:#a9cdf2;--warm:#e5a75c;
  --sea:#1a232c;--focus:#8ec2ff;--bar:rgba(20,26,33,.92);
  color-scheme:dark;
}}

*{box-sizing:border-box}
[hidden]{display:none!important}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important;animation:none!important}}
body{margin:0;background:var(--bg);color:var(--ink);font:400 1.08rem/1.62 var(--serif);font-optical-sizing:auto;overflow-x:clip}
a{color:var(--clay);text-underline-offset:.15em}
a:focus-visible,button:focus-visible,select:focus-visible,input:focus-visible,summary:focus-visible,[tabindex]:focus-visible{outline:3px solid var(--focus);outline-offset:2px;border-radius:4px}
h1,h2,h3{font-family:var(--serif);line-height:1.12;margin:0 0 .5em}
h2{font-size:clamp(1.9rem,4.2vw,3rem);font-weight:600;letter-spacing:-.01em}
h2 .anchor{color:inherit;text-decoration:none}
h3{font-size:1.2rem;font-weight:650}
p{margin:0 0 1em}
.skip{position:absolute;left:-999px;top:0}.skip:focus{left:8px;top:8px;z-index:60;background:var(--paper);padding:.4em .8em}
section{scroll-margin-top:52px;padding:clamp(3rem,8vw,6rem) clamp(16px,5vw,64px);max-width:1280px;margin:0 auto}
.lede{font-size:1.18rem;max-width:40em;color:var(--ink)}
figcaption{font:400 .82rem/1.45 var(--sans);color:var(--mut);margin-top:.55em}
figure{margin:0}
.note{font:400 .88rem/1.5 var(--sans);color:var(--mut);margin-top:1.6rem}

/* topbar */
.topbar{position:sticky;top:0;z-index:30;display:flex;align-items:center;gap:.9rem;height:46px;padding:0 clamp(12px,3vw,28px);background:var(--bar);backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);border-bottom:1px solid var(--line);font:400 .9rem/1 var(--sans);white-space:nowrap}
.topbar a{color:var(--ink);text-decoration:none}
.home{font-weight:600}
.topnav{display:flex;gap:1rem;overflow-x:auto;scrollbar-width:none;min-width:0}
.topnav::-webkit-scrollbar{display:none}
.topnav a{color:var(--mut);padding:.35em 0}
.topnav a[aria-current="true"]{color:var(--ink);box-shadow:inset 0 -2px var(--frost)}
.spacer{flex:1}
.chip{border:1px solid var(--line);border-radius:999px;padding:.35em .8em}
.icon-btn{width:34px;height:34px;border-radius:50%;border:1px solid var(--line);background:transparent;color:var(--ink);display:grid;place-items:center;cursor:pointer;padding:0;flex:none}
.icon-btn svg{display:block}.icon-btn svg[hidden]{display:none}
@media (max-width:560px){.home{display:none}.topnav{gap:.8rem}}

/* reading rail + progress hairline (thermometer-bulb marker) */
#rail{position:fixed;right:14px;top:50%;transform:translateY(-50%);z-index:25;display:flex;flex-direction:column;gap:.55rem}
#rail a{display:grid;place-items:center;width:22px;height:22px;border-radius:50%}
#rail i{display:block;width:9px;height:9px;border-radius:50%;background:var(--mut);opacity:.55}
#rail a[aria-current="true"] i{background:var(--heat);opacity:1;box-shadow:0 0 0 3px color-mix(in srgb,var(--heat) 25%,transparent)}
@media (max-width:80rem){#rail{display:none}}
#progress{position:fixed;top:0;left:0;right:0;height:3px;z-index:40;background:transparent;pointer-events:none}
#pmark{position:absolute;top:-4.5px;width:12px;height:12px;border-radius:50%;background:var(--heat);box-shadow:0 0 0 2px var(--bg);transform:translateX(-6px)}

/* hero */
.hero{display:grid;grid-template-columns:1fr 1fr;gap:clamp(1.5rem,5vw,4rem);align-items:center;min-height:calc(100svh - 46px);padding-top:clamp(1.5rem,4vw,3rem)}
.kicker{font:600 .8rem/1.3 var(--sans);letter-spacing:.12em;text-transform:uppercase;color:var(--frost-deep);margin-bottom:1.1em}
h1{font-size:clamp(2.7rem,7vw,5.6rem);font-weight:700;letter-spacing:-.025em;line-height:.98;margin-bottom:.35em}
.deck{font-size:clamp(1.12rem,1.9vw,1.4rem);line-height:1.5;max-width:31em}
.cta{display:flex;flex-wrap:wrap;gap:.7rem;margin-top:1.2em}
.start{display:inline-flex;align-items:center;gap:.5em;font:600 1rem/1 var(--sans);color:#fff;background:var(--frost-deep);text-decoration:none;padding:.85em 1.25em;border-radius:999px;min-height:44px}
:root[data-theme="dark"] .start{color:#10161c}
.ghost{display:inline-flex;align-items:center;font:600 1rem/1 var(--sans);color:var(--ink);background:transparent;border:1.5px solid var(--line);border-radius:999px;padding:.85em 1.25em;min-height:44px;text-decoration:none;cursor:pointer}
.hero-fig .thermo{display:block;height:min(70svh,560px);width:auto;margin:0 auto}
@media (max-width:820px){.hero{grid-template-columns:1fr;min-height:0}.hero-fig .thermo{height:min(52svh,420px)}}

/* share */
.share{display:flex;align-items:center;flex-wrap:wrap;gap:.6rem 1rem;padding-top:0;padding-bottom:0}
.share-label{font:400 .85rem var(--sans);color:var(--mut)}
.share-row{display:flex;gap:.5rem}
.sh{width:40px;height:40px;border-radius:50%;border:1px solid var(--line);background:transparent;color:var(--ink);display:grid;place-items:center;cursor:pointer;padding:0;text-decoration:none}
.sh:hover,.sh:focus-visible{border-color:var(--frost);color:var(--frost-deep)}
@media (pointer:coarse){.sh{width:44px;height:44px}}
.copy-note{font:400 .85rem var(--sans);color:var(--mut);min-height:1.2em}

/* thermometer svg (shared) */
.tube{fill:var(--paper);stroke:var(--line);stroke-width:2}
.coldfill{fill:var(--frost);opacity:.85}
.heatfill{fill:var(--heat);opacity:.9}
.bulb{fill:var(--frost);stroke:var(--line);stroke-width:2}
.tick{stroke:var(--mut);stroke-width:1.5}
.tick.minor{stroke-width:1;opacity:.6}
.tlab{font:400 13px var(--sans);fill:var(--mut);font-variant-numeric:tabular-nums}
.rec{stroke-width:3}
.rec.heatline{stroke:var(--heat)}
.rec.coldline{stroke:var(--frost-deep)}
:root[data-theme="dark"] .rec.coldline{stroke:var(--frost)}
.reclab{font:600 13px var(--sans)}
.reclab.heat{fill:var(--heat)}
.reclab.cold{fill:var(--frost-deep)}
:root[data-theme="dark"] .reclab.cold{fill:var(--frost)}
#stepmark .markline{stroke:var(--ink);stroke-width:2.5}
#stepmark .markhead{fill:var(--ink)}
#stepmark .marklab{font:700 15px var(--sans);fill:var(--ink);font-variant-numeric:tabular-nums}
#stepmark{transition:transform .5s ease-out}
.strip{width:100%;height:auto;display:block}
.strip .tube{stroke-width:1.5}
.strip .band{fill:var(--frost);opacity:.35;stroke:var(--frost-deep);stroke-width:1.5}
.strip .bandlab{font:600 14px var(--sans);fill:var(--ink)}
.stripfig{margin:1.4rem 0 .5rem}

/* scrolly journey */
.journey-cols{display:grid;grid-template-columns:minmax(230px,.9fr) 1.4fr;gap:clamp(1.5rem,4vw,3rem);align-items:start;margin-top:1.6rem}
.map-wrap{position:sticky;top:58px}
.map-wrap .thermo{display:block;height:min(74vh,600px);width:auto;margin:0 auto}
.steps{display:grid;gap:1.2rem}
.step{background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:1.2rem 1.3rem 1rem;scroll-margin-top:70px}
html.has-js .step{opacity:.55}
html.has-js .step.on{opacity:1;border-color:var(--frost);box-shadow:0 0 0 1px var(--frost)}
.step .wk{font:600 .8rem/1.4 var(--sans);letter-spacing:.06em;text-transform:uppercase;color:var(--frost-deep);margin-bottom:.6em}
.step[data-side="heat"] .wk{color:var(--heat)}
.wn{display:inline-grid;place-items:center;width:1.7em;height:1.7em;border-radius:50%;background:var(--frost-deep);color:#fff;font:600 .85rem var(--sans);margin-right:.5em}
:root[data-theme="dark"] .wn{color:#10161c}
.step[data-side="heat"] .wn{background:var(--heat)}
:root[data-theme="dark"] .step[data-side="heat"] .wn{color:#fff}
.bsrc{font:400 .8rem/1.4 var(--sans);color:var(--mut);margin:.8em 0 0}
.stepnav{display:flex;flex-wrap:wrap;gap:.6rem;margin-top:1em}
.stepbtn{font:600 .85rem/1 var(--sans);color:var(--ink);border:1px solid var(--line);border-radius:999px;padding:.7em 1.1em;text-decoration:none;min-height:44px;display:inline-flex;align-items:center}
.what{margin-top:1.2rem;font:400 .95rem/1.55 var(--sans)}
.what summary{cursor:pointer;color:var(--ink);font-weight:600;min-height:44px;display:inline-flex;align-items:center}
.what ul{margin:.4em 0 0;padding-left:1.2em;color:var(--mut)}
@media (max-width:820px){
  .journey-cols{grid-template-columns:1fr}
  .map-wrap{top:46px;z-index:20;background:var(--bar);backdrop-filter:blur(8px);border-bottom:1px solid var(--line);margin:0 calc(-1 * clamp(16px,5vw,64px));padding:.4rem 0}
  .map-wrap .thermo{height:30vh;min-height:200px}
  .map-wrap figcaption{display:none}
}

/* town */
.picker{display:flex;flex-wrap:wrap;gap:.7rem;align-items:center;margin:1.4rem 0;font:400 1rem var(--sans)}
.combo{position:relative;flex:1 1 16em;max-width:24em}
.picker input{font:400 1rem var(--sans);color:var(--ink);background:var(--paper);border:1.5px solid var(--line);border-radius:8px;padding:.7em 1em;min-height:44px;width:100%}
#suggest{position:absolute;top:calc(100% + 4px);left:0;right:0;z-index:35;background:var(--paper);border:1.5px solid var(--line);border-radius:8px;max-height:16em;overflow:auto;box-shadow:0 8px 24px rgba(0,0,0,.15)}
.sug{display:block;padding:.7em 1em;min-height:44px;cursor:pointer;font:400 .95rem var(--sans)}
.sug.act{background:var(--sea)}
.sug-msg{display:block;padding:.7em 1em;font:400 .9rem var(--sans);color:var(--mut)}
.picker button[type="submit"]{font:600 1rem/1 var(--sans);color:#fff;background:var(--frost-deep);border:0;border-radius:999px;padding:.85em 1.4em;min-height:44px;cursor:pointer}
:root[data-theme="dark"] .picker button[type="submit"]{color:#10161c}
.verdict{font-size:1.25rem;max-width:36em;font-weight:500;border-left:4px solid var(--frost);padding-left:1rem}
.alltowns{margin-top:1.6rem;font:400 .95rem var(--sans)}
.alltowns summary{cursor:pointer;font-weight:600;min-height:44px;display:inline-flex;align-items:center}
.tablewrap{overflow-x:auto;margin-top:.6rem}
table{border-collapse:collapse;min-width:52em}
th{font:600 .85rem var(--sans);text-align:left;color:var(--mut);padding:.4em 1em .4em 0;border-bottom:2px solid var(--line)}
td{border-bottom:1px solid var(--line);padding:.4em 1em .4em 0;font-variant-numeric:tabular-nums}

/* years */
.years-ctl{display:flex;flex-wrap:wrap;gap:1rem;align-items:center;margin:1.4rem 0;font:400 1rem var(--sans)}
.years-ctl label{font-weight:600}
#ystat{font-variant-numeric:tabular-nums;color:var(--frost-deep)}
#yrange{flex:1 1 16em;min-height:44px;accent-color:var(--frost-deep)}

/* cards: records, verify, guides */
.cgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(270px,1fr));gap:1.2rem;margin-top:1.6rem}
.rec,.ver,.guide{background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:1.3rem 1.4rem}
.rec .big{font:600 2rem/1.1 var(--serif);color:var(--heat);margin:.2em 0 .5em;font-variant-numeric:tabular-nums}
.rec:nth-child(even) .big{color:var(--frost-deep)}
.guide h3{margin-bottom:.3em}
.guide p{margin:0;font:400 .95rem/1.55 var(--sans);color:var(--mut)}

/* quiz */
.qlist{display:grid;gap:1.2rem;margin-top:1.4rem}
.q{background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:1.2rem 1.3rem}
.qq{font-size:1.1rem;font-weight:600}
.qn{display:inline-grid;place-items:center;width:1.7em;height:1.7em;border-radius:50%;background:var(--frost-deep);color:#fff;font:600 .85rem var(--sans);margin-right:.5em}
:root[data-theme="dark"] .qn{color:#10161c}
.opts{list-style:none;padding:0;margin:.8em 0 0;display:grid;gap:.5rem}
.opt{font:400 1rem var(--sans);color:var(--ink);background:transparent;border:1.5px solid var(--line);border-radius:8px;padding:.7em 1em;min-height:44px;cursor:pointer;text-align:left;width:100%}
.opt.picked{border-color:var(--frost)}
.opt.right{border-color:#2e7d43;background:rgba(46,125,67,.12)}
.opt.wrong{border-color:#b3261e;background:rgba(179,38,30,.10)}
.qfb{font:400 .92rem var(--sans);margin:.7em 0 0}
.score{font:600 1.2rem var(--serif);min-height:1.6em}
.qkey{font:400 .95rem var(--sans);color:var(--mut)}

/* faq */
.faqs .faq{background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:.9rem 1.2rem;margin-top:.8rem}
.faqs summary{cursor:pointer;font-weight:600;min-height:44px;display:flex;align-items:center}
.faqs p{margin:.6em 0 0}

/* method + sources + footer */
.method p,.src p{max-width:52em}
.src{font:400 .95rem/1.6 var(--sans);color:var(--mut)}
.src h2,.src h3{color:var(--ink)}
.sgroup{margin-bottom:1.4rem}
.sgroup ul{padding-left:1.2em;margin:.4em 0}
.sgroup li{margin-bottom:.3em}
.src a,.method p{overflow-wrap:anywhere}
.atlas{font:400 .95rem var(--sans);color:var(--mut)}
.foot{padding:2rem clamp(16px,5vw,64px) 3rem;font:400 .85rem var(--sans);color:var(--mut);border-top:1px solid var(--line);max-width:1280px;margin:0 auto}
.foot a{color:var(--mut)}
.nf main{max-width:40em;margin:20vh auto;padding:0 16px}

@media (max-width:560px){
  .combo{max-width:100%;flex-basis:100%}
  section{scroll-margin-top:60px}
}