@font-face{font-family:'Fraunces';font-style:italic;font-weight:300 900;font-display:swap;src:url(fonts/fraunces-italic-latin-ext.woff2) format('woff2');unicode-range:U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, 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:'Fraunces';font-style:italic;font-weight:300 900;font-display:swap;src:url(fonts/fraunces-italic-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:'Fraunces';font-style:normal;font-weight:300 900;font-display:swap;src:url(fonts/fraunces-normal-latin-ext.woff2) format('woff2');unicode-range:U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, 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:'Fraunces';font-style:normal;font-weight:300 900;font-display:swap;src:url(fonts/fraunces-normal-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-style:italic;font-weight:300 700;font-display:swap;src:url(fonts/source-serif-4-italic-latin-ext.woff2) format('woff2');unicode-range:U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, 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:'Source Serif 4';font-style:italic;font-weight:300 700;font-display:swap;src:url(fonts/source-serif-4-italic-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-style:normal;font-weight:300 700;font-display:swap;src:url(fonts/source-serif-4-normal-latin-ext.woff2) format('woff2');unicode-range:U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, 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:'Source Serif 4';font-style:normal;font-weight:300 700;font-display:swap;src:url(fonts/source-serif-4-normal-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}
/* ------------------------------------------------------------------ tokens */
:root{
  color-scheme:light;
  --bg:#f7f3ea; --surface:#fffdf8; --surface-2:#efe8d9;
  --text:#1b1a17; --text-2:#33312c; --muted:#4d4a43;
  --line:#c8bfae; --line-soft:#e0d8c8;
  --accent:#8f3d00; --accent-ink:#ffffff; --ok:#0f5132; --bad:#8a1c12;
  --p-night:#26304a; --p-shade:#8d99b3; --p-sun:#f4b400; --p-wall:#ddd5c4; --p-cursor:#111111; --p-bg:#ffffff;
  --shadow:0 1px 2px rgba(40,30,10,.08),0 8px 28px rgba(40,30,10,.10);
  --bar-h:3.25rem;
  --serif:"Fraunces",Georgia,"Times New Roman",serif;
  --body:"Source Serif 4",Georgia,"Times New Roman",serif;
}
:root[data-theme="dark"]{
  color-scheme:dark;
  --bg:#12141a; --surface:#1a1d25; --surface-2:#232733;
  --text:#f3eee4; --text-2:#d9d3c6; --muted:#b9b3a5;
  --line:#3b4050; --line-soft:#282c38;
  --accent:#ffb454; --accent-ink:#1a1206; --ok:#8fe0b0; --bad:#ff9d90;
  --p-night:#0a0d15; --p-shade:#42506f; --p-sun:#ffc21f; --p-wall:#2a2e3a; --p-cursor:#ffffff; --p-bg:#000000;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 34px rgba(0,0,0,.45);
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    color-scheme:dark;
    --bg:#12141a; --surface:#1a1d25; --surface-2:#232733;
    --text:#f3eee4; --text-2:#d9d3c6; --muted:#b9b3a5;
    --line:#3b4050; --line-soft:#282c38;
    --accent:#ffb454; --accent-ink:#1a1206; --ok:#8fe0b0; --bad:#ff9d90;
    --p-night:#0a0d15; --p-shade:#42506f; --p-sun:#ffc21f; --p-wall:#2a2e3a; --p-cursor:#ffffff; --p-bg:#000000;
    --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 34px rgba(0,0,0,.45);
  }
}

/* ------------------------------------------------------------------ base */
*,*::before,*::after{box-sizing:border-box}
html{scroll-padding-top:calc(var(--bar-h) + .5rem);-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--body);font-size:1.125rem;line-height:1.6;overflow-x:hidden}
a{color:var(--accent);text-underline-offset:.15em}
h1,h2,h3{font-family:var(--serif);line-height:1.15;font-weight:650;letter-spacing:-.01em}
h1{font-size:clamp(2.1rem,6vw,3.5rem);margin:.2rem 0 .8rem}
h2{font-size:clamp(1.6rem,4vw,2.2rem);margin:0 0 .8rem}
h3{font-size:1.2rem;margin:1.2rem 0 .3rem}
p{margin:0 0 1rem}
.wrap{max-width:44rem;margin:0 auto;padding:0 max(1rem,env(safe-area-inset-left))}
.wrap.wide{max-width:76rem}
.lede{font-size:1.2rem;color:var(--text-2)}
.soft{color:var(--muted);font-size:.92em}
.skip{position:absolute;left:-999px;top:0;background:var(--accent);color:var(--accent-ink);padding:.6rem 1rem;z-index:100;border-radius:0 0 .5rem 0}
.skip:focus{left:0}
.perma{margin-left:.4rem;font-size:.6em;color:var(--muted);text-decoration:none;opacity:0;transition:opacity .15s}
h2:hover .perma,.perma:focus-visible{opacity:1}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
[hidden]{display:none!important}

/* ------------------------------------------------------------------ top bar + rail */
.topbar{position:sticky;top:0;z-index:50;height:var(--bar-h);display:flex;align-items:center;gap:.4rem;padding:0 max(.75rem,env(safe-area-inset-right)) 0 max(.9rem,env(safe-area-inset-left));background:color-mix(in srgb,var(--bg) 90%,transparent);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);border-bottom:1px solid var(--line-soft)}
.topbar .home{font-weight:700;font-size:.95rem;color:var(--text);text-decoration:none;white-space:nowrap;padding:.7rem .3rem}
.topnav{display:flex;gap:.1rem;overflow-x:auto;scrollbar-width:none;min-width:0;flex:0 1 auto}
.topnav a{color:var(--text-2);text-decoration:none;font-size:.92rem;padding:.7rem .5rem;white-space:nowrap}
.topnav a[aria-current]{color:var(--accent);font-weight:700}
.spacer{flex:1}
.chip{display:inline-flex;align-items:center;gap:.4rem;min-height:2.75rem;padding:0 .8rem;border:1px solid var(--line);border-radius:999px;background:transparent;color:var(--text);text-decoration:none;font:inherit;font-size:.9rem;font-weight:600;white-space:nowrap;cursor:pointer}
.chip[aria-pressed="true"]{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}
.icon-btn{display:inline-grid;place-items:center;width:2.75rem;height:2.75rem;border-radius:50%;border:1px solid var(--line);background:transparent;color:var(--text);cursor:pointer;flex:none;font:inherit;font-size:1.2rem}
.icon-btn svg[hidden]{display:none}
@media (max-width:820px){.topnav{display:none}}
.rail{display:none}
@media (min-width:1300px){
  .rail{display:flex;flex-direction:column;gap:.2rem;position:fixed;right:1rem;top:50%;translate:0 -50%;z-index:40;padding:.4rem .35rem;border-radius:999px;background:color-mix(in srgb,var(--bg) 88%,transparent);border:1px solid var(--line-soft)}
  .rail a{position:relative;display:grid;place-items:center;width:1.9rem;height:1.9rem;color:var(--muted);text-decoration:none;font-size:.82rem}
  .rail .rlab{position:absolute;right:calc(100% + .4rem);top:50%;translate:0 -50%;white-space:nowrap;opacity:0;pointer-events:none;transition:opacity .15s;background:var(--surface);color:var(--text);padding:.1rem .45rem;border-radius:.3rem}
  .rail a:hover .rlab,.rail a:focus-visible .rlab{opacity:1}
  .rail .dot{width:.6rem;height:.6rem;border-radius:50%;border:1.5px solid var(--muted)}
  .rail a[aria-current] .dot{background:var(--accent);border-color:var(--accent)}
}

/* ------------------------------------------------------------------ hero */
.hero{padding:2.2rem 0 1.4rem}
.kicker{font-size:.9rem;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);font-weight:700;margin:0}
.deck{font-size:1.3rem;color:var(--text-2)}
.answer-box{border-left:4px solid var(--p-sun);background:var(--surface);padding:1rem 1.2rem;border-radius:0 .6rem .6rem 0;box-shadow:var(--shadow);margin:1.4rem 0}
.answer-box p:last-child{margin:0}
.answer-box b{font-family:var(--serif);font-size:1.15em}
.byline{font-size:.9rem;color:var(--muted)}
.btn{display:inline-flex;align-items:center;min-height:2.75rem;padding:.5rem 1.1rem;border-radius:999px;border:1.5px solid var(--accent);background:var(--accent);color:var(--accent-ink);font:inherit;font-weight:700;font-size:1rem;text-decoration:none;cursor:pointer}
.btn.ghost{background:transparent;color:var(--accent)}
.btn[aria-pressed="true"]{background:var(--text);border-color:var(--text);color:var(--bg)}
button.link{background:none;border:0;padding:0;font:inherit;font-weight:700;color:var(--accent);cursor:pointer;text-decoration:underline;text-underline-offset:.15em;min-height:1.6rem}
button.link[aria-pressed="true"]{color:var(--text);text-decoration-thickness:3px}

/* ------------------------------------------------------------------ address box */
.addr{position:relative;margin:1.2rem 0 .3rem}
.addr label{display:block;font-weight:700;font-size:.95rem;margin-bottom:.25rem}
input[type="search"],input[type="text"],select{font:inherit;font-size:1.1rem;min-height:3rem;padding:.4rem .9rem;border-radius:.7rem;border:1.5px solid var(--line);background:var(--surface);color:var(--text);width:100%}
.addr-list{list-style:none;margin:.2rem 0 0;padding:.2rem;position:absolute;left:0;right:0;z-index:20;background:var(--surface);border:1px solid var(--line);border-radius:.7rem;box-shadow:var(--shadow);max-height:20rem;overflow:auto}
.addr-list li{padding:.6rem .8rem;border-radius:.5rem;cursor:pointer;min-height:2.75rem;display:flex;align-items:center;gap:.5rem;flex-wrap:wrap}
.addr-list li:hover,.addr-list li[aria-selected="true"]{background:var(--surface-2)}
.addr-status{min-height:1.4em;color:var(--muted);font-size:.95rem;margin:.3rem 0 0}

/* ------------------------------------------------------------------ the tool */
.tool-sec{padding:1rem 0 2rem}
.tool{display:grid;grid-template-columns:minmax(0,1fr);gap:1rem;margin-top:.6rem}
@media (min-width:1040px){.tool{grid-template-columns:minmax(0,1.3fr) minmax(24rem,.9fr);align-items:start}}
.stage{position:relative;height:min(70svh,42rem);min-height:22rem;border-radius:.9rem;overflow:hidden;background:var(--p-shade);border:1px solid var(--line)}
@media (min-width:1040px){.stage{position:sticky;top:calc(var(--bar-h) + .5rem);height:calc(100svh - var(--bar-h) - 1.2rem)}}
#wcanvas{display:block;width:100%;height:100%;touch-action:none;cursor:grab}
.stage .hud{position:absolute;left:.7rem;top:.7rem;margin:0;padding:.35rem .75rem;border-radius:999px;background:rgba(12,14,20,.82);color:#f3eee4;font-size:.95rem;max-width:calc(100% - 1.4rem)}
.stage .hint{position:absolute;left:.7rem;bottom:.7rem;right:10.4rem;margin:0;padding:.4rem .75rem;border-radius:.6rem;background:rgba(12,14,20,.82);color:#f3eee4;font-size:.92rem}
.cam{position:absolute;right:.6rem;bottom:.6rem;display:grid;grid-template-columns:repeat(3,2.75rem);gap:.25rem}
.cam button{width:2.75rem;height:2.75rem;border-radius:.6rem;border:1px solid rgba(243,238,228,.4);background:rgba(12,14,20,.78);color:#f3eee4;font:inherit;font-size:1.15rem;cursor:pointer}
.legend3{position:absolute;right:.7rem;top:.7rem;display:flex;flex-direction:column;gap:.25rem;padding:.4rem .6rem;border-radius:.6rem;background:rgba(12,14,20,.82);color:#f3eee4;font-size:.82rem;list-style:none;margin:0}
.legend3 li{display:flex;align-items:center;gap:.4rem}
.legend3 i{display:inline-block;width:1rem;height:.8rem;border-radius:.15rem;border:1px solid rgba(243,238,228,.5)}
.legend3 i.est{background:repeating-linear-gradient(135deg,#9aa0ad 0 3px,#d7d3c8 3px 6px)}
.legend3 i.rec{background:#c9c0ae}
.legend3 i.new{background:#c4552a}
.legend3 i.blk{background:transparent;border:2px solid #e0301e}
.nogl{display:none;position:absolute;inset:3rem 1rem auto 1rem;padding:.8rem 1rem;border-radius:.7rem;background:rgba(12,14,20,.9);color:#f3eee4}
.no-webgl .nogl{display:block}
.panel{display:flex;flex-direction:column;gap:1rem}
.card{background:var(--surface);border:1px solid var(--line-soft);border-radius:.9rem;padding:1rem 1.1rem;box-shadow:var(--shadow)}
.card h3{margin:0 0 .5rem;font-size:1.1rem}
.card p{margin:0 0 .6rem}
.facade-line{font-family:var(--serif);font-size:1.15rem;font-weight:650;margin:0 0 .5rem}
.ctl{display:grid;grid-template-columns:6rem 1fr 6.4rem;gap:.6rem;align-items:center;margin:.5rem 0}
.ctl label{font-size:.95rem;font-weight:700}
.ctl output{font-variant-numeric:tabular-nums;text-align:right;font-size:.95rem;color:var(--text-2)}
input[type="range"]{width:100%;height:2.75rem;accent-color:var(--accent);background:transparent}
.row{display:flex;flex-wrap:wrap;gap:.4rem;align-items:center;margin:.4rem 0}
.now{min-height:4.6em;font-size:1.02rem;margin:.6rem 0 0}
table.keydays{width:100%;border-collapse:collapse;font-size:.98rem;margin:.2rem 0 .4rem}
table.keydays th,table.keydays td{padding:.5rem .4rem;text-align:left;border-bottom:1px solid var(--line-soft);vertical-align:top}
table.keydays thead th{font-size:.82rem;color:var(--muted);font-weight:700}
table.keydays tbody th{font-weight:400}
.rng{display:block;font-size:.85rem;color:var(--muted)}
.badge{display:inline-block;margin-left:.4rem;padding:.05rem .5rem;border-radius:.3rem;font-size:.8rem;font-weight:700;border:1.5px solid currentColor}
.badge.ok{color:var(--ok)} .badge.no{color:var(--bad)}
.yr{margin:.3rem 0 0}
.unc{font-size:.95rem;color:var(--text-2);margin:.5rem 0 0}
.plotwrap{position:relative;margin:.3rem 0 0}
.plotframe{position:relative;margin-left:2.6rem}
#plot{display:block;width:100%;height:15rem;image-rendering:pixelated;border:1px solid var(--line);border-radius:.3rem;background:var(--p-night)}
#plotov{position:absolute;inset:0;width:100%;height:100%;cursor:crosshair;touch-action:none;border-radius:.3rem}
.ylab{position:absolute;left:-2.6rem;width:2.3rem;text-align:right;font-size:.75rem;color:var(--muted);translate:0 -50%}
.xlabs{display:flex;justify-content:space-between;margin:.15rem 0 0 2.6rem;font-size:.75rem;color:var(--muted)}
.plot-key{display:flex;flex-wrap:wrap;gap:.2rem 1rem;list-style:none;padding:0;margin:.5rem 0 0;font-size:.85rem;color:var(--text-2)}
.plot-key li{display:flex;align-items:center;gap:.4rem}
.plot-key i{width:1rem;height:.8rem;border-radius:.15rem;border:1px solid var(--line);display:inline-block}
.k-n{background:var(--p-night)} .k-s{background:var(--p-shade)} .k-y{background:var(--p-sun)} .k-w{background:var(--p-wall)}
.block-box{border-top:1px solid var(--line-soft);margin-top:.6rem;padding-top:.5rem}
.block-res{margin:.6rem 0 0;padding:.6rem .8rem;border-left:4px solid var(--p-sun);background:var(--surface-2);border-radius:0 .5rem .5rem 0;font-size:1rem}

/* ------------------------------------------------------------------ chapters */
.chapter{padding:2.6rem 0 .6rem}
.chapter ul.plain{padding-left:1.2rem}
.chapter li{margin:.3rem 0}
.tscroll{overflow-x:auto;border:1px solid var(--line-soft);border-radius:.6rem;background:var(--surface);margin:1rem 0}
table.cov{border-collapse:collapse;width:100%;font-size:.95rem}
table.cov th,table.cov td{padding:.5rem .7rem;text-align:left;border-bottom:1px solid var(--line-soft);vertical-align:top}
table.cov thead th{font-size:.82rem;color:var(--muted);background:var(--surface-2)}
table.cov td.n{text-align:right;font-variant-numeric:tabular-nums}
.src{padding-left:1.1rem;font-size:.95rem}
.src li{margin:.3rem 0}
.related{margin-top:1.5rem;padding-top:1rem;border-top:1px solid var(--line-soft)}
.faq h3{font-size:1.1rem}

/* ------------------------------------------------------------------ share + footer */
.share{padding:1.2rem 0 2rem}
.share-row{display:flex;flex-wrap:nowrap;gap:.35rem;align-items:center}
.share-row .lab{font-size:.95rem;color:var(--muted);margin-right:.2rem}
.share-row a,.share-row button{display:inline-grid;place-items:center;flex:none;width:2.5rem;height:2.5rem;padding:0;border-radius:50%;border:1px solid var(--line-soft);background:transparent;color:var(--text-2);text-decoration:none;cursor:pointer;transition:color .15s,border-color .15s}
@media (pointer:coarse){.share-row a,.share-row button{width:2.75rem;height:2.75rem}}
.share-row a:hover,.share-row button:hover,.share-row a:focus-visible,.share-row button:focus-visible{color:var(--accent);border-color:var(--accent)}
.share-status{font-size:.95rem;color:var(--ok);min-height:1.2em;margin:.4rem 0 0}
.foot{border-top:1px solid var(--line-soft);padding:1.5rem 0 3rem;color:var(--muted);font-size:.95rem}
.nf{padding:4rem 1rem}
@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
@media (max-width:640px){.ctl{grid-template-columns:4.6rem 1fr 6rem}.stage .hint{right:.7rem;bottom:4.2rem}}

@media (max-width:1039px){
  .stage{position:sticky;top:var(--bar-h);z-index:6;height:42svh;min-height:15rem;margin:0 -0.5rem;border-radius:0 0 .9rem .9rem}
  .stage .hint{top:2.9rem;bottom:auto;right:.7rem;font-size:.82rem;padding:.25rem .6rem}
  .legend3{top:auto;right:auto;left:.7rem;bottom:.7rem;flex-direction:row;flex-wrap:wrap;max-width:calc(100% - 9.6rem);gap:.15rem .7rem;font-size:.7rem;padding:.3rem .5rem}
  .legend3 li:nth-child(n+3){display:none}
}

.examples{margin:.2rem 0 0;font-size:.95rem;color:var(--text-2)}

.dd{display:block}
table.keydays tbody th{min-width:8.5rem}