.lsm-main{padding-top:58px}.lsm-intro{display:grid;grid-template-columns:1.5fr 1fr;gap:60px;align-items:end;margin-bottom:38px}.lsm-intro h1{font-size:clamp(2.5rem,4.3vw,4rem);margin:0;line-height:1.12}.lsm-intro h1 span{color:var(--ink)}.lsm-intro .eyebrow{margin-bottom:20px}.lsm-intro .intro{font-size:1.0625rem;margin:0 0 4px}.intro strong{color:var(--ink);font-weight:600}.shapes{display:grid;grid-template-columns:1fr 1fr;gap:24px}.shape-card{border:1px solid var(--line);border-radius:14px;background:radial-gradient(ellipse at 50% 44%,#192e39 0,#0c171f 65%);overflow:hidden;min-width:0}.tetrah{--accent:#edb283;background:radial-gradient(ellipse at 50% 44%,#302820 0,#14191d 65%)}.shape-heading{padding:25px 28px 0;display:flex;align-items:center;justify-content:space-between}.shape-kicker{font-size:.875rem;color:var(--muted);margin:0 0 3px}.shape-heading h2{font-size:1.75rem;font-weight:550;letter-spacing:-.03em;margin:0}.shape-symbol{font-size:2.8rem;font-weight:300;line-height:1;color:var(--accent);opacity:.85}.model-stage{height:360px;position:relative}.model-stage canvas{display:block;width:100%;height:100%;touch-action:none;cursor:grab;outline-offset:-5px}.model-stage canvas:active{cursor:grabbing}.model-stage canvas:focus-visible{outline:2px solid var(--accent)}.model-status{position:absolute;left:24px;right:24px;top:50%;text-align:center;color:var(--muted);font-size:.875rem;pointer-events:none}.model-status[hidden]{display:none}.model-controls{display:flex;gap:8px;flex-wrap:wrap;padding:0 24px 20px}.model-controls button{border:1px solid #3c515a;border-radius:6px;background:#0b161d;color:#c3d1d8;padding:9px 12px;min-height:42px;font:inherit;font-size:.875rem;cursor:pointer}.model-controls button:hover{border-color:var(--accent);color:#fff}.model-controls button[aria-pressed=true]{border-color:var(--accent);color:var(--accent);background:#142b31}.model-controls button:focus-visible{outline:2px solid var(--accent);outline-offset:3px}.shape-caption{font-size:.9375rem;color:var(--muted);padding:17px 26px;margin:0;border-top:1px solid var(--line);min-height:80px}.model-help{font-size:.875rem;color:var(--muted);text-align:center;margin:20px 0 0}.concepts{display:grid;grid-template-columns:1fr 1.4fr;gap:86px;margin-top:80px;padding-top:48px;border-top:1px solid var(--line)}.concept-intro h2{font-size:2.1rem;font-weight:550;line-height:1.25;letter-spacing:-.025em;margin:0 0 24px}.concept-intro>p:not(.eyebrow){font-size:1rem;color:var(--muted);max-width:360px}.research-label{display:block;font-size:.875rem;color:var(--accent);margin-top:28px}.concept-list{list-style:none;margin:0;padding:0}.concept-list li{display:flex;gap:24px;padding:0 0 25px;margin:0 0 25px;border-bottom:1px solid var(--line)}.concept-list li:last-child{margin-bottom:0;border:0;padding-bottom:0}.concept-number{color:var(--accent);font-size:.875rem;padding-top:3px;font-variant-numeric:tabular-nums}.concept-list h3{font-size:1.125rem;font-weight:600;margin:0 0 9px}.concept-list p{font-size:1rem;color:var(--muted);margin:0}.concept-list strong{color:var(--ink);font-weight:550}.geometry-note{border-top:1px solid var(--line);margin-top:52px;padding-top:22px;color:var(--muted);font-size:.9375rem}.geometry-note summary{cursor:pointer;color:var(--ink);padding:4px 0;min-height:40px}.geometry-note p{max-width:900px;margin-top:12px}@media(max-width:800px){.lsm-intro{grid-template-columns:1fr;gap:22px}.lsm-intro .intro{max-width:650px}.concepts{gap:36px}.model-stage{height:300px}.shape-heading{padding:22px 20px 0}.model-controls{padding-inline:18px;gap:6px}.model-controls button{padding:8px 10px}.shape-caption{padding:16px 20px}}@media(max-width:600px){.lsm-main{padding-top:38px}.lsm-intro h1{font-size:2.45rem}.shapes{grid-template-columns:1fr;gap:20px}.model-stage{height:330px}.concepts{grid-template-columns:1fr;gap:35px;margin-top:50px;padding-top:32px}.concept-intro h2{font-size:1.9rem}.concept-intro>p:not(.eyebrow){max-width:none}.concept-intro .eyebrow{margin-bottom:16px}.shape-caption{min-height:0}.model-help{font-size:.8125rem;line-height:1.7}.concept-list li{gap:18px}}

.particle-models{margin-top:34px}.electron{--accent:#edb283;background:radial-gradient(ellipse at 50% 44%,#302820 0,#14191d 65%)}.particle-caption{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:70px;font-size:1.125rem;font-variant-numeric:tabular-nums}.count-t{color:#edb283}.count-o{color:#70e2d0}.particle-charge{color:var(--ink);font-size:1.25rem}.particle-card .shape-symbol{font-size:2.5rem}

.particle-arrangement{padding:0 26px 17px;margin:0;color:var(--muted);font-size:.9375rem}

.particle-section{margin-top:58px;padding-top:40px;border-top:1px solid var(--line)}.particle-intro{max-width:730px}.particle-intro .eyebrow{margin-bottom:16px}.particle-intro h2{font-size:clamp(2rem,4vw,3rem);line-height:1.15;letter-spacing:-.035em;font-weight:550;margin:0 0 18px}.particle-intro>p:last-child{font-size:1.0625rem;color:var(--muted);margin-bottom:24px}.particle-section>#particle-note{text-align:left;margin-top:0}.particle-card .shape-heading h2{font-size:clamp(1.3rem,2.2vw,1.75rem)}.particle-card .shape-kicker{font-size:.8125rem}.particle-card .shape-heading{gap:12px}.particle-symmetry{padding:0 26px 6px;margin:0;color:var(--accent);font-size:.9375rem}.particle-arrangement{min-height:62px}.particle-mass{padding:16px 26px 20px;border-top:1px solid var(--line)}.particle-mass>div{display:flex;justify-content:space-between;gap:16px;align-items:baseline}.particle-mass span{font-size:.875rem;color:var(--muted)}.particle-mass strong{font-size:1.25rem;font-weight:550;font-variant-numeric:tabular-nums}.particle-mass p{font-size:.875rem;color:var(--muted);margin:5px 0 0}.particle-accounting{margin-top:30px}.particle-card.neutron{grid-column:1/-1}.particle-card.neutron .model-stage{max-width:700px;margin-inline:auto}.particle-card.neutron .particle-arrangement{min-height:0}@media(max-width:600px){.particle-section{margin-top:38px;padding-top:30px}.particle-card .shape-heading h2{font-size:1.5rem}.particle-symmetry,.particle-arrangement{padding-inline:20px}.particle-arrangement{min-height:0}.particle-mass{padding-inline:20px}.particle-card .shape-kicker{font-size:.875rem}.particle-card.neutron{grid-column:auto}}

/* Public first-principles narrative. */
.lsm-intro{grid-template-columns:minmax(0,1.5fr) minmax(0,1fr);gap:44px}.lsm-intro h1{font-size:clamp(2.45rem,4.2vw,3.75rem);text-wrap:balance}.lsm-intro h1 span{color:var(--accent)}.lsm-intro .eyebrow{font-size:.875rem;letter-spacing:.08em}.first-principles{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.7fr);gap:30px 54px;padding:38px 0;margin:30px 0 0;border-block:1px solid var(--line);scroll-margin-top:28px}.first-principles .eyebrow{font-size:.875rem;letter-spacing:.08em;margin:0 0 15px}.first-principles h2{font-size:clamp(1.9rem,3.1vw,2.7rem);line-height:1.13;font-weight:550;letter-spacing:-.035em;margin:0}.principles-copy{min-width:0}.principles-copy p{font-size:1rem;color:var(--muted);line-height:1.8;margin:0 0 16px}.principles-copy strong{font-weight:550;color:var(--ink)}.principles-copy a{display:inline-block;color:var(--accent);font-size:.9375rem;padding-block:5px}.section-nav{scroll-margin-top:24px}@media(max-width:850px){.lsm-intro{grid-template-columns:1fr;gap:24px}.lsm-intro h1{font-size:clamp(2.45rem,6.7vw,3.75rem)}.first-principles{grid-template-columns:1fr;gap:24px;padding:30px 0}.first-principles h2 br{display:none}}@media(max-width:400px){.lsm-intro h1{font-size:2.3rem}.lsm-intro .eyebrow{max-width:270px}}