/* London's blue plaques, counted. Identity: the cobalt roundel on Portland stone by day, on a dark street by night.
   Colours live in tokens; the canvas reads the same tokens. */
@font-face{font-family:"Barlow Condensed";font-weight:900;font-style:normal;font-display:swap;src:url("fonts/BarlowCondensed.woff2") format("woff2")}
@font-face{font-family:"Source Serif 4";font-weight:200 900;font-style:normal;font-display:swap;src:url("fonts/SourceSerif4-400-latin.woff2") format("woff2");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:"Source Serif 4";font-weight:200 900;font-style:normal;font-display:swap;src:url("fonts/SourceSerif4-400-latin-ext.woff2") format("woff2");unicode-range:U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,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:"IBM Plex Sans";font-weight:100 700;font-style:normal;font-display:swap;src:url("fonts/IBMPlexSans-400-latin.woff2") format("woff2");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:"IBM Plex Sans";font-weight:100 700;font-style:normal;font-display:swap;src:url("fonts/IBMPlexSans-400-latin-ext.woff2") format("woff2");unicode-range:U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}

:root{
  --bg:#f2efe8;--surface:#fbf9f4;--ink:#16181d;--ink-soft:#494d56;--line:#cfcabd;--line-soft:#e2ded3;
  --acc:#17438a;--plaque:#1f55a8;--gold:#c07f08;--buff:#17438a;--buff-ink:#fbfaf5;
  --map-bg:#e8e4da;--land:#dfdacd;--speck:rgba(38,42,52,.21);--water:#a8c3d6;--map-line:rgba(255,255,255,.6);--hi:rgba(31,85,168,.20);--zero:rgba(184,62,38,.30);--reach:rgba(31,85,168,.78);
  --serif:"Source Serif 4",Georgia,"Times New Roman",serif;--sans:"IBM Plex Sans",system-ui,-apple-system,"Segoe UI",sans-serif;--cond:"Barlow Condensed","Arial Narrow",Impact,sans-serif;
  --bar:44px;color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){
  --bg:#0f1216;--surface:#181c22;--ink:#f1ede3;--ink-soft:#bcb7ab;--line:#353b46;--line-soft:#262b33;
  --acc:#a3c5ff;--plaque:#4d8ee8;--gold:#f2b53c;--buff:#17438a;--buff-ink:#fbfaf5;
  --map-bg:#0a0c0f;--land:#14181e;--speck:rgba(236,226,200,.24);--water:#1b3347;--map-line:rgba(255,255,255,.09);--hi:rgba(77,142,232,.28);--zero:rgba(232,112,82,.32);--reach:rgba(120,172,248,.9);
  color-scheme:dark}}
:root[data-theme=dark]{
  --bg:#0f1216;--surface:#181c22;--ink:#f1ede3;--ink-soft:#bcb7ab;--line:#353b46;--line-soft:#262b33;
  --acc:#a3c5ff;--plaque:#4d8ee8;--gold:#f2b53c;--buff:#17438a;--buff-ink:#fbfaf5;
  --map-bg:#0a0c0f;--land:#14181e;--speck:rgba(236,226,200,.24);--water:#1b3347;--map-line:rgba(255,255,255,.09);--hi:rgba(77,142,232,.28);--zero:rgba(232,112,82,.32);--reach:rgba(120,172,248,.9);
  color-scheme:dark}

*{box-sizing:border-box}
[hidden]{display:none!important}
svg[hidden]{display:none}
html{scroll-padding-top:calc(var(--bar) + 12px);-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--serif);font-size:1.0625rem;line-height:1.58}
a{color:inherit;text-decoration-color:var(--acc);text-underline-offset:.16em;text-decoration-thickness:.09em}
a:hover{color:var(--acc)}
:focus-visible{outline:2px solid var(--acc);outline-offset:2px}
.skip{position:absolute;left:-999px;top:0;background:var(--ink);color:var(--bg);padding:.5rem .8rem;z-index:50}
.skip:focus{left:8px;top:8px}
.vh{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

.topbar{position:sticky;top:0;z-index:30;height:var(--bar);display:flex;align-items:center;gap:.9rem;padding:0 .9rem;background:var(--bg);border-bottom:1px solid var(--line);font-family:var(--sans);font-size:.84rem}
.topbar .home{display:flex;align-items:center;gap:.45rem;font-weight:600;text-decoration:none;white-space:nowrap}
.home-ico{flex:none;color:var(--plaque)}
.topnav{display:flex;gap:1rem;overflow-x:auto;scrollbar-width:none;white-space:nowrap;min-width:0}
.topnav::-webkit-scrollbar{display:none}
.topnav a{text-decoration:none;color:var(--ink-soft)}
.topnav a:hover{color:var(--ink)}
.spacer{flex:1}
.lang-switch{font-weight:600;text-decoration:none;border:1px solid var(--line);border-radius:999px;padding:.12rem .55rem;white-space:nowrap}
.icon-btn{display:inline-grid;place-items:center;width:32px;height:32px;border-radius:50%;border:1px solid var(--line);background:transparent;color:var(--ink);cursor:pointer;flex:none}
.progress{position:absolute;left:0;right:0;bottom:-1px;height:2px;pointer-events:none}
.progress span{display:block;height:100%;background:var(--plaque);transform-origin:0 50%;transform:scaleX(0)}
@media (max-width:640px){.topnav{display:none}}

.scrolly{display:grid;grid-template-columns:minmax(0,28rem) minmax(0,1fr);grid-template-areas:"hero stage" "steps stage"}
.hero{grid-area:hero;padding:clamp(1.3rem,4vh,2.6rem) clamp(1rem,2.6vw,2.2rem) 1.6rem;min-height:calc(100svh - var(--bar));display:flex;flex-direction:column;justify-content:center}
.steps{grid-area:steps;padding:0 clamp(1rem,2.6vw,2.2rem) 30vh}
.stage{grid-area:stage;position:sticky;top:var(--bar);height:calc(100svh - var(--bar));align-self:start;background:var(--map-bg);border-left:1px solid var(--line);overflow:hidden}
#map{display:block;width:100%;height:100%;touch-action:pan-y;cursor:crosshair}
.stage-fallback{position:absolute;inset:0;display:none;place-items:center;padding:2rem;text-align:center;color:var(--ink-soft);font-family:var(--sans)}
.map-failed .stage-fallback{display:grid}
.stage-bar{position:absolute;left:0;right:0;bottom:0;display:flex;align-items:center;gap:.6rem;padding:.5rem .7rem;font-family:var(--sans);font-size:.8rem;background:linear-gradient(to top,var(--map-bg) 62%,transparent)}
#cap{flex:1;min-width:0;color:var(--ink);line-height:1.3}
.btn{display:inline-flex;align-items:center;gap:.4rem;min-height:36px;padding:.3rem .8rem;border:1px solid var(--ink);border-radius:999px;background:var(--surface);color:var(--ink);font:600 .82rem var(--sans);cursor:pointer;white-space:nowrap}
.btn:hover{border-color:var(--acc);color:var(--acc)}
.btn .ic-pause{display:none}.btn[data-on=true] .ic-pause{display:block}.btn[data-on=true] .ic-play{display:none}
#chip{position:absolute;left:.7rem;top:.7rem;max-width:calc(100% - 1.4rem);display:flex;flex-wrap:wrap;align-items:baseline;gap:.15rem .6rem;padding:.4rem .75rem;background:var(--surface);color:var(--ink);border:1px solid var(--ink);border-radius:999px;font:.84rem var(--sans)}
#chip b{font-weight:650}

.kicker{font:600 .78rem var(--sans);letter-spacing:.09em;text-transform:uppercase;color:var(--ink-soft);margin:0 0 .7rem}
h1{font:900 clamp(1.9rem,2.4vw + .6rem,2.55rem)/.99 var(--cond);letter-spacing:.005em;word-spacing:.08em;margin:0 0 .9rem;text-wrap:balance}
.deck{font-size:1.08rem;line-height:1.5;margin:0 0 1rem}
.deck b{font-weight:650}
.deck-src{font:.84rem/1.4 var(--sans);color:var(--ink-soft);margin:.7rem 0 0}
.hero.has-d .deck,.hero.has-d .deck-src{display:none}
.hero.has-d .kicker{order:-3}.hero.has-d h1{order:-2;font-size:1.7rem}.hero.has-d #result{order:-1;margin:0 0 1rem}.hero.has-d #whole{order:-1;align-self:flex-start;margin:0 0 1.2rem}

.pc label{font:600 .86rem var(--sans);display:block;margin-bottom:.3rem}
.pc-form{display:flex;gap:.5rem;align-items:stretch;margin:.2rem 0 .5rem}
.pc-in{flex:1;min-width:0;font:900 1.5rem/1 var(--cond);letter-spacing:.04em;text-transform:uppercase;padding:.5rem .7rem;border:2px solid var(--ink);border-radius:4px;background:var(--surface);color:var(--ink);height:52px}
.pc-in::placeholder{color:var(--ink-soft);opacity:1;text-transform:none;font:500 1rem var(--sans);letter-spacing:0}
.pc-go{font:700 .95rem var(--sans);padding:0 1.1rem;border:2px solid var(--buff);border-radius:4px;background:var(--buff);color:var(--buff-ink);cursor:pointer;height:52px}
.pc-go:hover{filter:brightness(1.12)}
.egs{font:.84rem var(--sans);color:var(--ink-soft);margin:.2rem 0 0;display:flex;flex-wrap:wrap;gap:.35rem .5rem;align-items:center}
.egs button{font:900 .98rem var(--cond);letter-spacing:.03em;background:transparent;border:1px solid var(--line);border-radius:3px;color:var(--ink);padding:.2rem .5rem;min-height:32px;cursor:pointer}
.egs button.loc{font:600 .82rem var(--sans);letter-spacing:0;border-radius:999px;padding:.2rem .7rem;border-color:var(--ink);margin-right:.3rem}
.egs button:hover{border-color:var(--acc);color:var(--acc)}
.tap{font:.84rem var(--sans);color:var(--ink-soft);margin:.45rem 0 0}
#pc-msg{font:.86rem var(--sans);color:var(--acc);min-height:1.2em;margin:.3rem 0 0}
#result{margin-top:.5rem;padding-top:.8rem;border-top:1px solid var(--line)}
.res-code{display:flex;align-items:baseline;gap:.6rem;margin:0 0 .5rem;font:.84rem var(--sans);color:var(--ink-soft)}
.res-code b{font:900 2rem/1 var(--cond);color:var(--ink)}
.pcard{display:flex;flex-direction:column;gap:.5rem;align-items:center;margin:.2rem 0 .4rem}
.pcard .res-main{align-self:stretch}
.hero.has-r{justify-content:flex-start}
.hero.has-r .deck,.hero.has-r .deck-src,.hero.has-r .tap,.hero.has-r .kicker{display:none}
.hero.has-r h1{font-size:1.45rem;margin-bottom:.6rem}
.hero.has-r .pc label{display:none}
.pcard .pl{flex:none;max-width:100%;height:auto}
.pcard-t{align-self:stretch}
.res-main{font-size:1.06rem;margin:.2rem 0 .45rem}
.res-main b{font-weight:680}
.res-meta{font:.88rem/1.45 var(--sans);color:var(--ink-soft);margin:.3rem 0}
.res-ins{font-size:.98rem;margin:.4rem 0;padding-left:.7rem;border-left:3px solid var(--plaque)}
.res-ins span{font:600 .8rem var(--sans);color:var(--ink-soft)}
.res-note{font-size:.98rem;margin:.5rem 0}
.res-more p{margin:.5rem 0;font-size:.98rem}
.res-d{font-size:.98rem;margin:.8rem 0 0;padding-top:.7rem;border-top:1px solid var(--line-soft)}
.plist{list-style:none;margin:.3rem 0 .5rem;padding:0;font:.9rem/1.35 var(--sans)}
.plist li{border-top:1px solid var(--line-soft)}
.plink{display:flex;align-items:baseline;gap:.5rem;width:100%;text-align:left;background:none;border:0;color:var(--ink);font:inherit;padding:.42rem 0;cursor:pointer;min-height:40px}
.plink i{flex:none;width:.7rem;height:.7rem;border-radius:50%;align-self:center;border:1px solid var(--line)}
.plink b{font-weight:600}
.plink span{color:var(--ink-soft)}
.plink:hover b{color:var(--acc)}
.plist .pcard{padding:.2rem 0 .8rem}
.more{margin:.2rem 0 .4rem}
.share-row{display:flex;align-items:center;gap:.4rem;flex-wrap:wrap;margin:.5rem 0 .3rem;font:.84rem var(--sans);color:var(--ink-soft)}
.share-row a,.share-row button{display:inline-grid;place-items:center;width:40px;height:40px;border-radius:50%;border:1px solid var(--line);background:transparent;color:var(--ink);cursor:pointer;text-decoration:none}
.share-row a:hover,.share-row button:hover{border-color:var(--acc);color:var(--acc)}
@media (pointer:coarse){.share-row a,.share-row button{width:44px;height:44px}}
.share-row [role=status]{flex-basis:100%;min-height:1.1em;color:var(--ink)}
.whole{margin-top:.6rem;align-self:flex-start}

.step{min-height:92vh;display:flex;flex-direction:column;justify-content:center;padding:1.2rem 0}
.step-card{background:var(--surface);border:1px solid var(--line);border-radius:6px;padding:1.05rem 1.15rem 1.1rem;opacity:.55;transition:opacity .3s}
.step.is-on .step-card,.no-js .step-card{opacity:1}
.step h2{font:900 1.7rem/1.02 var(--cond);word-spacing:.08em;margin:0 0 .55rem;text-wrap:balance}
.step h2 a,.s h2 a{text-decoration:none}
.step .yr{display:inline-block;font:900 .95rem/1 var(--cond);letter-spacing:.08em;color:var(--buff-ink);background:var(--buff);padding:.22rem .5rem .18rem;border-radius:2px;margin-bottom:.55rem}
.step p{margin:.55rem 0}
.step p:last-child{margin-bottom:0}
.fine{font:.8rem/1.4 var(--sans);color:var(--ink-soft)}
.dbtn{font:900 1em var(--cond);letter-spacing:.02em;color:var(--acc);background:none;border:0;border-bottom:1px dotted currentColor;padding:0;cursor:pointer}

.s{padding:clamp(2.2rem,6vw,4rem) 1rem;border-top:1px solid var(--line)}
.wrap{max-width:44rem;margin:0 auto}
.wide{max-width:62rem;margin:0 auto}
.s h2,.h-all{font:900 clamp(1.7rem,3vw,2.2rem)/1.02 var(--cond);word-spacing:.08em;margin:0 0 .7rem;text-wrap:balance}
.s h3{font:700 1rem var(--sans);margin:1.4rem 0 .3rem}
.lede{font-size:1.08rem}
.st-form{display:flex;gap:.5rem;margin:1rem 0 .4rem;flex-wrap:wrap}
.st-form input{flex:1 1 14rem;min-width:0;font:1.05rem var(--serif);padding:.55rem .7rem;border:2px solid var(--ink);border-radius:4px;background:var(--surface);color:var(--ink);height:48px}
.st-form select{font:600 .9rem var(--sans);padding:0 .6rem;border:2px solid var(--ink);border-radius:4px;background:var(--surface);color:var(--ink);height:48px}
#l-info{font:.86rem var(--sans);color:var(--ink-soft);min-height:1.3em;margin:.2rem 0}
.tbl{overflow-x:auto;margin:.4rem 0 .8rem}
table{border-collapse:collapse;width:100%;font:.9rem/1.35 var(--sans)}
th{text-align:left;font-weight:600;color:var(--ink-soft);border-bottom:2px solid var(--ink);padding:.4rem .6rem .4rem 0;white-space:nowrap}
td{border-bottom:1px solid var(--line-soft);padding:.42rem .6rem .42rem 0;vertical-align:top}
td em{color:var(--ink-soft)}
.bor{color:var(--ink-soft);font-size:.84rem}
.src{padding-left:1.1rem;font:.9rem/1.5 var(--sans)}
.src li{margin:.35rem 0}
.foot{display:flex;flex-wrap:wrap;gap:.4rem 1.2rem;padding:1.4rem 1rem 5rem;border-top:1px solid var(--line);font:.84rem var(--sans);color:var(--ink-soft)}
.d-page{max-width:44rem;margin:0 auto;padding:1.5rem 1rem}
.d-page img{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:4px}
.d-page h1{font-size:2rem}
.d-go{display:inline-block;margin-top:.6rem;font:700 .95rem var(--sans)}
.nf main{max-width:40rem;margin:4rem auto;padding:0 1rem}

.rail{position:fixed;right:10px;top:50%;transform:translateY(-50%);z-index:20;display:flex;flex-direction:column;gap:7px;padding:8px 6px;border-radius:999px;background:color-mix(in srgb,var(--surface) 86%,transparent);border:1px solid var(--line-soft)}
.rail a{position:relative;display:block;width:10px;height:10px;border-radius:50%;border:1.5px solid var(--ink-soft)}
.rail a[aria-current]{background:var(--plaque);border-color:var(--plaque)}
.rail a span{position:absolute;right:20px;top:50%;transform:translateY(-50%);white-space:nowrap;background:var(--ink);color:var(--bg);font:600 .76rem var(--sans);padding:.2rem .5rem;border-radius:3px;opacity:0;pointer-events:none}
.rail a:hover span,.rail a:focus-visible span{opacity:1}
@media (max-width:1100px){.rail{display:none}}
@media print{.rail,.stage,.topbar{display:none}}

@media (max-width:860px){
  .scrolly{display:block}
  .hero{min-height:0;padding-top:1.1rem;display:flex}
  .hero h1{font-size:1.85rem}
  .stage{height:46svh;border-left:0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);z-index:5}
  .steps{padding-bottom:12vh}
  .step{min-height:70vh;justify-content:flex-start;padding-top:1.4rem}
  .stage-bar .lbl{display:none}
  #play-label{display:none}
}
@media (prefers-reduced-motion:reduce){.step-card{transition:none}}