/* Brand tokens, shared with the homepage. Restyle freely: only the bar and the footer links are required. */
@font-face{font-family:"Instrument Serif";font-style:normal;font-weight:400;font-display:swap;src:url(fonts/instrument-serif-latin-400-normal.woff2) format("woff2")}
@font-face{font-family:"Instrument Serif";font-style:italic;font-weight:400;font-display:swap;src:url(fonts/instrument-serif-latin-400-italic.woff2) format("woff2")}
@font-face{font-family:"Hanken Grotesk";font-weight:100 900;font-display:swap;src:url(fonts/hanken-grotesk-latin-wght-normal.woff2) format("woff2")}
@font-face{font-family:"Martian Mono";font-weight:100 800;font-display:swap;src:url(fonts/martian-mono-latin-wght-normal.woff2) format("woff2")}

:root{--ink:#0B1020;--paper:#F4F0E8;--night:#1B2440;--signal:#FF8A1F;--muted-ink:#A3B2C8;--muted-paper:#4A5164;
--serif:"Instrument Serif",Georgia,serif;--sans:"Hanken Grotesk",system-ui,sans-serif;--mono:"Martian Mono",ui-monospace,monospace}
*,*::before,*::after{box-sizing:border-box}
body{margin:0;background:var(--paper);color:var(--ink);font:400 1.0625rem/1.6 var(--sans);-webkit-font-smoothing:antialiased}
:focus-visible{outline:3px solid var(--signal);outline-offset:3px;border-radius:4px}
.skip{position:absolute;left:-9999px;top:8px;background:var(--paper);padding:10px 14px;border-radius:8px}
.skip:focus{left:8px}
.bar{background:var(--ink);padding:16px clamp(20px,5vw,48px)}
.bar a{color:var(--paper);text-decoration:none;font:400 1.4rem/1 var(--serif)}
.opening{background:var(--ink);color:var(--paper);padding:clamp(56px,10vw,120px) 0}
.col{width:100%;max-width:700px;margin-inline:auto;padding:clamp(40px,7vw,72px) clamp(20px,5vw,32px)}
.opening .col{padding-block:0;max-width:960px}
h1,h2{font-family:var(--serif);font-weight:400;line-height:1.02;letter-spacing:-.01em;margin:0 0 .5em}
h1{font-size:clamp(2.8rem,9vw,6rem)}
h2{font-size:clamp(1.9rem,5vw,2.8rem)}
.promise{color:var(--muted-ink);font-size:clamp(1.1rem,2.4vw,1.4rem);max-width:34ch}
p{margin:0 0 1em}
.meta{font:400 .75rem/1.6 var(--mono);color:var(--muted-paper)}
.btn{display:inline-flex;align-items:center;min-height:50px;padding:0 1.6rem;border-radius:999px;background:var(--signal);color:var(--ink);font-weight:600;text-decoration:none}
.nojs{margin:0;padding:24px clamp(20px,5vw,48px);background:var(--ink);color:var(--muted-ink);font-size:.9rem}.nojs a{color:var(--paper)}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* ---- AI data centres, explained ---- */
:root{--elec:#B85A00;--site:#1F5FA8;--plant:#0E7C6B;--line:#D9D2C3;--card:#FBF9F4;--c-heat:#FFB066;--c-water:#7FB2F0;--c-plant:#5ED0BC}
html{scroll-behavior:smooth}
.sr-only{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.eyebrow{font:500 .75rem/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--muted-ink);margin:0 0 1.2rem}
.beatno{font:500 .75rem/1.4 var(--mono);letter-spacing:.06em;color:var(--muted-paper);margin:0 0 .6rem}
.opening h1{max-width:14ch}
.opening .promise{max-width:40ch}
.scope{font-size:.95rem;color:var(--muted-paper);border-left:3px solid var(--signal);padding-left:1rem}
.col.beat+.col.beat{border-top:1px solid var(--line)}
.sub-h{font:400 1.55rem/1.15 var(--serif);margin:1.8em 0 .5em}
.meta a,.srcs a,.method a,.col a:not(.btn){color:var(--ink);text-underline-offset:3px}
.btn.ghost{background:transparent;border:2px solid var(--ink);color:var(--ink);margin-left:.5rem}
.next .btn{margin-bottom:.6rem}
strong{font-weight:600}

/* the opening picture */
.journey{width:100%;height:auto;margin-top:2.4rem;display:block;max-width:760px}
.journey text{font:500 16px var(--sans);fill:var(--muted-ink)}
.journey .t-plant,.journey .t-bldg,.journey .t-heat,.journey .t-cool{font-weight:600}
.journey .t-plant{fill:#7FE0CF}.journey .t-bldg{fill:#8FC0FA}.journey .t-heat{fill:#FFB066}.journey .t-cool{fill:var(--paper)}
.journey rect{fill:var(--night);stroke:#3A4A78;stroke-width:2}
.journey .j-prompt rect{fill:var(--signal);stroke:none}.journey .j-prompt text{fill:var(--ink);font-weight:600}
.journey .racks rect{fill:#0B1020;stroke:#5C6FA6;stroke-width:2}
.journey .cool{fill:#142040}
.journey .stack{stroke:#5C6FA6;stroke-width:5;fill:none}
.journey .wire{stroke:var(--signal);stroke-width:4;fill:none}.journey .wire.thin{stroke-width:2;stroke-dasharray:4 6}
.journey .spark{fill:#FFD9A8}.journey .pkt{fill:var(--paper)}
.journey .heat path{stroke:#FFB066;stroke-width:4;fill:none;stroke-linecap:round;animation:rise 3s ease-in-out infinite}
.journey .heat path:nth-child(2){animation-delay:.4s}.journey .heat path:nth-child(3){animation-delay:.8s}
.journey .drop{stroke:none}.journey .dp{fill:#5ED0BC}.journey .db{fill:#7FB2F0;animation:pulse 3s ease-in-out infinite}
@keyframes rise{0%,100%{opacity:.35;transform:translateY(6px)}50%{opacity:1;transform:translateY(-6px)}}
@keyframes pulse{0%,100%{opacity:.5}50%{opacity:1}}
@media (prefers-reduced-motion:reduce){.journey .heat path,.journey .db{opacity:1}html{scroll-behavior:auto}}

/* beat 1 flow */
.flow{margin:2rem 0;padding:0}
.flow ol{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:0}
.flow .node{border:2px solid var(--ink);border-radius:14px;padding:.9rem 1.1rem;background:#fff;display:flex;flex-direction:column;gap:.25rem}
.flow .node>b{font:400 1.45rem/1.1 var(--serif)}
.flow .node.plant{display:grid;grid-template-columns:1fr auto;gap:.1rem .8rem;align-items:center}
.flow .node.plant>b{grid-column:1}.flow .node.plant>span{grid-column:1}.flow .node.plant .tag{grid-column:2;grid-row:1/3}
.flow .parts{display:grid;gap:.6rem;margin-top:.4rem}
.flow .parts span{display:block;border:1px solid var(--line);border-radius:10px;padding:.6rem .8rem;background:var(--card);font-size:.95rem}
.flow .parts span b{display:block;font-weight:600}
.flow .edge{display:flex;align-items:center;gap:.7rem;padding:.2rem 0 .2rem 1.6rem;min-height:44px}
.flow .arrow{display:block;width:4px;height:34px;border-radius:2px;background:var(--elec);position:relative}
.flow .arrow::after{content:"";position:absolute;left:-7px;bottom:-4px;border:9px solid transparent;border-top:12px solid var(--elec);border-bottom:0}
.flow .arrow.heat{background:repeating-linear-gradient(var(--elec) 0 6px,transparent 6px 11px)}
.flow .lab{font:500 .85rem var(--mono);color:var(--elec)}
.tag{font-style:normal;font:600 .8rem/1.2 var(--sans);padding:.3rem .65rem;border-radius:999px;white-space:nowrap;align-self:flex-start}
.tag.p{background:#D8F2EC;color:#0A5C50}.tag.b{background:#DCE9FA;color:#17497F}
.flow figcaption{font-size:.85rem;color:var(--muted-paper);margin-top:.8rem}

/* the interactive */
.lab-wrap{background:var(--card);border-block:1px solid var(--line)}
.col.wide{max-width:980px}
.lab{margin:1.6rem 0 0;border:2px solid var(--ink);border-radius:18px;background:#fff;overflow:hidden;overflow:clip}
.start{background:var(--ink);color:var(--paper);padding:1.2rem clamp(16px,3vw,28px)}
.start-label{font:500 .75rem/1.4 var(--mono);letter-spacing:.06em;text-transform:uppercase;color:var(--muted-ink);margin:0 0 .5rem}
.start-vals{display:flex;flex-wrap:wrap;gap:.4rem 2rem;margin:0 0 .3rem;font-size:1.05rem}
.start-vals b{font:400 2.3rem/1 var(--serif);color:var(--signal);margin-right:.25rem}
.start-note{margin:0;color:var(--muted-ink);font-size:.9rem}
.controls{padding:1.2rem clamp(16px,3vw,28px) .4rem;border-bottom:1px solid var(--line)}
fieldset{border:0;margin:0 0 1.2rem;padding:0;min-width:0}
legend{font:600 1rem/1.3 var(--sans);padding:0;margin-bottom:.6rem}
legend .sub{display:block;font-weight:400;font-size:.85rem;color:var(--muted-paper)}
.chips{display:flex;flex-wrap:wrap;gap:.5rem}
.chips input{position:absolute;opacity:0;width:1px;height:1px}
.chips label{display:inline-flex;align-items:center;min-height:48px;padding:.4rem 1.05rem;border:2px solid var(--ink);border-radius:999px;background:#fff;color:var(--ink);font:500 .95rem/1.2 var(--sans);cursor:pointer;user-select:none;-webkit-tap-highlight-color:transparent}
.chips input:checked+label{background:var(--ink);color:var(--paper)}
.chips input:focus-visible+label{outline:3px solid var(--signal);outline-offset:3px}
.chips input:disabled+label{opacity:.45;cursor:not-allowed;border-style:dashed}
.note{margin:.6rem 0 0;font-size:.88rem;color:var(--muted-paper);min-height:1.3em}
.out{padding:1.2rem clamp(16px,3vw,28px) .4rem}
.out-head{font:400 1.7rem/1.1 var(--serif);margin:0 0 .2rem}
.out-sub{margin:0 0 1rem;font-size:.9rem;color:var(--muted-paper)}
.meters{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.8rem}
.meter{border:1px solid var(--line);border-radius:12px;padding:.8rem .9rem;background:var(--card);min-width:0}
.meter h3{font:600 .85rem/1.2 var(--sans);margin:0 0 .3rem;color:var(--muted-paper);text-transform:none}
.meter .big{font:400 1.75rem/1.1 var(--serif);margin:0 0 .5rem;overflow-wrap:anywhere}
.meter .per{font-size:.82rem;margin:.5rem 0 0;color:var(--muted-paper);line-height:1.4}
.track{position:relative;height:16px;border-radius:8px;background:#E7E1D3;overflow:hidden}
.band{position:absolute;top:0;bottom:0;border-radius:8px;background:var(--elec);min-width:6px;transition:left .35s ease,width .35s ease,opacity .2s}
.meter[data-key=site] .band{background:var(--site)}
.meter[data-key=plant] .band{background:var(--plant)}
.meter[data-key=total] .band{background:var(--ink)}
.meter.na .band{opacity:0}
.meter.na .big{font-size:1.2rem;color:var(--muted-paper)}
.legend{font-size:.8rem;color:var(--muted-paper);margin:.9rem 0 0;display:flex;flex-wrap:wrap;gap:.3rem 1rem;align-items:center}
.sw{display:inline-block;width:26px;height:10px;border-radius:5px;vertical-align:middle;margin-right:.3rem}
.band-sw{background:linear-gradient(90deg,var(--elec),var(--site),var(--plant))}.pt-sw{width:8px;background:var(--ink)}
.read{padding:1rem clamp(16px,3vw,28px) 1.3rem}
.lesson{font-size:1.05rem;line-height:1.55;margin:0 0 .8rem;padding:.9rem 1rem;border-left:4px solid var(--signal);background:var(--card);border-radius:0 10px 10px 0}
.srcline{font-size:.85rem;color:var(--muted-paper);margin:0 0 1rem}
.srcline a{color:var(--ink)}
.reset{min-height:48px;padding:0 1.3rem;border-radius:999px;border:2px solid var(--ink);background:#fff;color:var(--ink);font:600 .95rem var(--sans);cursor:pointer}
.reset:hover{background:var(--ink);color:var(--paper)}
.aside{margin-top:1.6rem;padding:1rem 1.2rem;border:1px solid var(--line);border-radius:12px}
.aside h3{font:600 1rem/1.3 var(--sans);margin:0 0 .5rem}
.aside ul{margin:0;padding-left:1.1rem}.aside li{margin-bottom:.5rem;font-size:.95rem}
.nojs-note{border:1px dashed var(--ink);padding:.8rem 1rem;border-radius:10px}
@media (min-width:720px){.meters{grid-template-columns:repeat(4,minmax(0,1fr))}.meter .big{font-size:1.5rem}}
@media (max-width:420px){.chips label{padding:.35rem .9rem;font-size:.9rem}}

/* the worked case */
.worked{list-style:none;margin:1.2rem 0 .4rem;padding:0;display:grid;gap:1rem}
.worked li{border:1px solid var(--line);border-radius:12px;padding:.8rem 1rem;background:var(--card)}
.w-name{font-weight:600;margin:0 0 .2rem}
.w-line{margin:.2rem 0;font-size:.9rem;display:flex;flex-wrap:wrap;gap:.2rem .8rem;align-items:baseline}
.w-line .k{color:var(--muted-paper)}.w-line .k.b{color:var(--site);font-weight:600}.w-line .k.p{color:var(--plant);font-weight:600}
.w-line .v{font-weight:600}
.stack{display:flex;height:16px;border-radius:8px;overflow:hidden;background:#E7E1D3;margin:.4rem 0}
.seg{display:block;height:100%}.seg.b{background:var(--site);min-width:3px}.seg.p{background:var(--plant)}

/* demand bars */
.bars2{margin:1.4rem 0;padding:0}
.b2-row{display:grid;grid-template-columns:3rem 1fr auto;gap:.8rem;align-items:center;margin:.4rem 0}
.b2-k{font:500 .85rem var(--mono);color:var(--muted-paper)}
.b2-bar{display:block;height:22px;border-radius:6px;background:var(--elec)}
.b2-v{font-weight:600;white-space:nowrap}
.bars2 figcaption{font-size:.82rem;color:var(--muted-paper);margin-top:.6rem}
.b2-row{grid-template-columns:3rem minmax(0,1fr) 7.5rem}
.b2-row .b2-bar{max-width:100%}

/* reconciliation, places, unknowns */
.recon,.unk{margin:1rem 0}
.recon>div,.unk>div{padding:.9rem 0;border-top:1px solid var(--line)}
.recon>div:last-child,.unk>div:last-child{border-bottom:1px solid var(--line)}
.recon dt,.unk dt{font:400 1.35rem/1.2 var(--serif);margin:0 0 .3rem}
.unk dt{font:600 1rem/1.35 var(--sans)}
.recon dd,.unk dd{margin:0;font-size:.97rem}
.places{display:grid;gap:1rem;margin-top:1rem}
.places article{border:1px solid var(--line);border-radius:12px;padding:1rem 1.1rem;background:var(--card)}
.places h3{font:400 1.45rem/1.15 var(--serif);margin:0 0 .4rem}
.places p{margin:0;font-size:.97rem}
.srcs{padding-left:1.2rem}.srcs li{margin-bottom:.8rem;font-size:.93rem;overflow-wrap:anywhere}
.method{padding-left:1.1rem}.method li{margin-bottom:.7rem;font-size:.95rem}

.tries{display:grid;gap:.5rem;margin:1.2rem 0 .2rem}
.try{display:flex;align-items:center;gap:.7rem;min-height:52px;padding:.5rem 1.1rem;border-radius:14px;border:2px solid var(--signal);background:#fff;color:var(--ink);font:600 .95rem/1.25 var(--sans);text-align:left;cursor:pointer}
.try .n{flex:none;width:28px;height:28px;border-radius:50%;background:var(--ink);color:var(--paper);display:inline-flex;align-items:center;justify-content:center;font-size:.85rem}
.try:hover{background:#FFF2E3}
@media (min-width:720px){.tries{grid-template-columns:repeat(3,1fr)}}

.mini{display:none}
@media (max-width:719px){
  .mini{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:.2rem;position:sticky;bottom:0;z-index:5;background:var(--ink);color:var(--paper);padding:.5rem .5rem calc(.5rem + env(safe-area-inset-bottom));border-top:3px solid var(--signal)}
  .mini span{display:flex;flex-direction:column;min-width:0;text-align:center}
  .mini i{font:500 .68rem/1.2 var(--sans);font-style:normal;color:var(--muted-ink)}
  .mini b{font:600 .85rem/1.3 var(--sans);overflow-wrap:anywhere}
  .mini u{text-decoration:none;font:400 .65rem/1.2 var(--sans);color:var(--muted-ink)}
}
.meter .big small{font:500 .8rem/1.2 var(--sans);color:var(--muted-paper);display:inline-block}
.srcs a,.method a{display:inline-block;padding:.35rem 0}