@font-face{font-family:"Newsreader";font-style:normal;font-weight:200 800;font-display:swap;src:url(fonts/newsreader-latin.woff2) format("woff2");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:"Newsreader";font-style:normal;font-weight:200 800;font-display:swap;src:url(fonts/newsreader-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:"Newsreader";font-style:italic;font-weight:400;font-display:swap;src:url(fonts/newsreader-italic-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+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:"Newsreader";font-style:italic;font-weight:400;font-display:swap;src:url(fonts/newsreader-italic-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:"Plex Mono";font-style:normal;font-weight:400;font-display:swap;src:url(fonts/IBMPlexMono-Regular.woff2) format("woff2")}

/* The window onto space is the subject: it stays night in both themes. */
:root{
  --bg:#f3f0e8;--bg-2:#e9e4d8;--card:#fbfaf6;--ink:#14161d;--ink-2:#3b3f4c;--rule:#d2cbbb;--rule-2:#878070;
  --accent:#8a3b00;--link:#1b3b95;--curve:#b3541e;
  --space:#020308;--glass:rgba(6,9,20,.72);--s-ink:#eef0f7;--s-ink-2:#b9c0d4;--s-acc:#ffc877;--s-seen:#9fd3ff;--s-rule:rgba(255,255,255,.14);
  --bar-bg:rgba(243,240,232,.9);
  color-scheme:light;
}
:root[data-theme="dark"]{
  --bg:#05070e;--bg-2:#0b0f1c;--card:#0e1322;--ink:#eceef5;--ink-2:#c0c6d6;--rule:#232a40;--rule-2:#5a6480;
  --accent:#ffb454;--link:#a9c1ff;--curve:#ffb454;--bar-bg:rgba(5,7,14,.86);
  color-scheme:dark;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#05070e;--bg-2:#0b0f1c;--card:#0e1322;--ink:#eceef5;--ink-2:#c0c6d6;--rule:#232a40;--rule-2:#5a6480;
    --accent:#ffb454;--link:#a9c1ff;--curve:#ffb454;--bar-bg:rgba(5,7,14,.86);
    color-scheme:dark;
  }
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{margin:0;background:var(--bg);color:var(--ink);font:400 1.1875rem/1.6 "Newsreader",Georgia,serif;font-optical-sizing:auto}
a{color:var(--link);text-underline-offset:.18em;text-decoration-thickness:1px}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:3px solid var(--accent);outline-offset:3px;border-radius:3px}
b,strong{font-weight:640}
.skip{position:absolute;left:-999px;top:0;background:var(--card);color:var(--ink);padding:.5rem .8rem;z-index:99}
.skip:focus{left:.5rem;top:.5rem}
section[id],[id="first"]{scroll-margin-top:2.75rem}

/* ---- top bar ---- */
.topbar{position:sticky;top:0;z-index:40;display:flex;align-items:center;gap:.9rem;height:2.75rem;padding:0 1rem;background:var(--bar-bg);backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);border-bottom:1px solid var(--rule);font-size:.9rem}
.topbar a{color:var(--ink);text-decoration:none}
.topbar .home{font-weight:600;white-space:nowrap}
.topnav{display:flex;gap:1rem;overflow-x:auto;scrollbar-width:none;min-width:0;flex:0 1 auto}
.topnav::-webkit-scrollbar{display:none}
.topnav a{white-space:nowrap;color:var(--ink-2)}
.topnav a:hover,.topnav a[aria-current="true"]{color:var(--ink);text-decoration:underline}
.spacer{flex:1 1 0}
.chip{border:1px solid var(--rule-2);border-radius:99px;padding:.1rem .6rem;font-size:.82rem;white-space:nowrap}
.icon-btn{display:inline-grid;place-items:center;width:2.75rem;height:2.75rem;margin-right:-.6rem;background:none;border:0;color:var(--ink);cursor:pointer;border-radius:50%}
.icon-btn svg[hidden]{display:none}
@media (max-width:640px){.topnav{display:none}.topbar{gap:.6rem}}

/* ---- right rail ---- */
.rail{position:fixed;right:.9rem;top:50%;transform:translateY(-50%);z-index:30;display:flex;flex-direction:column;gap:.55rem}
.rail a{display:flex;align-items:center;justify-content:flex-end;gap:.5rem;text-decoration:none;color:var(--ink-2);font-size:.8rem;min-height:24px}
.rail a span{opacity:0;transform:translateX(6px);transition:opacity .2s,transform .2s;background:var(--card);color:var(--ink);padding:.1rem .45rem;border-radius:4px;border:1px solid var(--rule);white-space:nowrap}
.rail a:hover span,.rail a:focus-visible span{opacity:1;transform:none}
.rail i{width:8px;height:8px;border-radius:50%;border:1.5px solid var(--rule-2);flex:none;transition:background .2s,transform .2s;background:var(--bg)}
.rail a[aria-current="true"] i{background:var(--accent);border-color:var(--accent);transform:scale(1.3)}
@media (max-width:900px){.rail{display:none}}

/* ---- the flight ---- */
.flight{position:relative;background:var(--space);color:var(--s-ink);margin-top:-2.75rem}
.stage{position:sticky;top:0;height:100vh;height:100svh;overflow:hidden;z-index:1}
#sky{position:absolute;inset:0;width:100%;height:100%;display:block;touch-action:pan-y;cursor:grab;background:var(--space)}
#sky:active{cursor:grabbing}
#sky:focus-visible{outline-offset:-4px}
.hud{position:absolute;top:3.6rem;right:2.6rem;display:grid;grid-template-columns:repeat(2,minmax(0,auto));gap:.55rem 1.4rem;font:400 .8rem/1.2 "Plex Mono",ui-monospace,monospace;color:var(--s-ink);text-align:right;pointer-events:none;text-shadow:0 1px 3px #000}
.hud div{display:flex;flex-direction:column;gap:.15rem}
.hud .k{font-size:.68rem;letter-spacing:.06em;text-transform:uppercase;color:var(--s-ink-2)}
.hud .v{font-size:1rem;font-variant-numeric:tabular-nums}
.hud .big{grid-column:1/-1;order:-1}
.hud .big .v{font-size:1.9rem;color:var(--s-acc)}
.hud .big2{grid-column:1/-1;order:-1}
.hud .nt{text-transform:none}
.hud .big2 .v{font-size:1.35rem;color:var(--s-seen)}
.step.coda{min-height:180vh;align-items:center}
.coda .card{max-width:40rem;padding:1.6rem 1.8rem;background:rgba(4,6,14,.86)}
.coda .card h2{font-size:2.1rem}
.ledger{display:grid;grid-template-columns:1fr 1fr;gap:1rem;margin:1rem 0 1.2rem;padding:1rem 0;border-top:1px solid var(--s-rule);border-bottom:1px solid var(--s-rule)}
.ledger dt{font:400 .7rem/1.3 "Plex Mono",ui-monospace,monospace;letter-spacing:.06em;text-transform:uppercase;color:var(--s-ink-2);margin-bottom:.35rem}
.ledger dd{margin:0;font-size:1.55rem;line-height:1.15;font-variant-numeric:tabular-nums}
.ledger div:first-child dd{color:var(--s-acc)}
.ledger div:last-child dd{color:var(--s-seen)}
.look{position:absolute;left:50%;bottom:1.1rem;transform:translateX(-50%);display:flex;gap:.3rem;padding:.25rem;border-radius:99px;background:rgba(6,9,20,.6);border:1px solid var(--s-rule);backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px)}
.look button{font:inherit;font-size:.86rem;color:var(--s-ink-2);background:none;border:0;border-radius:99px;padding:.35rem .85rem;min-height:36px;cursor:pointer}
.look button[aria-pressed="true"]{background:var(--s-ink);color:#05070e}
.inset{position:absolute;right:2.6rem;bottom:4.2rem;width:min(30vw,220px);aspect-ratio:1;margin:0;border:1px solid rgba(255,200,119,.55);border-radius:50%;box-shadow:0 0 0 4px rgba(0,0,0,.35);pointer-events:none}
.inset[hidden]{display:none}
.inset figcaption{position:absolute;top:100%;left:50%;transform:translateX(-50%);margin-top:.35rem;width:max-content;max-width:60vw;font:400 .7rem/1.3 "Plex Mono",ui-monospace,monospace;color:var(--s-ink-2);text-align:center;text-shadow:0 1px 3px #000}
.nogl-msg{display:none}
.flight.nogl .nogl-msg{display:block;position:absolute;left:50%;top:40%;transform:translate(-50%,-50%);max-width:30rem;text-align:center;color:var(--s-ink-2)}
.flight.nogl .look,.flight.nogl .hud{display:none}
.steps{position:relative;z-index:2;margin-top:-100vh;margin-top:-100svh;pointer-events:none}
.step{min-height:125vh;display:flex;align-items:center;padding:0 1.25rem}
.step:first-child{min-height:100vh;min-height:100svh}
.step.last{min-height:140vh}
.card{pointer-events:auto;max-width:27rem;margin-left:max(1.25rem,5vw);padding:1.15rem 1.35rem;background:var(--glass);border:1px solid var(--s-rule);border-radius:10px;backdrop-filter:blur(5px);-webkit-backdrop-filter:blur(5px);font-size:1.06rem;line-height:1.55}
.card h2{font-weight:500;font-size:1.45rem;line-height:1.2;margin:0 0 .6rem;letter-spacing:-.005em}
.card p{margin:0 0 .7rem;color:var(--s-ink)}
.card p:last-child{margin-bottom:0}
.hero{align-items:flex-end;padding-bottom:12vh}
.hero-in{pointer-events:auto;max-width:44rem;margin-left:max(1.25rem,5vw);text-shadow:0 2px 14px #000,0 0 3px #000}
.kicker{font:400 .78rem/1.3 "Plex Mono",ui-monospace,monospace;letter-spacing:.12em;text-transform:uppercase;color:var(--s-acc);margin:0 0 1rem}
.hero h1{font-weight:400;font-size:clamp(2.5rem,6.2vw,5rem);line-height:1.02;letter-spacing:-.02em;margin:0 0 1.1rem;font-variation-settings:"opsz" 72}
.deck{font-size:clamp(1.12rem,1.6vw,1.34rem);line-height:1.5;color:var(--s-ink);max-width:36rem;margin:0 0 1.4rem}
.cue a{display:inline-flex;align-items:center;gap:.5rem;color:#05070e;background:var(--s-acc);text-decoration:none;font-weight:600;padding:.6rem 1.1rem;border-radius:99px;text-shadow:none}
.cue a::after{content:"↓"}
@media (max-width:700px){
  .hud{top:3.3rem;right:.9rem;left:.9rem;grid-template-columns:repeat(3,minmax(0,1fr));gap:.4rem .6rem;font-size:.7rem}
  .hud .v{font-size:.82rem}
  .hud .big .v{font-size:1.45rem}
  .hud .big,.hud .big2{grid-column:span 3}
  .hud .big2 .v{font-size:1.05rem}
  .coda .card{padding:1.1rem 1.1rem}
  .coda .card h2{font-size:1.6rem}
  .ledger{grid-template-columns:1fr;gap:.7rem}
  .ledger dd{font-size:1.3rem}
  .hud .k{font-size:.6rem}
  .step{align-items:flex-end;padding:0 .75rem 5.5rem}
  .card{margin:0;max-width:none;font-size:1rem;padding:1rem 1.05rem}
  .card h2{font-size:1.25rem}
  .hero{padding-bottom:5.5rem}
  .hero-in{margin:0}
  .inset{right:.9rem;top:12.4rem;bottom:auto;width:30vw}
}

/* ---- reading blocks ---- */
main{display:block}
.block{max-width:44rem;margin:0 auto;padding:4.5rem 1.25rem 1rem}
.block h2{font-weight:450;font-size:clamp(1.7rem,3.4vw,2.35rem);line-height:1.12;letter-spacing:-.01em;margin:0 0 1.1rem}
.block h2 a.anchor{color:inherit;text-decoration:none}
.block h2 a.anchor:hover{text-decoration:underline;text-decoration-thickness:1px}
.block p{margin:0 0 1rem}
.planner{margin:1.8rem 0 1rem;padding:1.2rem 1.3rem;border:1px solid var(--rule);border-radius:10px;background:var(--card)}
.planner label{display:block;font-weight:600;margin-bottom:.4rem}
.planner output{font-family:"Plex Mono",ui-monospace,monospace;font-weight:400;color:var(--accent);margin-left:.3rem}
.planner input[type=range]{width:100%;accent-color:var(--accent);min-height:44px}
.plan-out p{margin:.35rem 0}
.chart{margin:1.4rem 0 2rem}
.chart svg{width:100%;height:auto;display:block;overflow:visible}
.chart figcaption,.cubefig figcaption{font-size:.92rem;color:var(--ink-2);margin-top:.5rem}
.chart .grid{stroke:var(--rule);stroke-width:1}
.chart .tick{font:400 11px "Plex Mono",ui-monospace,monospace;fill:var(--ink-2)}
.chart .axis{font:400 12px "Newsreader",Georgia,serif;fill:var(--ink-2)}
.chart .curve{fill:none;stroke:var(--curve);stroke-width:2.2}
.chart .curve.same{stroke:var(--rule-2);stroke-dasharray:3 4;stroke-width:1.4}
.chart .lbl{font:400 11.5px "Newsreader",Georgia,serif;fill:var(--ink)}
.chart .lbl.same{fill:var(--ink-2)}
.chart .dest{fill:var(--ink)}
.chart .cur{stroke:var(--accent);stroke-width:1;stroke-dasharray:2 3}
.chart .cur-dot{fill:var(--accent);stroke:var(--bg);stroke-width:2}
.dests{width:100%;border-collapse:collapse;font-size:.95rem;margin:1rem 0}
.dests caption{text-align:left;font-weight:600;margin-bottom:.4rem}
.dests th,.dests td{padding:.45rem .5rem;border-bottom:1px solid var(--rule);text-align:left;vertical-align:top}
.dests th[scope=row]{font-weight:400}
.dests .n{text-align:right;font-family:"Plex Mono",ui-monospace,monospace;font-size:.85rem;white-space:nowrap}
@media (max-width:560px){.dests{font-size:.85rem}.dests th,.dests td{padding:.4rem .25rem}}
.cubefig{margin:1.6rem 0;background:var(--space);border-radius:10px;padding:0 0 1rem;overflow:hidden}
#cube{display:block;width:100%;height:280px}
.cubectl{display:flex;flex-wrap:wrap;align-items:center;gap:.6rem 1rem;padding:.6rem 1rem 0;color:var(--s-ink)}
.cubectl fieldset{border:0;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:.2rem .9rem;align-items:center}
.cubectl legend{float:left;margin-right:.6rem;font-size:.9rem;color:var(--s-ink-2)}
.cubectl label{display:inline-flex;align-items:center;gap:.3rem;min-height:36px;font-family:"Plex Mono",ui-monospace,monospace;font-size:.85rem}
.cubectl input{accent-color:var(--s-acc)}
.cubectl button{margin-left:auto;font:inherit;font-size:.86rem;color:var(--s-ink);background:none;border:1px solid var(--s-rule);border-radius:99px;padding:.3rem .9rem;min-height:36px;cursor:pointer}
.cubefig figcaption{padding:.4rem 1rem 0;color:var(--s-ink-2)}
.srcs{padding-left:1.1rem;font-size:.92rem}
.srcs li{margin:.35rem 0}
.srcs a{word-break:break-word}
.method{font-size:.98rem;color:var(--ink-2)}
.foot{max-width:44rem;margin:3rem auto 0;padding:1.5rem 1.25rem 3rem;border-top:1px solid var(--rule);font-size:.9rem;color:var(--ink-2)}
.foot p{margin:.2rem 0}
.foot a{color:var(--ink-2)}
body.nf main{max-width:36rem;margin:20vh auto;padding:0 1.25rem}
.dests thead .n{white-space:normal}
@media (max-width:560px){.dests .n{font-size:.74rem}.dests{table-layout:auto}}
.look button{white-space:nowrap}
@media (max-width:700px){.look button{padding:.3rem .65rem}.inset figcaption{left:auto;right:0;transform:none;max-width:44vw;text-align:right}}
.plan-limit{margin:1rem 0 0;padding:.8rem 1rem;border-left:3px solid var(--s-acc);background:rgba(127,127,127,.08);font-size:.95rem}