@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Newsreader:ital,opsz,wght@0,6..72,400;0,6..72,500;1,6..72,400&display=swap');
:root{color-scheme:light;--paper:#f6f7f8;--ink:#17242c;--muted:#52616a;--line:#d3dadd;--blue:#126784;--copper:#ac5528;--panel:#e8edf0;font-family:'DM Sans',-apple-system,BlinkMacSystemFont,'Hiragino Kaku Gothic ProN',sans-serif;color:var(--ink);background:var(--paper);font-size:16px}*{box-sizing:border-box}body{margin:0}a{color:inherit;text-decoration-thickness:1px;text-underline-offset:4px}button,input,select{font:inherit}button,select{min-height:42px;padding:9px 14px;border:1px solid var(--line);background:transparent;color:var(--ink);border-radius:5px;cursor:pointer}button:hover{border-color:var(--blue);background:#e6eff3}button[aria-pressed=true]{background:var(--ink);color:white;border-color:var(--ink)}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #bd6a2f;outline-offset:4px}button:disabled{opacity:.45;cursor:default}.skip{position:absolute;top:-100px}.skip:focus{top:10px;background:white;z-index:10;padding:12px}header{height:78px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);padding:0 4.5%}.brand{font-size:15px;font-weight:700;letter-spacing:.13em;text-decoration:none}.brand span{font-size:12px;font-weight:400;letter-spacing:.1em;margin-left:18px;color:var(--muted)}nav{display:flex;gap:24px;align-items:center}nav a{font-size:14px;text-decoration:none}nav button{font-size:14px}main{max-width:1600px;margin:auto;padding:0 4.5%}.intro{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:end;padding:52px 0 38px}.eyebrow{font-size:12px;font-weight:600;letter-spacing:.15em;text-transform:uppercase;color:var(--blue);margin:0 0 20px}h1{font-family:'Newsreader',Georgia,serif;font-weight:400;font-size:clamp(52px,5.8vw,84px);letter-spacing:-.035em;line-height:.94;margin:0}h1 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span:last-child{color:var(--blue)}#scene{width:100%;height:100%;touch-action:pan-y}#scene canvas{display:block;touch-action:pan-y!important}.camera-controls{position:absolute;bottom:52px;display:flex;gap:7px;left:0;right:0;justify-content:center;flex-wrap:wrap}.camera-controls button{background:#f6f7f8ed;font-size:13px;padding:8px 13px;min-height:38px}.scene-hint{position:absolute;bottom:12px;text-align:center;width:100%;font-size:12px;color:var(--muted);pointer-events:none}aside{padding:30px 27px;background:#fff;border-left:1px solid var(--line)}h2{font-family:'Newsreader',Georgia,serif;font-size:32px;font-weight:400;line-height:1.08;letter-spacing:-.02em;margin:0 0 20px}aside>p:not(.eyebrow):not(.note){font-size:15px;line-height:1.65;margin:0 0 18px}.readout{border-block:1px solid var(--line);padding:15px 0;margin:19px 0;display:flex;flex-direction:column;gap:5px}.readout strong{font-size:34px;font-weight:500;color:var(--blue);letter-spacing:-.04em}.readout 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12px}.lead{font-size:20px!important;color:var(--ink)!important}.equation{font-family:Georgia,'Times New Roman',serif;background:#e9eef1;border-left:3px solid var(--blue);padding:22px;font-size:24px;margin:25px 0;line-height:1.5}.equation small{display:block;font:13px/1.6 'DM Sans',sans-serif;color:var(--muted);margin-top:10px}.comparison{width:100%;border-collapse:collapse;margin:24px 0;font-size:14px}.comparison th,.comparison td{text-align:left;padding:14px 12px;border-bottom:1px solid var(--line);vertical-align:top;line-height:1.6}.comparison th{font-weight:600;color:var(--blue)}.comparison th:first-child{padding-left:0}.download-row{display:flex;gap:12px;flex-wrap:wrap;margin:22px 0}.download-row a{padding:15px 20px;background:var(--ink);color:white;border-radius:4px;text-decoration:none;font-size:14px}.sources{padding-left:22px;columns:2;column-gap:50px}.sources li{padding:0 0 16px 8px;break-inside:avoid;font-size:14px;line-height:1.7}.sources span{display:block;font-size:13px;color:var(--muted)}.boundary{border:1px solid var(--line);padding:22px;margin:20px 0;background:white}.boundary p{font-size:14px;margin:0;line-height:1.8}.sound-demo{margin-top:24px;padding-top:20px;border-top:1px solid var(--line)}.sound-demo p{font-size:13px;line-height:1.6}footer{display:flex;justify-content:space-between;gap:25px;padding:30px 0 45px;font-size:12px;letter-spacing:.05em;color:var(--muted)}[hidden]{display:none!important}#fallback{position:absolute;inset:70px 25px 125px;display:flex;align-items:center;justify-content:center;flex-direction:column;background:var(--panel);text-align:center}#fallback svg{max-width:100%;width:540px;height:270px}#fallback p{font-size:14px;max-width:490px}.ja h1{font-family:-apple-system,'Hiragino Mincho ProN',serif;font-size:clamp(43px,4.7vw,64px);line-height:1.3}.ja h2{font-family:-apple-system,'Hiragino Mincho ProN',serif;font-size:27px;line-height:1.5}.ja .eyebrow{letter-spacing:.06em}.ja .reading-section h2{font-size:33px}.ja .intro-copy>p:first-child{font-size:17px}.ja .stage-tabs button{font-size:14px}.ja .scene-wrap{height:650px}.ja aside>p:not(.eyebrow):not(.note){font-size:14px;line-height:1.85}@media(min-width:1450px){.scene-wrap{height:620px}}@media(max-width:1100px){.workspace{grid-template-columns:minmax(0,1fr) 320px}aside{padding:25px 22px}.intro{gap:30px}.scene-top span:last-child{display:none}}@media(max-width:850px){header{padding:0 5%;height:65px}.brand span{display:none}main{padding:0 5%}.intro{grid-template-columns:1fr;gap:26px;padding:35px 0}h1 br{display:none}h1{font-size:58px;line-height:1.06}.workspace{grid-template-columns:1fr}.scene-wrap,.ja .scene-wrap{height:470px}aside{border-left:0;border-top:1px solid var(--line);padding:26px}.stage-tabs{grid-template-columns:1fr 1fr}.stage-tabs button{min-height:49px;padding-left:17px}.stage-tabs button:nth-child(-n+2){border-bottom:1px solid var(--line)}.section-grid{grid-template-columns:1fr;gap:10px}.sources{columns:1}.reading-section{padding:40px 0}.intro-copy{max-width:none}.readout{flex-direction:row;align-items:baseline;gap:18px}.note{max-width:600px}footer{flex-direction:column}}@media(max-width:480px){h1{font-size:50px}.scene-wrap,.ja .scene-wrap{height:390px}.scene-top{left:18px;top:20px}.camera-controls{gap:5px}.camera-controls button{font-size:12px;padding:7px 10px}.scene-hint{font-size:11px}.stage-tabs button{font-size:13px;padding-left:10px}.comparison td,.comparison th{padding:10px 5px;font-size:12px}.reading-section h2{font-size:34px}.download-row a{flex:1;text-align:center}.intro-copy>p:first-child{font-size:16px}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}

.reference-link{font-size:13px;color:var(--blue);line-height:1.5}#force-graph{width:100%;height:85px}.camera-controls{padding:0 12px}aside{overflow:auto}.scene-top{font-size:11px}html[lang=ja] .reference-link{font-size:12px}@media(max-width:480px){.camera-controls{bottom:48px}.camera-controls button{min-height:34px}#scene-hint{padding:0 15px;line-height:1.4}}

#surface-detail{font-size:13px;padding:6px 10px;min-height:37px;margin-bottom:10px}.scene-top{background:linear-gradient(#e8edf0ee,#e8edf088);padding-bottom:8px}

.scene-wrap,.ja .scene-wrap{height:auto;min-height:620px}#scene{position:absolute;inset:0}.workspace{align-items:stretch}@media(max-width:850px){.scene-wrap,.ja .scene-wrap{height:470px;min-height:470px}}@media(max-width:480px){.scene-wrap,.ja .scene-wrap{height:400px;min-height:400px}}

/* Site theme tokens: both light and dark follow the shell's paper and ink. */
:root{--paper:var(--ig-paper,#faf8f4);--ink:var(--ig-ink,#1b1917);--muted:var(--ig-muted,#5d574f);--line:var(--ig-rule,#ded7cc);--panel:var(--ig-panel,#f3f0e9);--blue:light-dark(#0f5f7b,#86c8df);--copper:light-dark(#9a4a1f,#e8a777);--card:light-dark(#ffffff,#1b1916);--soft:light-dark(#eef1f1,#26231f);--body:light-dark(#33414a,#d4cec4);--prov-photo:light-dark(#a35a24,#e8a777);--prov-inferred:light-dark(#6c7178,#a2a7ad)}
body{background:var(--paper);color:var(--ink)}
button:hover{background:var(--soft)}button[aria-pressed=true]{background:var(--ink);color:var(--paper);border-color:var(--ink)}
aside{background:var(--card)}.scene-wrap{background:var(--panel)}.scene-top{color:var(--muted);background:none;font-weight:600}.scene-top span:last-child{color:var(--blue)}
.section-grid p,.prose p{color:var(--body)}.equation{background:var(--soft)}.boundary{background:var(--card)}.download-row a{background:var(--ink);color:var(--paper)}#fallback{background:var(--panel)}
.camera-controls{z-index:3}.camera-controls button{background:color-mix(in srgb,var(--card) 90%,transparent);backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px)}.camera-controls button[aria-pressed=true]{background:var(--ink);color:var(--paper)}
.callout-layer{position:absolute;inset:0;pointer-events:none;z-index:2;overflow:hidden}.callout-lines{position:absolute;inset:0;overflow:visible}.callout-lines polyline{fill:none;stroke:var(--ink);stroke-opacity:.6;stroke-width:1}.callout-lines circle{fill:var(--paper);stroke:var(--ink);stroke-width:1.5}
.callout{position:absolute;padding:6px 9px 7px 10px;border-radius:5px;background:color-mix(in srgb,var(--card) 93%,transparent);border:1px solid var(--line);border-left:3px solid var(--prov);box-shadow:0 3px 12px rgb(0 0 0/.08);font:12px/1.3 var(--ig-sans,'DM Sans',sans-serif);color:var(--ink)}
.callout b{display:block;font-weight:600;font-size:12.5px}.callout span{display:block;color:var(--muted);font-size:11px;margin-top:2px}
.prov-spec{--prov:var(--blue)}.prov-photo{--prov:var(--prov-photo)}.prov-inferred{--prov:var(--prov-inferred)}
.callout-dot{position:absolute;transform:translate(-50%,-50%);width:21px;height:21px;border-radius:50%;background:var(--prov);color:var(--card);font:700 11px/21px var(--ig-sans,'DM Sans',sans-serif);text-align:center;box-shadow:0 0 0 2px var(--card),0 2px 6px rgb(0 0 0/.25)}
.callout-list{list-style:none;margin:0 0 20px;padding:0 0 14px;display:grid;gap:8px;border-bottom:1px solid var(--line)}.callout-list li{font-size:13px;line-height:1.35}.callout-list b{display:flex;gap:8px;align-items:center;font-weight:600}.callout-list i{font-style:normal;flex:none;width:19px;height:19px;border-radius:50%;background:var(--prov);color:var(--card);font-size:10px;font-weight:700;display:inline-grid;place-items:center}.callout-list span{display:block;color:var(--muted);font-size:12px;margin-left:27px}
.prov-legend{margin:16px 0;padding:12px 0;border-block:1px solid var(--line);display:grid;gap:6px;font-size:13px}.prov-legend p{margin:0 0 2px;font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}.prov-legend span{display:flex;align-items:center;gap:9px}.prov-legend i{flex:none;width:16px;height:4px;border-radius:2px;background:var(--prov)}
#surface-detail{margin:6px 0 0}.reference-link{color:var(--blue)}
.fg-axis{stroke:var(--line)}.fg-a{stroke:var(--blue)}.fg-b{stroke:var(--copper)}.fg-sum{stroke:var(--ink)}.fg-a-t{fill:var(--blue)}.fg-b-t{fill:var(--copper)}.fg-sum-t{fill:var(--ink)}
.readout strong{color:var(--blue)}.eyebrow{color:var(--blue)}h1 em{color:var(--blue)}.comparison th{color:var(--blue)}
@media(max-width:620px){.scene-top{font-size:10px;letter-spacing:.08em}}
.workspace{align-items:start}.scene-wrap,.ja .scene-wrap{height:min(700px,calc(100vh - 100px));min-height:560px}
@media(max-width:850px){.scene-wrap,.ja .scene-wrap{height:500px;min-height:500px}}@media(max-width:480px){.scene-wrap,.ja .scene-wrap{height:430px;min-height:430px}}