@font-face{font-family:"Atkinson";font-style:normal;font-weight:200 800;font-display:swap;src:url("fonts/atkinson-latin.woff2") format("woff2");unicode-range:U+0000-00FF,U+2013-2014,U+2018-201E,U+2022,U+2026,U+2212,U+00D7,U+2192,U+21BA}
@font-face{font-family:"Atkinson";font-style:normal;font-weight:200 800;font-display:swap;src:url("fonts/atkinson-latin-ext.woff2") format("woff2");unicode-range:U+0100-024F,U+0218-021B,U+1E00-1EFF,U+20AC}
@font-face{font-family:"Fraunces";font-style:normal;font-weight:100 900;font-display:swap;src:url("fonts/fraunces-latin.woff2") format("woff2");unicode-range:U+0000-00FF,U+2013-2014,U+2018-201E,U+2212}
@font-face{font-family:"Fraunces";font-style:normal;font-weight:100 900;font-display:swap;src:url("fonts/fraunces-latin-ext.woff2") format("woff2");unicode-range:U+0100-024F,U+0218-021B,U+1E00-1EFF,U+20AC}

/* Light: ink on paper, the drawing like a pencil chart. Dark (default when the system is dark): the motorway at night. */
:root{
  --bg:#f4f1ea;--bg-2:#ebe6dc;--ink:#15171c;--ink-2:#3d424d;--line:#cfc7b7;--line-soft:#ddd6c8;
  --accent:#6b4300;--brake:#b8250f;--brake-text:#8f1c0a;--fast:#1f4f93;--chip:#e3ddd0;
  --trail-fast:#2b5aa0;--trail-mid:#8a6a2a;--trail-slow:#c0391f;--trail-alpha:.55;--trail-blend:source-over;
  --road:#e2ddd2;--road-line:#b9b1a2;--car-me:#111;--halo:rgba(0,0,0,.18);
  --grid:rgba(21,23,28,.10);--wave:#15171c;
  --serif:"Fraunces",Georgia,"Times New Roman",serif;--sans:"Atkinson",system-ui,-apple-system,"Segoe UI",sans-serif;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#070a11;--bg-2:#0d121d;--ink:#eef1f6;--ink-2:#b6bfcd;--line:#2a3245;--line-soft:#1d2433;
  --accent:#ffd27f;--brake:#ff5b47;--brake-text:#ff9585;--fast:#8cc0ff;--chip:#161d2b;
  --trail-fast:#9fcbff;--trail-mid:#ffd68a;--trail-slow:#ff4a36;--trail-alpha:.42;--trail-blend:lighter;
  --road:#111826;--road-line:#2c3549;--car-me:#ffffff;--halo:rgba(255,255,255,.22);
  --grid:rgba(238,241,246,.07);--wave:#ffffff;color-scheme:dark;
}}
:root[data-theme="dark"]{
  --bg:#070a11;--bg-2:#0d121d;--ink:#eef1f6;--ink-2:#b6bfcd;--line:#2a3245;--line-soft:#1d2433;
  --accent:#ffd27f;--brake:#ff5b47;--brake-text:#ff9585;--fast:#8cc0ff;--chip:#161d2b;
  --trail-fast:#9fcbff;--trail-mid:#ffd68a;--trail-slow:#ff4a36;--trail-alpha:.42;--trail-blend:lighter;
  --road:#111826;--road-line:#2c3549;--car-me:#ffffff;--halo:rgba(255,255,255,.22);
  --grid:rgba(238,241,246,.07);--wave:#ffffff;color-scheme:dark;
}

*{box-sizing:border-box}
[hidden]{display:none!important}
svg[hidden]{display:none!important}
html{-webkit-text-size-adjust:100%;scroll-padding-top:56px}
body{margin:0;background:var(--bg);color:var(--ink);font:400 1.0625rem/1.65 var(--sans);text-rendering:optimizeLegibility}
a{color:var(--accent);text-underline-offset:.18em;text-decoration-thickness:1px}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:4px}
strong{font-weight:700;color:var(--ink)}
.vh{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip-link{position:absolute;left:-999px;top:8px;background:var(--bg);color:var(--ink);padding:8px 12px;z-index:50}
.skip-link:focus{left:8px}

/* top bar: one line, quiet */
.topbar{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:14px;height:46px;padding:0 max(16px,env(safe-area-inset-right)) 0 max(16px,env(safe-area-inset-left));
  background:var(--bg);border-bottom:1px solid var(--line-soft);font-size:.9rem}
.brand{display:flex;align-items:center;gap:8px;color:var(--ink);text-decoration:none;font-weight:700;white-space:nowrap}
.brand svg{width:22px;height:22px;color:var(--ink-2)}
.topnav{display:flex;gap:16px;overflow:hidden}
.topnav a{color:var(--ink-2);text-decoration:none;white-space:nowrap}
.topnav a:hover{color:var(--ink)}
.spacer{flex:1}
.chip{color:var(--ink-2);text-decoration:none;font-size:.8rem;font-weight:700;letter-spacing:.04em;padding:4px 7px;border-radius:6px;min-width:32px;text-align:center}
.chip[aria-current="page"]{color:var(--ink);background:var(--chip)}
.icon-btn{display:grid;place-items:center;width:36px;height:36px;border:0;border-radius:50%;background:transparent;color:var(--ink);cursor:pointer}
.icon-btn:hover{background:var(--chip)}
.i-moon{display:none}
:root[data-theme="dark"] .i-sun{display:none}:root[data-theme="dark"] .i-moon{display:block}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .i-sun{display:none}:root:not([data-theme="light"]) .i-moon{display:block}}
@media (max-width:860px){.topnav{display:none}}
@media (max-width:420px){.brand span{display:none}}
.progress{position:fixed;top:46px;left:0;right:0;height:2px;z-index:19;pointer-events:none}
.progress i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--trail-fast),var(--brake))}

/* rail: hairline dots at the right edge, after the opening */
.rail{position:fixed;right:10px;top:50%;transform:translateY(-50%);display:flex;flex-direction:column;gap:10px;z-index:15;opacity:0;transition:opacity .4s;pointer-events:none}
.rail.on{opacity:1;pointer-events:auto}
.rail-dot{position:relative;display:block;width:16px;height:16px}
.rail-dot .dot{position:absolute;left:5px;top:5px;width:6px;height:6px;border-radius:50%;background:var(--line);transition:transform .2s,background .2s}
.rail-dot[aria-current="true"] .dot{background:var(--brake);transform:scale(1.35)}
.rail-label{position:absolute;right:22px;top:50%;transform:translateY(-50%);white-space:nowrap;font-size:.78rem;color:var(--ink);background:var(--bg);padding:2px 8px;border-radius:4px;border:1px solid var(--line-soft);opacity:0;pointer-events:none;transition:opacity .15s}
.rail-dot:hover .rail-label,.rail-dot:focus-visible .rail-label{opacity:1}
@media (max-width:1180px){.rail{display:none}}
@media print{.rail,.topbar,.progress{display:none}}

/* hero */
.hero{padding:clamp(28px,6vw,72px) 0 0}
.hero-text{max-width:760px;margin:0 auto;padding:0 16px}
.kicker{margin:0 0 12px;font-size:.82rem;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-2);font-weight:700}
h1{font:600 clamp(2rem,5.4vw,3.6rem)/1.06 var(--serif);letter-spacing:-.015em;margin:0 0 18px;outline:none;text-wrap:balance}
.deck{font-size:clamp(1.08rem,1.9vw,1.24rem);line-height:1.6;color:var(--ink-2);margin:0 0 8px;max-width:680px}
.deck strong{color:var(--brake-text)}
.hero-fig{margin:28px 0 0}
.hero-canvas{position:relative;width:100%;height:clamp(300px,62vh,660px);background:var(--bg-2);border-block:1px solid var(--line-soft)}
.hero-canvas canvas,.diag-wrap canvas,.road-wrap canvas,.ring-wrap canvas{position:absolute;inset:0;width:100%;height:100%;display:block}
.hero-fig figcaption,.fig figcaption{max-width:760px;margin:12px auto 0;padding:0 16px;font-size:.9rem;line-height:1.55;color:var(--ink-2)}
.axis{position:absolute;font-size:.74rem;color:var(--ink-2);letter-spacing:.03em;pointer-events:none;background:color-mix(in srgb,var(--bg-2) 82%,transparent);padding:1px 6px;border-radius:3px}
.ax-x{right:10px;bottom:6px}
.ax-y{left:4px;top:8px}

/* sections */
.sec{padding:clamp(40px,7vw,84px) 0 0}
.prose{max-width:720px;margin:0 auto;padding:0 16px}
.prose p{margin:0 0 1.05em}
h2{font:600 clamp(1.55rem,3.3vw,2.2rem)/1.15 var(--serif);letter-spacing:-.01em;margin:0 0 .7em;text-wrap:balance}
h3{font:700 1rem/1.3 var(--sans);margin:1.8em 0 .6em;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-2)}
.anchor{margin-left:.35em;font-size:.6em;color:var(--line);text-decoration:none;opacity:0;transition:opacity .15s;vertical-align:middle}
h2:hover .anchor,.anchor:focus-visible{opacity:1;color:var(--ink-2)}
.sources{padding-left:1.2em;font-size:.92rem;color:var(--ink-2)}
.sources li{margin:0 0 .5em}

/* figures */
.fig{margin:8px auto 34px;max-width:760px;padding:0 16px}
.fig.wide{max-width:1180px}
.road-wrap{position:relative;height:clamp(176px,22vw,230px);background:var(--bg-2);border:1px solid var(--line-soft);border-radius:10px;overflow:hidden}
.road-clock{position:absolute;right:10px;top:8px;font:700 .95rem/1 var(--sans);font-variant-numeric:tabular-nums;color:var(--ink);background:color-mix(in srgb,var(--bg-2) 80%,transparent);padding:4px 8px;border-radius:5px}
.diag-wrap{position:relative;height:clamp(220px,30vw,340px);margin-top:12px;background:var(--bg-2);border:1px solid var(--line-soft);border-radius:10px;overflow:hidden}
.controls{display:flex;flex-wrap:wrap;align-items:center;gap:10px 14px;margin:14px 0 6px}
.controls .time{flex:1 1 220px;display:flex}
input[type=range]{width:100%;accent-color:var(--brake);min-height:44px;background:transparent}
.btn{font:700 .92rem/1 var(--sans);min-height:44px;padding:0 16px;border-radius:999px;border:1px solid var(--line);background:transparent;color:var(--ink);cursor:pointer}
.btn:hover{border-color:var(--ink-2)}
.btn.primary{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.btn.play{min-width:11.5em}
.segs{display:flex;flex-wrap:wrap;align-items:center;gap:6px;margin:8px 0}
.seg-label{font-size:.85rem;color:var(--ink-2);margin-right:4px}
.seg{font:700 .85rem/1 var(--sans);min-height:40px;min-width:44px;padding:0 12px;border-radius:999px;border:1px solid var(--line);background:transparent;color:var(--ink-2);cursor:pointer}
.seg[aria-pressed="true"]{background:var(--ink);color:var(--bg);border-color:var(--ink)}
@media (pointer:coarse){.seg{min-height:44px}}

/* the queue */
.queue-fig canvas{display:block;width:100%;height:150px;background:var(--bg-2);border:1px solid var(--line-soft);border-radius:10px}
.sliders{display:grid;grid-template-columns:1fr 1fr;gap:6px 22px;margin-top:10px}
.sliders label{display:flex;flex-direction:column;font-size:.9rem;color:var(--ink-2)}
.sliders output{font-weight:700;color:var(--ink);font-variant-numeric:tabular-nums}
@media (max-width:560px){.sliders{grid-template-columns:1fr}}
.q-out{font-size:1.1rem;margin:6px 0 0}
.q-out strong{color:var(--brake-text)}
.hint{color:var(--ink-2);font-size:.9em}

/* the ring */
.ring-grid{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(0,1fr);grid-template-areas:"ring act" "ring opts" "diag diag";gap:14px 24px;align-items:start}
.ring-wrap{grid-area:ring;position:relative;aspect-ratio:1.45/1;background:var(--bg-2);border:1px solid var(--line-soft);border-radius:10px;overflow:hidden}
.ring-act{grid-area:act;display:flex;flex-direction:column;gap:12px}
.ring-opts{grid-area:opts;display:flex;flex-direction:column;gap:10px}
.ring-diag{grid-area:diag;height:clamp(180px,24vw,260px);margin-top:0}
.brake{display:flex;align-items:center;justify-content:center;gap:12px;min-height:64px;padding:0 22px;border-radius:14px;border:2px solid var(--brake);background:transparent;color:var(--ink);
  font:700 1.05rem/1.2 var(--sans);cursor:pointer;user-select:none;-webkit-user-select:none;touch-action:none;-webkit-touch-callout:none}
.brake .pedal{width:22px;height:30px;border-radius:5px;border:2px solid var(--brake);position:relative}
.brake .pedal::after{content:"";position:absolute;inset:5px 4px;border-radius:2px;background:var(--brake);opacity:.35}
.brake[data-on]{background:var(--brake-text);border-color:var(--brake-text);color:var(--bg)}
.brake[data-on] .pedal{border-color:var(--bg)}.brake[data-on] .pedal::after{background:var(--bg);opacity:.9}
.ring-out{min-height:3.4em;margin:0;font-size:1.02rem}
.ring-out strong{color:var(--brake-text)}
.toggles{display:flex;flex-wrap:wrap;gap:8px}
.tog{font:700 .88rem/1 var(--sans);min-height:44px;padding:0 14px;border-radius:999px;border:1px solid var(--line);background:transparent;color:var(--ink);cursor:pointer}
.tog[aria-pressed="true"]{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.tog.plain{color:var(--ink-2)}
@media (max-width:820px){.ring-grid{grid-template-columns:1fr;grid-template-areas:"ring" "act" "diag" "opts"}.ring-wrap{aspect-ratio:1.7/1}.ring-diag{height:170px}.ring-out{min-height:2.6em}}

/* share */
.share{margin:6px 0 4px}
.share-row{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.share-label{font-size:.85rem;color:var(--ink-2);margin-right:4px}
.ic{display:grid;place-items:center;width:40px;height:40px;border-radius:50%;border:1px solid var(--line-soft);background:transparent;color:var(--ink);cursor:pointer}
.ic:hover,.ic:focus-visible{border-color:var(--accent);color:var(--accent)}
@media (pointer:coarse){.ic{width:44px;height:44px}}
.share-msg{min-height:1.3em;margin:4px 0 0;font-size:.85rem;color:var(--ink-2)}
.end{margin-top:40px}

.site-footer{max-width:720px;margin:56px auto 0;padding:22px 16px calc(40px + env(safe-area-inset-bottom));border-top:1px solid var(--line-soft);display:flex;flex-wrap:wrap;gap:8px 22px;font-size:.88rem;color:var(--ink-2)}
.site-footer a{color:var(--ink-2)}

@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}

/* wide screens: the drawing is the opening screen, the title sits on a plate at its left */
@media (min-width:900px){
  .hero{position:relative;padding:0}
  .hero-fig{margin:0;position:relative}
  .hero-canvas{height:calc(100vh - 46px);min-height:560px;max-height:980px;border-top:0}
  .hero-fig::before{content:"";position:absolute;inset:0 0 auto 0;height:calc(100vh - 46px);min-height:560px;max-height:980px;z-index:1;pointer-events:none;
    background:linear-gradient(90deg,var(--bg-2) 0,var(--bg-2) 34%,color-mix(in srgb,var(--bg-2) 70%,transparent) 46%,transparent 60%)}
  .hero-text{position:absolute;z-index:2;left:max(32px,5vw);top:clamp(40px,11vh,130px);width:min(560px,40vw);padding:0;margin:0}
  .hero .deck{font-size:1.14rem}
  .hero-canvas .ax-y{left:auto;right:10px}
  .hero-fig figcaption{margin-top:14px}
}